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LeafOS / LeafOS-Project / android_art / c09e656f28e0787afd404ef03ba92b73d4117434 / . / runtime / thread.h
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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.
*/
#ifndef ART_RUNTIME_THREAD_H_
#define ART_RUNTIME_THREAD_H_
#include <atomic>
#include <bitset>
#include <deque>
#include <iosfwd>
#include <list>
#include <memory>
#include <string>
#include "base/atomic.h"
#include "base/bit_field.h"
#include "base/bit_utils.h"
#include "base/enums.h"
#include "base/locks.h"
#include "base/macros.h"
#include "base/safe_map.h"
#include "base/value_object.h"
#include "entrypoints/jni/jni_entrypoints.h"
#include "entrypoints/quick/quick_entrypoints.h"
#include "handle.h"
#include "handle_scope.h"
#include "interpreter/interpreter_cache.h"
#include "interpreter/shadow_frame.h"
#include "javaheapprof/javaheapsampler.h"
#include "jvalue.h"
#include "managed_stack.h"
#include "offsets.h"
#include "read_barrier_config.h"
#include "reflective_handle_scope.h"
#include "runtime_globals.h"
#include "runtime_stats.h"
#include "thread_state.h"
namespace unwindstack {
class AndroidLocalUnwinder;
} // namespace unwindstack
namespace art {
namespace gc {
namespace accounting {
template<class T> class AtomicStack;
} // namespace accounting
namespace collector {
class SemiSpace;
} // namespace collector
} // namespace gc
namespace instrumentation {
struct InstrumentationStackFrame;
} // namespace instrumentation
namespace mirror {
class Array;
class Class;
class ClassLoader;
class Object;
template<class T> class ObjectArray;
template<class T> class PrimitiveArray;
using IntArray = PrimitiveArray<int32_t>;
class StackTraceElement;
class String;
class Throwable;
} // namespace mirror
namespace verifier {
class MethodVerifier;
class VerifierDeps;
} // namespace verifier
class ArtMethod;
class BaseMutex;
class ClassLinker;
class Closure;
class Context;
class DeoptimizationContextRecord;
class DexFile;
class FrameIdToShadowFrame;
class IsMarkedVisitor;
class JavaVMExt;
class JNIEnvExt;
class Monitor;
class RootVisitor;
class ScopedObjectAccessAlreadyRunnable;
class ShadowFrame;
class StackedShadowFrameRecord;
enum class SuspendReason : char;
class Thread;
class ThreadList;
enum VisitRootFlags : uint8_t;
// A piece of data that can be held in the CustomTls. The destructor will be called during thread
// shutdown. The thread the destructor is called on is not necessarily the same thread it was stored
// on.
class TLSData {
public:
virtual ~TLSData() {}
};
// Thread priorities. These must match the Thread.MIN_PRIORITY,
// Thread.NORM_PRIORITY, and Thread.MAX_PRIORITY constants.
enum ThreadPriority {
kMinThreadPriority = 1,
kNormThreadPriority = 5,
kMaxThreadPriority = 10,
};
enum class ThreadFlag : uint32_t {
// If set, implies that suspend_count_ > 0 and the Thread should enter the safepoint handler.
kSuspendRequest = 1u << 0,
// Request that the thread do some checkpoint work and then continue.
kCheckpointRequest = 1u << 1,
// Request that the thread do empty checkpoint and then continue.
kEmptyCheckpointRequest = 1u << 2,
// Register that at least 1 suspend barrier needs to be passed.
kActiveSuspendBarrier = 1u << 3,
// Marks that a "flip function" needs to be executed on this thread.
kPendingFlipFunction = 1u << 4,
// Marks that the "flip function" is being executed by another thread.
//
// This is used to guards against multiple threads trying to run the
// "flip function" for the same thread while the thread is suspended.
//
// This is not needed when the thread is running the flip function
// on its own after transitioning to Runnable.
kRunningFlipFunction = 1u << 5,
// Marks that a thread is wating for "flip function" to complete.
//
// This is used to check if we need to broadcast the completion of the
// "flip function" to other threads. See also `kRunningFlipFunction`.
kWaitingForFlipFunction = 1u << 6,
// Request that compiled JNI stubs do not transition to Native or Runnable with
// inlined code, but take a slow path for monitoring method entry and exit events.
kMonitorJniEntryExit = 1u << 7,
// Indicates the last flag. Used for checking that the flags do not overlap thread state.
kLastFlag = kMonitorJniEntryExit
};
enum class StackedShadowFrameType {
kShadowFrameUnderConstruction,
kDeoptimizationShadowFrame,
};
// The type of method that triggers deoptimization. It contains info on whether
// the deoptimized method should advance dex_pc.
enum class DeoptimizationMethodType {
kKeepDexPc, // dex pc is required to be kept upon deoptimization.
kDefault // dex pc may or may not advance depending on other conditions.
};
// For the CC colector, normal weak reference access can be disabled on a per-thread basis, while
// processing references. After finishing, the reference processor asynchronously sets the
// per-thread flags back to kEnabled with release memory ordering semantics. Each mutator thread
// should check its flag with acquire semantics before assuming that it is enabled. However,
// that is often too expensive, so the reading thread sets it to kVisiblyEnabled after seeing it
// kEnabled. The Reference.get() intrinsic can thus read it in relaxed mode, and reread (by
// resorting to the slow path) with acquire semantics if it sees a value of kEnabled rather than
// kVisiblyEnabled.
enum class WeakRefAccessState : int32_t {
kVisiblyEnabled = 0, // Enabled, and previously read with acquire load by this thread.
kEnabled,
kDisabled
};
// This should match RosAlloc::kNumThreadLocalSizeBrackets.
static constexpr size_t kNumRosAllocThreadLocalSizeBracketsInThread = 16;
static constexpr size_t kSharedMethodHotnessThreshold = 0x1fff;
// Thread's stack layout for implicit stack overflow checks:
//
// +---------------------+ <- highest address of stack memory
// | |
// . . <- SP
// | |
// | |
// +---------------------+ <- stack_end
// | |
// | Gap |
// | |
// +---------------------+ <- stack_begin
// | |
// | Protected region |
// | |
// +---------------------+ <- lowest address of stack memory
//
// The stack always grows down in memory. At the lowest address is a region of memory
// that is set mprotect(PROT_NONE). Any attempt to read/write to this region will
// result in a segmentation fault signal. At any point, the thread's SP will be somewhere
// between the stack_end and the highest address in stack memory. An implicit stack
// overflow check is a read of memory at a certain offset below the current SP (4K typically).
// If the thread's SP is below the stack_end address this will be a read into the protected
// region. If the SP is above the stack_end address, the thread is guaranteed to have
// at least 4K of space. Because stack overflow checks are only performed in generated code,
// if the thread makes a call out to a native function (through JNI), that native function
// might only have 4K of memory (if the SP is adjacent to stack_end).
class Thread {
public:
static const size_t kStackOverflowImplicitCheckSize;
static constexpr bool kVerifyStack = kIsDebugBuild;
// Creates a new native thread corresponding to the given managed peer.
// Used to implement Thread.start.
static void CreateNativeThread(JNIEnv* env, jobject peer, size_t stack_size, bool daemon);
// Attaches the calling native thread to the runtime, returning the new native peer.
// Used to implement JNI AttachCurrentThread and AttachCurrentThreadAsDaemon calls.
static Thread* Attach(const char* thread_name,
bool as_daemon,
jobject thread_group,
bool create_peer,
bool should_run_callbacks);
// Attaches the calling native thread to the runtime, returning the new native peer.
static Thread* Attach(const char* thread_name, bool as_daemon, jobject thread_peer);
// Reset internal state of child thread after fork.
void InitAfterFork();
// Get the currently executing thread, frequently referred to as 'self'. This call has reasonably
// high cost and so we favor passing self around when possible.
// TODO: mark as PURE so the compiler may coalesce and remove?
static Thread* Current();
// On a runnable thread, check for pending thread suspension request and handle if pending.
void AllowThreadSuspension() REQUIRES_SHARED(Locks::mutator_lock_);
// Process pending thread suspension request and handle if pending.
void CheckSuspend(bool implicit = false) REQUIRES_SHARED(Locks::mutator_lock_);
// Process a pending empty checkpoint if pending.
void CheckEmptyCheckpointFromWeakRefAccess(BaseMutex* cond_var_mutex);
void CheckEmptyCheckpointFromMutex();
static Thread* FromManagedThread(const ScopedObjectAccessAlreadyRunnable& ts,
ObjPtr<mirror::Object> thread_peer)
REQUIRES(Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_)
REQUIRES_SHARED(Locks::mutator_lock_);
static Thread* FromManagedThread(const ScopedObjectAccessAlreadyRunnable& ts, jobject thread)
REQUIRES(Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_)
REQUIRES_SHARED(Locks::mutator_lock_);
// Translates 172 to pAllocArrayFromCode and so on.
template<PointerSize size_of_pointers>
static void DumpThreadOffset(std::ostream& os, uint32_t offset);
// Dumps a one-line summary of thread state (used for operator<<).
void ShortDump(std::ostream& os) const;
// Order of threads for ANRs (ANRs can be trimmed, so we print important ones first).
enum class DumpOrder : uint8_t {
kMain, // Always print the main thread first (there might not be one).
kBlocked, // Then print all threads that are blocked due to waiting on lock.
kLocked, // Then print all threads that are holding some lock already.
kDefault, // Print all other threads which might not be interesting for ANR.
};
// Dumps the detailed thread state and the thread stack (used for SIGQUIT).
