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LeafOS / LeafOS-Project / android_art / 9cc72669e50210439b70bb7723a9bfd40cd978cf / . / runtime / thread.cc
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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "thread.h"
#include <limits.h> // for INT_MAX
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <algorithm>
#include <atomic>
#include <bitset>
#include <cerrno>
#include <iostream>
#include <list>
#include <optional>
#include <sstream>
#include "android-base/file.h"
#include "android-base/stringprintf.h"
#include "android-base/strings.h"
#include "unwindstack/AndroidUnwinder.h"
#include "arch/context-inl.h"
#include "arch/context.h"
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/atomic.h"
#include "base/bit_utils.h"
#include "base/casts.h"
#include "base/file_utils.h"
#include "base/memory_tool.h"
#include "base/mutex.h"
#include "base/stl_util.h"
#include "base/systrace.h"
#include "base/time_utils.h"
#include "base/timing_logger.h"
#include "base/to_str.h"
#include "base/utils.h"
#include "class_linker-inl.h"
#include "class_root-inl.h"
#include "debugger.h"
#include "dex/descriptors_names.h"
#include "dex/dex_file-inl.h"
#include "dex/dex_file_annotations.h"
#include "dex/dex_file_types.h"
#include "entrypoints/entrypoint_utils.h"
#include "entrypoints/quick/quick_alloc_entrypoints.h"
#include "gc/accounting/card_table-inl.h"
#include "gc/accounting/heap_bitmap-inl.h"
#include "gc/allocator/rosalloc.h"
#include "gc/heap.h"
#include "gc/space/space-inl.h"
#include "gc_root.h"
#include "handle_scope-inl.h"
#include "indirect_reference_table-inl.h"
#include "instrumentation.h"
#include "intern_table.h"
#include "interpreter/interpreter.h"
#include "interpreter/shadow_frame-inl.h"
#include "java_frame_root_info.h"
#include "jni/java_vm_ext.h"
#include "jni/jni_internal.h"
#include "mirror/class-alloc-inl.h"
#include "mirror/class_loader.h"
#include "mirror/object_array-alloc-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/stack_frame_info.h"
#include "mirror/stack_trace_element.h"
#include "monitor.h"
#include "monitor_objects_stack_visitor.h"
#include "native_stack_dump.h"
#include "nativehelper/scoped_local_ref.h"
#include "nativehelper/scoped_utf_chars.h"
#include "nterp_helpers.h"
#include "nth_caller_visitor.h"
#include "oat/oat_quick_method_header.h"
#include "oat/stack_map.h"
#include "obj_ptr-inl.h"
#include "object_lock.h"
#include "palette/palette.h"
#include "quick/quick_method_frame_info.h"
#include "quick_exception_handler.h"
#include "read_barrier-inl.h"
#include "reflection.h"
#include "reflective_handle_scope-inl.h"
#include "runtime-inl.h"
#include "runtime.h"
#include "runtime_callbacks.h"
#include "scoped_thread_state_change-inl.h"
#include "scoped_disable_public_sdk_checker.h"
#include "stack.h"
#include "thread-inl.h"
#include "thread_list.h"
#include "trace.h"
#include "verify_object.h"
#include "well_known_classes-inl.h"
#ifdef ART_TARGET_ANDROID
#include <android/set_abort_message.h>
#endif
#if ART_USE_FUTEXES
#include "linux/futex.h"
#include "sys/syscall.h"
#ifndef SYS_futex
#define SYS_futex __NR_futex
#endif
#endif // ART_USE_FUTEXES
#pragma clang diagnostic push
#pragma clang diagnostic error "-Wconversion"
extern "C" __attribute__((weak)) void* __hwasan_tag_pointer(const volatile void* p,
unsigned char tag);
namespace art HIDDEN {
using android::base::StringAppendV;
using android::base::StringPrintf;
extern "C" NO_RETURN void artDeoptimize(Thread* self, bool skip_method_exit_callbacks);
bool Thread::is_started_ = false;
pthread_key_t Thread::pthread_key_self_;
ConditionVariable* Thread::resume_cond_ = nullptr;
const size_t Thread::kStackOverflowImplicitCheckSize = GetStackOverflowReservedBytes(kRuntimeISA);
bool (*Thread::is_sensitive_thread_hook_)() = nullptr;
Thread* Thread::jit_sensitive_thread_ = nullptr;
std::atomic<Mutex*> Thread::cp_placeholder_mutex_(nullptr);
#ifndef __BIONIC__
thread_local Thread* Thread::self_tls_ = nullptr;
#endif
static constexpr bool kVerifyImageObjectsMarked = kIsDebugBuild;
static const char* kThreadNameDuringStartup = "<native thread without managed peer>";
void Thread::InitCardTable() {
tlsPtr_.card_table = Runtime::Current()->GetHeap()->GetCardTable()->GetBiasedBegin();
}
static void UnimplementedEntryPoint() {
UNIMPLEMENTED(FATAL);
}
void InitEntryPoints(JniEntryPoints* jpoints,
QuickEntryPoints* qpoints,
bool monitor_jni_entry_exit);
void UpdateReadBarrierEntrypoints(QuickEntryPoints* qpoints, bool is_active);
void Thread::SetIsGcMarkingAndUpdateEntrypoints(bool is_marking) {
CHECK(gUseReadBarrier);
tls32_.is_gc_marking = is_marking;
UpdateReadBarrierEntrypoints(&tlsPtr_.quick_entrypoints, /* is_active= */ is_marking);
}
void Thread::InitTlsEntryPoints() {
ScopedTrace trace("InitTlsEntryPoints");
// Insert a placeholder so we can easily tell if we call an unimplemented entry point.
uintptr_t* begin = reinterpret_cast<uintptr_t*>(&tlsPtr_.jni_entrypoints);
uintptr_t* end = reinterpret_cast<uintptr_t*>(
reinterpret_cast<uint8_t*>(&tlsPtr_.quick_entrypoints) + sizeof(tlsPtr_.quick_entrypoints));
for (uintptr_t* it = begin; it != end; ++it) {
*it = reinterpret_cast<uintptr_t>(UnimplementedEntryPoint);
}
bool monitor_jni_entry_exit = false;
PaletteShouldReportJniInvocations(&monitor_jni_entry_exit);
if (monitor_jni_entry_exit) {
AtomicSetFlag(ThreadFlag::kMonitorJniEntryExit);
}
InitEntryPoints(&tlsPtr_.jni_entrypoints, &tlsPtr_.quick_entrypoints, monitor_jni_entry_exit);
}
void Thread::ResetQuickAllocEntryPointsForThread() {
ResetQuickAllocEntryPoints(&tlsPtr_.quick_entrypoints);
}
class DeoptimizationContextRecord {
public:
DeoptimizationContextRecord(const JValue& ret_val,
bool is_reference,
bool from_code,
ObjPtr<mirror::Throwable> pending_exception,
DeoptimizationMethodType method_type,
DeoptimizationContextRecord* link)
: ret_val_(ret_val),
is_reference_(is_reference),
from_code_(from_code),
pending_exception_(pending_exception.Ptr()),
deopt_method_type_(method_type),
link_(link) {}
JValue GetReturnValue() const { return ret_val_; }
bool IsReference() const { return is_reference_; }
bool GetFromCode() const { return from_code_; }
ObjPtr<mirror::Throwable> GetPendingException() const REQUIRES_SHARED(Locks::mutator_lock_) {
return pending_exception_;
}
DeoptimizationContextRecord* GetLink() const { return link_; }
mirror::Object** GetReturnValueAsGCRoot() {
DCHECK(is_reference_);
return ret_val_.GetGCRoot();
}
mirror::Object** GetPendingExceptionAsGCRoot() {
return reinterpret_cast<mirror::Object**>(&pending_exception_);
}
DeoptimizationMethodType GetDeoptimizationMethodType() const {
return deopt_method_type_;
}
private:
// The value returned by the method at the top of the stack before deoptimization.
JValue ret_val_;
// Indicates whether the returned value is a reference. If so, the GC will visit it.
const bool is_reference_;
// Whether the context was created from an explicit deoptimization in the code.
const bool from_code_;
// The exception that was pending before deoptimization (or null if there was no pending
// exception).
mirror::Throwable* pending_exception_;
// Whether the context was created for an (idempotent) runtime method.
const DeoptimizationMethodType deopt_method_type_;
// A link to the previous DeoptimizationContextRecord.
DeoptimizationContextRecord* const link_;
DISALLOW_COPY_AND_ASSIGN(DeoptimizationContextRecord);
};
class StackedShadowFrameRecord {
public:
StackedShadowFrameRecord(ShadowFrame* shadow_frame,
StackedShadowFrameType type,
StackedShadowFrameRecord* link)
: shadow_frame_(shadow_frame),
type_(type),
link_(link) {}
ShadowFrame* GetShadowFrame() const { return shadow_frame_; }
StackedShadowFrameType GetType() const { return type_; }
StackedShadowFrameRecord* GetLink() const { return link_; }
private:
ShadowFrame* const shadow_frame_;
const StackedShadowFrameType type_;
StackedShadowFrameRecord* const link_;
DISALLOW_COPY_AND_ASSIGN(StackedShadowFrameRecord);
};
void Thread::PushDeoptimizationContext(const JValue& return_value,
bool is_reference,
ObjPtr<mirror::Throwable> exception,
bool from_code,
DeoptimizationMethodType method_type) {
DCHECK(exception != Thread::GetDeoptimizationException());
DeoptimizationContextRecord* record = new DeoptimizationContextRecord(
return_value,
is_reference,
from_code,
exception,
method_type,
tlsPtr_.deoptimization_context_stack);
tlsPtr_.deoptimization_context_stack = record;
}
void Thread::PopDeoptimizationContext(JValue* result,
ObjPtr<mirror::Throwable>* exception,
bool* from_code,
DeoptimizationMethodType* method_type) {
AssertHasDeoptimizationContext();
DeoptimizationContextRecord* record = tlsPtr_.deoptimization_context_stack;
tlsPtr_.deoptimization_context_stack = record->GetLink();
result->SetJ(record->GetReturnValue().GetJ());
*exception = record->GetPendingException();
*from_code = record->GetFromCode();
*method_type = record->GetDeoptimizationMethodType();
delete record;
}
void Thread::AssertHasDeoptimizationContext() {
CHECK(tlsPtr_.deoptimization_context_stack != nullptr)
<< "No deoptimization context for thread " << *this;
}
enum {
kPermitAvailable = 0, // Incrementing consumes the permit
kNoPermit = 1, // Incrementing marks as waiter waiting
kNoPermitWaiterWaiting = 2
};
void Thread::Park(bool is_absolute, int64_t time) {
DCHECK(this == Thread::Current());
#if ART_USE_FUTEXES
// Consume the permit, or mark as waiting. This cannot cause park_state to go
// outside of its valid range (0, 1, 2), because in all cases where 2 is
// assigned it is set back to 1 before returning, and this method cannot run
// concurrently with itself since it operates on the current thread.
int old_state = tls32_.park_state_.fetch_add(1, std::memory_order_relaxed);
if (old_state == kNoPermit) {
// no permit was available. block thread until later.
Runtime::Current()->GetRuntimeCallbacks()->ThreadParkStart(is_absolute, time);
bool timed_out = false;
if (!is_absolute && time == 0) {
// Thread.getState() is documented to return waiting for untimed parks.
ScopedThreadSuspension sts(this, ThreadState::kWaiting);
DCHECK_EQ(NumberOfHeldMutexes(), 0u);
int result = futex(tls32_.park_state_.Address(),
FUTEX_WAIT_PRIVATE,
/* sleep if val = */ kNoPermitWaiterWaiting,
/* timeout */ nullptr,
nullptr,
0);
// This errno check must happen before the scope is closed, to ensure that
// no destructors (such as ScopedThreadSuspension) overwrite errno.
if (result == -1) {
switch (errno) {
case EAGAIN:
FALLTHROUGH_INTENDED;
case EINTR: break; // park() is allowed to spuriously return
default: PLOG(FATAL) << "Failed to park";
}
}
} else if (time > 0) {
// Only actually suspend and futex_wait if we're going to wait for some
// positive amount of time - the kernel will reject negative times with
// EINVAL, and a zero time will just noop.
// Thread.getState() is documented to return timed wait for timed parks.
ScopedThreadSuspension sts(this, ThreadState::kTimedWaiting);
DCHECK_EQ(NumberOfHeldMutexes(), 0u);
timespec timespec;
int result = 0;
if (is_absolute) {
// Time is millis when scheduled for an absolute time
timespec.tv_nsec = (time % 1000) * 1000000;
timespec.tv_sec = SaturatedTimeT(time / 1000);
// This odd looking pattern is recommended by futex documentation to
// wait until an absolute deadline, with otherwise identical behavior to
// FUTEX_WAIT_PRIVATE. This also allows parkUntil() to return at the
// correct time when the system clock changes.
result = futex(tls32_.park_state_.Address(),
FUTEX_WAIT_BITSET_PRIVATE | FUTEX_CLOCK_REALTIME,
/* sleep if val = */ kNoPermitWaiterWaiting,
&timespec,
nullptr,
static_cast<int>(FUTEX_BITSET_MATCH_ANY));
} else {
// Time is nanos when scheduled for a relative time
timespec.tv_sec = SaturatedTimeT(time / 1000000000);
timespec.tv_nsec = time % 1000000000;
result = futex(tls32_.park_state_.Address(),
FUTEX_WAIT_PRIVATE,
/* sleep if val = */ kNoPermitWaiterWaiting,
&timespec,
nullptr,
0);
}
// This errno check must happen before the scope is closed, to ensure that
// no destructors (such as ScopedThreadSuspension) overwrite errno.
if (result == -1) {
switch (errno) {
case ETIMEDOUT:
timed_out = true;
FALLTHROUGH_INTENDED;
case EAGAIN:
case EINTR: break; // park() is allowed to spuriously return
default: PLOG(FATAL) << "Failed to park";
}
}
}
// Mark as no longer waiting, and consume permit if there is one.
tls32_.park_state_.store(kNoPermit, std::memory_order_relaxed);
// TODO: Call to signal jvmti here
Runtime::Current()->GetRuntimeCallbacks()->ThreadParkFinished(timed_out);
} else {
// the fetch_add has consumed the permit. immediately return.
DCHECK_EQ(old_state, kPermitAvailable);
}
#else
#pragma clang diagnostic push
#pragma clang diagnostic warning "-W#warnings"
#warning "LockSupport.park/unpark implemented as noops without FUTEX support."
#pragma clang diagnostic pop
UNUSED(is_absolute, time);
UNIMPLEMENTED(WARNING);
sched_yield();
#endif
}
void Thread::Unpark() {
#if ART_USE_FUTEXES
// Set permit available; will be consumed either by fetch_add (when the thread
// tries to park) or store (when the parked thread is woken up)
if (tls32_.park_state_.exchange(kPermitAvailable, std::memory_order_relaxed)
== kNoPermitWaiterWaiting) {
int result = futex(tls32_.park_state_.Address(),
FUTEX_WAKE_PRIVATE,
/* number of waiters = */ 1,
nullptr,
nullptr,
0);
if (result == -1) {
PLOG(FATAL) << "Failed to unpark";
}
}
#else
UNIMPLEMENTED(WARNING);
#endif
}
void Thread::PushStackedShadowFrame(ShadowFrame* sf, StackedShadowFrameType type) {
StackedShadowFrameRecord* record = new StackedShadowFrameRecord(
sf, type, tlsPtr_.stacked_shadow_frame_record);
tlsPtr_.stacked_shadow_frame_record = record;
}
ShadowFrame* Thread::MaybePopDeoptimizedStackedShadowFrame() {
StackedShadowFrameRecord* record = tlsPtr_.stacked_shadow_frame_record;
if (record == nullptr ||
record->GetType() != StackedShadowFrameType::kDeoptimizationShadowFrame) {
return nullptr;
}
return PopStackedShadowFrame();
}
ShadowFrame* Thread::PopStackedShadowFrame() {
StackedShadowFrameRecord* record = tlsPtr_.stacked_shadow_frame_record;
DCHECK_NE(record, nullptr);
tlsPtr_.stacked_shadow_frame_record = record->GetLink();
ShadowFrame* shadow_frame = record->GetShadowFrame();
delete record;
return shadow_frame;
}
class FrameIdToShadowFrame {
public:
static FrameIdToShadowFrame* Create(size_t frame_id,
ShadowFrame* shadow_frame,
FrameIdToShadowFrame* next,
size_t num_vregs) {
// Append a bool array at the end to keep track of what vregs are updated by the debugger.
uint8_t* memory = new uint8_t[sizeof(FrameIdToShadowFrame) + sizeof(bool) * num_vregs];
return new (memory) FrameIdToShadowFrame(frame_id, shadow_frame, next);
}
static void Delete(FrameIdToShadowFrame* f) {
uint8_t* memory = reinterpret_cast<uint8_t*>(f);
delete[] memory;
}
size_t GetFrameId() const { return frame_id_; }
ShadowFrame* GetShadowFrame() const { return shadow_frame_; }
FrameIdToShadowFrame* GetNext() const { return next_; }
void SetNext(FrameIdToShadowFrame* next) { next_ = next; }
bool* GetUpdatedVRegFlags() {
return updated_vreg_flags_;
}
private:
FrameIdToShadowFrame(size_t frame_id,
ShadowFrame* shadow_frame,
FrameIdToShadowFrame* next)
: frame_id_(frame_id),
shadow_frame_(shadow_frame),
next_(next) {}
const size_t frame_id_;
ShadowFrame* const shadow_frame_;
FrameIdToShadowFrame* next_;
bool updated_vreg_flags_[0];
DISALLOW_COPY_AND_ASSIGN(FrameIdToShadowFrame);
};
static FrameIdToShadowFrame* FindFrameIdToShadowFrame(FrameIdToShadowFrame* head,
size_t frame_id) {
FrameIdToShadowFrame* found = nullptr;
for (FrameIdToShadowFrame* record = head; record != nullptr; record = record->GetNext()) {
if (record->GetFrameId() == frame_id) {
if (kIsDebugBuild) {
// Check we have at most one record for this frame.
CHECK(found == nullptr) << "Multiple records for the frame " << frame_id;
found = record;
} else {
return record;
}
}
}
return found;
}
ShadowFrame* Thread::FindDebuggerShadowFrame(size_t frame_id) {
FrameIdToShadowFrame* record = FindFrameIdToShadowFrame(
tlsPtr_.frame_id_to_shadow_frame, frame_id);
if (record != nullptr) {
return record->GetShadowFrame();
}
return nullptr;
}
// Must only be called when FindDebuggerShadowFrame(frame_id) returns non-nullptr.
bool* Thread::GetUpdatedVRegFlags(size_t frame_id) {
FrameIdToShadowFrame* record = FindFrameIdToShadowFrame(
tlsPtr_.frame_id_to_shadow_frame, frame_id);
CHECK(record != nullptr);
return record->GetUpdatedVRegFlags();
}
ShadowFrame* Thread::FindOrCreateDebuggerShadowFrame(size_t frame_id,
uint32_t num_vregs,
ArtMethod* method,
uint32_t dex_pc) {
ShadowFrame* shadow_frame = FindDebuggerShadowFrame(frame_id);
if (shadow_frame != nullptr) {
return shadow_frame;
}
VLOG(deopt) << "Create pre-deopted ShadowFrame for " << ArtMethod::PrettyMethod(method);
shadow_frame = ShadowFrame::CreateDeoptimizedFrame(num_vregs, method, dex_pc);
FrameIdToShadowFrame* record = FrameIdToShadowFrame::Create(frame_id,
shadow_frame,
tlsPtr_.frame_id_to_shadow_frame,
num_vregs);
for (uint32_t i = 0; i < num_vregs; i++) {
// Do this to clear all references for root visitors.
shadow_frame->SetVRegReference(i, nullptr);
// This flag will be changed to true if the debugger modifies the value.
record->GetUpdatedVRegFlags()[i] = false;
}
tlsPtr_.frame_id_to_shadow_frame = record;
return shadow_frame;
}
TLSData* Thread::GetCustomTLS(const char* key) {
MutexLock mu(Thread::Current(), *Locks::custom_tls_lock_);
auto it = custom_tls_.find(key);
return (it != custom_tls_.end()) ? it->second.get() : nullptr;
}
void Thread::SetCustomTLS(const char* key, TLSData* data) {
// We will swap the old data (which might be nullptr) with this and then delete it outside of the
// custom_tls_lock_.
std::unique_ptr<TLSData> old_data(data);
{
MutexLock mu(Thread::Current(), *Locks::custom_tls_lock_);
custom_tls_.GetOrCreate(key, []() { return std::unique_ptr<TLSData>(); }).swap(old_data);
}
}
void Thread::RemoveDebuggerShadowFrameMapping(size_t frame_id) {
FrameIdToShadowFrame* head = tlsPtr_.frame_id_to_shadow_frame;
if (head->GetFrameId() == frame_id) {
tlsPtr_.frame_id_to_shadow_frame = head->GetNext();
FrameIdToShadowFrame::Delete(head);
return;
}
FrameIdToShadowFrame* prev = head;
for (FrameIdToShadowFrame* record = head->GetNext();
record != nullptr;
prev = record, record = record->GetNext()) {
if (record->GetFrameId() == frame_id) {
prev->SetNext(record->GetNext());
FrameIdToShadowFrame::Delete(record);
return;
}
}
LOG(FATAL) << "No shadow frame for frame " << frame_id;
UNREACHABLE();
}
void Thread::InitTid() {
tls32_.tid = ::art::GetTid();
}
void Thread::InitAfterFork() {
// One thread (us) survived the fork, but we have a new tid so we need to
// update the value stashed in this Thread*.
InitTid();
}
void Thread::DeleteJPeer(JNIEnv* env) {
// Make sure nothing can observe both opeer and jpeer set at the same time.
jobject old_jpeer = tlsPtr_.jpeer;
CHECK(old_jpeer != nullptr);
tlsPtr_.jpeer = nullptr;
env->DeleteGlobalRef(old_jpeer);
}
void* Thread::CreateCallbackWithUffdGc(void* arg) {
return Thread::CreateCallback(arg);
}
void* Thread::CreateCallback(void* arg) {
Thread* self = reinterpret_cast<Thread*>(arg);
Runtime* runtime = Runtime::Current();
if (runtime == nullptr) {
LOG(ERROR) << "Thread attaching to non-existent runtime: " << *self;
return nullptr;
}
{
// TODO: pass self to MutexLock - requires self to equal Thread::Current(), which is only true
// after self->Init().
MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_);
// Check that if we got here we cannot be shutting down (as shutdown should never have started
// while threads are being born).
CHECK(!runtime->IsShuttingDownLocked());
// Note: given that the JNIEnv is created in the parent thread, the only failure point here is
// a mess in InitStackHwm. We do not have a reasonable way to recover from that, so abort
// the runtime in such a case. In case this ever changes, we need to make sure here to
// delete the tmp_jni_env, as we own it at this point.
CHECK(self->Init(runtime->GetThreadList(), runtime->GetJavaVM(), self->tlsPtr_.tmp_jni_env));
self->tlsPtr_.tmp_jni_env = nullptr;
Runtime::Current()->EndThreadBirth();
}
{
ScopedObjectAccess soa(self);
self->InitStringEntryPoints();
// Copy peer into self, deleting global reference when done.
CHECK(self->tlsPtr_.jpeer != nullptr);
self->tlsPtr_.opeer = soa.Decode<mirror::Object>(self->tlsPtr_.jpeer).Ptr();
// Make sure nothing can observe both opeer and jpeer set at the same time.
self->DeleteJPeer(self->GetJniEnv());
self->SetThreadName(self->GetThreadName()->ToModifiedUtf8().c_str());
ArtField* priorityField = WellKnownClasses::java_lang_Thread_priority;
self->SetNativePriority(priorityField->GetInt(self->tlsPtr_.opeer));
runtime->GetRuntimeCallbacks()->ThreadStart(self);
// Unpark ourselves if the java peer was unparked before it started (see
// b/28845097#comment49 for more information)
ArtField* unparkedField = WellKnownClasses::java_lang_Thread_unparkedBeforeStart;
bool should_unpark = false;
{
// Hold the lock here, so that if another thread calls unpark before the thread starts
// we don't observe the unparkedBeforeStart field before the unparker writes to it,
// which could cause a lost unpark.
art::MutexLock mu(soa.Self(), *art::Locks::thread_list_lock_);
should_unpark = unparkedField->GetBoolean(self->tlsPtr_.opeer) == JNI_TRUE;
}
if (should_unpark) {
self->Unpark();
}
// Invoke the 'run' method of our java.lang.Thread.
ObjPtr<mirror::Object> receiver = self->tlsPtr_.opeer;
WellKnownClasses::java_lang_Thread_run->InvokeVirtual<'V'>(self, receiver);
}
// Detach and delete self.