DumpOrder Dump(std::ostream& os,
bool dump_native_stack = true,
bool force_dump_stack = false) const
REQUIRES_SHARED(Locks::mutator_lock_);
DumpOrder Dump(std::ostream& os,
unwindstack::AndroidLocalUnwinder& unwinder,
bool dump_native_stack = true,
bool force_dump_stack = false) const
REQUIRES_SHARED(Locks::mutator_lock_);
DumpOrder DumpJavaStack(std::ostream& os,
bool check_suspended = true,
bool dump_locks = true) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Dumps the SIGQUIT per-thread header. 'thread' can be null for a non-attached thread, in which
// case we use 'tid' to identify the thread, and we'll include as much information as we can.
static void DumpState(std::ostream& os, const Thread* thread, pid_t tid)
REQUIRES_SHARED(Locks::mutator_lock_);
ThreadState GetState() const {
return GetStateAndFlags(std::memory_order_relaxed).GetState();
}
ThreadState SetState(ThreadState new_state);
int GetSuspendCount() const REQUIRES(Locks::thread_suspend_count_lock_) {
return tls32_.suspend_count;
}
int GetUserCodeSuspendCount() const REQUIRES(Locks::thread_suspend_count_lock_,
Locks::user_code_suspension_lock_) {
return tls32_.user_code_suspend_count;
}
bool IsSuspended() const {
StateAndFlags state_and_flags = GetStateAndFlags(std::memory_order_relaxed);
return state_and_flags.GetState() != ThreadState::kRunnable &&
state_and_flags.IsFlagSet(ThreadFlag::kSuspendRequest);
}
void DecrDefineClassCount() {
tls32_.define_class_counter--;
}
void IncrDefineClassCount() {
tls32_.define_class_counter++;
}
uint32_t GetDefineClassCount() const {
return tls32_.define_class_counter;
}
// If delta > 0 and (this != self or suspend_barrier is not null), this function may temporarily
// release thread_suspend_count_lock_ internally.
ALWAYS_INLINE
bool ModifySuspendCount(Thread* self,
int delta,
AtomicInteger* suspend_barrier,
SuspendReason reason)
WARN_UNUSED
REQUIRES(Locks::thread_suspend_count_lock_);
// Requests a checkpoint closure to run on another thread. The closure will be run when the
// thread notices the request, either in an explicit runtime CheckSuspend() call, or in a call
// originating from a compiler generated suspend point check. This returns true if the closure
// was added and will (eventually) be executed. It returns false otherwise.
//
// Since multiple closures can be queued and some closures can delay other threads from running,
// no closure should attempt to suspend another thread while running.
// TODO We should add some debug option that verifies this.
//
// This guarantees that the RequestCheckpoint invocation happens-before the function invocation:
// RequestCheckpointFunction holds thread_suspend_count_lock_, and RunCheckpointFunction
// acquires it.
bool RequestCheckpoint(Closure* function)
REQUIRES(Locks::thread_suspend_count_lock_);
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution. This is
// due to the fact that Thread::Current() needs to go to sleep to allow the targeted thread to
// execute the checkpoint for us if it is Runnable. The suspend_state is the state that the thread
// will go into while it is awaiting the checkpoint to be run.
// NB Passing ThreadState::kRunnable may cause the current thread to wait in a condition variable
// while holding the mutator_lock_. Callers should ensure that this will not cause any problems
// for the closure or the rest of the system.
// NB Since multiple closures can be queued and some closures can delay other threads from running
// no closure should attempt to suspend another thread while running.
bool RequestSynchronousCheckpoint(Closure* function,
ThreadState suspend_state = ThreadState::kWaiting)
REQUIRES_SHARED(Locks::mutator_lock_)
RELEASE(Locks::thread_list_lock_)
REQUIRES(!Locks::thread_suspend_count_lock_);
bool RequestEmptyCheckpoint()
REQUIRES(Locks::thread_suspend_count_lock_);
// Set the flip function. This is done with all threads suspended, except for the calling thread.
void SetFlipFunction(Closure* function);
// Ensure that thread flip function started running. If no other thread is executing
// it, the calling thread shall run the flip function and then notify other threads
// that have tried to do that concurrently. After this function returns, the
// `ThreadFlag::kPendingFlipFunction` is cleared but another thread may still
// run the flip function as indicated by the `ThreadFlag::kRunningFlipFunction`.
void EnsureFlipFunctionStarted(Thread* self) REQUIRES_SHARED(Locks::mutator_lock_);
// Wait for the flip function to complete if still running on another thread.
void WaitForFlipFunction(Thread* self) REQUIRES_SHARED(Locks::mutator_lock_);
gc::accounting::AtomicStack<mirror::Object>* GetThreadLocalMarkStack() {
CHECK(gUseReadBarrier);
return tlsPtr_.thread_local_mark_stack;
}
void SetThreadLocalMarkStack(gc::accounting::AtomicStack<mirror::Object>* stack) {
CHECK(gUseReadBarrier);
tlsPtr_.thread_local_mark_stack = stack;
}
// Called when thread detected that the thread_suspend_count_ was non-zero. Gives up share of
// mutator_lock_ and waits until it is resumed and thread_suspend_count_ is zero.
void FullSuspendCheck(bool implicit = false)
REQUIRES(!Locks::thread_suspend_count_lock_)
REQUIRES_SHARED(Locks::mutator_lock_);
// Transition from non-runnable to runnable state acquiring share on mutator_lock_.
ALWAYS_INLINE ThreadState TransitionFromSuspendedToRunnable()
REQUIRES(!Locks::thread_suspend_count_lock_)
SHARED_LOCK_FUNCTION(Locks::mutator_lock_);
// Transition from runnable into a state where mutator privileges are denied. Releases share of
// mutator lock.
ALWAYS_INLINE void TransitionFromRunnableToSuspended(ThreadState new_state)
REQUIRES(!Locks::thread_suspend_count_lock_, !Roles::uninterruptible_)
UNLOCK_FUNCTION(Locks::mutator_lock_);
// Once called thread suspension will cause an assertion failure.
const char* StartAssertNoThreadSuspension(const char* cause) ACQUIRE(Roles::uninterruptible_) {
Roles::uninterruptible_.Acquire(); // No-op.
if (kIsDebugBuild) {
CHECK(cause != nullptr);
const char* previous_cause = tlsPtr_.last_no_thread_suspension_cause;
tls32_.no_thread_suspension++;
tlsPtr_.last_no_thread_suspension_cause = cause;
return previous_cause;
} else {
return nullptr;
}
}
// End region where no thread suspension is expected.
void EndAssertNoThreadSuspension(const char* old_cause) RELEASE(Roles::uninterruptible_) {
if (kIsDebugBuild) {
CHECK_IMPLIES(old_cause == nullptr, tls32_.no_thread_suspension == 1);
CHECK_GT(tls32_.no_thread_suspension, 0U);
tls32_.no_thread_suspension--;
tlsPtr_.last_no_thread_suspension_cause = old_cause;
}
Roles::uninterruptible_.Release(); // No-op.
}
// End region where no thread suspension is expected. Returns the current open region in case we
// want to reopen it. Used for ScopedAllowThreadSuspension. Not supported if no_thread_suspension
// is larger than one.
const char* EndAssertNoThreadSuspension() RELEASE(Roles::uninterruptible_) WARN_UNUSED {
const char* ret = nullptr;
if (kIsDebugBuild) {
CHECK_EQ(tls32_.no_thread_suspension, 1u);
tls32_.no_thread_suspension--;
ret = tlsPtr_.last_no_thread_suspension_cause;
tlsPtr_.last_no_thread_suspension_cause = nullptr;
}
Roles::uninterruptible_.Release(); // No-op.
return ret;
}
void AssertThreadSuspensionIsAllowable(bool check_locks = true) const;
// Return true if thread suspension is allowable.
bool IsThreadSuspensionAllowable() const;
bool IsDaemon() const {
return tls32_.daemon;
}
size_t NumberOfHeldMutexes() const;
bool HoldsLock(ObjPtr<mirror::Object> object) const REQUIRES_SHARED(Locks::mutator_lock_);
/*
* Changes the priority of this thread to match that of the java.lang.Thread object.
*
* We map a priority value from 1-10 to Linux "nice" values, where lower
* numbers indicate higher priority.
*/
void SetNativePriority(int newPriority);
/*
* Returns the priority of this thread by querying the system.
* This is useful when attaching a thread through JNI.
*
* Returns a value from 1 to 10 (compatible with java.lang.Thread values).
*/
int GetNativePriority() const;
// Guaranteed to be non-zero.
uint32_t GetThreadId() const {
return tls32_.thin_lock_thread_id;
}
pid_t GetTid() const {
return tls32_.tid;
}
// Returns the java.lang.Thread's name, or null if this Thread* doesn't have a peer.
ObjPtr<mirror::String> GetThreadName() const REQUIRES_SHARED(Locks::mutator_lock_);
// Sets 'name' to the java.lang.Thread's name. This requires no transition to managed code,
// allocation, or locking.
void GetThreadName(std::string& name) const;
// Sets the thread's name.
void SetThreadName(const char* name) REQUIRES_SHARED(Locks::mutator_lock_);
// Returns the thread-specific CPU-time clock in microseconds or -1 if unavailable.
uint64_t GetCpuMicroTime() const;
mirror::Object* GetPeer() const REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(Thread::Current() == this) << "Use GetPeerFromOtherThread instead";
CHECK(tlsPtr_.jpeer == nullptr);
return tlsPtr_.opeer;
}
// GetPeer is not safe if called on another thread in the middle of the CC thread flip and
// the thread's stack may have not been flipped yet and peer may be a from-space (stale) ref.
// This function will explicitly mark/forward it.
mirror::Object* GetPeerFromOtherThread() const REQUIRES_SHARED(Locks::mutator_lock_);
bool HasPeer() const {
return tlsPtr_.jpeer != nullptr || tlsPtr_.opeer != nullptr;
}
RuntimeStats* GetStats() {
return &tls64_.stats;
}
bool IsStillStarting() const;
bool IsExceptionPending() const {
return tlsPtr_.exception != nullptr;
}
bool IsAsyncExceptionPending() const {
return tlsPtr_.async_exception != nullptr;
}
mirror::Throwable* GetException() const REQUIRES_SHARED(Locks::mutator_lock_) {
return tlsPtr_.exception;
}
void AssertPendingException() const;
void AssertPendingOOMException() const REQUIRES_SHARED(Locks::mutator_lock_);
void AssertNoPendingException() const;
void AssertNoPendingExceptionForNewException(const char* msg) const;
void SetException(ObjPtr<mirror::Throwable> new_exception) REQUIRES_SHARED(Locks::mutator_lock_);
// Set an exception that is asynchronously thrown from a different thread. This will be checked
// periodically and might overwrite the current 'Exception'. This can only be called from a
// checkpoint.
//
// The caller should also make sure that the thread has been deoptimized so that the exception
// could be detected on back-edges.
void SetAsyncException(ObjPtr<mirror::Throwable> new_exception)
REQUIRES_SHARED(Locks::mutator_lock_);
void ClearException() REQUIRES_SHARED(Locks::mutator_lock_) {
tlsPtr_.exception = nullptr;
}
// Move the current async-exception to the main exception. This should be called when the current
// thread is ready to deal with any async exceptions. Returns true if there is an async exception
// that needs to be dealt with, false otherwise.
bool ObserveAsyncException() REQUIRES_SHARED(Locks::mutator_lock_);
// Find catch block and perform long jump to appropriate exception handle. When
// is_method_exit_exception is true, the exception was thrown by the method exit callback and we
// should not send method unwind for the method on top of the stack since method exit callback was
// already called.
NO_RETURN void QuickDeliverException(bool is_method_exit_exception = false)
REQUIRES_SHARED(Locks::mutator_lock_);
Context* GetLongJumpContext();
void ReleaseLongJumpContext(Context* context) {
if (tlsPtr_.long_jump_context != nullptr) {
ReleaseLongJumpContextInternal();
}
tlsPtr_.long_jump_context = context;
}
// Get the current method and dex pc. If there are errors in retrieving the dex pc, this will
// abort the runtime iff abort_on_error is true.
ArtMethod* GetCurrentMethod(uint32_t* dex_pc,
bool check_suspended = true,
bool abort_on_error = true) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Returns whether the given exception was thrown by the current Java method being executed
// (Note that this includes native Java methods).
bool IsExceptionThrownByCurrentMethod(ObjPtr<mirror::Throwable> exception) const
REQUIRES_SHARED(Locks::mutator_lock_);
void SetTopOfStack(ArtMethod** top_method) {
tlsPtr_.managed_stack.SetTopQuickFrame(top_method);
}
void SetTopOfStackGenericJniTagged(ArtMethod** top_method) {
tlsPtr_.managed_stack.SetTopQuickFrameGenericJniTagged(top_method);
}
void SetTopOfShadowStack(ShadowFrame* top) {
tlsPtr_.managed_stack.SetTopShadowFrame(top);
}
bool HasManagedStack() const {
return tlsPtr_.managed_stack.HasTopQuickFrame() || tlsPtr_.managed_stack.HasTopShadowFrame();
}
// If 'msg' is null, no detail message is set.
void ThrowNewException(const char* exception_class_descriptor, const char* msg)
REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
// If 'msg' is null, no detail message is set. An exception must be pending, and will be
// used as the new exception's cause.
void ThrowNewWrappedException(const char* exception_class_descriptor, const char* msg)
REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
void ThrowNewExceptionF(const char* exception_class_descriptor, const char* fmt, ...)
__attribute__((format(printf, 3, 4)))
REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
void ThrowNewExceptionV(const char* exception_class_descriptor, const char* fmt, va_list ap)
REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
// OutOfMemoryError is special, because we need to pre-allocate an instance.
// Only the GC should call this.
void ThrowOutOfMemoryError(const char* msg) REQUIRES_SHARED(Locks::mutator_lock_)
REQUIRES(!Roles::uninterruptible_);
static void Startup();
static void FinishStartup();
static void Shutdown();
// Notify this thread's thread-group that this thread has started.
// Note: the given thread-group is used as a fast path and verified in debug build. If the value
// is null, the thread's thread-group is loaded from the peer.
void NotifyThreadGroup(ScopedObjectAccessAlreadyRunnable& soa, jobject thread_group = nullptr)
REQUIRES_SHARED(Locks::mutator_lock_);
// JNI methods
JNIEnvExt* GetJniEnv() const {
return tlsPtr_.jni_env;
}
// Convert a jobject into a Object*
ObjPtr<mirror::Object> DecodeJObject(jobject obj) const REQUIRES_SHARED(Locks::mutator_lock_);
// Checks if the weak global ref has been cleared by the GC without decoding it.
bool IsJWeakCleared(jweak obj) const REQUIRES_SHARED(Locks::mutator_lock_);
mirror::Object* GetMonitorEnterObject() const REQUIRES_SHARED(Locks::mutator_lock_) {
return tlsPtr_.monitor_enter_object;
}
void SetMonitorEnterObject(mirror::Object* obj) REQUIRES_SHARED(Locks::mutator_lock_) {
tlsPtr_.monitor_enter_object = obj;
}
// Implements java.lang.Thread.interrupted.
bool Interrupted();
// Implements java.lang.Thread.isInterrupted.
bool IsInterrupted();
void Interrupt(Thread* self) REQUIRES(!wait_mutex_);
void SetInterrupted(bool i) {
tls32_.interrupted.store(i, std::memory_order_seq_cst);
}
void Notify() REQUIRES(!wait_mutex_);
ALWAYS_INLINE void PoisonObjectPointers() {
++poison_object_cookie_;
}
ALWAYS_INLINE static void PoisonObjectPointersIfDebug();
ALWAYS_INLINE uintptr_t GetPoisonObjectCookie() const {
return poison_object_cookie_;
}
// Parking for 0ns of relative time means an untimed park, negative (though
// should be handled in java code) returns immediately
void Park(bool is_absolute, int64_t time) REQUIRES_SHARED(Locks::mutator_lock_);
void Unpark();
private:
void NotifyLocked(Thread* self) REQUIRES(wait_mutex_);
public:
Mutex* GetWaitMutex() const LOCK_RETURNED(wait_mutex_) {
return wait_mutex_;
}
ConditionVariable* GetWaitConditionVariable() const REQUIRES(wait_mutex_) {
return wait_cond_;
}
Monitor* GetWaitMonitor() const REQUIRES(wait_mutex_) {
return wait_monitor_;
}
void SetWaitMonitor(Monitor* mon) REQUIRES(wait_mutex_) {
wait_monitor_ = mon;
}
// Waiter link-list support.
Thread* GetWaitNext() const {
return tlsPtr_.wait_next;
}
void SetWaitNext(Thread* next) {
tlsPtr_.wait_next = next;
}
jobject GetClassLoaderOverride() {
return tlsPtr_.class_loader_override;
}
void SetClassLoaderOverride(jobject class_loader_override);
// Create the internal representation of a stack trace, that is more time
// and space efficient to compute than the StackTraceElement[].
jobject CreateInternalStackTrace(const ScopedObjectAccessAlreadyRunnable& soa) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Convert an internal stack trace representation (returned by CreateInternalStackTrace) to a
// StackTraceElement[]. If output_array is null, a new array is created, otherwise as many
// frames as will fit are written into the given array. If stack_depth is non-null, it's updated
// with the number of valid frames in the returned array.
static jobjectArray InternalStackTraceToStackTraceElementArray(
const ScopedObjectAccessAlreadyRunnable& soa, jobject internal,
jobjectArray output_array = nullptr, int* stack_depth = nullptr)
REQUIRES_SHARED(Locks::mutator_lock_);
static jint InternalStackTraceToStackFrameInfoArray(
const ScopedObjectAccessAlreadyRunnable& soa,
jlong mode, // See java.lang.StackStreamFactory for the mode flags
jobject internal,
jint startLevel,
jint batchSize,
jint startIndex,
jobjectArray output_array) // java.lang.StackFrameInfo[]
REQUIRES_SHARED(Locks::mutator_lock_);
jobjectArray CreateAnnotatedStackTrace(const ScopedObjectAccessAlreadyRunnable& soa) const
REQUIRES_SHARED(Locks::mutator_lock_);
bool HasDebuggerShadowFrames() const {
return tlsPtr_.frame_id_to_shadow_frame != nullptr;
}
// This is done by GC using a checkpoint (or in a stop-the-world pause).
void SweepInterpreterCache(IsMarkedVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_);
void VisitRoots(RootVisitor* visitor, VisitRootFlags flags)
REQUIRES_SHARED(Locks::mutator_lock_);
void VisitReflectiveTargets(ReflectiveValueVisitor* visitor)
REQUIRES(Locks::mutator_lock_);
void VerifyStack() REQUIRES_SHARED(Locks::mutator_lock_) {
if (kVerifyStack) {
VerifyStackImpl();
}
}
//
// Offsets of various members of native Thread class, used by compiled code.