Runtime::Current()->GetThreadList()->Unregister(self, /* should_run_callbacks= */ true);
return nullptr;
}
Thread* Thread::FromManagedThread(Thread* self, ObjPtr<mirror::Object> thread_peer) {
ArtField* f = WellKnownClasses::java_lang_Thread_nativePeer;
Thread* result = reinterpret_cast64<Thread*>(f->GetLong(thread_peer));
// Check that if we have a result it is either suspended or we hold the thread_list_lock_
// to stop it from going away.
if (kIsDebugBuild) {
MutexLock mu(self, *Locks::thread_suspend_count_lock_);
if (result != nullptr && !result->IsSuspended()) {
Locks::thread_list_lock_->AssertHeld(self);
}
}
return result;
}
Thread* Thread::FromManagedThread(const ScopedObjectAccessAlreadyRunnable& soa,
jobject java_thread) {
return FromManagedThread(soa.Self(), soa.Decode<mirror::Object>(java_thread));
}
static size_t FixStackSize(size_t stack_size) {
// A stack size of zero means "use the default".
if (stack_size == 0) {
stack_size = Runtime::Current()->GetDefaultStackSize();
}
// Dalvik used the bionic pthread default stack size for native threads,
// so include that here to support apps that expect large native stacks.
stack_size += 1 * MB;
// Under sanitization, frames of the interpreter may become bigger, both for C code as
// well as the ShadowFrame. Ensure a larger minimum size. Otherwise initialization
// of all core classes cannot be done in all test circumstances.
if (kMemoryToolIsAvailable) {
stack_size = std::max(2 * MB, stack_size);
}
// It's not possible to request a stack smaller than the system-defined PTHREAD_STACK_MIN.
if (stack_size < PTHREAD_STACK_MIN) {
stack_size = PTHREAD_STACK_MIN;
}
if (Runtime::Current()->GetImplicitStackOverflowChecks()) {
// If we are going to use implicit stack checks, allocate space for the protected
// region at the bottom of the stack.
stack_size += Thread::kStackOverflowImplicitCheckSize +
GetStackOverflowReservedBytes(kRuntimeISA);
} else {
// It's likely that callers are trying to ensure they have at least a certain amount of
// stack space, so we should add our reserved space on top of what they requested, rather
// than implicitly take it away from them.
stack_size += GetStackOverflowReservedBytes(kRuntimeISA);
}
// Some systems require the stack size to be a multiple of the system page size, so round up.
stack_size = RoundUp(stack_size, gPageSize);
return stack_size;
}
// Return the nearest page-aligned address below the current stack top.
NO_INLINE
static uint8_t* FindStackTop() {
return reinterpret_cast<uint8_t*>(
AlignDown(__builtin_frame_address(0), gPageSize));
}
// Install a protected region in the stack. This is used to trigger a SIGSEGV if a stack
// overflow is detected. It is located right below the stack_begin_.
ATTRIBUTE_NO_SANITIZE_ADDRESS
void Thread::InstallImplicitProtection() {
uint8_t* pregion = tlsPtr_.stack_begin - GetStackOverflowProtectedSize();
// Page containing current top of stack.
uint8_t* stack_top = FindStackTop();
// Try to directly protect the stack.
VLOG(threads) << "installing stack protected region at " << std::hex <<
static_cast<void*>(pregion) << " to " <<
static_cast<void*>(pregion + GetStackOverflowProtectedSize() - 1);
if (ProtectStack(/* fatal_on_error= */ false)) {
// Tell the kernel that we won't be needing these pages any more.
// NB. madvise will probably write zeroes into the memory (on linux it does).
size_t unwanted_size =
reinterpret_cast<uintptr_t>(stack_top) - reinterpret_cast<uintptr_t>(pregion) - gPageSize;
madvise(pregion, unwanted_size, MADV_DONTNEED);
return;
}
// There is a little complexity here that deserves a special mention. On some
// architectures, the stack is created using a VM_GROWSDOWN flag
// to prevent memory being allocated when it's not needed. This flag makes the
// kernel only allocate memory for the stack by growing down in memory. Because we
// want to put an mprotected region far away from that at the stack top, we need
// to make sure the pages for the stack are mapped in before we call mprotect.
//
// The failed mprotect in UnprotectStack is an indication of a thread with VM_GROWSDOWN
// with a non-mapped stack (usually only the main thread).
//
// We map in the stack by reading every page from the stack bottom (highest address)
// to the stack top. (We then madvise this away.) This must be done by reading from the
// current stack pointer downwards.
//
// Accesses too far below the current machine register corresponding to the stack pointer (e.g.,
// ESP on x86[-32], SP on ARM) might cause a SIGSEGV (at least on x86 with newer kernels). We
// thus have to move the stack pointer. We do this portably by using a recursive function with a
// large stack frame size.
// (Defensively) first remove the protection on the protected region as we'll want to read
// and write it. Ignore errors.
UnprotectStack();
VLOG(threads) << "Need to map in stack for thread at " << std::hex <<
static_cast<void*>(pregion);
struct RecurseDownStack {
// This function has an intentionally large stack size.
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wframe-larger-than="
NO_INLINE
__attribute__((no_sanitize("memtag"))) static void Touch(uintptr_t target) {
volatile size_t zero = 0;
// Use a large local volatile array to ensure a large frame size. Do not use anything close
// to a full page for ASAN. It would be nice to ensure the frame size is at most a page, but
// there is no pragma support for this.
// Note: for ASAN we need to shrink the array a bit, as there's other overhead.
constexpr size_t kAsanMultiplier =
#ifdef ADDRESS_SANITIZER
2u;
#else
1u;
#endif
// Keep space uninitialized as it can overflow the stack otherwise (should Clang actually
// auto-initialize this local variable).
volatile char space[gPageSize - (kAsanMultiplier * 256)] __attribute__((uninitialized));
[[maybe_unused]] char sink = space[zero];
// Remove tag from the pointer. Nop in non-hwasan builds.
uintptr_t addr = reinterpret_cast<uintptr_t>(
__hwasan_tag_pointer != nullptr ? __hwasan_tag_pointer(space, 0) : space);
if (addr >= target + gPageSize) {
Touch(target);
}
zero *= 2; // Try to avoid tail recursion.
}
#pragma GCC diagnostic pop
};
RecurseDownStack::Touch(reinterpret_cast<uintptr_t>(pregion));
VLOG(threads) << "(again) installing stack protected region at " << std::hex <<
static_cast<void*>(pregion) << " to " <<
static_cast<void*>(pregion + GetStackOverflowProtectedSize() - 1);
// Protect the bottom of the stack to prevent read/write to it.
ProtectStack(/* fatal_on_error= */ true);
// Tell the kernel that we won't be needing these pages any more.
// NB. madvise will probably write zeroes into the memory (on linux it does).
size_t unwanted_size =
reinterpret_cast<uintptr_t>(stack_top) - reinterpret_cast<uintptr_t>(pregion) - gPageSize;
madvise(pregion, unwanted_size, MADV_DONTNEED);
}
template <bool kSupportTransaction>
static void SetNativePeer(ObjPtr<mirror::Object> java_peer, Thread* thread)
REQUIRES_SHARED(Locks::mutator_lock_) {
ArtField* field = WellKnownClasses::java_lang_Thread_nativePeer;
if (kSupportTransaction && Runtime::Current()->IsActiveTransaction()) {
field->SetLong</*kTransactionActive=*/ true>(java_peer, reinterpret_cast<jlong>(thread));
} else {
field->SetLong</*kTransactionActive=*/ false>(java_peer, reinterpret_cast<jlong>(thread));
}
}
static void SetNativePeer(JNIEnv* env, jobject java_peer, Thread* thread) {
ScopedObjectAccess soa(env);
SetNativePeer</*kSupportTransaction=*/ false>(soa.Decode<mirror::Object>(java_peer), thread);
}
void Thread::CreateNativeThread(JNIEnv* env, jobject java_peer, size_t stack_size, bool is_daemon) {
CHECK(java_peer != nullptr);
Thread* self = static_cast<JNIEnvExt*>(env)->GetSelf();
if (VLOG_IS_ON(threads)) {
ScopedObjectAccess soa(env);
ArtField* f = WellKnownClasses::java_lang_Thread_name;
ObjPtr<mirror::String> java_name =
f->GetObject(soa.Decode<mirror::Object>(java_peer))->AsString();
std::string thread_name;
if (java_name != nullptr) {
thread_name = java_name->ToModifiedUtf8();
} else {
thread_name = "(Unnamed)";
}
VLOG(threads) << "Creating native thread for " << thread_name;
self->Dump(LOG_STREAM(INFO));
}
Runtime* runtime = Runtime::Current();
// Atomically start the birth of the thread ensuring the runtime isn't shutting down.
bool thread_start_during_shutdown = false;
{
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
if (runtime->IsShuttingDownLocked()) {
thread_start_during_shutdown = true;
} else {
runtime->StartThreadBirth();
}
}
if (thread_start_during_shutdown) {
ScopedLocalRef<jclass> error_class(env, env->FindClass("java/lang/InternalError"));
env->ThrowNew(error_class.get(), "Thread starting during runtime shutdown");
return;
}
Thread* child_thread = new Thread(is_daemon);
// Use global JNI ref to hold peer live while child thread starts.
child_thread->tlsPtr_.jpeer = env->NewGlobalRef(java_peer);
stack_size = FixStackSize(stack_size);
// Thread.start is synchronized, so we know that nativePeer is 0, and know that we're not racing
// to assign it.
SetNativePeer(env, java_peer, child_thread);
// Try to allocate a JNIEnvExt for the thread. We do this here as we might be out of memory and
// do not have a good way to report this on the child's side.
std::string error_msg;
std::unique_ptr<JNIEnvExt> child_jni_env_ext(
JNIEnvExt::Create(child_thread, Runtime::Current()->GetJavaVM(), &error_msg));
int pthread_create_result = 0;
if (child_jni_env_ext.get() != nullptr) {
pthread_t new_pthread;
pthread_attr_t attr;
child_thread->tlsPtr_.tmp_jni_env = child_jni_env_ext.get();
CHECK_PTHREAD_CALL(pthread_attr_init, (&attr), "new thread");
CHECK_PTHREAD_CALL(pthread_attr_setdetachstate, (&attr, PTHREAD_CREATE_DETACHED),
"PTHREAD_CREATE_DETACHED");
CHECK_PTHREAD_CALL(pthread_attr_setstacksize, (&attr, stack_size), stack_size);
pthread_create_result = pthread_create(&new_pthread,
&attr,
gUseUserfaultfd ? Thread::CreateCallbackWithUffdGc
: Thread::CreateCallback,
child_thread);
CHECK_PTHREAD_CALL(pthread_attr_destroy, (&attr), "new thread");
if (pthread_create_result == 0) {
// pthread_create started the new thread. The child is now responsible for managing the
// JNIEnvExt we created.
// Note: we can't check for tmp_jni_env == nullptr, as that would require synchronization
// between the threads.
child_jni_env_ext.release(); // NOLINT pthreads API.
return;
}
}
// Either JNIEnvExt::Create or pthread_create(3) failed, so clean up.
{
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
runtime->EndThreadBirth();
}
// Manually delete the global reference since Thread::Init will not have been run. Make sure
// nothing can observe both opeer and jpeer set at the same time.
child_thread->DeleteJPeer(env);
delete child_thread;
child_thread = nullptr;
// TODO: remove from thread group?
SetNativePeer(env, java_peer, nullptr);
{
std::string msg(child_jni_env_ext.get() == nullptr ?
StringPrintf("Could not allocate JNI Env: %s", error_msg.c_str()) :
StringPrintf("pthread_create (%s stack) failed: %s",
PrettySize(stack_size).c_str(), strerror(pthread_create_result)));
ScopedObjectAccess soa(env);
soa.Self()->ThrowOutOfMemoryError(msg.c_str());
}
}
bool Thread::Init(ThreadList* thread_list, JavaVMExt* java_vm, JNIEnvExt* jni_env_ext) {
// This function does all the initialization that must be run by the native thread it applies to.
// (When we create a new thread from managed code, we allocate the Thread* in Thread::Create so
// we can handshake with the corresponding native thread when it's ready.) Check this native
// thread hasn't been through here already...
CHECK(Thread::Current() == nullptr);
// Set pthread_self_ ahead of pthread_setspecific, that makes Thread::Current function, this
// avoids pthread_self_ ever being invalid when discovered from Thread::Current().
tlsPtr_.pthread_self = pthread_self();
CHECK(is_started_);
ScopedTrace trace("Thread::Init");
SetUpAlternateSignalStack();
if (!InitStackHwm()) {
return false;
}
InitCpu();
InitTlsEntryPoints();
RemoveSuspendTrigger();
InitCardTable();
InitTid();
#ifdef __BIONIC__
__get_tls()[TLS_SLOT_ART_THREAD_SELF] = this;
#else
CHECK_PTHREAD_CALL(pthread_setspecific, (Thread::pthread_key_self_, this), "attach self");
Thread::self_tls_ = this;
#endif
DCHECK_EQ(Thread::Current(), this);
tls32_.thin_lock_thread_id = thread_list->AllocThreadId(this);
if (jni_env_ext != nullptr) {
DCHECK_EQ(jni_env_ext->GetVm(), java_vm);
DCHECK_EQ(jni_env_ext->GetSelf(), this);
tlsPtr_.jni_env = jni_env_ext;
} else {
std::string error_msg;
tlsPtr_.jni_env = JNIEnvExt::Create(this, java_vm, &error_msg);
if (tlsPtr_.jni_env == nullptr) {
LOG(ERROR) << "Failed to create JNIEnvExt: " << error_msg;
return false;
}
}
ScopedTrace trace3("ThreadList::Register");
thread_list->Register(this);
return true;
}
template <typename PeerAction>
Thread* Thread::Attach(const char* thread_name,
bool as_daemon,
PeerAction peer_action,
bool should_run_callbacks) {
Runtime* runtime = Runtime::Current();
ScopedTrace trace("Thread::Attach");
if (runtime == nullptr) {
LOG(ERROR) << "Thread attaching to non-existent runtime: " <<
((thread_name != nullptr) ? thread_name : "(Unnamed)");
return nullptr;
}
Thread* self;
{
ScopedTrace trace2("Thread birth");
MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_);
if (runtime->IsShuttingDownLocked()) {
LOG(WARNING) << "Thread attaching while runtime is shutting down: " <<
((thread_name != nullptr) ? thread_name : "(Unnamed)");
return nullptr;
} else {
Runtime::Current()->StartThreadBirth();
self = new Thread(as_daemon);
bool init_success = self->Init(runtime->GetThreadList(), runtime->GetJavaVM());
Runtime::Current()->EndThreadBirth();
if (!init_success) {
delete self;
return nullptr;
}
}
}
self->InitStringEntryPoints();
CHECK_NE(self->GetState(), ThreadState::kRunnable);
self->SetState(ThreadState::kNative);
// Run the action that is acting on the peer.
if (!peer_action(self)) {
runtime->GetThreadList()->Unregister(self, should_run_callbacks);
// Unregister deletes self, no need to do this here.
return nullptr;
}
if (VLOG_IS_ON(threads)) {
if (thread_name != nullptr) {
VLOG(threads) << "Attaching thread " << thread_name;
} else {
VLOG(threads) << "Attaching unnamed thread.";
}
ScopedObjectAccess soa(self);
self->Dump(LOG_STREAM(INFO));
}
if (should_run_callbacks) {
ScopedObjectAccess soa(self);
runtime->GetRuntimeCallbacks()->ThreadStart(self);
}
return self;
}
Thread* Thread::Attach(const char* thread_name,
bool as_daemon,
jobject thread_group,
bool create_peer,
bool should_run_callbacks) {
auto create_peer_action = [&](Thread* self) {
// If we're the main thread, ClassLinker won't be created until after we're attached,
// so that thread needs a two-stage attach. Regular threads don't need this hack.
// In the compiler, all threads need this hack, because no-one's going to be getting
// a native peer!
if (create_peer) {
self->CreatePeer(thread_name, as_daemon, thread_group);
if (self->IsExceptionPending()) {
// We cannot keep the exception around, as we're deleting self. Try to be helpful and log
// the failure but do not dump the exception details. If we fail to allocate the peer, we
// usually also fail to allocate an exception object and throw a pre-allocated OOME without
// any useful information. If we do manage to allocate the exception object, the memory
// information in the message could have been collected too late and therefore misleading.
{
ScopedObjectAccess soa(self);
LOG(ERROR) << "Exception creating thread peer: "
<< ((thread_name != nullptr) ? thread_name : "<null>");
self->ClearException();
}
return false;
}
} else {
// These aren't necessary, but they improve diagnostics for unit tests & command-line tools.
if (thread_name != nullptr) {
self->SetCachedThreadName(thread_name);
::art::SetThreadName(thread_name);
} else if (self->GetJniEnv()->IsCheckJniEnabled()) {
LOG(WARNING) << *Thread::Current() << " attached without supplying a name";
}
}
return true;
};
return Attach(thread_name, as_daemon, create_peer_action, should_run_callbacks);
}
Thread* Thread::Attach(const char* thread_name, bool as_daemon, jobject thread_peer) {
auto set_peer_action = [&](Thread* self) {
// Install the given peer.
DCHECK(self == Thread::Current());
ScopedObjectAccess soa(self);
ObjPtr<mirror::Object> peer = soa.Decode<mirror::Object>(thread_peer);
self->tlsPtr_.opeer = peer.Ptr();
SetNativePeer</*kSupportTransaction=*/ false>(peer, self);
return true;
};
return Attach(thread_name, as_daemon, set_peer_action, /* should_run_callbacks= */ true);
}
void Thread::CreatePeer(const char* name, bool as_daemon, jobject thread_group) {
Runtime* runtime = Runtime::Current();
CHECK(runtime->IsStarted());
Thread* self = this;
DCHECK_EQ(self, Thread::Current());
ScopedObjectAccess soa(self);
StackHandleScope<4u> hs(self);
DCHECK(WellKnownClasses::java_lang_ThreadGroup->IsInitialized());
Handle<mirror::Object> thr_group = hs.NewHandle(soa.Decode<mirror::Object>(
thread_group != nullptr ? thread_group : runtime->GetMainThreadGroup()));
Handle<mirror::String> thread_name = hs.NewHandle(
name != nullptr ? mirror::String::AllocFromModifiedUtf8(self, name) : nullptr);
// Add missing null check in case of OOM b/18297817
if (name != nullptr && UNLIKELY(thread_name == nullptr)) {
CHECK(self->IsExceptionPending());
return;
}
jint thread_priority = GetNativePriority();
DCHECK(WellKnownClasses::java_lang_Thread->IsInitialized());
Handle<mirror::Object> peer =
hs.NewHandle(WellKnownClasses::java_lang_Thread->AllocObject(self));
if (UNLIKELY(peer == nullptr)) {
CHECK(IsExceptionPending());
return;
}
tlsPtr_.opeer = peer.Get();
WellKnownClasses::java_lang_Thread_init->InvokeInstance<'V', 'L', 'L', 'I', 'Z'>(
self, peer.Get(), thr_group.Get(), thread_name.Get(), thread_priority, as_daemon);
if (self->IsExceptionPending()) {
return;
}
SetNativePeer</*kSupportTransaction=*/ false>(peer.Get(), self);
MutableHandle<mirror::String> peer_thread_name(hs.NewHandle(GetThreadName()));
if (peer_thread_name == nullptr) {
// The Thread constructor should have set the Thread.name to a
// non-null value. However, because we can run without code
// available (in the compiler, in tests), we manually assign the
// fields the constructor should have set.
if (runtime->IsActiveTransaction()) {
InitPeer<true>(tlsPtr_.opeer,
as_daemon,
thr_group.Get(),
thread_name.Get(),
thread_priority);
} else {
InitPeer<false>(tlsPtr_.opeer,
as_daemon,
thr_group.Get(),
thread_name.Get(),
thread_priority);
}
peer_thread_name.Assign(GetThreadName());
}
// 'thread_name' may have been null, so don't trust 'peer_thread_name' to be non-null.
if (peer_thread_name != nullptr) {
SetThreadName(peer_thread_name->ToModifiedUtf8().c_str());
}
}
ObjPtr<mirror::Object> Thread::CreateCompileTimePeer(const char* name,
bool as_daemon,
jobject thread_group) {
Runtime* runtime = Runtime::Current();
CHECK(!runtime->IsStarted());
Thread* self = this;
DCHECK_EQ(self, Thread::Current());
ScopedObjectAccessUnchecked soa(self);
StackHandleScope<3u> hs(self);
DCHECK(WellKnownClasses::java_lang_ThreadGroup->IsInitialized());
Handle<mirror::Object> thr_group = hs.NewHandle(soa.Decode<mirror::Object>(
thread_group != nullptr ? thread_group : runtime->GetMainThreadGroup()));
Handle<mirror::String> thread_name = hs.NewHandle(
name != nullptr ? mirror::String::AllocFromModifiedUtf8(self, name) : nullptr);
// Add missing null check in case of OOM b/18297817
if (name != nullptr && UNLIKELY(thread_name == nullptr)) {
CHECK(self->IsExceptionPending());
return nullptr;
}
jint thread_priority = kNormThreadPriority; // Always normalize to NORM priority.
DCHECK(WellKnownClasses::java_lang_Thread->IsInitialized());
Handle<mirror::Object> peer = hs.NewHandle(
WellKnownClasses::java_lang_Thread->AllocObject(self));
if (peer == nullptr) {
CHECK(Thread::Current()->IsExceptionPending());
return nullptr;
}
// We cannot call Thread.init, as it will recursively ask for currentThread.
// The Thread constructor should have set the Thread.name to a
// non-null value. However, because we can run without code
// available (in the compiler, in tests), we manually assign the
// fields the constructor should have set.
if (runtime->IsActiveTransaction()) {
InitPeer<true>(peer.Get(),
as_daemon,
thr_group.Get(),
thread_name.Get(),
thread_priority);
} else {
InitPeer<false>(peer.Get(),
as_daemon,
thr_group.Get(),
thread_name.Get(),
thread_priority);
}
return peer.Get();
}
template<bool kTransactionActive>
void Thread::InitPeer(ObjPtr<mirror::Object> peer,
bool as_daemon,
ObjPtr<mirror::Object> thread_group,
ObjPtr<mirror::String> thread_name,
jint thread_priority) {
WellKnownClasses::java_lang_Thread_daemon->SetBoolean<kTransactionActive>(peer,
static_cast<uint8_t>(as_daemon ? 1u : 0u));
WellKnownClasses::java_lang_Thread_group->SetObject<kTransactionActive>(peer, thread_group);
WellKnownClasses::java_lang_Thread_name->SetObject<kTransactionActive>(peer, thread_name);
WellKnownClasses::java_lang_Thread_priority->SetInt<kTransactionActive>(peer, thread_priority);
}
void Thread::SetCachedThreadName(const char* name) {
DCHECK(name != kThreadNameDuringStartup);
const char* old_name = tlsPtr_.name.exchange(name == nullptr ? nullptr : strdup(name));
if (old_name != nullptr && old_name != kThreadNameDuringStartup) {
// Deallocate it, carefully. Note that the load has to be ordered wrt the store of the xchg.
for (uint32_t i = 0; UNLIKELY(tls32_.num_name_readers.load(std::memory_order_seq_cst) != 0);
++i) {
static constexpr uint32_t kNumSpins = 1000;
// Ugly, but keeps us from having to do anything on the reader side.
if (i > kNumSpins) {
usleep(500);
}
}
// We saw the reader count drop to zero since we replaced the name; old one is now safe to
// deallocate.
free(const_cast<char *>(old_name));
}
}
void Thread::SetThreadName(const char* name) {
SetCachedThreadName(name);
::art::SetThreadName(name);
Dbg::DdmSendThreadNotification(this, CHUNK_TYPE("THNM"));
}
static void GetThreadStack(pthread_t thread,
void** stack_base,
size_t* stack_size,
size_t* guard_size) {
#if defined(__APPLE__)
*stack_size = pthread_get_stacksize_np(thread);
void* stack_addr = pthread_get_stackaddr_np(thread);
// Check whether stack_addr is the base or end of the stack.
// (On Mac OS 10.7, it's the end.)
int stack_variable;
if (stack_addr > &stack_variable) {
*stack_base = reinterpret_cast<uint8_t*>(stack_addr) - *stack_size;
} else {
*stack_base = stack_addr;
}
// This is wrong, but there doesn't seem to be a way to get the actual value on the Mac.
pthread_attr_t attributes;
CHECK_PTHREAD_CALL(pthread_attr_init, (&attributes), __FUNCTION__);
CHECK_PTHREAD_CALL(pthread_attr_getguardsize, (&attributes, guard_size), __FUNCTION__);
CHECK_PTHREAD_CALL(pthread_attr_destroy, (&attributes), __FUNCTION__);
#else
pthread_attr_t attributes;
CHECK_PTHREAD_CALL(pthread_getattr_np, (thread, &attributes), __FUNCTION__);
CHECK_PTHREAD_CALL(pthread_attr_getstack, (&attributes, stack_base, stack_size), __FUNCTION__);
CHECK_PTHREAD_CALL(pthread_attr_getguardsize, (&attributes, guard_size), __FUNCTION__);
CHECK_PTHREAD_CALL(pthread_attr_destroy, (&attributes), __FUNCTION__);
#if defined(__GLIBC__)
// If we're the main thread, check whether we were run with an unlimited stack. In that case,
// glibc will have reported a 2GB stack for our 32-bit process, and our stack overflow detection
// will be broken because we'll die long before we get close to 2GB.
bool is_main_thread = (::art::GetTid() == static_cast<uint32_t>(getpid()));
if (is_main_thread) {
rlimit stack_limit;
if (getrlimit(RLIMIT_STACK, &stack_limit) == -1) {
PLOG(FATAL) << "getrlimit(RLIMIT_STACK) failed";
}
if (stack_limit.rlim_cur == RLIM_INFINITY) {
size_t old_stack_size = *stack_size;
// Use the kernel default limit as our size, and adjust the base to match.
*stack_size = 8 * MB;
*stack_base = reinterpret_cast<uint8_t*>(*stack_base) + (old_stack_size - *stack_size);
VLOG(threads) << "Limiting unlimited stack (reported as " << PrettySize(old_stack_size) << ")"
<< " to " << PrettySize(*stack_size)
<< " with base " << *stack_base;
}
}
#endif
#endif
}
bool Thread::InitStackHwm() {
ScopedTrace trace("InitStackHwm");
void* read_stack_base;
size_t read_stack_size;
size_t read_guard_size;
GetThreadStack(tlsPtr_.pthread_self, &read_stack_base, &read_stack_size, &read_guard_size);
tlsPtr_.stack_begin = reinterpret_cast<uint8_t*>(read_stack_base);
tlsPtr_.stack_size = read_stack_size;
// The minimum stack size we can cope with is the protected region size + stack overflow check
// region size + some memory for normal stack usage.
//
// The protected region is located at the beginning (lowest address) of the stack region.
// Therefore, it starts at a page-aligned address. Its size should be a multiple of page sizes.
// Typically, it is one page in size, however this varies in some configurations.
//
// The overflow reserved bytes is size of the stack overflow check region, located right after
// the protected region, so also starts at a page-aligned address. The size is discretionary.
// Typically it is 8K, but this varies in some configurations.
//
// The rest of the stack memory is available for normal stack usage. It is located right after
// the stack overflow check region, so its starting address isn't necessarily page-aligned. The
// size of the region is discretionary, however should be chosen in a way that the overall stack
// size is a multiple of page sizes. Historically, it is chosen to be at least 4 KB.
//
// On systems with 4K page size, typically the minimum stack size will be 4+8+4 = 16K.
// The thread won't be able to do much with this stack: even the GC takes between 8K and 12K.
DCHECK_ALIGNED_PARAM(static_cast<size_t>(GetStackOverflowProtectedSize()),
static_cast<int32_t>(gPageSize));
size_t min_stack = GetStackOverflowProtectedSize() +
RoundUp(GetStackOverflowReservedBytes(kRuntimeISA) + 4 * KB, gPageSize);
if (read_stack_size <= min_stack) {
// Note, as we know the stack is small, avoid operations that could use a lot of stack.
LogHelper::LogLineLowStack(__PRETTY_FUNCTION__,
__LINE__,
::android::base::ERROR,
"Attempt to attach a thread with a too-small stack");
return false;
}
// This is included in the SIGQUIT output, but it's useful here for thread debugging.
VLOG(threads) << StringPrintf("Native stack is at %p (%s with %s guard)",
read_stack_base,
PrettySize(read_stack_size).c_str(),
PrettySize(read_guard_size).c_str());
// Set stack_end_ to the bottom of the stack saving space of stack overflows
Runtime* runtime = Runtime::Current();
bool implicit_stack_check =
runtime->GetImplicitStackOverflowChecks() && !runtime->IsAotCompiler();
ResetDefaultStackEnd();
// Install the protected region if we are doing implicit overflow checks.
if (implicit_stack_check) {
// The thread might have protected region at the bottom. We need
// to install our own region so we need to move the limits
// of the stack to make room for it.
tlsPtr_.stack_begin += read_guard_size + GetStackOverflowProtectedSize();
tlsPtr_.stack_end += read_guard_size + GetStackOverflowProtectedSize();
tlsPtr_.stack_size -= read_guard_size + GetStackOverflowProtectedSize();
InstallImplicitProtection();
}
// Consistency check.
CHECK_GT(FindStackTop(), reinterpret_cast<void*>(tlsPtr_.stack_end));
return true;
}
void Thread::ShortDump(std::ostream& os) const {
os << "Thread[";
if (GetThreadId() != 0) {
// If we're in kStarting, we won't have a thin lock id or tid yet.
os << GetThreadId()
<< ",tid=" << GetTid() << ',';
}
tls32_.num_name_readers.fetch_add(1, std::memory_order_seq_cst);
const char* name = tlsPtr_.name.load();
os << GetState()
<< ",Thread*=" << this
<< ",peer=" << tlsPtr_.opeer
<< ",\"" << (name == nullptr ? "null" : name) << "\""
<< "]";
tls32_.num_name_readers.fetch_sub(1 /* at least memory_order_release */);
}
Thread::DumpOrder Thread::Dump(std::ostream& os,
bool dump_native_stack,
bool force_dump_stack) const {
DumpState(os);
return DumpStack(os, dump_native_stack, force_dump_stack);
}
Thread::DumpOrder Thread::Dump(std::ostream& os,
unwindstack::AndroidLocalUnwinder& unwinder,
bool dump_native_stack,
bool force_dump_stack) const {
DumpState(os);
return DumpStack(os, unwinder, dump_native_stack, force_dump_stack);
}
ObjPtr<mirror::String> Thread::GetThreadName() const {
if (tlsPtr_.opeer == nullptr) {
return nullptr;
}
ObjPtr<mirror::Object> name = WellKnownClasses::java_lang_Thread_name->GetObject(tlsPtr_.opeer);
return name == nullptr ? nullptr : name->AsString();
}
void Thread::GetThreadName(std::string& name) const {
tls32_.num_name_readers.fetch_add(1, std::memory_order_seq_cst);
// The store part of the increment has to be ordered with respect to the following load.
const char* c_name = tlsPtr_.name.load(std::memory_order_seq_cst);
name.assign(c_name == nullptr ? "<no name>" : c_name);
tls32_.num_name_readers.fetch_sub(1 /* at least memory_order_release */);
}
uint64_t Thread::GetCpuMicroTime() const {
#if defined(__linux__)
clockid_t cpu_clock_id;
pthread_getcpuclockid(tlsPtr_.pthread_self, &cpu_clock_id);
timespec now;
clock_gettime(cpu_clock_id, &now);
return static_cast<uint64_t>(now.tv_sec) * UINT64_C(1000000) +
static_cast<uint64_t>(now.tv_nsec) / UINT64_C(1000);
#else // __APPLE__
UNIMPLEMENTED(WARNING);
return -1;
#endif
}
// Attempt to rectify locks so that we dump thread list with required locks before exiting.
void Thread::UnsafeLogFatalForSuspendCount(Thread* self, Thread* thread) NO_THREAD_SAFETY_ANALYSIS {
LOG(ERROR) << *thread << " suspend count already zero.";
Locks::thread_suspend_count_lock_->Unlock(self);
if (!Locks::mutator_lock_->IsSharedHeld(self)) {
Locks::mutator_lock_->SharedTryLock(self);
if (!Locks::mutator_lock_->IsSharedHeld(self)) {
LOG(WARNING) << "Dumping thread list without holding mutator_lock_";
}
}
if (!Locks::thread_list_lock_->IsExclusiveHeld(self)) {
Locks::thread_list_lock_->TryLock(self);
if (!Locks::thread_list_lock_->IsExclusiveHeld(self)) {
LOG(WARNING) << "Dumping thread list without holding thread_list_lock_";
}
}
std::ostringstream ss;
Runtime::Current()->GetThreadList()->Dump(ss);
LOG(FATAL) << ss.str();
UNREACHABLE();
}
bool Thread::PassActiveSuspendBarriers() {
DCHECK_EQ(this, Thread::Current());
DCHECK_NE(GetState(), ThreadState::kRunnable);
// Grab the suspend_count lock and copy the current set of barriers. Then clear the list and the
// flag. The IncrementSuspendCount function requires the lock so we prevent a race between setting
// the kActiveSuspendBarrier flag and clearing it.
// TODO: Consider doing this without the temporary vector. That code will be a bit
// tricky, since the WrappedSuspend1Barrier may disappear once the barrier is decremented.
std::vector<AtomicInteger*> pass_barriers{};
{
MutexLock mu(this, *Locks::thread_suspend_count_lock_);
if (!ReadFlag(ThreadFlag::kActiveSuspendBarrier)) {
// Quick exit test: The barriers have already been claimed - this is possible as there may
// be a race to claim and it doesn't matter who wins. All of the callers of this function
// (except SuspendAllInternal) will first test the kActiveSuspendBarrier flag without the
// lock. Here we double-check whether the barrier has been passed with the
// suspend_count_lock_.
return false;
}
if (tlsPtr_.active_suspendall_barrier != nullptr) {
// We have at most one active active_suspendall_barrier. See thread.h comment.
pass_barriers.push_back(tlsPtr_.active_suspendall_barrier);
tlsPtr_.active_suspendall_barrier = nullptr;
}
for (WrappedSuspend1Barrier* w = tlsPtr_.active_suspend1_barriers; w != nullptr; w = w->next_) {
pass_barriers.push_back(&(w->barrier_));
}
tlsPtr_.active_suspend1_barriers = nullptr;
AtomicClearFlag(ThreadFlag::kActiveSuspendBarrier);
CHECK_GT(pass_barriers.size(), 0U); // Since kActiveSuspendBarrier was set.
// Decrement suspend barrier(s) while we still hold the lock, since SuspendThread may
// remove and deallocate suspend barriers while holding suspend_count_lock_ .
// There will typically only be a single barrier to pass here.
for (AtomicInteger*& barrier : pass_barriers) {
int32_t old_val = barrier->fetch_sub(1, std::memory_order_release);
CHECK_GT(old_val, 0) << "Unexpected value for PassActiveSuspendBarriers(): " << old_val;
if (old_val != 1) {
// We're done with it.
barrier = nullptr;
}
}
}
// Finally do futex_wakes after releasing the lock.
for (AtomicInteger* barrier : pass_barriers) {
#if ART_USE_FUTEXES
if (barrier != nullptr) {
futex(barrier->Address(), FUTEX_WAKE_PRIVATE, INT_MAX, nullptr, nullptr, 0);
}
#endif
}
return true;
}
void Thread::RunCheckpointFunction() {
DCHECK_EQ(Thread::Current(), this);
CHECK(!GetStateAndFlags(std::memory_order_relaxed).IsAnyOfFlagsSet(FlipFunctionFlags()));
// Grab the suspend_count lock, get the next checkpoint and update all the checkpoint fields. If
// there are no more checkpoints we will also clear the kCheckpointRequest flag.
Closure* checkpoint;
{
MutexLock mu(this, *Locks::thread_suspend_count_lock_);
checkpoint = tlsPtr_.checkpoint_function;
if (!checkpoint_overflow_.empty()) {
// Overflow list not empty, copy the first one out and continue.
tlsPtr_.checkpoint_function = checkpoint_overflow_.front();
checkpoint_overflow_.pop_front();
} else {
// No overflow checkpoints. Clear the kCheckpointRequest flag
tlsPtr_.checkpoint_function = nullptr;
AtomicClearFlag(ThreadFlag::kCheckpointRequest);
}
}
// Outside the lock, run the checkpoint function.
ScopedTrace trace("Run checkpoint function");
CHECK(checkpoint != nullptr) << "Checkpoint flag set without pending checkpoint";
checkpoint->Run(this);
}
void Thread::RunEmptyCheckpoint() {
// Note: Empty checkpoint does not access the thread's stack,
// so we do not need to check for the flip function.
DCHECK_EQ(Thread::Current(), this);
AtomicClearFlag(ThreadFlag::kEmptyCheckpointRequest);
Runtime::Current()->GetThreadList()->EmptyCheckpointBarrier()->Pass(this);
}
bool Thread::RequestCheckpoint(Closure* function) {
bool success;
do {
StateAndFlags old_state_and_flags = GetStateAndFlags(std::memory_order_relaxed);
if (old_state_and_flags.GetState() != ThreadState::kRunnable) {
return false; // Fail, thread is suspended and so can't run a checkpoint.
}
StateAndFlags new_state_and_flags = old_state_and_flags;
new_state_and_flags.SetFlag(ThreadFlag::kCheckpointRequest);
success = tls32_.state_and_flags.CompareAndSetWeakSequentiallyConsistent(
old_state_and_flags.GetValue(), new_state_and_flags.GetValue());
} while (!success);
// Succeeded setting checkpoint flag, now insert the actual checkpoint.
if (tlsPtr_.checkpoint_function == nullptr) {
tlsPtr_.checkpoint_function = function;
} else {
checkpoint_overflow_.push_back(function);
}
DCHECK(ReadFlag(ThreadFlag::kCheckpointRequest));
TriggerSuspend();
return true;
}
bool Thread::RequestEmptyCheckpoint() {
StateAndFlags old_state_and_flags = GetStateAndFlags(std::memory_order_relaxed);
if (old_state_and_flags.GetState() != ThreadState::kRunnable) {
// If it's not runnable, we don't need to do anything because it won't be in the middle of a
// heap access (eg. the read barrier).
return false;
}
// We must be runnable to request a checkpoint.
DCHECK_EQ(old_state_and_flags.GetState(), ThreadState::kRunnable);
StateAndFlags new_state_and_flags = old_state_and_flags;
new_state_and_flags.SetFlag(ThreadFlag::kEmptyCheckpointRequest);
bool success = tls32_.state_and_flags.CompareAndSetStrongSequentiallyConsistent(
old_state_and_flags.GetValue(), new_state_and_flags.GetValue());
if (success) {
TriggerSuspend();
}
return success;
}
class BarrierClosure : public Closure {
public:
explicit BarrierClosure(Closure* wrapped) : wrapped_(wrapped), barrier_(0) {}
void Run(Thread* self) override {
wrapped_->Run(self);
barrier_.Pass(self);
}
void Wait(Thread* self, ThreadState wait_state) {
if (wait_state != ThreadState::kRunnable) {
barrier_.Increment<Barrier::kDisallowHoldingLocks>(self, 1);
} else {
barrier_.Increment<Barrier::kAllowHoldingLocks>(self, 1);
}
}
private:
Closure* wrapped_;
Barrier barrier_;
};
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution.
bool Thread::RequestSynchronousCheckpoint(Closure* function, ThreadState wait_state) {
Thread* self = Thread::Current();
if (this == self) {
Locks::thread_list_lock_->AssertExclusiveHeld(self);
// Unlock the tll before running so that the state is the same regardless of thread.
Locks::thread_list_lock_->ExclusiveUnlock(self);
// Asked to run on this thread. Just run.
function->Run(this);
return true;
}
// The current thread is not this thread.
VerifyState();
Locks::thread_list_lock_->AssertExclusiveHeld(self);
// If target "this" thread is runnable, try to schedule a checkpoint. Do some gymnastics to not
// hold the suspend-count lock for too long.
if (GetState() == ThreadState::kRunnable) {
BarrierClosure barrier_closure(function);
bool installed = false;
{
MutexLock mu(self, *Locks::thread_suspend_count_lock_);
installed = RequestCheckpoint(&barrier_closure);
}
if (installed) {
// Relinquish the thread-list lock. We should not wait holding any locks. We cannot
// reacquire it since we don't know if 'this' hasn't been deleted yet.
Locks::thread_list_lock_->ExclusiveUnlock(self);
ScopedThreadStateChange sts(self, wait_state);
// Wait state can be kRunnable, in which case, for lock ordering purposes, it's as if we ran
// the closure ourselves. This means that the target thread should not acquire a pre-mutator
// lock without running the checkpoint, and the closure should not acquire a pre-mutator
// lock or suspend.
barrier_closure.Wait(self, wait_state);
return true;
}
// No longer runnable. Fall-through.
}
// Target "this" thread was not runnable. Suspend it, hopefully redundantly,
// but it might have become runnable in the meantime.
// Although this is a thread suspension, the target thread only blocks while we run the
// checkpoint, which is presumed to terminate quickly even if other threads are blocked.
// Note: IncrementSuspendCount also expects the thread_list_lock to be held unless this == self.
{
bool is_suspended = false;
WrappedSuspend1Barrier wrapped_barrier{};
{
MutexLock suspend_count_mu(self, *Locks::thread_suspend_count_lock_);
// If wait_state is kRunnable, function may not suspend. We thus never block because
// we ourselves are being asked to suspend.
if (UNLIKELY(wait_state != ThreadState::kRunnable && self->GetSuspendCount() != 0)) {
// We are being asked to suspend while we are suspending another thread that may be
// responsible for our suspension. This is likely to result in deadlock if we each
// block on the suspension request. Instead we wait for the situation to change.
ThreadExitFlag target_status;
NotifyOnThreadExit(&target_status);
for (int iter_count = 1; self->GetSuspendCount() != 0; ++iter_count) {
Locks::thread_suspend_count_lock_->ExclusiveUnlock(self);
Locks::thread_list_lock_->ExclusiveUnlock(self);
{
ScopedThreadStateChange sts(self, wait_state);
usleep(ThreadList::kThreadSuspendSleepUs);
}
CHECK_LT(iter_count, ThreadList::kMaxSuspendRetries);
Locks::thread_list_lock_->ExclusiveLock(self);
if (target_status.HasExited()) {
Locks::thread_list_lock_->ExclusiveUnlock(self);
DCheckUnregisteredEverywhere(&target_status, &target_status);
return false;
}
Locks::thread_suspend_count_lock_->ExclusiveLock(self);
}
UnregisterThreadExitFlag(&target_status);
}
IncrementSuspendCount(self, nullptr, &wrapped_barrier, SuspendReason::kInternal);
VerifyState();
DCHECK_GT(GetSuspendCount(), 0);
if (wait_state != ThreadState::kRunnable) {
DCHECK_EQ(self->GetSuspendCount(), 0);
}
// Since we've incremented the suspend count, "this" thread can no longer disappear.
Locks::thread_list_lock_->ExclusiveUnlock(self);
if (IsSuspended()) {
// See the discussion in mutator_gc_coord.md and SuspendAllInternal for the race here.
RemoveFirstSuspend1Barrier(&wrapped_barrier);
if (!HasActiveSuspendBarrier()) {
AtomicClearFlag(ThreadFlag::kActiveSuspendBarrier);
}
is_suspended = true;
}
}
if (!is_suspended) {
// This waits while holding the mutator lock. Effectively `self` becomes
// impossible to suspend until `this` responds to the suspend request.
// Arguably that's not making anything qualitatively worse.
bool success = !Runtime::Current()
->GetThreadList()
->WaitForSuspendBarrier(&wrapped_barrier.barrier_)
.has_value();
CHECK(success);
}
// Ensure that the flip function for this thread, if pending, is finished *before*
// the checkpoint function is run. Otherwise, we may end up with both `to' and 'from'
// space references on the stack, confusing the GC's thread-flip logic. The caller is
// runnable so can't have a pending flip function.
DCHECK_EQ(self->GetState(), ThreadState::kRunnable);
DCHECK(IsSuspended());
DCHECK(!self->GetStateAndFlags(std::memory_order_relaxed).IsAnyOfFlagsSet(FlipFunctionFlags()));
EnsureFlipFunctionStarted(self, this);
// Since we're runnable, and kPendingFlipFunction is set with all threads suspended, it
// cannot be set again here. Thus kRunningFlipFunction is either already set after the
// EnsureFlipFunctionStarted call, or will not be set before we call Run().
if (ReadFlag(ThreadFlag::kRunningFlipFunction)) {
WaitForFlipFunction(self);
}
function->Run(this);
}
{
MutexLock mu2(self, *Locks::thread_suspend_count_lock_);
DCHECK_NE(GetState(), ThreadState::kRunnable);
DCHECK_GT(GetSuspendCount(), 0);
DecrementSuspendCount(self);
resume_cond_->Broadcast(self);
}
Locks::thread_list_lock_->AssertNotHeld(self);
return true;
}
void Thread::SetFlipFunction(Closure* function) {
// This is called with all threads suspended, except for the calling thread.
DCHECK(IsSuspended() || Thread::Current() == this);
DCHECK(function != nullptr);
DCHECK(GetFlipFunction() == nullptr);
tlsPtr_.flip_function.store(function, std::memory_order_relaxed);
DCHECK(!GetStateAndFlags(std::memory_order_relaxed).IsAnyOfFlagsSet(FlipFunctionFlags()));
AtomicSetFlag(ThreadFlag::kPendingFlipFunction, std::memory_order_release);
}
bool Thread::EnsureFlipFunctionStarted(Thread* self,
Thread* target,
StateAndFlags old_state_and_flags,
ThreadExitFlag* tef,
bool* finished) {
// Note: If tef is non-null, *target may have been destroyed. We have to be careful about
// accessing it. That is the reason this is static and not a member function.
DCHECK(self == Current());
bool check_exited = (tef != nullptr);
// Check that the thread can't unexpectedly exit while we are running.
DCHECK(self == target || check_exited || target->ReadFlag(ThreadFlag::kSuspendRequest) ||
Locks::thread_list_lock_->IsExclusiveHeld(self))
<< *target;
bool become_runnable;
auto maybe_release = [=]() NO_THREAD_SAFETY_ANALYSIS /* conditionally unlocks */ {
if (check_exited) {
Locks::thread_list_lock_->Unlock(self);
}
};
auto set_finished = [=](bool value) {
if (finished != nullptr) {
*finished = value;
}
};
if (check_exited) {
Locks::thread_list_lock_->Lock(self);
if (tef->HasExited()) {
Locks::thread_list_lock_->Unlock(self);
set_finished(true);
return false;
}
}
target->VerifyState();
if (old_state_and_flags.GetValue() == 0) {
become_runnable = false;
old_state_and_flags = target->GetStateAndFlags(std::memory_order_relaxed);
} else {
become_runnable = true;
DCHECK(!check_exited);
DCHECK(target == self);
DCHECK(old_state_and_flags.IsFlagSet(ThreadFlag::kPendingFlipFunction));
DCHECK(!old_state_and_flags.IsFlagSet(ThreadFlag::kSuspendRequest));
}
while (true) {
DCHECK(!check_exited || (Locks::thread_list_lock_->IsExclusiveHeld(self) && !tef->HasExited()));
if (!old_state_and_flags.IsFlagSet(ThreadFlag::kPendingFlipFunction)) {
maybe_release();
set_finished(!old_state_and_flags.IsFlagSet(ThreadFlag::kRunningFlipFunction));
return false;
}
DCHECK(!old_state_and_flags.IsFlagSet(ThreadFlag::kRunningFlipFunction));
StateAndFlags new_state_and_flags =
old_state_and_flags.WithFlag(ThreadFlag::kRunningFlipFunction)
.WithoutFlag(ThreadFlag::kPendingFlipFunction);
if (become_runnable) {
DCHECK_EQ(self, target);
DCHECK_NE(self->GetState(), ThreadState::kRunnable);
new_state_and_flags = new_state_and_flags.WithState(ThreadState::kRunnable);
}
if (target->tls32_.state_and_flags.CompareAndSetWeakAcquire(old_state_and_flags.GetValue(),
new_state_and_flags.GetValue())) {
if (become_runnable) {
self->GetMutatorLock()->TransitionFromSuspendedToRunnable(self);
}
art::Locks::mutator_lock_->AssertSharedHeld(self);
maybe_release();
// Thread will not go away while kRunningFlipFunction is set.
target->RunFlipFunction(self);
// At this point, no flip function flags should be set. It's unsafe to DCHECK that, since
// the thread may now have exited.
set_finished(true);
return become_runnable;
}
if (become_runnable) {
DCHECK(!check_exited); // We didn't acquire thread_list_lock_ .
// Let caller retry.
return false;
}
old_state_and_flags = target->GetStateAndFlags(std::memory_order_acquire);
}
// Unreachable.
}
void Thread::RunFlipFunction(Thread* self) {
// This function is called either by the thread running `ThreadList::FlipThreadRoots()` or when
// a thread becomes runnable, after we've successfully set the kRunningFlipFunction ThreadFlag.