//
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThinLockIdOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, thin_lock_thread_id));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> TidOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, tid));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> InterruptedOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, interrupted));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> WeakRefAccessEnabledOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, weak_ref_access_enabled));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadFlagsOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, state_and_flags));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> IsGcMarkingOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, is_gc_marking));
}
template <PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> DeoptCheckRequiredOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, is_deopt_check_required));
}
static constexpr size_t IsGcMarkingSize() {
return sizeof(tls32_.is_gc_marking);
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> SharedMethodHotnessOffset() {
return ThreadOffset<pointer_size>(
OFFSETOF_MEMBER(Thread, tls32_) +
OFFSETOF_MEMBER(tls_32bit_sized_values, shared_method_hotness));
}
// Deoptimize the Java stack.
void DeoptimizeWithDeoptimizationException(JValue* result) REQUIRES_SHARED(Locks::mutator_lock_);
private:
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadOffsetFromTlsPtr(size_t tls_ptr_offset) {
size_t base = OFFSETOF_MEMBER(Thread, tlsPtr_);
size_t scale = (pointer_size > kRuntimePointerSize) ?
static_cast<size_t>(pointer_size) / static_cast<size_t>(kRuntimePointerSize) : 1;
size_t shrink = (kRuntimePointerSize > pointer_size) ?
static_cast<size_t>(kRuntimePointerSize) / static_cast<size_t>(pointer_size) : 1;
return ThreadOffset<pointer_size>(base + ((tls_ptr_offset * scale) / shrink));
}
public:
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> QuickEntryPointOffset(
size_t quick_entrypoint_offset) {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, quick_entrypoints) + quick_entrypoint_offset);
}
static constexpr uint32_t QuickEntryPointOffsetWithSize(size_t quick_entrypoint_offset,
PointerSize pointer_size) {
if (pointer_size == PointerSize::k32) {
return QuickEntryPointOffset<PointerSize::k32>(quick_entrypoint_offset).
Uint32Value();
} else {
return QuickEntryPointOffset<PointerSize::k64>(quick_entrypoint_offset).
Uint32Value();
}
}
template<PointerSize pointer_size>
static ThreadOffset<pointer_size> JniEntryPointOffset(size_t jni_entrypoint_offset) {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, jni_entrypoints) + jni_entrypoint_offset);
}
// Return the entry point offset integer value for ReadBarrierMarkRegX, where X is `reg`.
template <PointerSize pointer_size>
static constexpr int32_t ReadBarrierMarkEntryPointsOffset(size_t reg) {
// The entry point list defines 30 ReadBarrierMarkRegX entry points.
DCHECK_LT(reg, 30u);
// The ReadBarrierMarkRegX entry points are ordered by increasing
// register number in Thread::tls_Ptr_.quick_entrypoints.
return QUICK_ENTRYPOINT_OFFSET(pointer_size, pReadBarrierMarkReg00).Int32Value()
+ static_cast<size_t>(pointer_size) * reg;
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> SelfOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values, self));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ExceptionOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values, exception));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> PeerOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values, opeer));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> CardTableOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values, card_table));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadSuspendTriggerOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, suspend_trigger));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadLocalPosOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
thread_local_pos));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadLocalEndOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
thread_local_end));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadLocalObjectsOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
thread_local_objects));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> RosAllocRunsOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
rosalloc_runs));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadLocalAllocStackTopOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
thread_local_alloc_stack_top));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> ThreadLocalAllocStackEndOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
thread_local_alloc_stack_end));
}
// Size of stack less any space reserved for stack overflow
size_t GetStackSize() const {
return tlsPtr_.stack_size - (tlsPtr_.stack_end - tlsPtr_.stack_begin);
}
ALWAYS_INLINE uint8_t* GetStackEndForInterpreter(bool implicit_overflow_check) const;
uint8_t* GetStackEnd() const {
return tlsPtr_.stack_end;
}
// Set the stack end to that to be used during a stack overflow
void SetStackEndForStackOverflow() REQUIRES_SHARED(Locks::mutator_lock_);
// Set the stack end to that to be used during regular execution
ALWAYS_INLINE void ResetDefaultStackEnd();
bool IsHandlingStackOverflow() const {
return tlsPtr_.stack_end == tlsPtr_.stack_begin;
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> StackEndOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, stack_end));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> JniEnvOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, jni_env));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> TopOfManagedStackOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, managed_stack) +
ManagedStack::TaggedTopQuickFrameOffset());
}
const ManagedStack* GetManagedStack() const {
return &tlsPtr_.managed_stack;
}
// Linked list recording fragments of managed stack.
void PushManagedStackFragment(ManagedStack* fragment) {
tlsPtr_.managed_stack.PushManagedStackFragment(fragment);
}
void PopManagedStackFragment(const ManagedStack& fragment) {
tlsPtr_.managed_stack.PopManagedStackFragment(fragment);
}
ALWAYS_INLINE ShadowFrame* PushShadowFrame(ShadowFrame* new_top_frame);
ALWAYS_INLINE ShadowFrame* PopShadowFrame();
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> TopShadowFrameOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(
OFFSETOF_MEMBER(tls_ptr_sized_values, managed_stack) +
ManagedStack::TopShadowFrameOffset());
}
// Is the given obj in one of this thread's JNI transition frames?
bool IsJniTransitionReference(jobject obj) const REQUIRES_SHARED(Locks::mutator_lock_);
void HandleScopeVisitRoots(RootVisitor* visitor, uint32_t thread_id)
REQUIRES_SHARED(Locks::mutator_lock_);
BaseHandleScope* GetTopHandleScope() REQUIRES_SHARED(Locks::mutator_lock_) {
return tlsPtr_.top_handle_scope;
}
void PushHandleScope(BaseHandleScope* handle_scope) REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK_EQ(handle_scope->GetLink(), tlsPtr_.top_handle_scope);
tlsPtr_.top_handle_scope = handle_scope;
}
BaseHandleScope* PopHandleScope() REQUIRES_SHARED(Locks::mutator_lock_) {
BaseHandleScope* handle_scope = tlsPtr_.top_handle_scope;
DCHECK(handle_scope != nullptr);
tlsPtr_.top_handle_scope = tlsPtr_.top_handle_scope->GetLink();
return handle_scope;
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> TopHandleScopeOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
top_handle_scope));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> MutatorLockOffset() {
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
mutator_lock));
}
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> HeldMutexOffset(LockLevel level) {
DCHECK_LT(enum_cast<size_t>(level), arraysize(tlsPtr_.held_mutexes));
return ThreadOffsetFromTlsPtr<pointer_size>(OFFSETOF_MEMBER(tls_ptr_sized_values,
held_mutexes[level]));
}
BaseReflectiveHandleScope* GetTopReflectiveHandleScope() {
return tlsPtr_.top_reflective_handle_scope;
}
void PushReflectiveHandleScope(BaseReflectiveHandleScope* scope) {
DCHECK_EQ(scope->GetLink(), tlsPtr_.top_reflective_handle_scope);
DCHECK_EQ(scope->GetThread(), this);
tlsPtr_.top_reflective_handle_scope = scope;
}
BaseReflectiveHandleScope* PopReflectiveHandleScope() {
BaseReflectiveHandleScope* handle_scope = tlsPtr_.top_reflective_handle_scope;
DCHECK(handle_scope != nullptr);
tlsPtr_.top_reflective_handle_scope = tlsPtr_.top_reflective_handle_scope->GetLink();
return handle_scope;
}
bool GetIsGcMarking() const {
CHECK(gUseReadBarrier);
return tls32_.is_gc_marking;
}
void SetIsGcMarkingAndUpdateEntrypoints(bool is_marking);
bool IsDeoptCheckRequired() const { return tls32_.is_deopt_check_required; }
void SetDeoptCheckRequired(bool flag) { tls32_.is_deopt_check_required = flag; }
bool GetWeakRefAccessEnabled() const; // Only safe for current thread.
void SetWeakRefAccessEnabled(bool enabled) {
DCHECK(gUseReadBarrier);
WeakRefAccessState new_state = enabled ?
WeakRefAccessState::kEnabled : WeakRefAccessState::kDisabled;
tls32_.weak_ref_access_enabled.store(new_state, std::memory_order_release);
}
uint32_t GetDisableThreadFlipCount() const {
return tls32_.disable_thread_flip_count;
}
void IncrementDisableThreadFlipCount() {
++tls32_.disable_thread_flip_count;
}
void DecrementDisableThreadFlipCount() {
DCHECK_GT(tls32_.disable_thread_flip_count, 0U);
--tls32_.disable_thread_flip_count;
}
// Returns true if the thread is a runtime thread (eg from a ThreadPool).
bool IsRuntimeThread() const {
return is_runtime_thread_;
}
void SetIsRuntimeThread(bool is_runtime_thread) {
is_runtime_thread_ = is_runtime_thread;
}
uint32_t CorePlatformApiCookie() {
return core_platform_api_cookie_;
}
void SetCorePlatformApiCookie(uint32_t cookie) {
core_platform_api_cookie_ = cookie;
}
// Returns true if the thread is allowed to load java classes.
bool CanLoadClasses() const;
// Returns the fake exception used to activate deoptimization.
static mirror::Throwable* GetDeoptimizationException() {
// Note that the mirror::Throwable must be aligned to kObjectAlignment or else it cannot be
// represented by ObjPtr.
return reinterpret_cast<mirror::Throwable*>(0x100);
}
// Currently deoptimization invokes verifier which can trigger class loading
// and execute Java code, so there might be nested deoptimizations happening.