DCHECK(ReadFlag(ThreadFlag::kRunningFlipFunction));
Closure* flip_function = GetFlipFunction();
tlsPtr_.flip_function.store(nullptr, std::memory_order_relaxed);
DCHECK(flip_function != nullptr);
VerifyState();
flip_function->Run(this);
DCHECK(!ReadFlag(ThreadFlag::kPendingFlipFunction));
VerifyState();
AtomicClearFlag(ThreadFlag::kRunningFlipFunction, std::memory_order_release);
// From here on this thread may go away, and it is no longer safe to access.
// Notify all threads that are waiting for completion.
// TODO: Should we create a separate mutex and condition variable instead
// of piggy-backing on the `thread_suspend_count_lock_` and `resume_cond_`?
MutexLock mu(self, *Locks::thread_suspend_count_lock_);
resume_cond_->Broadcast(self);
}
void Thread::WaitForFlipFunction(Thread* self) const {
// Another thread is running the flip function. Wait for it to complete.
// Check the flag while holding the mutex so that we do not miss the broadcast.
// Repeat the check after waiting to guard against spurious wakeups (and because
// we share the `thread_suspend_count_lock_` and `resume_cond_` with other code).
// Check that the thread can't unexpectedly exit while we are running.
DCHECK(self == this || ReadFlag(ThreadFlag::kSuspendRequest) ||
Locks::thread_list_lock_->IsExclusiveHeld(self));
MutexLock mu(self, *Locks::thread_suspend_count_lock_);
while (true) {
StateAndFlags old_state_and_flags = GetStateAndFlags(std::memory_order_acquire);
if (!old_state_and_flags.IsFlagSet(ThreadFlag::kRunningFlipFunction)) {
return;
}
// We sometimes hold mutator lock here. OK since the flip function must complete quickly.
resume_cond_->WaitHoldingLocks(self);
}
}
void Thread::WaitForFlipFunctionTestingExited(Thread* self, ThreadExitFlag* tef) {
Locks::thread_list_lock_->Lock(self);
if (tef->HasExited()) {
Locks::thread_list_lock_->Unlock(self);
return;
}
// We need to hold suspend_count_lock_ to avoid missed wakeups when the flip function finishes.
// We need to hold thread_list_lock_ because the tef test result is only valid while we hold the
// lock, and once kRunningFlipFunction is no longer set, "this" may be deallocated. Hence the
// complicated locking dance.
MutexLock mu(self, *Locks::thread_suspend_count_lock_);
while (true) {
StateAndFlags old_state_and_flags = GetStateAndFlags(std::memory_order_acquire);
Locks::thread_list_lock_->Unlock(self); // So we can wait or return.
if (!old_state_and_flags.IsFlagSet(ThreadFlag::kRunningFlipFunction)) {
return;
}
resume_cond_->WaitHoldingLocks(self);
Locks::thread_suspend_count_lock_->Unlock(self); // To re-lock thread_list_lock.
Locks::thread_list_lock_->Lock(self);
Locks::thread_suspend_count_lock_->Lock(self);
if (tef->HasExited()) {
Locks::thread_list_lock_->Unlock(self);
return;
}
}
}
void Thread::FullSuspendCheck(bool implicit) {
ScopedTrace trace(__FUNCTION__);
DCHECK(!ReadFlag(ThreadFlag::kSuspensionImmune));
DCHECK(this == Thread::Current());
VLOG(threads) << this << " self-suspending";
// Make thread appear suspended to other threads, release mutator_lock_.
// Transition to suspended and back to runnable, re-acquire share on mutator_lock_.
ScopedThreadSuspension(this, ThreadState::kSuspended); // NOLINT
if (implicit) {
// For implicit suspend check we want to `madvise()` away
// the alternate signal stack to avoid wasting memory.
MadviseAwayAlternateSignalStack();
}
VLOG(threads) << this << " self-reviving";
}
static std::string GetSchedulerGroupName(pid_t tid) {
// /proc/<pid>/cgroup looks like this:
// 2:devices:/
// 1:cpuacct,cpu:/
// We want the third field from the line whose second field contains the "cpu" token.
std::string cgroup_file;
if (!android::base::ReadFileToString(StringPrintf("/proc/self/task/%d/cgroup", tid),
&cgroup_file)) {
return "";
}
std::vector<std::string> cgroup_lines;
Split(cgroup_file, '\n', &cgroup_lines);
for (size_t i = 0; i < cgroup_lines.size(); ++i) {
std::vector<std::string> cgroup_fields;
Split(cgroup_lines[i], ':', &cgroup_fields);
std::vector<std::string> cgroups;
Split(cgroup_fields[1], ',', &cgroups);
for (size_t j = 0; j < cgroups.size(); ++j) {
if (cgroups[j] == "cpu") {
return cgroup_fields[2].substr(1); // Skip the leading slash.
}
}
}
return "";
}
void Thread::DumpState(std::ostream& os, const Thread* thread, pid_t tid) {
std::string group_name;
int priority;
bool is_daemon = false;
Thread* self = Thread::Current();
// Don't do this if we are aborting since the GC may have all the threads suspended. This will
// cause ScopedObjectAccessUnchecked to deadlock.
if (gAborting == 0 && self != nullptr && thread != nullptr && thread->tlsPtr_.opeer != nullptr) {
ScopedObjectAccessUnchecked soa(self);
priority = WellKnownClasses::java_lang_Thread_priority->GetInt(thread->tlsPtr_.opeer);
is_daemon = WellKnownClasses::java_lang_Thread_daemon->GetBoolean(thread->tlsPtr_.opeer);
ObjPtr<mirror::Object> thread_group =
WellKnownClasses::java_lang_Thread_group->GetObject(thread->tlsPtr_.opeer);
if (thread_group != nullptr) {
ObjPtr<mirror::Object> group_name_object =
WellKnownClasses::java_lang_ThreadGroup_name->GetObject(thread_group);
group_name = (group_name_object != nullptr)
? group_name_object->AsString()->ToModifiedUtf8()
: "<null>";
}
} else if (thread != nullptr) {
priority = thread->GetNativePriority();
} else {
palette_status_t status = PaletteSchedGetPriority(tid, &priority);
CHECK(status == PALETTE_STATUS_OK || status == PALETTE_STATUS_CHECK_ERRNO);
}
std::string scheduler_group_name(GetSchedulerGroupName(tid));
if (scheduler_group_name.empty()) {
scheduler_group_name = "default";
}
if (thread != nullptr) {
thread->tls32_.num_name_readers.fetch_add(1, std::memory_order_seq_cst);
os << '"' << thread->tlsPtr_.name.load() << '"';
thread->tls32_.num_name_readers.fetch_sub(1 /* at least memory_order_release */);
if (is_daemon) {
os << " daemon";
}
os << " prio=" << priority
<< " tid=" << thread->GetThreadId()
<< " " << thread->GetState();
if (thread->IsStillStarting()) {
os << " (still starting up)";
}
if (thread->tls32_.disable_thread_flip_count != 0) {
os << " DisableFlipCount = " << thread->tls32_.disable_thread_flip_count;
}
os << "\n";
} else {
os << '"' << ::art::GetThreadName(tid) << '"'
<< " prio=" << priority
<< " (not attached)\n";
}
if (thread != nullptr) {
auto suspend_log_fn = [&]() REQUIRES(Locks::thread_suspend_count_lock_) {
StateAndFlags state_and_flags = thread->GetStateAndFlags(std::memory_order_relaxed);
static_assert(
static_cast<std::underlying_type_t<ThreadState>>(ThreadState::kRunnable) == 0u);
state_and_flags.SetState(ThreadState::kRunnable); // Clear state bits.
os << " | group=\"" << group_name << "\""
<< " sCount=" << thread->tls32_.suspend_count
<< " ucsCount=" << thread->tls32_.user_code_suspend_count
<< " flags=" << state_and_flags.GetValue()
<< " obj=" << reinterpret_cast<void*>(thread->tlsPtr_.opeer)
<< " self=" << reinterpret_cast<const void*>(thread) << "\n";
};
if (Locks::thread_suspend_count_lock_->IsExclusiveHeld(self)) {
Locks::thread_suspend_count_lock_->AssertExclusiveHeld(self); // For annotalysis.
suspend_log_fn();
} else {
MutexLock mu(self, *Locks::thread_suspend_count_lock_);
suspend_log_fn();
}
}
os << " | sysTid=" << tid
<< " nice=" << getpriority(PRIO_PROCESS, static_cast<id_t>(tid))
<< " cgrp=" << scheduler_group_name;
if (thread != nullptr) {
int policy;
sched_param sp;
#if !defined(__APPLE__)
// b/36445592 Don't use pthread_getschedparam since pthread may have exited.
policy = sched_getscheduler(tid);
if (policy == -1) {
PLOG(WARNING) << "sched_getscheduler(" << tid << ")";
}
int sched_getparam_result = sched_getparam(tid, &sp);
if (sched_getparam_result == -1) {
PLOG(WARNING) << "sched_getparam(" << tid << ", &sp)";
sp.sched_priority = -1;
}
#else
CHECK_PTHREAD_CALL(pthread_getschedparam, (thread->tlsPtr_.pthread_self, &policy, &sp),
__FUNCTION__);
#endif
os << " sched=" << policy << "/" << sp.sched_priority
<< " handle=" << reinterpret_cast<void*>(thread->tlsPtr_.pthread_self);
}
os << "\n";
// Grab the scheduler stats for this thread.
std::string scheduler_stats;
if (android::base::ReadFileToString(StringPrintf("/proc/self/task/%d/schedstat", tid),
&scheduler_stats)
&& !scheduler_stats.empty()) {
scheduler_stats = android::base::Trim(scheduler_stats); // Lose the trailing '\n'.
} else {
scheduler_stats = "0 0 0";
}
char native_thread_state = '?';
int utime = 0;
int stime = 0;
int task_cpu = 0;
GetTaskStats(tid, &native_thread_state, &utime, &stime, &task_cpu);
os << " | state=" << native_thread_state
<< " schedstat=( " << scheduler_stats << " )"
<< " utm=" << utime
<< " stm=" << stime
<< " core=" << task_cpu
<< " HZ=" << sysconf(_SC_CLK_TCK) << "\n";
if (thread != nullptr) {
os << " | stack=" << reinterpret_cast<void*>(thread->tlsPtr_.stack_begin) << "-"
<< reinterpret_cast<void*>(thread->tlsPtr_.stack_end) << " stackSize="
<< PrettySize(thread->tlsPtr_.stack_size) << "\n";
// Dump the held mutexes.
os << " | held mutexes=";
for (size_t i = 0; i < kLockLevelCount; ++i) {
if (i != kMonitorLock) {
BaseMutex* mutex = thread->GetHeldMutex(static_cast<LockLevel>(i));
if (mutex != nullptr) {
os << " \"" << mutex->GetName() << "\"";
if (mutex->IsReaderWriterMutex()) {
ReaderWriterMutex* rw_mutex = down_cast<ReaderWriterMutex*>(mutex);
if (rw_mutex->GetExclusiveOwnerTid() == tid) {
os << "(exclusive held)";
} else {
os << "(shared held)";
}
}
}
}
}
os << "\n";
}
}
void Thread::DumpState(std::ostream& os) const {
Thread::DumpState(os, this, GetTid());
}
struct StackDumpVisitor : public MonitorObjectsStackVisitor {
StackDumpVisitor(std::ostream& os_in,
Thread* thread_in,
Context* context,
bool can_allocate,
bool check_suspended = true,
bool dump_locks = true)
REQUIRES_SHARED(Locks::mutator_lock_)
: MonitorObjectsStackVisitor(thread_in,
context,
check_suspended,
can_allocate && dump_locks),
os(os_in),
last_method(nullptr),
last_line_number(0),
repetition_count(0) {}
virtual ~StackDumpVisitor() {
if (frame_count == 0) {
os << " (no managed stack frames)\n";
}
}
static constexpr size_t kMaxRepetition = 3u;
VisitMethodResult StartMethod(ArtMethod* m, [[maybe_unused]] size_t frame_nr) override
REQUIRES_SHARED(Locks::mutator_lock_) {
m = m->GetInterfaceMethodIfProxy(kRuntimePointerSize);
ObjPtr<mirror::DexCache> dex_cache = m->GetDexCache();
int line_number = -1;
uint32_t dex_pc = GetDexPc(false);
if (dex_cache != nullptr) { // be tolerant of bad input
const DexFile* dex_file = dex_cache->GetDexFile();
line_number = annotations::GetLineNumFromPC(dex_file, m, dex_pc);
}
if (line_number == last_line_number && last_method == m) {
++repetition_count;
} else {
if (repetition_count >= kMaxRepetition) {
os << " ... repeated " << (repetition_count - kMaxRepetition) << " times\n";
}
repetition_count = 0;
last_line_number = line_number;
last_method = m;
}
if (repetition_count >= kMaxRepetition) {
// Skip visiting=printing anything.
return VisitMethodResult::kSkipMethod;
}
os << " at " << m->PrettyMethod(false);
if (m->IsNative()) {
os << "(Native method)";
} else {
const char* source_file(m->GetDeclaringClassSourceFile());
if (line_number == -1) {
// If we failed to map to a line number, use
// the dex pc as the line number and leave source file null
source_file = nullptr;
line_number = static_cast<int32_t>(dex_pc);
}
os << "(" << (source_file != nullptr ? source_file : "unavailable")
<< ":" << line_number << ")";
}
os << "\n";
// Go and visit locks.
return VisitMethodResult::kContinueMethod;
}
VisitMethodResult EndMethod([[maybe_unused]] ArtMethod* m) override {
return VisitMethodResult::kContinueMethod;
}
void VisitWaitingObject(ObjPtr<mirror::Object> obj, [[maybe_unused]] ThreadState state) override
REQUIRES_SHARED(Locks::mutator_lock_) {
PrintObject(obj, " - waiting on ", ThreadList::kInvalidThreadId);
}
void VisitSleepingObject(ObjPtr<mirror::Object> obj)
override
REQUIRES_SHARED(Locks::mutator_lock_) {
PrintObject(obj, " - sleeping on ", ThreadList::kInvalidThreadId);
}
void VisitBlockedOnObject(ObjPtr<mirror::Object> obj,
ThreadState state,
uint32_t owner_tid)
override
REQUIRES_SHARED(Locks::mutator_lock_) {
const char* msg;
switch (state) {
case ThreadState::kBlocked:
msg = " - waiting to lock ";
break;
case ThreadState::kWaitingForLockInflation:
msg = " - waiting for lock inflation of ";
break;
default:
LOG(FATAL) << "Unreachable";
UNREACHABLE();
}
PrintObject(obj, msg, owner_tid);
num_blocked++;
}
void VisitLockedObject(ObjPtr<mirror::Object> obj)
override
REQUIRES_SHARED(Locks::mutator_lock_) {
PrintObject(obj, " - locked ", ThreadList::kInvalidThreadId);
num_locked++;
}
void PrintObject(ObjPtr<mirror::Object> obj,
const char* msg,
uint32_t owner_tid) REQUIRES_SHARED(Locks::mutator_lock_) {
if (obj == nullptr) {
os << msg << "an unknown object";
} else {
const std::string pretty_type(obj->PrettyTypeOf());
// It's often unsafe to allow lock inflation here. We may be the only runnable thread, or
// this may be called from a checkpoint. We get the hashcode on a best effort basis.
static constexpr int kNumRetries = 3;
static constexpr int kSleepMicros = 10;
int32_t hash_code;
for (int i = 0;; ++i) {
hash_code = obj->IdentityHashCodeNoInflation();
if (hash_code != 0 || i == kNumRetries) {
break;
}
usleep(kSleepMicros);
}
if (hash_code == 0) {
os << msg
<< StringPrintf("<@addr=0x%" PRIxPTR "> (a %s)",
reinterpret_cast<intptr_t>(obj.Ptr()),
pretty_type.c_str());
} else {
// - waiting on <0x608c468> (a java.lang.Class<java.lang.ref.ReferenceQueue>)
os << msg << StringPrintf("<0x%08x> (a %s)", hash_code, pretty_type.c_str());
}
}
if (owner_tid != ThreadList::kInvalidThreadId) {
os << " held by thread " << owner_tid;
}
os << "\n";
}
std::ostream& os;
ArtMethod* last_method;
int last_line_number;
size_t repetition_count;
size_t num_blocked = 0;
size_t num_locked = 0;
};
static bool ShouldShowNativeStack(const Thread* thread)
REQUIRES_SHARED(Locks::mutator_lock_) {
ThreadState state = thread->GetState();
// In native code somewhere in the VM (one of the kWaitingFor* states)? That's interesting.
if (state > ThreadState::kWaiting && state < ThreadState::kStarting) {
return true;
}
// In an Object.wait variant or Thread.sleep? That's not interesting.
if (state == ThreadState::kTimedWaiting ||
state == ThreadState::kSleeping ||
state == ThreadState::kWaiting) {
return false;
}
// Threads with no managed stack frames should be shown.
if (!thread->HasManagedStack()) {
return true;
}
// In some other native method? That's interesting.
// We don't just check kNative because native methods will be in state kSuspended if they're
// calling back into the VM, or kBlocked if they're blocked on a monitor, or one of the
// thread-startup states if it's early enough in their life cycle (http://b/7432159).
ArtMethod* current_method = thread->GetCurrentMethod(nullptr);
return current_method != nullptr && current_method->IsNative();
}
Thread::DumpOrder Thread::DumpJavaStack(std::ostream& os,
bool check_suspended,
bool dump_locks) const {
// Dumping the Java stack involves the verifier for locks. The verifier operates under the
// assumption that there is no exception pending on entry. Thus, stash any pending exception.
// Thread::Current() instead of this in case a thread is dumping the stack of another suspended
// thread.
ScopedExceptionStorage ses(Thread::Current());
std::unique_ptr<Context> context(Context::Create());
StackDumpVisitor dumper(os, const_cast<Thread*>(this), context.get(),
!tls32_.throwing_OutOfMemoryError, check_suspended, dump_locks);
dumper.WalkStack();
if (IsJitSensitiveThread()) {
return DumpOrder::kMain;
} else if (dumper.num_blocked > 0) {
return DumpOrder::kBlocked;
} else if (dumper.num_locked > 0) {
return DumpOrder::kLocked;
} else {
return DumpOrder::kDefault;
}
}
Thread::DumpOrder Thread::DumpStack(std::ostream& os,
bool dump_native_stack,
bool force_dump_stack) const {
unwindstack::AndroidLocalUnwinder unwinder;
return DumpStack(os, unwinder, dump_native_stack, force_dump_stack);
}
Thread::DumpOrder Thread::DumpStack(std::ostream& os,
unwindstack::AndroidLocalUnwinder& unwinder,
bool dump_native_stack,
bool force_dump_stack) const {
// TODO: we call this code when dying but may not have suspended the thread ourself. The
// IsSuspended check is therefore racy with the use for dumping (normally we inhibit
// the race with the thread_suspend_count_lock_).
bool dump_for_abort = (gAborting > 0);
bool safe_to_dump = (this == Thread::Current() || IsSuspended());
if (!kIsDebugBuild) {
// We always want to dump the stack for an abort, however, there is no point dumping another
// thread's stack in debug builds where we'll hit the not suspended check in the stack walk.
safe_to_dump = (safe_to_dump || dump_for_abort);
}
DumpOrder dump_order = DumpOrder::kDefault;
if (safe_to_dump || force_dump_stack) {
uint64_t nanotime = NanoTime();
// If we're currently in native code, dump that stack before dumping the managed stack.
if (dump_native_stack && (dump_for_abort || force_dump_stack || ShouldShowNativeStack(this))) {
ArtMethod* method =
GetCurrentMethod(nullptr,
/*check_suspended=*/ !force_dump_stack,
/*abort_on_error=*/ !(dump_for_abort || force_dump_stack));
DumpNativeStack(os, unwinder, GetTid(), " native: ", method);
}
dump_order = DumpJavaStack(os,
/*check_suspended=*/ !force_dump_stack,
/*dump_locks=*/ !force_dump_stack);
Runtime* runtime = Runtime::Current();
std::optional<uint64_t> start = runtime != nullptr ? runtime->SiqQuitNanoTime() : std::nullopt;
if (start.has_value()) {
os << "DumpLatencyMs: " << static_cast<float>(nanotime - start.value()) / 1000000.0 << "\n";
}
} else {
os << "Not able to dump stack of thread that isn't suspended";
}
return dump_order;
}
void Thread::ThreadExitCallback(void* arg) {
Thread* self = reinterpret_cast<Thread*>(arg);
if (self->tls32_.thread_exit_check_count == 0) {
LOG(WARNING) << "Native thread exiting without having called DetachCurrentThread (maybe it's "
"going to use a pthread_key_create destructor?): " << *self;
CHECK(is_started_);
#ifdef __BIONIC__
__get_tls()[TLS_SLOT_ART_THREAD_SELF] = self;
#else
CHECK_PTHREAD_CALL(pthread_setspecific, (Thread::pthread_key_self_, self), "reattach self");
Thread::self_tls_ = self;
#endif
self->tls32_.thread_exit_check_count = 1;
} else {
LOG(FATAL) << "Native thread exited without calling DetachCurrentThread: " << *self;
}
}
void Thread::Startup() {
CHECK(!is_started_);
is_started_ = true;
{
// MutexLock to keep annotalysis happy.
//
// Note we use null for the thread because Thread::Current can
// return garbage since (is_started_ == true) and
// Thread::pthread_key_self_ is not yet initialized.
// This was seen on glibc.
MutexLock mu(nullptr, *Locks::thread_suspend_count_lock_);
resume_cond_ = new ConditionVariable("Thread resumption condition variable",
*Locks::thread_suspend_count_lock_);
}
// Allocate a TLS slot.
CHECK_PTHREAD_CALL(pthread_key_create, (&Thread::pthread_key_self_, Thread::ThreadExitCallback),
"self key");
// Double-check the TLS slot allocation.
if (pthread_getspecific(pthread_key_self_) != nullptr) {
LOG(FATAL) << "Newly-created pthread TLS slot is not nullptr";
}
#ifndef __BIONIC__
CHECK(Thread::self_tls_ == nullptr);
#endif
}
void Thread::FinishStartup() {
Runtime* runtime = Runtime::Current();
CHECK(runtime->IsStarted());
// Finish attaching the main thread.
ScopedObjectAccess soa(Thread::Current());
soa.Self()->CreatePeer("main", false, runtime->GetMainThreadGroup());
soa.Self()->AssertNoPendingException();
runtime->RunRootClinits(soa.Self());
// The thread counts as started from now on. We need to add it to the ThreadGroup. For regular
// threads, this is done in Thread.start() on the Java side.
soa.Self()->NotifyThreadGroup(soa, runtime->GetMainThreadGroup());
soa.Self()->AssertNoPendingException();
}
void Thread::Shutdown() {
CHECK(is_started_);
is_started_ = false;
CHECK_PTHREAD_CALL(pthread_key_delete, (Thread::pthread_key_self_), "self key");
MutexLock mu(Thread::Current(), *Locks::thread_suspend_count_lock_);
if (resume_cond_ != nullptr) {
delete resume_cond_;
resume_cond_ = nullptr;
}
}
void Thread::NotifyThreadGroup(ScopedObjectAccessAlreadyRunnable& soa, jobject thread_group) {
ObjPtr<mirror::Object> thread_object = soa.Self()->GetPeer();
ObjPtr<mirror::Object> thread_group_object = soa.Decode<mirror::Object>(thread_group);
if (thread_group == nullptr || kIsDebugBuild) {
// There is always a group set. Retrieve it.
thread_group_object = WellKnownClasses::java_lang_Thread_group->GetObject(thread_object);
if (kIsDebugBuild && thread_group != nullptr) {
CHECK(thread_group_object == soa.Decode<mirror::Object>(thread_group));
}
}
WellKnownClasses::java_lang_ThreadGroup_add->InvokeVirtual<'V', 'L'>(
soa.Self(), thread_group_object, thread_object);
}
void Thread::SignalExitFlags() {
ThreadExitFlag* next;
for (ThreadExitFlag* tef = tlsPtr_.thread_exit_flags; tef != nullptr; tef = next) {
DCHECK(!tef->exited_);
tef->exited_ = true;
next = tef->next_;
if (kIsDebugBuild) {
ThreadExitFlag* const garbage_tef = reinterpret_cast<ThreadExitFlag*>(1);
// Link fields should no longer be used.
tef->prev_ = tef->next_ = garbage_tef;
}
}
tlsPtr_.thread_exit_flags = nullptr; // Now unused.