// We need to save the ongoing deoptimization shadow frames and return
// values on stacks.
// 'from_code' denotes whether the deoptimization was explicitly made from
// compiled code.
// 'method_type' contains info on whether deoptimization should advance
// dex_pc.
void PushDeoptimizationContext(const JValue& return_value,
bool is_reference,
ObjPtr<mirror::Throwable> exception,
bool from_code,
DeoptimizationMethodType method_type)
REQUIRES_SHARED(Locks::mutator_lock_);
void PopDeoptimizationContext(JValue* result,
ObjPtr<mirror::Throwable>* exception,
bool* from_code,
DeoptimizationMethodType* method_type)
REQUIRES_SHARED(Locks::mutator_lock_);
void AssertHasDeoptimizationContext()
REQUIRES_SHARED(Locks::mutator_lock_);
void PushStackedShadowFrame(ShadowFrame* sf, StackedShadowFrameType type);
ShadowFrame* PopStackedShadowFrame();
ShadowFrame* MaybePopDeoptimizedStackedShadowFrame();
// For debugger, find the shadow frame that corresponds to a frame id.
// Or return null if there is none.
ShadowFrame* FindDebuggerShadowFrame(size_t frame_id)
REQUIRES_SHARED(Locks::mutator_lock_);
// For debugger, find the bool array that keeps track of the updated vreg set
// for a frame id.
bool* GetUpdatedVRegFlags(size_t frame_id) REQUIRES_SHARED(Locks::mutator_lock_);
// For debugger, find the shadow frame that corresponds to a frame id. If
// one doesn't exist yet, create one and track it in frame_id_to_shadow_frame.
ShadowFrame* FindOrCreateDebuggerShadowFrame(size_t frame_id,
uint32_t num_vregs,
ArtMethod* method,
uint32_t dex_pc)
REQUIRES_SHARED(Locks::mutator_lock_);
// Delete the entry that maps from frame_id to shadow_frame.
void RemoveDebuggerShadowFrameMapping(size_t frame_id)
REQUIRES_SHARED(Locks::mutator_lock_);
// While getting this map requires shared the mutator lock, manipulating it
// should actually follow these rules:
// (1) The owner of this map (the thread) can change it with its mutator lock.
// (2) Other threads can read this map when the owner is suspended and they
// hold the mutator lock.
// (3) Other threads can change this map when owning the mutator lock exclusively.
//
// The reason why (3) needs the mutator lock exclusively (and not just having
// the owner suspended) is that we don't want other threads to concurrently read the map.
//
// TODO: Add a class abstraction to express these rules.
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* GetInstrumentationStack()
REQUIRES_SHARED(Locks::mutator_lock_) {
return tlsPtr_.instrumentation_stack;
}
std::vector<ArtMethod*>* GetStackTraceSample() const {
DCHECK(!IsAotCompiler());
return tlsPtr_.deps_or_stack_trace_sample.stack_trace_sample;
}
void SetStackTraceSample(std::vector<ArtMethod*>* sample) {
DCHECK(!IsAotCompiler());
tlsPtr_.deps_or_stack_trace_sample.stack_trace_sample = sample;
}
verifier::VerifierDeps* GetVerifierDeps() const {
DCHECK(IsAotCompiler());
return tlsPtr_.deps_or_stack_trace_sample.verifier_deps;
}
// It is the responsability of the caller to make sure the verifier_deps
// entry in the thread is cleared before destruction of the actual VerifierDeps
// object, or the thread.
void SetVerifierDeps(verifier::VerifierDeps* verifier_deps) {
DCHECK(IsAotCompiler());
DCHECK(verifier_deps == nullptr || tlsPtr_.deps_or_stack_trace_sample.verifier_deps == nullptr);
tlsPtr_.deps_or_stack_trace_sample.verifier_deps = verifier_deps;
}
uint64_t GetTraceClockBase() const {
return tls64_.trace_clock_base;
}
void SetTraceClockBase(uint64_t clock_base) {
tls64_.trace_clock_base = clock_base;
}
BaseMutex* GetHeldMutex(LockLevel level) const {
return tlsPtr_.held_mutexes[level];
}
void SetHeldMutex(LockLevel level, BaseMutex* mutex) {
tlsPtr_.held_mutexes[level] = mutex;
}
void ClearSuspendBarrier(AtomicInteger* target)
REQUIRES(Locks::thread_suspend_count_lock_);
bool ReadFlag(ThreadFlag flag) const {
return GetStateAndFlags(std::memory_order_relaxed).IsFlagSet(flag);
}
void AtomicSetFlag(ThreadFlag flag, std::memory_order order = std::memory_order_seq_cst) {
tls32_.state_and_flags.fetch_or(enum_cast<uint32_t>(flag), order);
}
void AtomicClearFlag(ThreadFlag flag, std::memory_order order = std::memory_order_seq_cst) {
tls32_.state_and_flags.fetch_and(~enum_cast<uint32_t>(flag), order);
}
void ResetQuickAllocEntryPointsForThread();
// Returns the remaining space in the TLAB.
size_t TlabSize() const {
return tlsPtr_.thread_local_end - tlsPtr_.thread_local_pos;
}
// Returns pos offset from start.
size_t GetTlabPosOffset() const {
return tlsPtr_.thread_local_pos - tlsPtr_.thread_local_start;
}
// Returns the remaining space in the TLAB if we were to expand it to maximum capacity.
size_t TlabRemainingCapacity() const {
return tlsPtr_.thread_local_limit - tlsPtr_.thread_local_pos;
}
// Expand the TLAB by a fixed number of bytes. There must be enough capacity to do so.
void ExpandTlab(size_t bytes) {
tlsPtr_.thread_local_end += bytes;
DCHECK_LE(tlsPtr_.thread_local_end, tlsPtr_.thread_local_limit);
}
// Called from Concurrent mark-compact GC to slide the TLAB pointers backwards
// to adjust to post-compact addresses.
void AdjustTlab(size_t slide_bytes);
// Doesn't check that there is room.
mirror::Object* AllocTlab(size_t bytes);
void SetTlab(uint8_t* start, uint8_t* end, uint8_t* limit);
bool HasTlab() const;
void ResetTlab();
uint8_t* GetTlabStart() {
return tlsPtr_.thread_local_start;
}
uint8_t* GetTlabPos() {
return tlsPtr_.thread_local_pos;
}
uint8_t* GetTlabEnd() {
return tlsPtr_.thread_local_end;
}
// Remove the suspend trigger for this thread by making the suspend_trigger_ TLS value
// equal to a valid pointer.
// TODO: does this need to atomic? I don't think so.
void RemoveSuspendTrigger() {
tlsPtr_.suspend_trigger = reinterpret_cast<uintptr_t*>(&tlsPtr_.suspend_trigger);
}
// Trigger a suspend check by making the suspend_trigger_ TLS value an invalid pointer.
// The next time a suspend check is done, it will load from the value at this address
// and trigger a SIGSEGV.
// Only needed if Runtime::implicit_suspend_checks_ is true and fully implemented. It currently
// is always false. Client code currently just looks at the thread flags directly to determine
// whether we should suspend, so this call is currently unnecessary.
void TriggerSuspend() {
tlsPtr_.suspend_trigger = nullptr;
}
// Push an object onto the allocation stack.
bool PushOnThreadLocalAllocationStack(mirror::Object* obj)
REQUIRES_SHARED(Locks::mutator_lock_);
// Set the thread local allocation pointers to the given pointers.
void SetThreadLocalAllocationStack(StackReference<mirror::Object>* start,
StackReference<mirror::Object>* end);
// Resets the thread local allocation pointers.
void RevokeThreadLocalAllocationStack();
size_t GetThreadLocalBytesAllocated() const {
return tlsPtr_.thread_local_end - tlsPtr_.thread_local_start;
}
size_t GetThreadLocalObjectsAllocated() const {
return tlsPtr_.thread_local_objects;
}
void* GetRosAllocRun(size_t index) const {
return tlsPtr_.rosalloc_runs[index];
}
void SetRosAllocRun(size_t index, void* run) {
tlsPtr_.rosalloc_runs[index] = run;
}
bool ProtectStack(bool fatal_on_error = true);
bool UnprotectStack();
bool IsTransitioningToRunnable() const {
return tls32_.is_transitioning_to_runnable;
}
void SetIsTransitioningToRunnable(bool value) {
tls32_.is_transitioning_to_runnable = value;
}
uint32_t DecrementForceInterpreterCount() REQUIRES(Locks::thread_list_lock_) {
return --tls32_.force_interpreter_count;
}
uint32_t IncrementForceInterpreterCount() REQUIRES(Locks::thread_list_lock_) {
return ++tls32_.force_interpreter_count;
}
void SetForceInterpreterCount(uint32_t value) REQUIRES(Locks::thread_list_lock_) {
tls32_.force_interpreter_count = value;
}
uint32_t ForceInterpreterCount() const {
return tls32_.force_interpreter_count;
}
bool IsForceInterpreter() const {
return tls32_.force_interpreter_count != 0;
}
bool IncrementMakeVisiblyInitializedCounter() {
tls32_.make_visibly_initialized_counter += 1u;
DCHECK_LE(tls32_.make_visibly_initialized_counter, kMakeVisiblyInitializedCounterTriggerCount);
if (tls32_.make_visibly_initialized_counter == kMakeVisiblyInitializedCounterTriggerCount) {
tls32_.make_visibly_initialized_counter = 0u;
return true;
}
return false;
}
void PushVerifier(verifier::MethodVerifier* verifier);
void PopVerifier(verifier::MethodVerifier* verifier);
void InitStringEntryPoints();
void ModifyDebugDisallowReadBarrier(int8_t delta) {
if (kCheckDebugDisallowReadBarrierCount) {
debug_disallow_read_barrier_ += delta;
}
}
uint8_t GetDebugDisallowReadBarrierCount() const {
return kCheckDebugDisallowReadBarrierCount ? debug_disallow_read_barrier_ : 0u;
}
// Gets the current TLSData associated with the key or nullptr if there isn't any. Note that users
// do not gain ownership of TLSData and must synchronize with SetCustomTls themselves to prevent
// it from being deleted.
TLSData* GetCustomTLS(const char* key) REQUIRES(!Locks::custom_tls_lock_);
// Sets the tls entry at 'key' to data. The thread takes ownership of the TLSData. The destructor
// will be run when the thread exits or when SetCustomTLS is called again with the same key.
void SetCustomTLS(const char* key, TLSData* data) REQUIRES(!Locks::custom_tls_lock_);
// Returns true if the current thread is the jit sensitive thread.
bool IsJitSensitiveThread() const {
return this == jit_sensitive_thread_;
}
bool IsSystemDaemon() const REQUIRES_SHARED(Locks::mutator_lock_);
// Returns true if StrictMode events are traced for the current thread.
static bool IsSensitiveThread() {
if (is_sensitive_thread_hook_ != nullptr) {
return (*is_sensitive_thread_hook_)();
}
return false;
}
// Set to the read barrier marking entrypoints to be non-null.
void SetReadBarrierEntrypoints();
static jobject CreateCompileTimePeer(JNIEnv* env,
const char* name,
bool as_daemon,
jobject thread_group)
REQUIRES_SHARED(Locks::mutator_lock_);
ALWAYS_INLINE InterpreterCache* GetInterpreterCache() {
return &interpreter_cache_;
}
// Clear all thread-local interpreter caches.
//
// Since the caches are keyed by memory pointer to dex instructions, this must be
// called when any dex code is unloaded (before different code gets loaded at the
// same memory location).
//
// If presence of cache entry implies some pre-conditions, this must also be
// called if the pre-conditions might no longer hold true.
static void ClearAllInterpreterCaches();
template<PointerSize pointer_size>
static constexpr ThreadOffset<pointer_size> InterpreterCacheOffset() {
return ThreadOffset<pointer_size>(OFFSETOF_MEMBER(Thread, interpreter_cache_));
}
static constexpr int InterpreterCacheSizeLog2() {
return WhichPowerOf2(InterpreterCache::kSize);
}
static constexpr uint32_t AllThreadFlags() {
return enum_cast<uint32_t>(ThreadFlag::kLastFlag) |
(enum_cast<uint32_t>(ThreadFlag::kLastFlag) - 1u);
}
static constexpr uint32_t SuspendOrCheckpointRequestFlags() {
return enum_cast<uint32_t>(ThreadFlag::kSuspendRequest) |
enum_cast<uint32_t>(ThreadFlag::kCheckpointRequest) |
enum_cast<uint32_t>(ThreadFlag::kEmptyCheckpointRequest);
}
static constexpr uint32_t FlipFunctionFlags() {
return enum_cast<uint32_t>(ThreadFlag::kPendingFlipFunction) |
enum_cast<uint32_t>(ThreadFlag::kRunningFlipFunction) |
enum_cast<uint32_t>(ThreadFlag::kWaitingForFlipFunction);
}
static constexpr uint32_t StoredThreadStateValue(ThreadState state) {
return StateAndFlags::EncodeState(state);
}
void ResetSharedMethodHotness() {
tls32_.shared_method_hotness = kSharedMethodHotnessThreshold;
}
uint32_t GetSharedMethodHotness() const {
return tls32_.shared_method_hotness;
}
uint32_t DecrementSharedMethodHotness() {
tls32_.shared_method_hotness = (tls32_.shared_method_hotness - 1) & 0xffff;
return tls32_.shared_method_hotness;
}
private:
explicit Thread(bool daemon);
~Thread() REQUIRES(!Locks::mutator_lock_, !Locks::thread_suspend_count_lock_);
void Destroy(bool should_run_callbacks);
// Deletes and clears the tlsPtr_.jpeer field. Done in a way so that both it and opeer cannot be
// observed to be set at the same time by instrumentation.
void DeleteJPeer(JNIEnv* env);
// Attaches the calling native thread to the runtime, returning the new native peer.
// Used to implement JNI AttachCurrentThread and AttachCurrentThreadAsDaemon calls.
template <typename PeerAction>
static Thread* Attach(const char* thread_name,
bool as_daemon,
PeerAction p,
bool should_run_callbacks);
void CreatePeer(const char* name, bool as_daemon, jobject thread_group);
template<bool kTransactionActive>
static void InitPeer(ScopedObjectAccessAlreadyRunnable& soa,
ObjPtr<mirror::Object> peer,
jboolean thread_is_daemon,
jobject thread_group,
jobject thread_name,
jint thread_priority)
REQUIRES_SHARED(Locks::mutator_lock_);
// Avoid use, callers should use SetState.
// Used only by `Thread` destructor and stack trace collection in semi-space GC (currently
// disabled by `kStoreStackTraces = false`).
// NO_THREAD_SAFETY_ANALYSIS: This function is "Unsafe" and can be called in
// different states, so clang cannot perform the thread safety analysis.
ThreadState SetStateUnsafe(ThreadState new_state) NO_THREAD_SAFETY_ANALYSIS {
StateAndFlags old_state_and_flags = GetStateAndFlags(std::memory_order_relaxed);
ThreadState old_state = old_state_and_flags.GetState();
if (old_state == new_state) {
// Nothing to do.
} else if (old_state == ThreadState::kRunnable) {
// Need to run pending checkpoint and suspend barriers. Run checkpoints in runnable state in
// case they need to use a ScopedObjectAccess. If we are holding the mutator lock and a SOA
// attempts to TransitionFromSuspendedToRunnable, it results in a deadlock.
TransitionToSuspendedAndRunCheckpoints(new_state);
// Since we transitioned to a suspended state, check the pass barrier requests.
PassActiveSuspendBarriers();
} else {
while (true) {
StateAndFlags new_state_and_flags = old_state_and_flags;
new_state_and_flags.SetState(new_state);
if (LIKELY(tls32_.state_and_flags.CompareAndSetWeakAcquire(
old_state_and_flags.GetValue(),
new_state_and_flags.GetValue()))) {
break;
}
// Reload state and flags.
old_state_and_flags = GetStateAndFlags(std::memory_order_relaxed);
DCHECK_EQ(old_state, old_state_and_flags.GetState());
}
}
return old_state;
}
MutatorMutex* GetMutatorLock() RETURN_CAPABILITY(Locks::mutator_lock_) {
DCHECK_EQ(tlsPtr_.mutator_lock, Locks::mutator_lock_);
return tlsPtr_.mutator_lock;
}
void VerifyStackImpl() REQUIRES_SHARED(Locks::mutator_lock_);
void DumpState(std::ostream& os) const REQUIRES_SHARED(Locks::mutator_lock_);
DumpOrder DumpStack(std::ostream& os,
bool dump_native_stack = true,
bool force_dump_stack = false) const
REQUIRES_SHARED(Locks::mutator_lock_);
DumpOrder DumpStack(std::ostream& os,
unwindstack::AndroidLocalUnwinder& unwinder,
bool dump_native_stack = true,
bool force_dump_stack = false) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Out-of-line conveniences for debugging in gdb.
static Thread* CurrentFromGdb(); // Like Thread::Current.
// Like Thread::Dump(std::cerr).
void DumpFromGdb() const REQUIRES_SHARED(Locks::mutator_lock_);
// A wrapper around CreateCallback used when userfaultfd GC is used to
// identify the GC by stacktrace.
static NO_INLINE void* CreateCallbackWithUffdGc(void* arg);
static void* CreateCallback(void* arg);
void HandleUncaughtExceptions(ScopedObjectAccessAlreadyRunnable& soa)
REQUIRES_SHARED(Locks::mutator_lock_);
void RemoveFromThreadGroup(ScopedObjectAccessAlreadyRunnable& soa)
REQUIRES_SHARED(Locks::mutator_lock_);
// Initialize a thread.