}
Thread::Thread(bool daemon)
: tls32_(daemon),
wait_monitor_(nullptr),
is_runtime_thread_(false) {
wait_mutex_ = new Mutex("a thread wait mutex", LockLevel::kThreadWaitLock);
wait_cond_ = new ConditionVariable("a thread wait condition variable", *wait_mutex_);
tlsPtr_.mutator_lock = Locks::mutator_lock_;
DCHECK(tlsPtr_.mutator_lock != nullptr);
tlsPtr_.name.store(kThreadNameDuringStartup, std::memory_order_relaxed);
CHECK_NE(GetStackOverflowProtectedSize(), 0u);
static_assert((sizeof(Thread) % 4) == 0U,
"art::Thread has a size which is not a multiple of 4.");
DCHECK_EQ(GetStateAndFlags(std::memory_order_relaxed).GetValue(), 0u);
StateAndFlags state_and_flags = StateAndFlags(0u).WithState(ThreadState::kNative);
tls32_.state_and_flags.store(state_and_flags.GetValue(), std::memory_order_relaxed);
tls32_.interrupted.store(false, std::memory_order_relaxed);
// Initialize with no permit; if the java Thread was unparked before being
// started, it will unpark itself before calling into java code.
tls32_.park_state_.store(kNoPermit, std::memory_order_relaxed);
memset(&tlsPtr_.held_mutexes[0], 0, sizeof(tlsPtr_.held_mutexes));
std::fill(tlsPtr_.rosalloc_runs,
tlsPtr_.rosalloc_runs + kNumRosAllocThreadLocalSizeBracketsInThread,
gc::allocator::RosAlloc::GetDedicatedFullRun());
tlsPtr_.checkpoint_function = nullptr;
tlsPtr_.active_suspendall_barrier = nullptr;
tlsPtr_.active_suspend1_barriers = nullptr;
tlsPtr_.flip_function.store(nullptr, std::memory_order_relaxed);
tlsPtr_.thread_local_mark_stack = nullptr;
ResetTlab();
}
bool Thread::CanLoadClasses() const {
return !IsRuntimeThread() || !Runtime::Current()->IsJavaDebuggable();
}
bool Thread::IsStillStarting() const {
// You might think you can check whether the state is kStarting, but for much of thread startup,
// the thread is in kNative; it might also be in kVmWait.
// You might think you can check whether the peer is null, but the peer is actually created and
// assigned fairly early on, and needs to be.
// It turns out that the last thing to change is the thread name; that's a good proxy for "has
// this thread _ever_ entered kRunnable".
return (tlsPtr_.jpeer == nullptr && tlsPtr_.opeer == nullptr) ||
(tlsPtr_.name.load() == kThreadNameDuringStartup);
}
void Thread::AssertPendingException() const {
CHECK(IsExceptionPending()) << "Pending exception expected.";
}
void Thread::AssertPendingOOMException() const {
AssertPendingException();
auto* e = GetException();
CHECK_EQ(e->GetClass(), WellKnownClasses::java_lang_OutOfMemoryError.Get()) << e->Dump();
}
void Thread::AssertNoPendingException() const {
if (UNLIKELY(IsExceptionPending())) {
ScopedObjectAccess soa(Thread::Current());
LOG(FATAL) << "No pending exception expected: " << GetException()->Dump();
}
}
void Thread::AssertNoPendingExceptionForNewException(const char* msg) const {
if (UNLIKELY(IsExceptionPending())) {
ScopedObjectAccess soa(Thread::Current());
LOG(FATAL) << "Throwing new exception '" << msg << "' with unexpected pending exception: "
<< GetException()->Dump();
}
}
class MonitorExitVisitor : public SingleRootVisitor {
public:
explicit MonitorExitVisitor(Thread* self) : self_(self) { }
// NO_THREAD_SAFETY_ANALYSIS due to MonitorExit.
void VisitRoot(mirror::Object* entered_monitor,
[[maybe_unused]] const RootInfo& info) override NO_THREAD_SAFETY_ANALYSIS {
if (self_->HoldsLock(entered_monitor)) {
LOG(WARNING) << "Calling MonitorExit on object "
<< entered_monitor << " (" << entered_monitor->PrettyTypeOf() << ")"
<< " left locked by native thread "
<< *Thread::Current() << " which is detaching";
entered_monitor->MonitorExit(self_);
}
}
private:
Thread* const self_;
};
void Thread::Destroy(bool should_run_callbacks) {
Thread* self = this;
DCHECK_EQ(self, Thread::Current());
if (tlsPtr_.jni_env != nullptr) {
{
ScopedObjectAccess soa(self);
MonitorExitVisitor visitor(self);
// On thread detach, all monitors entered with JNI MonitorEnter are automatically exited.
tlsPtr_.jni_env->monitors_.VisitRoots(&visitor, RootInfo(kRootVMInternal));
}
// Release locally held global references which releasing may require the mutator lock.
if (tlsPtr_.jpeer != nullptr) {
// If pthread_create fails we don't have a jni env here.
tlsPtr_.jni_env->DeleteGlobalRef(tlsPtr_.jpeer);
tlsPtr_.jpeer = nullptr;
}
if (tlsPtr_.class_loader_override != nullptr) {
tlsPtr_.jni_env->DeleteGlobalRef(tlsPtr_.class_loader_override);
tlsPtr_.class_loader_override = nullptr;
}
}
if (tlsPtr_.opeer != nullptr) {
ScopedObjectAccess soa(self);
// We may need to call user-supplied managed code, do this before final clean-up.
HandleUncaughtExceptions();
RemoveFromThreadGroup();
Runtime* runtime = Runtime::Current();
if (runtime != nullptr && should_run_callbacks) {
runtime->GetRuntimeCallbacks()->ThreadDeath(self);
}
// this.nativePeer = 0;
SetNativePeer</*kSupportTransaction=*/ true>(tlsPtr_.opeer, nullptr);
// Thread.join() is implemented as an Object.wait() on the Thread.lock object. Signal anyone
// who is waiting.
ObjPtr<mirror::Object> lock =
WellKnownClasses::java_lang_Thread_lock->GetObject(tlsPtr_.opeer);
// (This conditional is only needed for tests, where Thread.lock won't have been set.)
if (lock != nullptr) {
StackHandleScope<1> hs(self);
Handle<mirror::Object> h_obj(hs.NewHandle(lock));
ObjectLock<mirror::Object> locker(self, h_obj);
locker.NotifyAll();
}
tlsPtr_.opeer = nullptr;
}
{
ScopedObjectAccess soa(self);
Runtime::Current()->GetHeap()->RevokeThreadLocalBuffers(this);
if (UNLIKELY(self->GetMethodTraceBuffer() != nullptr)) {
Trace::FlushThreadBuffer(self);
}
}
// Mark-stack revocation must be performed at the very end. No
// checkpoint/flip-function or read-barrier should be called after this.
if (gUseReadBarrier) {
Runtime::Current()->GetHeap()->ConcurrentCopyingCollector()->RevokeThreadLocalMarkStack(this);
}
}
Thread::~Thread() {
CHECK(tlsPtr_.class_loader_override == nullptr);
CHECK(tlsPtr_.jpeer == nullptr);
CHECK(tlsPtr_.opeer == nullptr);
bool initialized = (tlsPtr_.jni_env != nullptr); // Did Thread::Init run?
if (initialized) {
delete tlsPtr_.jni_env;
tlsPtr_.jni_env = nullptr;
}
CHECK_NE(GetState(), ThreadState::kRunnable);
CHECK(!ReadFlag(ThreadFlag::kCheckpointRequest));
CHECK(!ReadFlag(ThreadFlag::kEmptyCheckpointRequest));
CHECK(!ReadFlag(ThreadFlag::kSuspensionImmune));
CHECK(tlsPtr_.checkpoint_function == nullptr);
CHECK_EQ(checkpoint_overflow_.size(), 0u);
// A pending flip function request is OK. FlipThreadRoots will have been notified that we
// exited, and nobody will attempt to process the request.
// Make sure we processed all deoptimization requests.
CHECK(tlsPtr_.deoptimization_context_stack == nullptr) << "Missed deoptimization";
CHECK(tlsPtr_.frame_id_to_shadow_frame == nullptr) <<
"Not all deoptimized frames have been consumed by the debugger.";
// We may be deleting a still born thread.
SetStateUnsafe(ThreadState::kTerminated);
delete wait_cond_;
delete wait_mutex_;
if (tlsPtr_.long_jump_context != nullptr) {
delete tlsPtr_.long_jump_context;
}
if (initialized) {
CleanupCpu();
}
SetCachedThreadName(nullptr); // Deallocate name.
delete tlsPtr_.deps_or_stack_trace_sample.stack_trace_sample;
CHECK_EQ(tlsPtr_.method_trace_buffer, nullptr);
Runtime::Current()->GetHeap()->AssertThreadLocalBuffersAreRevoked(this);
TearDownAlternateSignalStack();
}
void Thread::HandleUncaughtExceptions() {
Thread* self = this;
DCHECK_EQ(self, Thread::Current());
if (!self->IsExceptionPending()) {
return;
}
// Get and clear the exception.
ObjPtr<mirror::Object> exception = self->GetException();
self->ClearException();
// Call the Thread instance's dispatchUncaughtException(Throwable)
WellKnownClasses::java_lang_Thread_dispatchUncaughtException->InvokeFinal<'V', 'L'>(
self, tlsPtr_.opeer, exception);
// If the dispatchUncaughtException threw, clear that exception too.
self->ClearException();
}
void Thread::RemoveFromThreadGroup() {
Thread* self = this;
DCHECK_EQ(self, Thread::Current());
// this.group.threadTerminated(this);
// group can be null if we're in the compiler or a test.
ObjPtr<mirror::Object> group =
WellKnownClasses::java_lang_Thread_group->GetObject(tlsPtr_.opeer);
if (group != nullptr) {
WellKnownClasses::java_lang_ThreadGroup_threadTerminated->InvokeVirtual<'V', 'L'>(
self, group, tlsPtr_.opeer);
}
}
template <bool kPointsToStack>
class JniTransitionReferenceVisitor : public StackVisitor {
public:
JniTransitionReferenceVisitor(Thread* thread, void* obj) REQUIRES_SHARED(Locks::mutator_lock_)
: StackVisitor(thread, /*context=*/ nullptr, StackVisitor::StackWalkKind::kSkipInlinedFrames),
obj_(obj),
found_(false) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* m = GetMethod();
if (!m->IsNative() || m->IsCriticalNative()) {
return true;
}
if (kPointsToStack) {
uint8_t* sp = reinterpret_cast<uint8_t*>(GetCurrentQuickFrame());
size_t frame_size = GetCurrentQuickFrameInfo().FrameSizeInBytes();
uint32_t* current_vreg = reinterpret_cast<uint32_t*>(sp + frame_size + sizeof(ArtMethod*));
if (!m->IsStatic()) {
if (current_vreg == obj_) {
found_ = true;
return false;
}
current_vreg += 1u;
}
uint32_t shorty_length;
const char* shorty = m->GetShorty(&shorty_length);
for (size_t i = 1; i != shorty_length; ++i) {
switch (shorty[i]) {
case 'D':
case 'J':
current_vreg += 2u;
break;
case 'L':
if (current_vreg == obj_) {
found_ = true;
return false;
}
FALLTHROUGH_INTENDED;
default:
current_vreg += 1u;
break;
}
}
// Continue only if the object is somewhere higher on the stack.
return obj_ >= current_vreg;
} else { // if (kPointsToStack)
if (m->IsStatic() && obj_ == m->GetDeclaringClassAddressWithoutBarrier()) {
found_ = true;
return false;
}
return true;
}
}
bool Found() const {
return found_;
}
private:
void* obj_;
bool found_;
};
bool Thread::IsJniTransitionReference(jobject obj) const {
DCHECK(obj != nullptr);
// We need a non-const pointer for stack walk even if we're not modifying the thread state.
Thread* thread = const_cast<Thread*>(this);
uint8_t* raw_obj = reinterpret_cast<uint8_t*>(obj);
if (static_cast<size_t>(raw_obj - tlsPtr_.stack_begin) < tlsPtr_.stack_size) {
JniTransitionReferenceVisitor</*kPointsToStack=*/ true> visitor(thread, raw_obj);
visitor.WalkStack();
return visitor.Found();
} else {
JniTransitionReferenceVisitor</*kPointsToStack=*/ false> visitor(thread, raw_obj);
visitor.WalkStack();
return visitor.Found();
}
}
void Thread::HandleScopeVisitRoots(RootVisitor* visitor, uint32_t thread_id) {
BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor(
visitor, RootInfo(kRootNativeStack, thread_id));
for (BaseHandleScope* cur = tlsPtr_.top_handle_scope; cur; cur = cur->GetLink()) {
cur->VisitRoots(buffered_visitor);
}
}
ObjPtr<mirror::Object> Thread::DecodeGlobalJObject(jobject obj) const {
DCHECK(obj != nullptr);
IndirectRef ref = reinterpret_cast<IndirectRef>(obj);
IndirectRefKind kind = IndirectReferenceTable::GetIndirectRefKind(ref);
DCHECK_NE(kind, kJniTransition);
DCHECK_NE(kind, kLocal);
ObjPtr<mirror::Object> result;
bool expect_null = false;
if (kind == kGlobal) {
result = tlsPtr_.jni_env->vm_->DecodeGlobal(ref);
} else {
DCHECK_EQ(kind, kWeakGlobal);
result = tlsPtr_.jni_env->vm_->DecodeWeakGlobal(const_cast<Thread*>(this), ref);
if (Runtime::Current()->IsClearedJniWeakGlobal(result)) {
// This is a special case where it's okay to return null.
expect_null = true;
result = nullptr;
}
}
DCHECK(expect_null || result != nullptr)
<< "use of deleted " << ToStr<IndirectRefKind>(kind).c_str()
<< " " << static_cast<const void*>(obj);
return result;
}
bool Thread::IsJWeakCleared(jweak obj) const {
CHECK(obj != nullptr);
IndirectRef ref = reinterpret_cast<IndirectRef>(obj);
IndirectRefKind kind = IndirectReferenceTable::GetIndirectRefKind(ref);
CHECK_EQ(kind, kWeakGlobal);
return tlsPtr_.jni_env->vm_->IsWeakGlobalCleared(const_cast<Thread*>(this), ref);
}
// Implements java.lang.Thread.interrupted.
bool Thread::Interrupted() {
DCHECK_EQ(Thread::Current(), this);
// No other thread can concurrently reset the interrupted flag.
bool interrupted = tls32_.interrupted.load(std::memory_order_seq_cst);
if (interrupted) {
tls32_.interrupted.store(false, std::memory_order_seq_cst);
}
return interrupted;
}
// Implements java.lang.Thread.isInterrupted.
bool Thread::IsInterrupted() {
return tls32_.interrupted.load(std::memory_order_seq_cst);
}
void Thread::Interrupt(Thread* self) {
{
MutexLock mu(self, *wait_mutex_);
if (tls32_.interrupted.load(std::memory_order_seq_cst)) {
return;
}
tls32_.interrupted.store(true, std::memory_order_seq_cst);
NotifyLocked(self);
}
Unpark();
}
void Thread::Notify() {
Thread* self = Thread::Current();
MutexLock mu(self, *wait_mutex_);
NotifyLocked(self);
}
void Thread::NotifyLocked(Thread* self) {
if (wait_monitor_ != nullptr) {
wait_cond_->Signal(self);
}
}
void Thread::SetClassLoaderOverride(jobject class_loader_override) {
if (tlsPtr_.class_loader_override != nullptr) {
GetJniEnv()->DeleteGlobalRef(tlsPtr_.class_loader_override);
}
tlsPtr_.class_loader_override = GetJniEnv()->NewGlobalRef(class_loader_override);
}
using ArtMethodDexPcPair = std::pair<ArtMethod*, uint32_t>;
// Counts the stack trace depth and also fetches the first max_saved_frames frames.
class FetchStackTraceVisitor : public StackVisitor {
public:
explicit FetchStackTraceVisitor(Thread* thread,
ArtMethodDexPcPair* saved_frames = nullptr,
size_t max_saved_frames = 0)
REQUIRES_SHARED(Locks::mutator_lock_)
: StackVisitor(thread, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames),
saved_frames_(saved_frames),
max_saved_frames_(max_saved_frames) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
// We want to skip frames up to and including the exception's constructor.
// Note we also skip the frame if it doesn't have a method (namely the callee
// save frame)
ArtMethod* m = GetMethod();
if (skipping_ && !m->IsRuntimeMethod() &&
!GetClassRoot<mirror::Throwable>()->IsAssignableFrom(m->GetDeclaringClass())) {
skipping_ = false;
}
if (!skipping_) {
if (!m->IsRuntimeMethod()) { // Ignore runtime frames (in particular callee save).
if (depth_ < max_saved_frames_) {
saved_frames_[depth_].first = m;
saved_frames_[depth_].second = m->IsProxyMethod() ? dex::kDexNoIndex : GetDexPc();
}
++depth_;
}
} else {
++skip_depth_;
}
return true;
}
uint32_t GetDepth() const {
return depth_;
}
uint32_t GetSkipDepth() const {
return skip_depth_;
}
private:
uint32_t depth_ = 0;
uint32_t skip_depth_ = 0;
bool skipping_ = true;
ArtMethodDexPcPair* saved_frames_;
const size_t max_saved_frames_;
DISALLOW_COPY_AND_ASSIGN(FetchStackTraceVisitor);
};
class BuildInternalStackTraceVisitor : public StackVisitor {
public:
BuildInternalStackTraceVisitor(Thread* self, Thread* thread, uint32_t skip_depth)
: StackVisitor(thread, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames),
self_(self),
skip_depth_(skip_depth),
pointer_size_(Runtime::Current()->GetClassLinker()->GetImagePointerSize()) {}
bool Init(uint32_t depth) REQUIRES_SHARED(Locks::mutator_lock_) ACQUIRE(Roles::uninterruptible_) {
// Allocate method trace as an object array where the first element is a pointer array that
// contains the ArtMethod pointers and dex PCs. The rest of the elements are the declaring
// class of the ArtMethod pointers.
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
StackHandleScope<1> hs(self_);
ObjPtr<mirror::Class> array_class =
GetClassRoot<mirror::ObjectArray<mirror::Object>>(class_linker);
// The first element is the methods and dex pc array, the other elements are declaring classes
// for the methods to ensure classes in the stack trace don't get unloaded.
Handle<mirror::ObjectArray<mirror::Object>> trace(
hs.NewHandle(mirror::ObjectArray<mirror::Object>::Alloc(
hs.Self(), array_class, static_cast<int32_t>(depth) + 1)));
if (trace == nullptr) {
// Acquire uninterruptible_ in all paths.
self_->StartAssertNoThreadSuspension("Building internal stack trace");
self_->AssertPendingOOMException();
return false;
}
ObjPtr<mirror::PointerArray> methods_and_pcs =
class_linker->AllocPointerArray(self_, depth * 2);
const char* last_no_suspend_cause =
self_->StartAssertNoThreadSuspension("Building internal stack trace");
if (methods_and_pcs == nullptr) {
self_->AssertPendingOOMException();
return false;
}
trace->Set</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(0, methods_and_pcs);
trace_ = trace.Get();
// If We are called from native, use non-transactional mode.
CHECK(last_no_suspend_cause == nullptr) << last_no_suspend_cause;
return true;
}
virtual ~BuildInternalStackTraceVisitor() RELEASE(Roles::uninterruptible_) {
self_->EndAssertNoThreadSuspension(nullptr);
}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
if (trace_ == nullptr) {
return true; // We're probably trying to fillInStackTrace for an OutOfMemoryError.
}
if (skip_depth_ > 0) {
skip_depth_--;
return true;
}
ArtMethod* m = GetMethod();
if (m->IsRuntimeMethod()) {
return true; // Ignore runtime frames (in particular callee save).
}
AddFrame(m, m->IsProxyMethod() ? dex::kDexNoIndex : GetDexPc());
return true;
}
void AddFrame(ArtMethod* method, uint32_t dex_pc) REQUIRES_SHARED(Locks::mutator_lock_) {
ObjPtr<mirror::PointerArray> methods_and_pcs = GetTraceMethodsAndPCs();
methods_and_pcs->SetElementPtrSize</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
count_, method, pointer_size_);
methods_and_pcs->SetElementPtrSize</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
static_cast<uint32_t>(methods_and_pcs->GetLength()) / 2 + count_, dex_pc, pointer_size_);
// Save the declaring class of the method to ensure that the declaring classes of the methods
// do not get unloaded while the stack trace is live. However, this does not work for copied
// methods because the declaring class of a copied method points to an interface class which
// may be in a different class loader. Instead, retrieve the class loader associated with the
// allocator that holds the copied method. This is much cheaper than finding the actual class.
ObjPtr<mirror::Object> keep_alive;
if (UNLIKELY(method->IsCopied())) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
keep_alive = class_linker->GetHoldingClassLoaderOfCopiedMethod(self_, method);
} else {
keep_alive = method->GetDeclaringClass();
}
trace_->Set</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
static_cast<int32_t>(count_) + 1, keep_alive);
++count_;
}
ObjPtr<mirror::PointerArray> GetTraceMethodsAndPCs() const REQUIRES_SHARED(Locks::mutator_lock_) {
return ObjPtr<mirror::PointerArray>::DownCast(trace_->Get(0));
}
mirror::ObjectArray<mirror::Object>* GetInternalStackTrace() const {
return trace_;
}
private:
Thread* const self_;
// How many more frames to skip.
uint32_t skip_depth_;
// Current position down stack trace.
uint32_t count_ = 0;
// An object array where the first element is a pointer array that contains the `ArtMethod`
// pointers on the stack and dex PCs. The rest of the elements are referencing objects
// that shall keep the methods alive, namely the declaring class of the `ArtMethod` for
// declared methods and the class loader for copied methods (because it's faster to find
// the class loader than the actual class that holds the copied method). The `trace_[i+1]`
// contains the declaring class or class loader of the `ArtMethod` of the i'th frame.
// We're initializing a newly allocated trace, so we do not need to record that under
// a transaction. If the transaction is aborted, the whole trace shall be unreachable.
mirror::ObjectArray<mirror::Object>* trace_ = nullptr;
// For cross compilation.
const PointerSize pointer_size_;
DISALLOW_COPY_AND_ASSIGN(BuildInternalStackTraceVisitor);
};
jobject Thread::CreateInternalStackTrace(const ScopedObjectAccessAlreadyRunnable& soa) const {
// Compute depth of stack, save frames if possible to avoid needing to recompute many.
constexpr size_t kMaxSavedFrames = 256;
std::unique_ptr<ArtMethodDexPcPair[]> saved_frames(new ArtMethodDexPcPair[kMaxSavedFrames]);
FetchStackTraceVisitor count_visitor(const_cast<Thread*>(this),
&saved_frames[0],
kMaxSavedFrames);
count_visitor.WalkStack();
const uint32_t depth = count_visitor.GetDepth();
const uint32_t skip_depth = count_visitor.GetSkipDepth();
// Build internal stack trace.
BuildInternalStackTraceVisitor build_trace_visitor(
soa.Self(), const_cast<Thread*>(this), skip_depth);
if (!build_trace_visitor.Init(depth)) {
return nullptr; // Allocation failed.
}
// If we saved all of the frames we don't even need to do the actual stack walk. This is faster
// than doing the stack walk twice.
if (depth < kMaxSavedFrames) {
for (size_t i = 0; i < depth; ++i) {
build_trace_visitor.AddFrame(saved_frames[i].first, saved_frames[i].second);
}
} else {
build_trace_visitor.WalkStack();
}
mirror::ObjectArray<mirror::Object>* trace = build_trace_visitor.GetInternalStackTrace();
if (kIsDebugBuild) {
ObjPtr<mirror::PointerArray> trace_methods = build_trace_visitor.GetTraceMethodsAndPCs();
// Second half of trace_methods is dex PCs.
for (uint32_t i = 0; i < static_cast<uint32_t>(trace_methods->GetLength() / 2); ++i) {
auto* method = trace_methods->GetElementPtrSize<ArtMethod*>(
i, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
CHECK(method != nullptr);
}
}
return soa.AddLocalReference<jobject>(trace);
}
bool Thread::IsExceptionThrownByCurrentMethod(ObjPtr<mirror::Throwable> exception) const {
// Only count the depth since we do not pass a stack frame array as an argument.
FetchStackTraceVisitor count_visitor(const_cast<Thread*>(this));
count_visitor.WalkStack();
return count_visitor.GetDepth() == static_cast<uint32_t>(exception->GetStackDepth());
}
static ObjPtr<mirror::StackTraceElement> CreateStackTraceElement(
const ScopedObjectAccessAlreadyRunnable& soa,
ArtMethod* method,
uint32_t dex_pc) REQUIRES_SHARED(Locks::mutator_lock_) {
int32_t line_number;
StackHandleScope<3> hs(soa.Self());
auto class_name_object(hs.NewHandle<mirror::String>(nullptr));
auto source_name_object(hs.NewHandle<mirror::String>(nullptr));
if (method->IsProxyMethod()) {
line_number = -1;
class_name_object.Assign(method->GetDeclaringClass()->GetName());
// source_name_object intentionally left null for proxy methods
} else {
line_number = method->GetLineNumFromDexPC(dex_pc);
// Allocate element, potentially triggering GC
// TODO: reuse class_name_object via Class::name_?
const char* descriptor = method->GetDeclaringClassDescriptor();
CHECK(descriptor != nullptr);
std::string class_name(PrettyDescriptor(descriptor));
class_name_object.Assign(
mirror::String::AllocFromModifiedUtf8(soa.Self(), class_name.c_str()));
if (class_name_object == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
const char* source_file = method->GetDeclaringClassSourceFile();
if (line_number == -1) {
// Make the line_number field of StackTraceElement hold the dex pc.