//
// The third parameter is not mandatory. If given, the thread will use this JNIEnvExt. In case
// Init succeeds, this means the thread takes ownership of it. If Init fails, it is the caller's
// responsibility to destroy the given JNIEnvExt. If the parameter is null, Init will try to
// create a JNIEnvExt on its own (and potentially fail at that stage, indicated by a return value
// of false).
bool Init(ThreadList*, JavaVMExt*, JNIEnvExt* jni_env_ext = nullptr)
REQUIRES(Locks::runtime_shutdown_lock_);
void InitCardTable();
void InitCpu();
void CleanupCpu();
void InitTlsEntryPoints();
void InitTid();
void InitPthreadKeySelf();
bool InitStackHwm();
void SetUpAlternateSignalStack();
void TearDownAlternateSignalStack();
void MadviseAwayAlternateSignalStack();
ALWAYS_INLINE void TransitionToSuspendedAndRunCheckpoints(ThreadState new_state)
REQUIRES(!Locks::thread_suspend_count_lock_, !Roles::uninterruptible_)
REQUIRES_SHARED(Locks::mutator_lock_);
ALWAYS_INLINE void PassActiveSuspendBarriers()
REQUIRES(!Locks::thread_suspend_count_lock_, !Roles::uninterruptible_);
// Registers the current thread as the jit sensitive thread. Should be called just once.
static void SetJitSensitiveThread() {
if (jit_sensitive_thread_ == nullptr) {
jit_sensitive_thread_ = Thread::Current();
} else {
LOG(WARNING) << "Attempt to set the sensitive thread twice. Tid:"
<< Thread::Current()->GetTid();
}
}
static void SetSensitiveThreadHook(bool (*is_sensitive_thread_hook)()) {
is_sensitive_thread_hook_ = is_sensitive_thread_hook;
}
bool ModifySuspendCountInternal(Thread* self,
int delta,
AtomicInteger* suspend_barrier,
SuspendReason reason)
WARN_UNUSED
REQUIRES(Locks::thread_suspend_count_lock_);
// Runs a single checkpoint function. If there are no more pending checkpoint functions it will
// clear the kCheckpointRequest flag. The caller is responsible for calling this in a loop until
// the kCheckpointRequest flag is cleared.
void RunCheckpointFunction()
REQUIRES(!Locks::thread_suspend_count_lock_)
REQUIRES_SHARED(Locks::mutator_lock_);
void RunEmptyCheckpoint();
bool PassActiveSuspendBarriers(Thread* self)
REQUIRES(!Locks::thread_suspend_count_lock_);
// Install the protected region for implicit stack checks.
void InstallImplicitProtection();
template <bool kPrecise>
void VisitRoots(RootVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_);
static bool IsAotCompiler();
void ReleaseLongJumpContextInternal();
void SetCachedThreadName(const char* name);
// Helper class for manipulating the 32 bits of atomically changed state and flags.
class StateAndFlags {
public:
explicit StateAndFlags(uint32_t value) :value_(value) {}
uint32_t GetValue() const {
return value_;
}
void SetValue(uint32_t value) {
value_ = value;
}
bool IsAnyOfFlagsSet(uint32_t flags) const {
DCHECK_EQ(flags & ~AllThreadFlags(), 0u);
return (value_ & flags) != 0u;
}
bool IsFlagSet(ThreadFlag flag) const {
return (value_ & enum_cast<uint32_t>(flag)) != 0u;
}
void SetFlag(ThreadFlag flag) {
value_ |= enum_cast<uint32_t>(flag);
}
StateAndFlags WithFlag(ThreadFlag flag) const {
StateAndFlags result = *this;
result.SetFlag(flag);
return result;
}
StateAndFlags WithoutFlag(ThreadFlag flag) const {
StateAndFlags result = *this;
result.ClearFlag(flag);
return result;
}
void ClearFlag(ThreadFlag flag) {
value_ &= ~enum_cast<uint32_t>(flag);
}
ThreadState GetState() const {
ThreadState state = ThreadStateField::Decode(value_);
ValidateThreadState(state);
return state;
}
void SetState(ThreadState state) {
ValidateThreadState(state);
value_ = ThreadStateField::Update(state, value_);
}
StateAndFlags WithState(ThreadState state) const {
StateAndFlags result = *this;
result.SetState(state);
return result;
}
static constexpr uint32_t EncodeState(ThreadState state) {
ValidateThreadState(state);
return ThreadStateField::Encode(state);
}
private:
static constexpr void ValidateThreadState(ThreadState state) {
if (kIsDebugBuild && state != ThreadState::kRunnable) {
CHECK_GE(state, ThreadState::kTerminated);
CHECK_LE(state, ThreadState::kSuspended);
CHECK_NE(state, ThreadState::kObsoleteRunnable);
}
}
// The value holds thread flags and thread state.
uint32_t value_;
static constexpr size_t kThreadStateBitSize = BitSizeOf<std::underlying_type_t<ThreadState>>();
static constexpr size_t kThreadStatePosition = BitSizeOf<uint32_t>() - kThreadStateBitSize;
using ThreadStateField = BitField<ThreadState, kThreadStatePosition, kThreadStateBitSize>;
static_assert(
WhichPowerOf2(enum_cast<uint32_t>(ThreadFlag::kLastFlag)) < kThreadStatePosition);
};
static_assert(sizeof(StateAndFlags) == sizeof(uint32_t), "Unexpected StateAndFlags size");
StateAndFlags GetStateAndFlags(std::memory_order order) const {
return StateAndFlags(tls32_.state_and_flags.load(order));
}
// Format state and flags as a hex string. For diagnostic output.
std::string StateAndFlagsAsHexString() const;
// Run the flip function and, if requested, notify other threads that may have tried
// to do that concurrently.
void RunFlipFunction(Thread* self, bool notify) REQUIRES_SHARED(Locks::mutator_lock_);
static void ThreadExitCallback(void* arg);
// Maximum number of suspend barriers.
static constexpr uint32_t kMaxSuspendBarriers = 3;
// Has Thread::Startup been called?
static bool is_started_;
// TLS key used to retrieve the Thread*.
static pthread_key_t pthread_key_self_;
// Used to notify threads that they should attempt to resume, they will suspend again if
// their suspend count is > 0.
static ConditionVariable* resume_cond_ GUARDED_BY(Locks::thread_suspend_count_lock_);
// Hook passed by framework which returns true
// when StrictMode events are traced for the current thread.
static bool (*is_sensitive_thread_hook_)();
// Stores the jit sensitive thread (which for now is the UI thread).
static Thread* jit_sensitive_thread_;
static constexpr uint32_t kMakeVisiblyInitializedCounterTriggerCount = 128;
/***********************************************************************************************/
// Thread local storage. Fields are grouped by size to enable 32 <-> 64 searching to account for
// pointer size differences. To encourage shorter encoding, more frequently used values appear
// first if possible.
/***********************************************************************************************/
struct PACKED(4) tls_32bit_sized_values {
// We have no control over the size of 'bool', but want our boolean fields
// to be 4-byte quantities.
using bool32_t = uint32_t;
explicit tls_32bit_sized_values(bool is_daemon)
: state_and_flags(0u),
suspend_count(0),
thin_lock_thread_id(0),
tid(0),
daemon(is_daemon),
throwing_OutOfMemoryError(false),
no_thread_suspension(0),
thread_exit_check_count(0),
is_transitioning_to_runnable(false),
is_gc_marking(false),
is_deopt_check_required(false),
weak_ref_access_enabled(WeakRefAccessState::kVisiblyEnabled),
disable_thread_flip_count(0),
user_code_suspend_count(0),
force_interpreter_count(0),
make_visibly_initialized_counter(0),
define_class_counter(0),
num_name_readers(0),
shared_method_hotness(kSharedMethodHotnessThreshold)
{}
// The state and flags field must be changed atomically so that flag values aren't lost.
// See `StateAndFlags` for bit assignments of `ThreadFlag` and `ThreadState` values.
// Keeping the state and flags together allows an atomic CAS to change from being
// Suspended to Runnable without a suspend request occurring.
Atomic<uint32_t> state_and_flags;
static_assert(sizeof(state_and_flags) == sizeof(uint32_t),
"Size of state_and_flags and uint32 are different");
// A non-zero value is used to tell the current thread to enter a safe point
// at the next poll.
int suspend_count GUARDED_BY(Locks::thread_suspend_count_lock_);
// Thin lock thread id. This is a small integer used by the thin lock implementation.
// This is not to be confused with the native thread's tid, nor is it the value returned
// by java.lang.Thread.getId --- this is a distinct value, used only for locking. One
// important difference between this id and the ids visible to managed code is that these
// ones get reused (to ensure that they fit in the number of bits available).
uint32_t thin_lock_thread_id;
// System thread id.
uint32_t tid;
// Is the thread a daemon?
const bool32_t daemon;
// A boolean telling us whether we're recursively throwing OOME.
bool32_t throwing_OutOfMemoryError;
// A positive value implies we're in a region where thread suspension isn't expected.
uint32_t no_thread_suspension;
// How many times has our pthread key's destructor been called?
uint32_t thread_exit_check_count;
// True if the thread is in TransitionFromSuspendedToRunnable(). This is used to distinguish the
// non-runnable threads (eg. kNative, kWaiting) that are about to transition to runnable from
// the rest of them.
bool32_t is_transitioning_to_runnable;
// True if the GC is in the marking phase. This is used for the CC collector only. This is
// thread local so that we can simplify the logic to check for the fast path of read barriers of
// GC roots.
bool32_t is_gc_marking;
// True if we need to check for deoptimization when returning from the runtime functions. This
// is required only when a class is redefined to prevent executing code that has field offsets
// embedded. For non-debuggable apps redefinition is not allowed and this flag should always be
// set to false.
bool32_t is_deopt_check_required;
// Thread "interrupted" status; stays raised until queried or thrown.
Atomic<bool32_t> interrupted;
AtomicInteger park_state_;
// Determines whether the thread is allowed to directly access a weak ref
// (Reference::GetReferent() and system weaks) and to potentially mark an object alive/gray.
// This is used for concurrent reference processing of the CC collector only. This is thread
// local so that we can enable/disable weak ref access by using a checkpoint and avoid a race
// around the time weak ref access gets disabled and concurrent reference processing begins
// (if weak ref access is disabled during a pause, this is not an issue.) Other collectors use
// Runtime::DisallowNewSystemWeaks() and ReferenceProcessor::EnableSlowPath(). Can be
// concurrently accessed by GetReferent() and set (by iterating over threads).