// source_name_object is intentionally left null if we failed to map the dex pc to
// a line number (most probably because there is no debug info). See b/30183883.
line_number = static_cast<int32_t>(dex_pc);
} else {
if (source_file != nullptr) {
source_name_object.Assign(mirror::String::AllocFromModifiedUtf8(soa.Self(), source_file));
if (source_name_object == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
}
}
}
const char* method_name = method->GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetName();
CHECK(method_name != nullptr);
Handle<mirror::String> method_name_object(
hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), method_name)));
if (method_name_object == nullptr) {
return nullptr;
}
return mirror::StackTraceElement::Alloc(soa.Self(),
class_name_object,
method_name_object,
source_name_object,
line_number);
}
jobjectArray Thread::InternalStackTraceToStackTraceElementArray(
const ScopedObjectAccessAlreadyRunnable& soa,
jobject internal,
jobjectArray output_array,
int* stack_depth) {
// Decode the internal stack trace into the depth, method trace and PC trace.
// Subtract one for the methods and PC trace.
int32_t depth = soa.Decode<mirror::Array>(internal)->GetLength() - 1;
DCHECK_GE(depth, 0);
ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
jobjectArray result;
if (output_array != nullptr) {
// Reuse the array we were given.
result = output_array;
// ...adjusting the number of frames we'll write to not exceed the array length.
const int32_t traces_length =
soa.Decode<mirror::ObjectArray<mirror::StackTraceElement>>(result)->GetLength();
depth = std::min(depth, traces_length);
} else {
// Create java_trace array and place in local reference table
ObjPtr<mirror::ObjectArray<mirror::StackTraceElement>> java_traces =
class_linker->AllocStackTraceElementArray(soa.Self(), static_cast<size_t>(depth));
if (java_traces == nullptr) {
return nullptr;
}
result = soa.AddLocalReference<jobjectArray>(java_traces);
}
if (stack_depth != nullptr) {
*stack_depth = depth;
}
for (uint32_t i = 0; i < static_cast<uint32_t>(depth); ++i) {
ObjPtr<mirror::ObjectArray<mirror::Object>> decoded_traces =
soa.Decode<mirror::Object>(internal)->AsObjectArray<mirror::Object>();
// Methods and dex PC trace is element 0.
DCHECK(decoded_traces->Get(0)->IsIntArray() || decoded_traces->Get(0)->IsLongArray());
const ObjPtr<mirror::PointerArray> method_trace =
ObjPtr<mirror::PointerArray>::DownCast(decoded_traces->Get(0));
// Prepare parameters for StackTraceElement(String cls, String method, String file, int line)
ArtMethod* method = method_trace->GetElementPtrSize<ArtMethod*>(i, kRuntimePointerSize);
uint32_t dex_pc = method_trace->GetElementPtrSize<uint32_t>(
i + static_cast<uint32_t>(method_trace->GetLength()) / 2, kRuntimePointerSize);
const ObjPtr<mirror::StackTraceElement> obj = CreateStackTraceElement(soa, method, dex_pc);
if (obj == nullptr) {
return nullptr;
}
// We are called from native: use non-transactional mode.
soa.Decode<mirror::ObjectArray<mirror::StackTraceElement>>(result)->Set<false>(
static_cast<int32_t>(i), obj);
}
return result;
}
[[nodiscard]] static ObjPtr<mirror::StackFrameInfo> InitStackFrameInfo(
const ScopedObjectAccessAlreadyRunnable& soa,
ClassLinker* class_linker,
Handle<mirror::StackFrameInfo> stackFrameInfo,
ArtMethod* method,
uint32_t dex_pc) REQUIRES_SHARED(Locks::mutator_lock_) {
StackHandleScope<4> hs(soa.Self());
int32_t line_number;
auto source_name_object(hs.NewHandle<mirror::String>(nullptr));
if (method->IsProxyMethod()) {
line_number = -1;
// source_name_object intentionally left null for proxy methods
} else {
line_number = method->GetLineNumFromDexPC(dex_pc);
if (line_number == -1) {
// Make the line_number field of StackFrameInfo hold the dex pc.
// source_name_object is intentionally left null if we failed to map the dex pc to
// a line number (most probably because there is no debug info). See b/30183883.
line_number = static_cast<int32_t>(dex_pc);
} else {
const char* source_file = method->GetDeclaringClassSourceFile();
if (source_file != nullptr) {
source_name_object.Assign(mirror::String::AllocFromModifiedUtf8(soa.Self(), source_file));
if (source_name_object == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
}
}
}
Handle<mirror::Class> declaring_class_object(
hs.NewHandle<mirror::Class>(method->GetDeclaringClass()));
ArtMethod* interface_method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
const char* method_name = interface_method->GetName();
CHECK(method_name != nullptr);
Handle<mirror::String> method_name_object(
hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), method_name)));
if (method_name_object == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
dex::ProtoIndex proto_idx =
method->GetDexFile()->GetIndexForProtoId(interface_method->GetPrototype());
Handle<mirror::MethodType> method_type_object(hs.NewHandle<mirror::MethodType>(
class_linker->ResolveMethodType(soa.Self(), proto_idx, interface_method)));
if (method_type_object == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
stackFrameInfo->AssignFields(declaring_class_object,
method_type_object,
method_name_object,
source_name_object,
line_number,
static_cast<int32_t>(dex_pc));
return stackFrameInfo.Get();
}
constexpr jlong FILL_CLASS_REFS_ONLY = 0x2; // StackStreamFactory.FILL_CLASS_REFS_ONLY
jint Thread::InternalStackTraceToStackFrameInfoArray(
const ScopedObjectAccessAlreadyRunnable& soa,
jlong mode, // See java.lang.StackStreamFactory for the mode flags
jobject internal,
jint startLevel,
jint batchSize,
jint startBufferIndex,
jobjectArray output_array) {
// Decode the internal stack trace into the depth, method trace and PC trace.
// Subtract one for the methods and PC trace.
int32_t depth = soa.Decode<mirror::Array>(internal)->GetLength() - 1;
DCHECK_GE(depth, 0);
StackHandleScope<6> hs(soa.Self());
Handle<mirror::ObjectArray<mirror::Object>> framesOrClasses =
hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Object>>(output_array));
jint endBufferIndex = startBufferIndex;
if (startLevel < 0 || startLevel >= depth) {
return endBufferIndex;
}
int32_t bufferSize = framesOrClasses->GetLength();
if (startBufferIndex < 0 || startBufferIndex >= bufferSize) {
return endBufferIndex;
}
// The FILL_CLASS_REFS_ONLY flag is defined in AbstractStackWalker.fetchStackFrames() javadoc.
bool isClassArray = (mode & FILL_CLASS_REFS_ONLY) != 0;
Handle<mirror::ObjectArray<mirror::Object>> decoded_traces =
hs.NewHandle(soa.Decode<mirror::Object>(internal)->AsObjectArray<mirror::Object>());
// Methods and dex PC trace is element 0.
DCHECK(decoded_traces->Get(0)->IsIntArray() || decoded_traces->Get(0)->IsLongArray());
Handle<mirror::PointerArray> method_trace =
hs.NewHandle(ObjPtr<mirror::PointerArray>::DownCast(decoded_traces->Get(0)));
ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
Handle<mirror::Class> sfi_class =
hs.NewHandle(class_linker->FindSystemClass(soa.Self(), "Ljava/lang/StackFrameInfo;"));
DCHECK(sfi_class != nullptr);
MutableHandle<mirror::StackFrameInfo> frame = hs.NewHandle<mirror::StackFrameInfo>(nullptr);
MutableHandle<mirror::Class> clazz = hs.NewHandle<mirror::Class>(nullptr);
for (uint32_t i = static_cast<uint32_t>(startLevel); i < static_cast<uint32_t>(depth); ++i) {
if (endBufferIndex >= startBufferIndex + batchSize || endBufferIndex >= bufferSize) {
break;
}
ArtMethod* method = method_trace->GetElementPtrSize<ArtMethod*>(i, kRuntimePointerSize);
if (isClassArray) {
clazz.Assign(method->GetDeclaringClass());
framesOrClasses->Set(endBufferIndex, clazz.Get());
} else {
// Prepare parameters for fields in StackFrameInfo
uint32_t dex_pc = method_trace->GetElementPtrSize<uint32_t>(
i + static_cast<uint32_t>(method_trace->GetLength()) / 2, kRuntimePointerSize);
ObjPtr<mirror::Object> frameObject = framesOrClasses->Get(endBufferIndex);
// If libcore didn't allocate the object, we just stop here, but it's unlikely.
if (frameObject == nullptr || !frameObject->InstanceOf(sfi_class.Get())) {
break;
}
frame.Assign(ObjPtr<mirror::StackFrameInfo>::DownCast(frameObject));
frame.Assign(InitStackFrameInfo(soa, class_linker, frame, method, dex_pc));
// Break if InitStackFrameInfo fails to allocate objects or assign the fields.
if (frame == nullptr) {
break;
}
}
++endBufferIndex;
}
return endBufferIndex;
}
jobjectArray Thread::CreateAnnotatedStackTrace(const ScopedObjectAccessAlreadyRunnable& soa) const {
// This code allocates. Do not allow it to operate with a pending exception.
if (IsExceptionPending()) {
return nullptr;
}
class CollectFramesAndLocksStackVisitor : public MonitorObjectsStackVisitor {
public:
CollectFramesAndLocksStackVisitor(const ScopedObjectAccessAlreadyRunnable& soaa_in,
Thread* self,
Context* context)
: MonitorObjectsStackVisitor(self, context),
wait_jobject_(soaa_in.Env(), nullptr),
block_jobject_(soaa_in.Env(), nullptr),
soaa_(soaa_in) {}
protected:
VisitMethodResult StartMethod(ArtMethod* m, [[maybe_unused]] size_t frame_nr) override
REQUIRES_SHARED(Locks::mutator_lock_) {
ObjPtr<mirror::StackTraceElement> obj = CreateStackTraceElement(
soaa_, m, GetDexPc(/* abort on error */ false));
if (obj == nullptr) {
return VisitMethodResult::kEndStackWalk;
}
stack_trace_elements_.emplace_back(soaa_.Env(), soaa_.AddLocalReference<jobject>(obj.Ptr()));
return VisitMethodResult::kContinueMethod;
}
VisitMethodResult EndMethod([[maybe_unused]] ArtMethod* m) override {
lock_objects_.push_back({});
lock_objects_[lock_objects_.size() - 1].swap(frame_lock_objects_);
DCHECK_EQ(lock_objects_.size(), stack_trace_elements_.size());
return VisitMethodResult::kContinueMethod;
}
void VisitWaitingObject(ObjPtr<mirror::Object> obj, [[maybe_unused]] ThreadState state) override
REQUIRES_SHARED(Locks::mutator_lock_) {
wait_jobject_.reset(soaa_.AddLocalReference<jobject>(obj));
}
void VisitSleepingObject(ObjPtr<mirror::Object> obj)
override
REQUIRES_SHARED(Locks::mutator_lock_) {
wait_jobject_.reset(soaa_.AddLocalReference<jobject>(obj));
}
void VisitBlockedOnObject(ObjPtr<mirror::Object> obj,
[[maybe_unused]] ThreadState state,
[[maybe_unused]] uint32_t owner_tid) override
REQUIRES_SHARED(Locks::mutator_lock_) {
block_jobject_.reset(soaa_.AddLocalReference<jobject>(obj));
}
void VisitLockedObject(ObjPtr<mirror::Object> obj)
override
REQUIRES_SHARED(Locks::mutator_lock_) {
frame_lock_objects_.emplace_back(soaa_.Env(), soaa_.AddLocalReference<jobject>(obj));
}
public:
std::vector<ScopedLocalRef<jobject>> stack_trace_elements_;
ScopedLocalRef<jobject> wait_jobject_;
ScopedLocalRef<jobject> block_jobject_;
std::vector<std::vector<ScopedLocalRef<jobject>>> lock_objects_;
private:
const ScopedObjectAccessAlreadyRunnable& soaa_;
std::vector<ScopedLocalRef<jobject>> frame_lock_objects_;
};
std::unique_ptr<Context> context(Context::Create());
CollectFramesAndLocksStackVisitor dumper(soa, const_cast<Thread*>(this), context.get());
dumper.WalkStack();
// There should not be a pending exception. Otherwise, return with it pending.
if (IsExceptionPending()) {
return nullptr;
}
// Now go and create Java arrays.
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
StackHandleScope<6> hs(soa.Self());
Handle<mirror::Class> h_aste_array_class = hs.NewHandle(class_linker->FindSystemClass(
soa.Self(),
"[Ldalvik/system/AnnotatedStackTraceElement;"));
if (h_aste_array_class == nullptr) {
return nullptr;
}
Handle<mirror::Class> h_aste_class = hs.NewHandle(h_aste_array_class->GetComponentType());
Handle<mirror::Class> h_o_array_class =
hs.NewHandle(GetClassRoot<mirror::ObjectArray<mirror::Object>>(class_linker));
DCHECK(h_o_array_class != nullptr); // Class roots must be already initialized.
// Make sure the AnnotatedStackTraceElement.class is initialized, b/76208924 .
class_linker->EnsureInitialized(soa.Self(),
h_aste_class,
/* can_init_fields= */ true,
/* can_init_parents= */ true);
if (soa.Self()->IsExceptionPending()) {
// This should not fail in a healthy runtime.
return nullptr;
}
ArtField* stack_trace_element_field =
h_aste_class->FindDeclaredInstanceField("stackTraceElement", "Ljava/lang/StackTraceElement;");
DCHECK(stack_trace_element_field != nullptr);
ArtField* held_locks_field =
h_aste_class->FindDeclaredInstanceField("heldLocks", "[Ljava/lang/Object;");
DCHECK(held_locks_field != nullptr);
ArtField* blocked_on_field =
h_aste_class->FindDeclaredInstanceField("blockedOn", "Ljava/lang/Object;");
DCHECK(blocked_on_field != nullptr);
int32_t length = static_cast<int32_t>(dumper.stack_trace_elements_.size());
ObjPtr<mirror::ObjectArray<mirror::Object>> array =
mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), h_aste_array_class.Get(), length);
if (array == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
ScopedLocalRef<jobjectArray> result(soa.Env(), soa.Env()->AddLocalReference<jobjectArray>(array));
MutableHandle<mirror::Object> handle(hs.NewHandle<mirror::Object>(nullptr));
MutableHandle<mirror::ObjectArray<mirror::Object>> handle2(
hs.NewHandle<mirror::ObjectArray<mirror::Object>>(nullptr));
for (size_t i = 0; i != static_cast<size_t>(length); ++i) {
handle.Assign(h_aste_class->AllocObject(soa.Self()));
if (handle == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
// Set stack trace element.
stack_trace_element_field->SetObject<false>(
handle.Get(), soa.Decode<mirror::Object>(dumper.stack_trace_elements_[i].get()));
// Create locked-on array.
if (!dumper.lock_objects_[i].empty()) {
handle2.Assign(mirror::ObjectArray<mirror::Object>::Alloc(
soa.Self(), h_o_array_class.Get(), static_cast<int32_t>(dumper.lock_objects_[i].size())));
if (handle2 == nullptr) {
soa.Self()->AssertPendingOOMException();
return nullptr;
}
int32_t j = 0;
for (auto& scoped_local : dumper.lock_objects_[i]) {
if (scoped_local == nullptr) {
continue;
}
handle2->Set(j, soa.Decode<mirror::Object>(scoped_local.get()));
DCHECK(!soa.Self()->IsExceptionPending());
j++;
}
held_locks_field->SetObject<false>(handle.Get(), handle2.Get());
}
// Set blocked-on object.
if (i == 0) {
if (dumper.block_jobject_ != nullptr) {
blocked_on_field->SetObject<false>(
handle.Get(), soa.Decode<mirror::Object>(dumper.block_jobject_.get()));
}
}
ScopedLocalRef<jobject> elem(soa.Env(), soa.AddLocalReference<jobject>(handle.Get()));
soa.Env()->SetObjectArrayElement(result.get(), static_cast<jsize>(i), elem.get());
DCHECK(!soa.Self()->IsExceptionPending());
}
return result.release();
}
void Thread::ThrowNewExceptionF(const char* exception_class_descriptor, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
ThrowNewExceptionV(exception_class_descriptor, fmt, args);
va_end(args);
}
void Thread::ThrowNewExceptionV(const char* exception_class_descriptor,
const char* fmt, va_list ap) {
std::string msg;
StringAppendV(&msg, fmt, ap);
ThrowNewException(exception_class_descriptor, msg.c_str());
}
void Thread::ThrowNewException(const char* exception_class_descriptor,
const char* msg) {
// Callers should either clear or call ThrowNewWrappedException.
AssertNoPendingExceptionForNewException(msg);
ThrowNewWrappedException(exception_class_descriptor, msg);
}
static ObjPtr<mirror::ClassLoader> GetCurrentClassLoader(Thread* self)
REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* method = self->GetCurrentMethod(nullptr);
return method != nullptr
? method->GetDeclaringClass()->GetClassLoader()
: nullptr;
}
void Thread::ThrowNewWrappedException(const char* exception_class_descriptor,
const char* msg) {
DCHECK_EQ(this, Thread::Current());
ScopedObjectAccessUnchecked soa(this);
StackHandleScope<3> hs(soa.Self());
// Disable public sdk checks if we need to throw exceptions.
// The checks are only used in AOT compilation and may block (exception) class
// initialization if it needs access to private fields (e.g. serialVersionUID).
//
// Since throwing an exception will EnsureInitialization and the public sdk may
// block that, disable the checks. It's ok to do so, because the thrown exceptions
// are not part of the application code that needs to verified.
ScopedDisablePublicSdkChecker sdpsc;
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(GetCurrentClassLoader(soa.Self())));
ScopedLocalRef<jobject> cause(GetJniEnv(), soa.AddLocalReference<jobject>(GetException()));
ClearException();
Runtime* runtime = Runtime::Current();
auto* cl = runtime->GetClassLinker();
Handle<mirror::Class> exception_class(
hs.NewHandle(cl->FindClass(this, exception_class_descriptor, class_loader)));
if (UNLIKELY(exception_class == nullptr)) {
CHECK(IsExceptionPending());
LOG(ERROR) << "No exception class " << PrettyDescriptor(exception_class_descriptor);
return;
}
if (UNLIKELY(!runtime->GetClassLinker()->EnsureInitialized(soa.Self(), exception_class, true,
true))) {
DCHECK(IsExceptionPending());
return;
}
DCHECK_IMPLIES(runtime->IsStarted(), exception_class->IsThrowableClass());
Handle<mirror::Throwable> exception(
hs.NewHandle(ObjPtr<mirror::Throwable>::DownCast(exception_class->AllocObject(this))));
// If we couldn't allocate the exception, throw the pre-allocated out of memory exception.
if (exception == nullptr) {
Dump(LOG_STREAM(WARNING)); // The pre-allocated OOME has no stack, so help out and log one.
SetException(Runtime::Current()->GetPreAllocatedOutOfMemoryErrorWhenThrowingException());
return;
}
// Choose an appropriate constructor and set up the arguments.
const char* signature;
ScopedLocalRef<jstring> msg_string(GetJniEnv(), nullptr);
if (msg != nullptr) {
// Ensure we remember this and the method over the String allocation.
msg_string.reset(
soa.AddLocalReference<jstring>(mirror::String::AllocFromModifiedUtf8(this, msg)));
if (UNLIKELY(msg_string.get() == nullptr)) {
CHECK(IsExceptionPending()); // OOME.
return;
}
if (cause.get() == nullptr) {
signature = "(Ljava/lang/String;)V";
} else {
signature = "(Ljava/lang/String;Ljava/lang/Throwable;)V";
}
} else {
if (cause.get() == nullptr) {
signature = "()V";
} else {
signature = "(Ljava/lang/Throwable;)V";
}
}
ArtMethod* exception_init_method =
exception_class->FindConstructor(signature, cl->GetImagePointerSize());
CHECK(exception_init_method != nullptr) << "No <init>" << signature << " in "
<< PrettyDescriptor(exception_class_descriptor);
if (UNLIKELY(!runtime->IsStarted())) {
// Something is trying to throw an exception without a started runtime, which is the common
// case in the compiler. We won't be able to invoke the constructor of the exception, so set
// the exception fields directly.
if (msg != nullptr) {
exception->SetDetailMessage(DecodeJObject(msg_string.get())->AsString());
}
if (cause.get() != nullptr) {
exception->SetCause(DecodeJObject(cause.get())->AsThrowable());
}
ScopedLocalRef<jobject> trace(GetJniEnv(), CreateInternalStackTrace(soa));
if (trace.get() != nullptr) {
exception->SetStackState(DecodeJObject(trace.get()).Ptr());
}
SetException(exception.Get());
} else {
jvalue jv_args[2];
size_t i = 0;
if (msg != nullptr) {
jv_args[i].l = msg_string.get();
++i;
}
if (cause.get() != nullptr) {
jv_args[i].l = cause.get();
++i;
}
ScopedLocalRef<jobject> ref(soa.Env(), soa.AddLocalReference<jobject>(exception.Get()));
InvokeWithJValues(soa, ref.get(), exception_init_method, jv_args);
if (LIKELY(!IsExceptionPending())) {
SetException(exception.Get());
}
}
}
void Thread::ThrowOutOfMemoryError(const char* msg) {
LOG(WARNING) << "Throwing OutOfMemoryError "
<< '"' << msg << '"'
<< " (VmSize " << GetProcessStatus("VmSize")
<< (tls32_.throwing_OutOfMemoryError ? ", recursive case)" : ")");
ScopedTrace trace("OutOfMemoryError");
if (!tls32_.throwing_OutOfMemoryError) {
tls32_.throwing_OutOfMemoryError = true;
ThrowNewException("Ljava/lang/OutOfMemoryError;", msg);
tls32_.throwing_OutOfMemoryError = false;
} else {
Dump(LOG_STREAM(WARNING)); // The pre-allocated OOME has no stack, so help out and log one.
SetException(Runtime::Current()->GetPreAllocatedOutOfMemoryErrorWhenThrowingOOME());
}
}
Thread* Thread::CurrentFromGdb() {
return Thread::Current();
}
void Thread::DumpFromGdb() const {
std::ostringstream ss;
Dump(ss);
std::string str(ss.str());
// log to stderr for debugging command line processes
std::cerr << str;
#ifdef ART_TARGET_ANDROID
// log to logcat for debugging frameworks processes
LOG(INFO) << str;
#endif
}
// Explicitly instantiate 32 and 64bit thread offset dumping support.
template
void Thread::DumpThreadOffset<PointerSize::k32>(std::ostream& os, uint32_t offset);
template
void Thread::DumpThreadOffset<PointerSize::k64>(std::ostream& os, uint32_t offset);
template<PointerSize ptr_size>
void Thread::DumpThreadOffset(std::ostream& os, uint32_t offset) {
#define DO_THREAD_OFFSET(x, y) \
if (offset == (x).Uint32Value()) { \
os << (y); \
return; \
}
DO_THREAD_OFFSET(ThreadFlagsOffset<ptr_size>(), "state_and_flags")
DO_THREAD_OFFSET(CardTableOffset<ptr_size>(), "card_table")
DO_THREAD_OFFSET(ExceptionOffset<ptr_size>(), "exception")
DO_THREAD_OFFSET(PeerOffset<ptr_size>(), "peer");
DO_THREAD_OFFSET(JniEnvOffset<ptr_size>(), "jni_env")
DO_THREAD_OFFSET(SelfOffset<ptr_size>(), "self")
DO_THREAD_OFFSET(StackEndOffset<ptr_size>(), "stack_end")
DO_THREAD_OFFSET(ThinLockIdOffset<ptr_size>(), "thin_lock_thread_id")
DO_THREAD_OFFSET(IsGcMarkingOffset<ptr_size>(), "is_gc_marking")
DO_THREAD_OFFSET(TopOfManagedStackOffset<ptr_size>(), "top_quick_frame_method")
DO_THREAD_OFFSET(TopShadowFrameOffset<ptr_size>(), "top_shadow_frame")
DO_THREAD_OFFSET(TopHandleScopeOffset<ptr_size>(), "top_handle_scope")
DO_THREAD_OFFSET(ThreadSuspendTriggerOffset<ptr_size>(), "suspend_trigger")
#undef DO_THREAD_OFFSET
#define JNI_ENTRY_POINT_INFO(x) \
if (JNI_ENTRYPOINT_OFFSET(ptr_size, x).Uint32Value() == offset) { \
os << #x; \
return; \
}
JNI_ENTRY_POINT_INFO(pDlsymLookup)
JNI_ENTRY_POINT_INFO(pDlsymLookupCritical)
#undef JNI_ENTRY_POINT_INFO
#define QUICK_ENTRY_POINT_INFO(x) \
if (QUICK_ENTRYPOINT_OFFSET(ptr_size, x).Uint32Value() == offset) { \
os << #x; \
return; \
}
QUICK_ENTRY_POINT_INFO(pAllocArrayResolved)
QUICK_ENTRY_POINT_INFO(pAllocArrayResolved8)
QUICK_ENTRY_POINT_INFO(pAllocArrayResolved16)
QUICK_ENTRY_POINT_INFO(pAllocArrayResolved32)
QUICK_ENTRY_POINT_INFO(pAllocArrayResolved64)
QUICK_ENTRY_POINT_INFO(pAllocObjectResolved)
QUICK_ENTRY_POINT_INFO(pAllocObjectInitialized)
QUICK_ENTRY_POINT_INFO(pAllocObjectWithChecks)
QUICK_ENTRY_POINT_INFO(pAllocStringObject)
QUICK_ENTRY_POINT_INFO(pAllocStringFromBytes)
QUICK_ENTRY_POINT_INFO(pAllocStringFromChars)
QUICK_ENTRY_POINT_INFO(pAllocStringFromString)
QUICK_ENTRY_POINT_INFO(pInstanceofNonTrivial)
QUICK_ENTRY_POINT_INFO(pCheckInstanceOf)
QUICK_ENTRY_POINT_INFO(pInitializeStaticStorage)
QUICK_ENTRY_POINT_INFO(pResolveTypeAndVerifyAccess)
QUICK_ENTRY_POINT_INFO(pResolveType)
QUICK_ENTRY_POINT_INFO(pResolveString)
QUICK_ENTRY_POINT_INFO(pSet8Instance)
QUICK_ENTRY_POINT_INFO(pSet8Static)
QUICK_ENTRY_POINT_INFO(pSet16Instance)
QUICK_ENTRY_POINT_INFO(pSet16Static)
QUICK_ENTRY_POINT_INFO(pSet32Instance)
QUICK_ENTRY_POINT_INFO(pSet32Static)
QUICK_ENTRY_POINT_INFO(pSet64Instance)
QUICK_ENTRY_POINT_INFO(pSet64Static)
QUICK_ENTRY_POINT_INFO(pSetObjInstance)
QUICK_ENTRY_POINT_INFO(pSetObjStatic)
QUICK_ENTRY_POINT_INFO(pGetByteInstance)
QUICK_ENTRY_POINT_INFO(pGetBooleanInstance)
QUICK_ENTRY_POINT_INFO(pGetByteStatic)
QUICK_ENTRY_POINT_INFO(pGetBooleanStatic)
QUICK_ENTRY_POINT_INFO(pGetShortInstance)
QUICK_ENTRY_POINT_INFO(pGetCharInstance)
QUICK_ENTRY_POINT_INFO(pGetShortStatic)
QUICK_ENTRY_POINT_INFO(pGetCharStatic)
QUICK_ENTRY_POINT_INFO(pGet32Instance)
QUICK_ENTRY_POINT_INFO(pGet32Static)
QUICK_ENTRY_POINT_INFO(pGet64Instance)
QUICK_ENTRY_POINT_INFO(pGet64Static)
QUICK_ENTRY_POINT_INFO(pGetObjInstance)
QUICK_ENTRY_POINT_INFO(pGetObjStatic)
QUICK_ENTRY_POINT_INFO(pAputObject)
QUICK_ENTRY_POINT_INFO(pJniMethodStart)
QUICK_ENTRY_POINT_INFO(pJniMethodEnd)
QUICK_ENTRY_POINT_INFO(pJniMethodEntryHook)
QUICK_ENTRY_POINT_INFO(pJniDecodeReferenceResult)
QUICK_ENTRY_POINT_INFO(pJniLockObject)
QUICK_ENTRY_POINT_INFO(pJniUnlockObject)
QUICK_ENTRY_POINT_INFO(pQuickGenericJniTrampoline)
QUICK_ENTRY_POINT_INFO(pLockObject)
QUICK_ENTRY_POINT_INFO(pUnlockObject)
QUICK_ENTRY_POINT_INFO(pCmpgDouble)
QUICK_ENTRY_POINT_INFO(pCmpgFloat)
QUICK_ENTRY_POINT_INFO(pCmplDouble)
QUICK_ENTRY_POINT_INFO(pCmplFloat)
QUICK_ENTRY_POINT_INFO(pCos)
QUICK_ENTRY_POINT_INFO(pSin)
QUICK_ENTRY_POINT_INFO(pAcos)
QUICK_ENTRY_POINT_INFO(pAsin)
QUICK_ENTRY_POINT_INFO(pAtan)
QUICK_ENTRY_POINT_INFO(pAtan2)
QUICK_ENTRY_POINT_INFO(pCbrt)
QUICK_ENTRY_POINT_INFO(pCosh)
QUICK_ENTRY_POINT_INFO(pExp)
QUICK_ENTRY_POINT_INFO(pExpm1)
QUICK_ENTRY_POINT_INFO(pHypot)
QUICK_ENTRY_POINT_INFO(pLog)
QUICK_ENTRY_POINT_INFO(pLog10)
QUICK_ENTRY_POINT_INFO(pNextAfter)
QUICK_ENTRY_POINT_INFO(pSinh)
QUICK_ENTRY_POINT_INFO(pTan)
QUICK_ENTRY_POINT_INFO(pTanh)
QUICK_ENTRY_POINT_INFO(pFmod)
QUICK_ENTRY_POINT_INFO(pL2d)
QUICK_ENTRY_POINT_INFO(pFmodf)
QUICK_ENTRY_POINT_INFO(pL2f)
QUICK_ENTRY_POINT_INFO(pD2iz)
QUICK_ENTRY_POINT_INFO(pF2iz)
QUICK_ENTRY_POINT_INFO(pIdivmod)
QUICK_ENTRY_POINT_INFO(pD2l)
QUICK_ENTRY_POINT_INFO(pF2l)
QUICK_ENTRY_POINT_INFO(pLdiv)
QUICK_ENTRY_POINT_INFO(pLmod)
QUICK_ENTRY_POINT_INFO(pLmul)
QUICK_ENTRY_POINT_INFO(pShlLong)
QUICK_ENTRY_POINT_INFO(pShrLong)
QUICK_ENTRY_POINT_INFO(pUshrLong)
QUICK_ENTRY_POINT_INFO(pIndexOf)
QUICK_ENTRY_POINT_INFO(pStringCompareTo)
QUICK_ENTRY_POINT_INFO(pMemcpy)
QUICK_ENTRY_POINT_INFO(pQuickImtConflictTrampoline)
QUICK_ENTRY_POINT_INFO(pQuickResolutionTrampoline)
QUICK_ENTRY_POINT_INFO(pQuickToInterpreterBridge)
QUICK_ENTRY_POINT_INFO(pInvokeDirectTrampolineWithAccessCheck)
QUICK_ENTRY_POINT_INFO(pInvokeInterfaceTrampolineWithAccessCheck)
QUICK_ENTRY_POINT_INFO(pInvokeStaticTrampolineWithAccessCheck)
QUICK_ENTRY_POINT_INFO(pInvokeSuperTrampolineWithAccessCheck)
QUICK_ENTRY_POINT_INFO(pInvokeVirtualTrampolineWithAccessCheck)
QUICK_ENTRY_POINT_INFO(pInvokePolymorphic)
QUICK_ENTRY_POINT_INFO(pTestSuspend)
QUICK_ENTRY_POINT_INFO(pDeliverException)
QUICK_ENTRY_POINT_INFO(pThrowArrayBounds)
QUICK_ENTRY_POINT_INFO(pThrowDivZero)
QUICK_ENTRY_POINT_INFO(pThrowNullPointer)
QUICK_ENTRY_POINT_INFO(pThrowStackOverflow)
QUICK_ENTRY_POINT_INFO(pDeoptimize)
QUICK_ENTRY_POINT_INFO(pA64Load)
QUICK_ENTRY_POINT_INFO(pA64Store)
QUICK_ENTRY_POINT_INFO(pNewEmptyString)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_B)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BB)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BI)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BII)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BIII)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BIIString)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BString)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BIICharset)
QUICK_ENTRY_POINT_INFO(pNewStringFromBytes_BCharset)
QUICK_ENTRY_POINT_INFO(pNewStringFromChars_C)
QUICK_ENTRY_POINT_INFO(pNewStringFromChars_CII)
QUICK_ENTRY_POINT_INFO(pNewStringFromChars_IIC)
QUICK_ENTRY_POINT_INFO(pNewStringFromCodePoints)
QUICK_ENTRY_POINT_INFO(pNewStringFromString)
QUICK_ENTRY_POINT_INFO(pNewStringFromStringBuffer)
QUICK_ENTRY_POINT_INFO(pNewStringFromStringBuilder)
QUICK_ENTRY_POINT_INFO(pNewStringFromUtf16Bytes_BII)
QUICK_ENTRY_POINT_INFO(pJniReadBarrier)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg00)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg01)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg02)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg03)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg04)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg05)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg06)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg07)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg08)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg09)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg10)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg11)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg12)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg13)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg14)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg15)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg16)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg17)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg18)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg19)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg20)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg21)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg22)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg23)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg24)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg25)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg26)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg27)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg28)
QUICK_ENTRY_POINT_INFO(pReadBarrierMarkReg29)
QUICK_ENTRY_POINT_INFO(pReadBarrierSlow)
QUICK_ENTRY_POINT_INFO(pReadBarrierForRootSlow)
#undef QUICK_ENTRY_POINT_INFO
os << offset;
}
void Thread::QuickDeliverException(bool skip_method_exit_callbacks) {
// Get exception from thread.
ObjPtr<mirror::Throwable> exception = GetException();
CHECK(exception != nullptr);
if (exception == GetDeoptimizationException()) {
// This wasn't a real exception, so just clear it here. If there was an actual exception it
// will be recorded in the DeoptimizationContext and it will be restored later.
ClearException();
artDeoptimize(this, skip_method_exit_callbacks);
UNREACHABLE();
}
ReadBarrier::MaybeAssertToSpaceInvariant(exception.Ptr());
// This is a real exception: let the instrumentation know about it. Exception throw listener
// could set a breakpoint or install listeners that might require a deoptimization. Hence the
// deoptimization check needs to happen after calling the listener.
instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
if (instrumentation->HasExceptionThrownListeners() &&
IsExceptionThrownByCurrentMethod(exception)) {
// Instrumentation may cause GC so keep the exception object safe.
StackHandleScope<1> hs(this);
HandleWrapperObjPtr<mirror::Throwable> h_exception(hs.NewHandleWrapper(&exception));
instrumentation->ExceptionThrownEvent(this, exception);
}
// Does instrumentation need to deoptimize the stack or otherwise go to interpreter for something?
// Note: we do this *after* reporting the exception to instrumentation in case it now requires
// deoptimization. It may happen if a debugger is attached and requests new events (single-step,
// breakpoint, ...) when the exception is reported.
// Frame pop can be requested on a method unwind callback which requires a deopt. We could
// potentially check after each unwind callback to see if a frame pop was requested and deopt if
// needed. Since this is a debug only feature and this path is only taken when an exception is
// thrown, it is not performance critical and we keep it simple by just deopting if method exit
// listeners are installed and frame pop feature is supported.
bool needs_deopt =
instrumentation->HasMethodExitListeners() && Runtime::Current()->AreNonStandardExitsEnabled();
if (Dbg::IsForcedInterpreterNeededForException(this) || IsForceInterpreter() || needs_deopt) {
NthCallerVisitor visitor(this, 0, false);
visitor.WalkStack();
if (visitor.GetCurrentQuickFrame() != nullptr) {
if (Runtime::Current()->IsAsyncDeoptimizeable(visitor.GetOuterMethod(), visitor.caller_pc)) {
// method_type shouldn't matter due to exception handling.
const DeoptimizationMethodType method_type = DeoptimizationMethodType::kDefault;
// Save the exception into the deoptimization context so it can be restored
// before entering the interpreter.
PushDeoptimizationContext(
JValue(),
/* is_reference= */ false,
exception,
/* from_code= */ false,
method_type);
artDeoptimize(this, skip_method_exit_callbacks);
UNREACHABLE();
} else {
LOG(WARNING) << "Got a deoptimization request on un-deoptimizable method "
<< visitor.caller->PrettyMethod();
}
} else {
// This is either top of call stack, or shadow frame.
DCHECK(visitor.caller == nullptr || visitor.IsShadowFrame());
}
}
// Don't leave exception visible while we try to find the handler, which may cause class
// resolution.
ClearException();
QuickExceptionHandler exception_handler(this, false);
exception_handler.FindCatch(exception, skip_method_exit_callbacks);
if (exception_handler.GetClearException()) {
// Exception was cleared as part of delivery.
DCHECK(!IsExceptionPending());
} else {
// Exception was put back with a throw location.
DCHECK(IsExceptionPending());
// Check the to-space invariant on the re-installed exception (if applicable).
ReadBarrier::MaybeAssertToSpaceInvariant(GetException());
}
exception_handler.DoLongJump();
}
Context* Thread::GetLongJumpContext() {
Context* result = tlsPtr_.long_jump_context;
if (result == nullptr) {
result = Context::Create();
} else {
tlsPtr_.long_jump_context = nullptr; // Avoid context being shared.
result->Reset();
}
return result;
}
ArtMethod* Thread::GetCurrentMethod(uint32_t* dex_pc_out,
bool check_suspended,
bool abort_on_error) const {
// Note: this visitor may return with a method set, but dex_pc_ being DexFile:kDexNoIndex. This is
// so we don't abort in a special situation (thinlocked monitor) when dumping the Java
// stack.
ArtMethod* method = nullptr;
uint32_t dex_pc = dex::kDexNoIndex;
StackVisitor::WalkStack(
[&](const StackVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* m = visitor->GetMethod();
if (m->IsRuntimeMethod()) {
// Continue if this is a runtime method.
return true;
}
method = m;
dex_pc = visitor->GetDexPc(abort_on_error);
return false;
},
const_cast<Thread*>(this),
/* context= */ nullptr,
StackVisitor::StackWalkKind::kIncludeInlinedFrames,
check_suspended);
if (dex_pc_out != nullptr) {
*dex_pc_out = dex_pc;
}
return method;
}
bool Thread::HoldsLock(ObjPtr<mirror::Object> object) const {
return object != nullptr && object->GetLockOwnerThreadId() == GetThreadId();
}
extern std::vector<StackReference<mirror::Object>*> GetProxyReferenceArguments(ArtMethod** sp)
REQUIRES_SHARED(Locks::mutator_lock_);
// RootVisitor parameters are: (const Object* obj, size_t vreg, const StackVisitor* visitor).
template <typename RootVisitor, bool kPrecise = false>
class ReferenceMapVisitor : public StackVisitor {
public:
ReferenceMapVisitor(Thread* thread, Context* context, RootVisitor& visitor)
REQUIRES_SHARED(Locks::mutator_lock_)
// We are visiting the references in compiled frames, so we do not need
// to know the inlined frames.
: StackVisitor(thread, context, StackVisitor::StackWalkKind::kSkipInlinedFrames),
visitor_(visitor),
visit_declaring_class_(!Runtime::Current()->GetHeap()->IsPerformingUffdCompaction()) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
if (false) {
LOG(INFO) << "Visiting stack roots in " << ArtMethod::PrettyMethod(GetMethod())
<< StringPrintf("@ PC:%04x", GetDexPc());
}
ShadowFrame* shadow_frame = GetCurrentShadowFrame();
if (shadow_frame != nullptr) {
VisitShadowFrame(shadow_frame);
} else if (GetCurrentOatQuickMethodHeader()->IsNterpMethodHeader()) {
VisitNterpFrame();
} else {
VisitQuickFrame();
}
return true;
}
void VisitShadowFrame(ShadowFrame* shadow_frame) REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* m = shadow_frame->GetMethod();
VisitDeclaringClass(m);
DCHECK(m != nullptr);
size_t num_regs = shadow_frame->NumberOfVRegs();
// handle scope for JNI or References for interpreter.
for (size_t reg = 0; reg < num_regs; ++reg) {
mirror::Object* ref = shadow_frame->GetVRegReference(reg);
if (ref != nullptr) {
mirror::Object* new_ref = ref;
visitor_(&new_ref, reg, this);
if (new_ref != ref) {
shadow_frame->SetVRegReference(reg, new_ref);
}
}
}
// Mark lock count map required for structured locking checks.
shadow_frame->GetLockCountData().VisitMonitors(visitor_, /* vreg= */ -1, this);
}
private:
// Visiting the declaring class is necessary so that we don't unload the class of a method that
// is executing. We need to ensure that the code stays mapped. NO_THREAD_SAFETY_ANALYSIS since
// the threads do not all hold the heap bitmap lock for parallel GC.
void VisitDeclaringClass(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_)
NO_THREAD_SAFETY_ANALYSIS {
if (!visit_declaring_class_) {
return;
}
ObjPtr<mirror::Class> klass = method->GetDeclaringClassUnchecked<kWithoutReadBarrier>();
// klass can be null for runtime methods.
if (klass != nullptr) {
if (kVerifyImageObjectsMarked) {
gc::Heap* const heap = Runtime::Current()->GetHeap();
gc::space::ContinuousSpace* space = heap->FindContinuousSpaceFromObject(klass,
/*fail_ok=*/true);
if (space != nullptr && space->IsImageSpace()) {
bool failed = false;
if (!space->GetLiveBitmap()->Test(klass.Ptr())) {
failed = true;
LOG(FATAL_WITHOUT_ABORT) << "Unmarked object in image " << *space;
} else if (!heap->GetLiveBitmap()->Test(klass.Ptr())) {
failed = true;
LOG(FATAL_WITHOUT_ABORT) << "Unmarked object in image through live bitmap " << *space;
}
if (failed) {
GetThread()->Dump(LOG_STREAM(FATAL_WITHOUT_ABORT));
space->AsImageSpace()->DumpSections(LOG_STREAM(FATAL_WITHOUT_ABORT));
LOG(FATAL_WITHOUT_ABORT) << "Method@" << method->GetDexMethodIndex() << ":" << method
<< " klass@" << klass.Ptr();
// Pretty info last in case it crashes.
LOG(FATAL) << "Method " << method->PrettyMethod() << " klass "
<< klass->PrettyClass();
}
}
}
mirror::Object* new_ref = klass.Ptr();
visitor_(&new_ref, /* vreg= */ JavaFrameRootInfo::kMethodDeclaringClass, this);
if (new_ref != klass) {
method->CASDeclaringClass(klass.Ptr(), new_ref->AsClass());
}
}
}
void VisitNterpFrame() REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod** cur_quick_frame = GetCurrentQuickFrame();
StackReference<mirror::Object>* vreg_ref_base =
reinterpret_cast<StackReference<mirror::Object>*>(NterpGetReferenceArray(cur_quick_frame));
StackReference<mirror::Object>* vreg_int_base =
reinterpret_cast<StackReference<mirror::Object>*>(NterpGetRegistersArray(cur_quick_frame));
CodeItemDataAccessor accessor((*cur_quick_frame)->DexInstructionData());
const uint16_t num_regs = accessor.RegistersSize();
// An nterp frame has two arrays: a dex register array and a reference array
// that shadows the dex register array but only containing references
// (non-reference dex registers have nulls). See nterp_helpers.cc.
for (size_t reg = 0; reg < num_regs; ++reg) {
StackReference<mirror::Object>* ref_addr = vreg_ref_base + reg;
mirror::Object* ref = ref_addr->AsMirrorPtr();
if (ref != nullptr) {
mirror::Object* new_ref = ref;
visitor_(&new_ref, reg, this);
if (new_ref != ref) {
ref_addr->Assign(new_ref);
StackReference<mirror::Object>* int_addr = vreg_int_base + reg;
int_addr->Assign(new_ref);
}
}
}
}
template <typename T>
ALWAYS_INLINE
inline void VisitQuickFrameWithVregCallback() REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod** cur_quick_frame = GetCurrentQuickFrame();
DCHECK(cur_quick_frame != nullptr);
ArtMethod* m = *cur_quick_frame;
VisitDeclaringClass(m);
if (m->IsNative()) {
// TODO: Spill the `this` reference in the AOT-compiled String.charAt()
// slow-path for throwing SIOOBE, so that we can remove this carve-out.
if (UNLIKELY(m->IsIntrinsic()) &&
m->GetIntrinsic() == enum_cast<uint32_t>(Intrinsics::kStringCharAt)) {
// The String.charAt() method is AOT-compiled with an intrinsic implementation
// instead of a JNI stub. It has a slow path that constructs a runtime frame
// for throwing SIOOBE and in that path we do not get the `this` pointer
// spilled on the stack, so there is nothing to visit. We can distinguish
// this from the GenericJni path by checking that the PC is in the boot image
// (PC shall be known thanks to the runtime frame for throwing SIOOBE).
// Note that JIT does not emit that intrinic implementation.
const void* pc = reinterpret_cast<const void*>(GetCurrentQuickFramePc());
if (pc != nullptr && Runtime::Current()->GetHeap()->IsInBootImageOatFile(pc)) {
return;
}
}
// Native methods spill their arguments to the reserved vregs in the caller's frame
// and use pointers to these stack references as jobject, jclass, jarray, etc.
// Note: We can come here for a @CriticalNative method when it needs to resolve the
// target native function but there would be no references to visit below.
const size_t frame_size = GetCurrentQuickFrameInfo().FrameSizeInBytes();
const size_t method_pointer_size = static_cast<size_t>(kRuntimePointerSize);
uint32_t* current_vreg = reinterpret_cast<uint32_t*>(
reinterpret_cast<uint8_t*>(cur_quick_frame) + frame_size + method_pointer_size);
auto visit = [&]() REQUIRES_SHARED(Locks::mutator_lock_) {
auto* ref_addr = reinterpret_cast<StackReference<mirror::Object>*>(current_vreg);
mirror::Object* ref = ref_addr->AsMirrorPtr();
if (ref != nullptr) {
mirror::Object* new_ref = ref;
visitor_(&new_ref, /* vreg= */ JavaFrameRootInfo::kNativeReferenceArgument, this);
if (ref != new_ref) {
ref_addr->Assign(new_ref);
}
}
};
const char* shorty = m->GetShorty();
if (!m->IsStatic()) {
visit();
current_vreg += 1u;
}
for (shorty += 1u; *shorty != 0; ++shorty) {
switch (*shorty) {
case 'D':
case 'J':
current_vreg += 2u;
break;
case 'L':
visit();
FALLTHROUGH_INTENDED;
default:
current_vreg += 1u;
break;
}
}
} else if (!m->IsRuntimeMethod() && (!m->IsProxyMethod() || m->IsConstructor())) {
// Process register map (which native, runtime and proxy methods don't have)
const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
DCHECK(method_header->IsOptimized());
StackReference<mirror::Object>* vreg_base =
reinterpret_cast<StackReference<mirror::Object>*>(cur_quick_frame);
uintptr_t native_pc_offset = method_header->NativeQuickPcOffset(GetCurrentQuickFramePc());
CodeInfo code_info = kPrecise
? CodeInfo(method_header) // We will need dex register maps.
: CodeInfo::DecodeGcMasksOnly(method_header);
StackMap map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
DCHECK(map.IsValid());
T vreg_info(m, code_info, map, visitor_);
// Visit stack entries that hold pointers.
BitMemoryRegion stack_mask = code_info.GetStackMaskOf(map);
for (size_t i = 0; i < stack_mask.size_in_bits(); ++i) {
if (stack_mask.LoadBit(i)) {
StackReference<mirror::Object>* ref_addr = vreg_base + i;
mirror::Object* ref = ref_addr->AsMirrorPtr();
if (ref != nullptr) {
mirror::Object* new_ref = ref;
vreg_info.VisitStack(&new_ref, i, this);
if (ref != new_ref) {
ref_addr->Assign(new_ref);
}
}
}
}
// Visit callee-save registers that hold pointers.
uint32_t register_mask = code_info.GetRegisterMaskOf(map);
for (uint32_t i = 0; i < BitSizeOf<uint32_t>(); ++i) {
if (register_mask & (1 << i)) {
mirror::Object** ref_addr = reinterpret_cast<mirror::Object**>(GetGPRAddress(i));
if (kIsDebugBuild && ref_addr == nullptr) {
std::string thread_name;
GetThread()->GetThreadName(thread_name);
LOG(FATAL_WITHOUT_ABORT) << "On thread " << thread_name;
DescribeStack(GetThread());
LOG(FATAL) << "Found an unsaved callee-save register " << i << " (null GPRAddress) "
<< "set in register_mask=" << register_mask << " at " << DescribeLocation();
}
if (*ref_addr != nullptr) {
vreg_info.VisitRegister(ref_addr, i, this);
}
}
}
} else if (!m->IsRuntimeMethod() && m->IsProxyMethod()) {
// If this is a proxy method, visit its reference arguments.
DCHECK(!m->IsStatic());
DCHECK(!m->IsNative());
std::vector<StackReference<mirror::Object>*> ref_addrs =
GetProxyReferenceArguments(cur_quick_frame);
for (StackReference<mirror::Object>* ref_addr : ref_addrs) {
mirror::Object* ref = ref_addr->AsMirrorPtr();
if (ref != nullptr) {
mirror::Object* new_ref = ref;
visitor_(&new_ref, /* vreg= */ JavaFrameRootInfo::kProxyReferenceArgument, this);
if (ref != new_ref) {
ref_addr->Assign(new_ref);
}
}
}
}
}
void VisitQuickFrame() REQUIRES_SHARED(Locks::mutator_lock_) {
if (kPrecise) {
VisitQuickFramePrecise();
} else {
VisitQuickFrameNonPrecise();
}
}
void VisitQuickFrameNonPrecise() REQUIRES_SHARED(Locks::mutator_lock_) {
struct UndefinedVRegInfo {
UndefinedVRegInfo([[maybe_unused]] ArtMethod* method,
[[maybe_unused]] const CodeInfo& code_info,
[[maybe_unused]] const StackMap& map,
RootVisitor& _visitor)
: visitor(_visitor) {}
ALWAYS_INLINE
void VisitStack(mirror::Object** ref,
[[maybe_unused]] size_t stack_index,
const StackVisitor* stack_visitor) REQUIRES_SHARED(Locks::mutator_lock_) {
visitor(ref, JavaFrameRootInfo::kImpreciseVreg, stack_visitor);
}
ALWAYS_INLINE
void VisitRegister(mirror::Object** ref,
[[maybe_unused]] size_t register_index,
const StackVisitor* stack_visitor) REQUIRES_SHARED(Locks::mutator_lock_) {
visitor(ref, JavaFrameRootInfo::kImpreciseVreg, stack_visitor);
}
RootVisitor& visitor;
};
VisitQuickFrameWithVregCallback<UndefinedVRegInfo>();
}
void VisitQuickFramePrecise() REQUIRES_SHARED(Locks::mutator_lock_) {
struct StackMapVRegInfo {
StackMapVRegInfo(ArtMethod* method,
const CodeInfo& _code_info,
const StackMap& map,
RootVisitor& _visitor)
: number_of_dex_registers(method->DexInstructionData().RegistersSize()),
code_info(_code_info),
dex_register_map(code_info.GetDexRegisterMapOf(map)),
visitor(_visitor) {
DCHECK_EQ(dex_register_map.size(), number_of_dex_registers);
}
// TODO: If necessary, we should consider caching a reverse map instead of the linear
// lookups for each location.
void FindWithType(const size_t index,
const DexRegisterLocation::Kind kind,
mirror::Object** ref,
const StackVisitor* stack_visitor)
REQUIRES_SHARED(Locks::mutator_lock_) {
bool found = false;
for (size_t dex_reg = 0; dex_reg != number_of_dex_registers; ++dex_reg) {
DexRegisterLocation location = dex_register_map[dex_reg];
if (location.GetKind() == kind && static_cast<size_t>(location.GetValue()) == index) {
visitor(ref, dex_reg, stack_visitor);
found = true;
}
}
if (!found) {
// If nothing found, report with unknown.
visitor(ref, JavaFrameRootInfo::kUnknownVreg, stack_visitor);
}
}
void VisitStack(mirror::Object** ref, size_t stack_index, const StackVisitor* stack_visitor)
REQUIRES_SHARED(Locks::mutator_lock_) {
const size_t stack_offset = stack_index * kFrameSlotSize;
FindWithType(stack_offset,
DexRegisterLocation::Kind::kInStack,
ref,
stack_visitor);
}
void VisitRegister(mirror::Object** ref,
size_t register_index,
const StackVisitor* stack_visitor)
REQUIRES_SHARED(Locks::mutator_lock_) {
FindWithType(register_index,
DexRegisterLocation::Kind::kInRegister,
ref,
stack_visitor);
}
size_t number_of_dex_registers;
const CodeInfo& code_info;
DexRegisterMap dex_register_map;
RootVisitor& visitor;
};
VisitQuickFrameWithVregCallback<StackMapVRegInfo>();
}
// Visitor for when we visit a root.
RootVisitor& visitor_;
bool visit_declaring_class_;
};
class RootCallbackVisitor {
public:
RootCallbackVisitor(RootVisitor* visitor, uint32_t tid) : visitor_(visitor), tid_(tid) {}
void operator()(mirror::Object** obj, size_t vreg, const StackVisitor* stack_visitor) const
REQUIRES_SHARED(Locks::mutator_lock_) {
visitor_->VisitRoot(obj, JavaFrameRootInfo(tid_, stack_visitor, vreg));
}
private:
RootVisitor* const visitor_;
const uint32_t tid_;
};
void Thread::VisitReflectiveTargets(ReflectiveValueVisitor* visitor) {
for (BaseReflectiveHandleScope* brhs = GetTopReflectiveHandleScope();
brhs != nullptr;
brhs = brhs->GetLink()) {
brhs->VisitTargets(visitor);
}
}
// FIXME: clang-r433403 reports the below function exceeds frame size limit.
// http://b/197647048
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wframe-larger-than="
template <bool kPrecise>
void Thread::VisitRoots(RootVisitor* visitor) {
const uint32_t thread_id = GetThreadId();
visitor->VisitRootIfNonNull(&tlsPtr_.opeer, RootInfo(kRootThreadObject, thread_id));
if (tlsPtr_.exception != nullptr && tlsPtr_.exception != GetDeoptimizationException()) {
visitor->VisitRoot(reinterpret_cast<mirror::Object**>(&tlsPtr_.exception),
RootInfo(kRootNativeStack, thread_id));
}
if (tlsPtr_.async_exception != nullptr) {
visitor->VisitRoot(reinterpret_cast<mirror::Object**>(&tlsPtr_.async_exception),
RootInfo(kRootNativeStack, thread_id));
}
visitor->VisitRootIfNonNull(&tlsPtr_.monitor_enter_object, RootInfo(kRootNativeStack, thread_id));
tlsPtr_.jni_env->VisitJniLocalRoots(visitor, RootInfo(kRootJNILocal, thread_id));
tlsPtr_.jni_env->VisitMonitorRoots(visitor, RootInfo(kRootJNIMonitor, thread_id));
HandleScopeVisitRoots(visitor, thread_id);
// Visit roots for deoptimization.
if (tlsPtr_.stacked_shadow_frame_record != nullptr) {
RootCallbackVisitor visitor_to_callback(visitor, thread_id);
ReferenceMapVisitor<RootCallbackVisitor, kPrecise> mapper(this, nullptr, visitor_to_callback);
for (StackedShadowFrameRecord* record = tlsPtr_.stacked_shadow_frame_record;
record != nullptr;
record = record->GetLink()) {
for (ShadowFrame* shadow_frame = record->GetShadowFrame();
shadow_frame != nullptr;
shadow_frame = shadow_frame->GetLink()) {
mapper.VisitShadowFrame(shadow_frame);
}
}
}
for (DeoptimizationContextRecord* record = tlsPtr_.deoptimization_context_stack;
record != nullptr;
record = record->GetLink()) {
if (record->IsReference()) {
visitor->VisitRootIfNonNull(record->GetReturnValueAsGCRoot(),
RootInfo(kRootThreadObject, thread_id));
}
visitor->VisitRootIfNonNull(record->GetPendingExceptionAsGCRoot(),
RootInfo(kRootThreadObject, thread_id));
}
if (tlsPtr_.frame_id_to_shadow_frame != nullptr) {
RootCallbackVisitor visitor_to_callback(visitor, thread_id);
ReferenceMapVisitor<RootCallbackVisitor, kPrecise> mapper(this, nullptr, visitor_to_callback);
for (FrameIdToShadowFrame* record = tlsPtr_.frame_id_to_shadow_frame;
record != nullptr;
record = record->GetNext()) {
mapper.VisitShadowFrame(record->GetShadowFrame());
}
}
// Visit roots on this thread's stack
RuntimeContextType context;
RootCallbackVisitor visitor_to_callback(visitor, thread_id);
ReferenceMapVisitor<RootCallbackVisitor, kPrecise> mapper(this, &context, visitor_to_callback);
mapper.template WalkStack<StackVisitor::CountTransitions::kNo>(false);
}
#pragma GCC diagnostic pop
static void SweepCacheEntry(IsMarkedVisitor* visitor, const Instruction* inst, size_t* value)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (inst == nullptr) {
return;
}
using Opcode = Instruction::Code;
Opcode opcode = inst->Opcode();
switch (opcode) {
case Opcode::NEW_INSTANCE:
case Opcode::CHECK_CAST:
case Opcode::INSTANCE_OF:
case Opcode::NEW_ARRAY:
case Opcode::CONST_CLASS: {
mirror::Class* klass = reinterpret_cast<mirror::Class*>(*value);
if (klass == nullptr || klass == Runtime::GetWeakClassSentinel()) {
return;
}
mirror::Class* new_klass = down_cast<mirror::Class*>(visitor->IsMarked(klass));
if (new_klass == nullptr) {
*value = reinterpret_cast<size_t>(Runtime::GetWeakClassSentinel());
} else if (new_klass != klass) {
*value = reinterpret_cast<size_t>(new_klass);
}
return;
}
case Opcode::CONST_STRING:
case Opcode::CONST_STRING_JUMBO: {
mirror::Object* object = reinterpret_cast<mirror::Object*>(*value);
if (object == nullptr) {
return;
}
mirror::Object* new_object = visitor->IsMarked(object);
// We know the string is marked because it's a strongly-interned string that
// is always alive (see b/117621117 for trying to make those strings weak).
if (kIsDebugBuild && new_object == nullptr) {
// (b/275005060) Currently the problem is reported only on CC GC.
// Therefore we log it with more information. But since the failure rate
// is quite high, sampling it.
if (gUseReadBarrier) {
Runtime* runtime = Runtime::Current();
gc::collector::ConcurrentCopying* cc = runtime->GetHeap()->ConcurrentCopyingCollector();
CHECK_NE(cc, nullptr);
LOG(FATAL) << cc->DumpReferenceInfo(object, "string")
<< " string interned: " << std::boolalpha
<< runtime->GetInternTable()->LookupStrong(Thread::Current(),
down_cast<mirror::String*>(object))
<< std::noboolalpha;
} else {
// Other GCs
LOG(FATAL) << __FUNCTION__
<< ": IsMarked returned null for a strongly interned string: " << object;
}
} else if (new_object != object) {
*value = reinterpret_cast<size_t>(new_object);
}
return;
}
default:
// The following opcode ranges store non-reference values.
if ((Opcode::IGET <= opcode && opcode <= Opcode::SPUT_SHORT) ||
(Opcode::INVOKE_VIRTUAL <= opcode && opcode <= Opcode::INVOKE_INTERFACE_RANGE)) {
return; // Nothing to do for the GC.
}
// New opcode is using the cache. We need to explicitly handle it in this method.
DCHECK(false) << "Unhandled opcode " << inst->Opcode();
}
}
void Thread::SweepInterpreterCache(IsMarkedVisitor* visitor) {
for (InterpreterCache::Entry& entry : GetInterpreterCache()->GetArray()) {
SweepCacheEntry(visitor, reinterpret_cast<const Instruction*>(entry.first), &entry.second);
}
}
// FIXME: clang-r433403 reports the below function exceeds frame size limit.
// http://b/197647048
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wframe-larger-than="
void Thread::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) {
if ((flags & VisitRootFlags::kVisitRootFlagPrecise) != 0) {
VisitRoots</* kPrecise= */ true>(visitor);
} else {
VisitRoots</* kPrecise= */ false>(visitor);
}
}
#pragma GCC diagnostic pop
class VerifyRootVisitor : public SingleRootVisitor {
public:
void VisitRoot(mirror::Object* root, [[maybe_unused]] const RootInfo& info) override
REQUIRES_SHARED(Locks::mutator_lock_) {
VerifyObject(root);
}
};
void Thread::VerifyStackImpl() {
if (Runtime::Current()->GetHeap()->IsObjectValidationEnabled()) {
VerifyRootVisitor visitor;
std::unique_ptr<Context> context(Context::Create());
RootCallbackVisitor visitor_to_callback(&visitor, GetThreadId());
ReferenceMapVisitor<RootCallbackVisitor> mapper(this, context.get(), visitor_to_callback);
mapper.WalkStack();
}
}
// Set the stack end to that to be used during a stack overflow
void Thread::SetStackEndForStackOverflow() {
// During stack overflow we allow use of the full stack.
if (tlsPtr_.stack_end == tlsPtr_.stack_begin) {
// However, we seem to have already extended to use the full stack.
LOG(ERROR) << "Need to increase kStackOverflowReservedBytes (currently "
<< GetStackOverflowReservedBytes(kRuntimeISA) << ")?";
DumpStack(LOG_STREAM(ERROR));
LOG(FATAL) << "Recursive stack overflow.";
}
tlsPtr_.stack_end = tlsPtr_.stack_begin;
// Remove the stack overflow protection if is it set up.
bool implicit_stack_check = Runtime::Current()->GetImplicitStackOverflowChecks();
if (implicit_stack_check) {
if (!UnprotectStack()) {
LOG(ERROR) << "Unable to remove stack protection for stack overflow";
}
}
}
void Thread::SetTlab(uint8_t* start, uint8_t* end, uint8_t* limit) {
DCHECK_LE(start, end);
DCHECK_LE(end, limit);
tlsPtr_.thread_local_start = start;
tlsPtr_.thread_local_pos = tlsPtr_.thread_local_start;
tlsPtr_.thread_local_end = end;
tlsPtr_.thread_local_limit = limit;
tlsPtr_.thread_local_objects = 0;
}
void Thread::ResetTlab() {
gc::Heap* const heap = Runtime::Current()->GetHeap();
if (heap->GetHeapSampler().IsEnabled()) {
// Note: We always ResetTlab before SetTlab, therefore we can do the sample
// offset adjustment here.
heap->AdjustSampleOffset(GetTlabPosOffset());
VLOG(heap) << "JHP: ResetTlab, Tid: " << GetTid()
<< " adjustment = "
<< (tlsPtr_.thread_local_pos - tlsPtr_.thread_local_start);
}
SetTlab(nullptr, nullptr, nullptr);
}
bool Thread::HasTlab() const {
const bool has_tlab = tlsPtr_.thread_local_pos != nullptr;
if (has_tlab) {
DCHECK(tlsPtr_.thread_local_start != nullptr && tlsPtr_.thread_local_end != nullptr);
} else {
DCHECK(tlsPtr_.thread_local_start == nullptr && tlsPtr_.thread_local_end == nullptr);
}
return has_tlab;
}
void Thread::AdjustTlab(size_t slide_bytes) {
if (HasTlab()) {
tlsPtr_.thread_local_start -= slide_bytes;
tlsPtr_.thread_local_pos -= slide_bytes;
tlsPtr_.thread_local_end -= slide_bytes;
tlsPtr_.thread_local_limit -= slide_bytes;
}
}
std::ostream& operator<<(std::ostream& os, const Thread& thread) {
thread.ShortDump(os);
return os;
}
bool Thread::ProtectStack(bool fatal_on_error) {
void* pregion = tlsPtr_.stack_begin - GetStackOverflowProtectedSize();
VLOG(threads) << "Protecting stack at " << pregion;
if (mprotect(pregion, GetStackOverflowProtectedSize(), PROT_NONE) == -1) {
if (fatal_on_error) {
// b/249586057, LOG(FATAL) times out
LOG(ERROR) << "Unable to create protected region in stack for implicit overflow check. "
"Reason: "
<< strerror(errno) << " size: " << GetStackOverflowProtectedSize();
exit(1);
}
return false;
}
return true;
}
bool Thread::UnprotectStack() {
void* pregion = tlsPtr_.stack_begin - GetStackOverflowProtectedSize();
VLOG(threads) << "Unprotecting stack at " << pregion;
return mprotect(pregion, GetStackOverflowProtectedSize(), PROT_READ|PROT_WRITE) == 0;
}
size_t Thread::NumberOfHeldMutexes() const {
size_t count = 0;
for (BaseMutex* mu : tlsPtr_.held_mutexes) {
count += mu != nullptr ? 1 : 0;
}
return count;
}
void Thread::DeoptimizeWithDeoptimizationException(JValue* result) {
DCHECK_EQ(GetException(), Thread::GetDeoptimizationException());
ClearException();
ObjPtr<mirror::Throwable> pending_exception;
bool from_code = false;
DeoptimizationMethodType method_type;
PopDeoptimizationContext(result, &pending_exception, &from_code, &method_type);
SetTopOfStack(nullptr);
// Restore the exception that was pending before deoptimization then interpret the
// deoptimized frames.
if (pending_exception != nullptr) {
SetException(pending_exception);
}
ShadowFrame* shadow_frame = MaybePopDeoptimizedStackedShadowFrame();
// We may not have a shadow frame if we deoptimized at the return of the
// quick_to_interpreter_bridge which got directly called by art_quick_invoke_stub.
if (shadow_frame != nullptr) {
SetTopOfShadowStack(shadow_frame);
interpreter::EnterInterpreterFromDeoptimize(this,
shadow_frame,
result,
from_code,
method_type);
}
}
void Thread::SetAsyncException(ObjPtr<mirror::Throwable> new_exception) {
CHECK(new_exception != nullptr);
Runtime::Current()->SetAsyncExceptionsThrown();
if (kIsDebugBuild) {
// Make sure we are in a checkpoint.
MutexLock mu(Thread::Current(), *Locks::thread_suspend_count_lock_);
CHECK(this == Thread::Current() || GetSuspendCount() >= 1)
<< "It doesn't look like this was called in a checkpoint! this: "
<< this << " count: " << GetSuspendCount();
}
tlsPtr_.async_exception = new_exception.Ptr();
}
bool Thread::ObserveAsyncException() {
DCHECK(this == Thread::Current());
if (tlsPtr_.async_exception != nullptr) {
if (tlsPtr_.exception != nullptr) {
LOG(WARNING) << "Overwriting pending exception with async exception. Pending exception is: "
<< tlsPtr_.exception->Dump();
LOG(WARNING) << "Async exception is " << tlsPtr_.async_exception->Dump();
}
tlsPtr_.exception = tlsPtr_.async_exception;
tlsPtr_.async_exception = nullptr;
return true;
} else {
return IsExceptionPending();
}
}
void Thread::SetException(ObjPtr<mirror::Throwable> new_exception) {
CHECK(new_exception != nullptr);
// TODO: DCHECK(!IsExceptionPending());
tlsPtr_.exception = new_exception.Ptr();
}
bool Thread::IsAotCompiler() {
return Runtime::Current()->IsAotCompiler();
}
mirror::Object* Thread::GetPeerFromOtherThread() {
Thread* self = Thread::Current();
if (this == self) {
// We often call this on every thread, including ourselves.
return GetPeer();
}
// If "this" thread is not suspended, it could disappear.
DCHECK(IsSuspended()) << *this;
DCHECK(tlsPtr_.jpeer == nullptr);
// Some JVMTI code may unfortunately hold thread_list_lock_, but if it does, it should hold the
// mutator lock in exclusive mode, and we should not have a pending flip function.
if (kIsDebugBuild && Locks::thread_list_lock_->IsExclusiveHeld(self)) {
Locks::mutator_lock_->AssertExclusiveHeld(self);
CHECK(!ReadFlag(ThreadFlag::kPendingFlipFunction));
}
// Ensure that opeer is not obsolete.
EnsureFlipFunctionStarted(self, this);
if (ReadFlag(ThreadFlag::kRunningFlipFunction)) {
// Does not release mutator lock. Hence no new flip requests can be issued.
WaitForFlipFunction(self);
}
return tlsPtr_.opeer;
}
mirror::Object* Thread::LockedGetPeerFromOtherThread(ThreadExitFlag* tef) {
DCHECK(tlsPtr_.jpeer == nullptr);
Thread* self = Thread::Current();
Locks::thread_list_lock_->AssertHeld(self);
if (ReadFlag(ThreadFlag::kPendingFlipFunction)) {
// It is unsafe to call EnsureFlipFunctionStarted with thread_list_lock_. Thus we temporarily
// release it, taking care to handle the case in which "this" thread disapppears while we no
// longer hold it.
Locks::thread_list_lock_->Unlock(self);
EnsureFlipFunctionStarted(self, this, StateAndFlags(0), tef);
Locks::thread_list_lock_->Lock(self);
if (tef->HasExited()) {
return nullptr;
}
}
if (ReadFlag(ThreadFlag::kRunningFlipFunction)) {
// Does not release mutator lock. Hence no new flip requests can be issued.
WaitForFlipFunction(self);
}
return tlsPtr_.opeer;
}
void Thread::SetReadBarrierEntrypoints() {
// Make sure entrypoints aren't null.
UpdateReadBarrierEntrypoints(&tlsPtr_.quick_entrypoints, /* is_active=*/ true);
}
void Thread::ClearAllInterpreterCaches() {
static struct ClearInterpreterCacheClosure : Closure {
void Run(Thread* thread) override {
thread->GetInterpreterCache()->Clear(thread);
}
} closure;
Runtime::Current()->GetThreadList()->RunCheckpoint(&closure);
}
void Thread::ReleaseLongJumpContextInternal() {
// Each QuickExceptionHandler gets a long jump context and uses
// it for doing the long jump, after finding catch blocks/doing deoptimization.
// Both finding catch blocks and deoptimization can trigger another
// exception such as a result of class loading. So there can be nested
// cases of exception handling and multiple contexts being used.
// ReleaseLongJumpContext tries to save the context in tlsPtr_.long_jump_context
// for reuse so there is no need to always allocate a new one each time when
// getting a context. Since we only keep one context for reuse, delete the
// existing one since the passed in context is yet to be used for longjump.
delete tlsPtr_.long_jump_context;
}
void Thread::SetNativePriority(int new_priority) {
palette_status_t status = PaletteSchedSetPriority(GetTid(), new_priority);
CHECK(status == PALETTE_STATUS_OK || status == PALETTE_STATUS_CHECK_ERRNO);
}
int Thread::GetNativePriority() const {
int priority = 0;
palette_status_t status = PaletteSchedGetPriority(GetTid(), &priority);
CHECK(status == PALETTE_STATUS_OK || status == PALETTE_STATUS_CHECK_ERRNO);
return priority;
}
void Thread::AbortInThis(std::string message) {
std::string thread_name;
Thread::Current()->GetThreadName(thread_name);
LOG(ERROR) << message;
LOG(ERROR) << "Aborting culprit thread";
Runtime::Current()->SetAbortMessage(("Caused " + thread_name + " failure : " + message).c_str());
// Unlike Runtime::Abort() we do not fflush(nullptr), since we want to send the signal with as
// little delay as possible.
int res = pthread_kill(tlsPtr_.pthread_self, SIGABRT);
if (res != 0) {
LOG(ERROR) << "pthread_kill failed with " << res << " " << strerror(res) << " target was "
<< tls32_.tid;
} else {
// Wait for our process to be aborted.
sleep(10 /* seconds */);
}
// The process should have died long before we got here. Never return.
LOG(FATAL) << "Failed to abort in culprit thread: " << message;
UNREACHABLE();
}
bool Thread::IsSystemDaemon() const {
if (GetPeer() == nullptr) {
return false;
}
return WellKnownClasses::java_lang_Thread_systemDaemon->GetBoolean(GetPeer());
}
std::string Thread::StateAndFlagsAsHexString() const {
std::stringstream result_stream;
result_stream << std::hex << GetStateAndFlags(std::memory_order_relaxed).GetValue();
return result_stream.str();
}
ScopedExceptionStorage::ScopedExceptionStorage(art::Thread* self)
: self_(self), hs_(self_), excp_(hs_.NewHandle<art::mirror::Throwable>(self_->GetException())) {
self_->ClearException();
}
void ScopedExceptionStorage::SuppressOldException(const char* message) {
CHECK(self_->IsExceptionPending()) << *self_;
ObjPtr<mirror::Throwable> old_suppressed(excp_.Get());
excp_.Assign(self_->GetException());
if (old_suppressed != nullptr) {
LOG(WARNING) << message << "Suppressing old exception: " << old_suppressed->Dump();
}
self_->ClearException();
}
ScopedExceptionStorage::~ScopedExceptionStorage() {
CHECK(!self_->IsExceptionPending()) << *self_;
if (!excp_.IsNull()) {
self_->SetException(excp_.Get());
}
}
} // namespace art
#pragma clang diagnostic pop // -Wconversion