// Can be changed from kEnabled to kVisiblyEnabled by readers. No other concurrent access is
// possible when that happens.
mutable std::atomic<WeakRefAccessState> weak_ref_access_enabled;
// A thread local version of Heap::disable_thread_flip_count_. This keeps track of how many
// levels of (nested) JNI critical sections the thread is in and is used to detect a nested JNI
// critical section enter.
uint32_t disable_thread_flip_count;
// How much of 'suspend_count_' is by request of user code, used to distinguish threads
// suspended by the runtime from those suspended by user code.
// This should have GUARDED_BY(Locks::user_code_suspension_lock_) but auto analysis cannot be
// told that AssertHeld should be good enough.
int user_code_suspend_count GUARDED_BY(Locks::thread_suspend_count_lock_);
// Count of how many times this thread has been forced to interpreter. If this is not 0 the
// thread must remain in interpreted code as much as possible.
uint32_t force_interpreter_count;
// Counter for calls to initialize a class that's initialized but not visibly initialized.
// When this reaches kMakeVisiblyInitializedCounterTriggerCount, we call the runtime to
// make initialized classes visibly initialized. This is needed because we usually make
// classes visibly initialized in batches but we do not want to be stuck with a class
// initialized but not visibly initialized for a long time even if no more classes are
// being initialized anymore.
uint32_t make_visibly_initialized_counter;
// Counter for how many nested define-classes are ongoing in this thread. Used to allow waiting
// for threads to be done with class-definition work.
uint32_t define_class_counter;
// A count of the number of readers of tlsPtr_.name that may still be looking at a string they
// retrieved.
mutable std::atomic<uint32_t> num_name_readers;
static_assert(std::atomic<uint32_t>::is_always_lock_free);
// Thread-local hotness counter for shared memory methods. Initialized with
// `kSharedMethodHotnessThreshold`. The interpreter decrements it and goes
// into the runtime when hitting zero. Note that all previous decrements
// could have been executed by another method than the one seeing zero.
// There is a second level counter in `Jit::shared_method_counters_` to make
// sure we at least have a few samples before compiling a method.
uint32_t shared_method_hotness;
} tls32_;
struct PACKED(8) tls_64bit_sized_values {
tls_64bit_sized_values() : trace_clock_base(0) {
}
// The clock base used for tracing.
uint64_t trace_clock_base;
RuntimeStats stats;
} tls64_;
struct PACKED(sizeof(void*)) tls_ptr_sized_values {
tls_ptr_sized_values() : card_table(nullptr),
exception(nullptr),
stack_end(nullptr),
managed_stack(),
suspend_trigger(nullptr),
jni_env(nullptr),
tmp_jni_env(nullptr),
self(nullptr),
opeer(nullptr),
jpeer(nullptr),
stack_begin(nullptr),
stack_size(0),
deps_or_stack_trace_sample(),
wait_next(nullptr),
monitor_enter_object(nullptr),
top_handle_scope(nullptr),
class_loader_override(nullptr),
long_jump_context(nullptr),
instrumentation_stack(nullptr),
stacked_shadow_frame_record(nullptr),
deoptimization_context_stack(nullptr),
frame_id_to_shadow_frame(nullptr),
name(nullptr),
pthread_self(0),
last_no_thread_suspension_cause(nullptr),
checkpoint_function(nullptr),
thread_local_start(nullptr),
thread_local_pos(nullptr),
thread_local_end(nullptr),
thread_local_limit(nullptr),
thread_local_objects(0),
thread_local_alloc_stack_top(nullptr),
thread_local_alloc_stack_end(nullptr),
mutator_lock(nullptr),
flip_function(nullptr),
method_verifier(nullptr),
thread_local_mark_stack(nullptr),
async_exception(nullptr),
top_reflective_handle_scope(nullptr) {
std::fill(held_mutexes, held_mutexes + kLockLevelCount, nullptr);
}
// The biased card table, see CardTable for details.
uint8_t* card_table;
// The pending exception or null.
mirror::Throwable* exception;
// The end of this thread's stack. This is the lowest safely-addressable address on the stack.
// We leave extra space so there's room for the code that throws StackOverflowError.
uint8_t* stack_end;
// The top of the managed stack often manipulated directly by compiler generated code.
ManagedStack managed_stack;
// In certain modes, setting this to 0 will trigger a SEGV and thus a suspend check. It is
// normally set to the address of itself.
uintptr_t* suspend_trigger;
// Every thread may have an associated JNI environment
JNIEnvExt* jni_env;
// Temporary storage to transfer a pre-allocated JNIEnvExt from the creating thread to the
// created thread.
JNIEnvExt* tmp_jni_env;
// Initialized to "this". On certain architectures (such as x86) reading off of Thread::Current
// is easy but getting the address of Thread::Current is hard. This field can be read off of
// Thread::Current to give the address.
Thread* self;
// Our managed peer (an instance of java.lang.Thread). The jobject version is used during thread
// start up, until the thread is registered and the local opeer_ is used.
mirror::Object* opeer;
jobject jpeer;
// The "lowest addressable byte" of the stack.
uint8_t* stack_begin;
// Size of the stack.
size_t stack_size;
// Sampling profiler and AOT verification cannot happen on the same run, so we share
// the same entry for the stack trace and the verifier deps.
union DepsOrStackTraceSample {
DepsOrStackTraceSample() {
verifier_deps = nullptr;
stack_trace_sample = nullptr;
}
// Pointer to previous stack trace captured by sampling profiler.
std::vector<ArtMethod*>* stack_trace_sample;
// When doing AOT verification, per-thread VerifierDeps.
verifier::VerifierDeps* verifier_deps;
} deps_or_stack_trace_sample;
// The next thread in the wait set this thread is part of or null if not waiting.
Thread* wait_next;
// If we're blocked in MonitorEnter, this is the object we're trying to lock.
mirror::Object* monitor_enter_object;
// Top of linked list of handle scopes or null for none.
BaseHandleScope* top_handle_scope;
// Needed to get the right ClassLoader in JNI_OnLoad, but also
// useful for testing.
jobject class_loader_override;
// Thread local, lazily allocated, long jump context. Used to deliver exceptions.
Context* long_jump_context;
// Additional stack used by method instrumentation to store method and return pc values.
// Stored as a pointer since std::map is not PACKED.
// !DO NOT CHANGE! to std::unordered_map: the users of this map require an
// ordered iteration on the keys (which are stack addresses).
// Also see Thread::GetInstrumentationStack for the requirements on
// manipulating and reading this map.
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* instrumentation_stack;
// For gc purpose, a shadow frame record stack that keeps track of:
// 1) shadow frames under construction.
// 2) deoptimization shadow frames.
StackedShadowFrameRecord* stacked_shadow_frame_record;
// Deoptimization return value record stack.
DeoptimizationContextRecord* deoptimization_context_stack;
// For debugger, a linked list that keeps the mapping from frame_id to shadow frame.
// Shadow frames may be created before deoptimization happens so that the debugger can
// set local values there first.
FrameIdToShadowFrame* frame_id_to_shadow_frame;
// A cached copy of the java.lang.Thread's (modified UTF-8) name.
// If this is not null or kThreadNameDuringStartup, then it owns the malloc memory holding
// the string. Updated in an RCU-like manner.
std::atomic<const char*> name;
static_assert(std::atomic<const char*>::is_always_lock_free);
// A cached pthread_t for the pthread underlying this Thread*.
pthread_t pthread_self;
// If no_thread_suspension_ is > 0, what is causing that assertion.
const char* last_no_thread_suspension_cause;
// Pending checkpoint function or null if non-pending. If this checkpoint is set and someone\
// requests another checkpoint, it goes to the checkpoint overflow list.
Closure* checkpoint_function GUARDED_BY(Locks::thread_suspend_count_lock_);
// Pending barriers that require passing or NULL if non-pending. Installation guarding by
// Locks::thread_suspend_count_lock_.
// They work effectively as art::Barrier, but implemented directly using AtomicInteger and futex
// to avoid additional cost of a mutex and a condition variable, as used in art::Barrier.
AtomicInteger* active_suspend_barriers[kMaxSuspendBarriers];
// Thread-local allocation pointer. Moved here to force alignment for thread_local_pos on ARM.
uint8_t* thread_local_start;
// thread_local_pos and thread_local_end must be consecutive for ldrd and are 8 byte aligned for
// potentially better performance.
uint8_t* thread_local_pos;
uint8_t* thread_local_end;
// Thread local limit is how much we can expand the thread local buffer to, it is greater or
// equal to thread_local_end.
uint8_t* thread_local_limit;
size_t thread_local_objects;
// Entrypoint function pointers.
// TODO: move this to more of a global offset table model to avoid per-thread duplication.
JniEntryPoints jni_entrypoints;
QuickEntryPoints quick_entrypoints;
// There are RosAlloc::kNumThreadLocalSizeBrackets thread-local size brackets per thread.
void* rosalloc_runs[kNumRosAllocThreadLocalSizeBracketsInThread];
// Thread-local allocation stack data/routines.
StackReference<mirror::Object>* thread_local_alloc_stack_top;
StackReference<mirror::Object>* thread_local_alloc_stack_end;
// Pointer to the mutator lock.
// This is the same as `Locks::mutator_lock_` but cached for faster state transitions.
MutatorMutex* mutator_lock;
// Support for Mutex lock hierarchy bug detection.
BaseMutex* held_mutexes[kLockLevelCount];
// The function used for thread flip.
Closure* flip_function;
// Current method verifier, used for root marking.
verifier::MethodVerifier* method_verifier;
// Thread-local mark stack for the concurrent copying collector.
gc::accounting::AtomicStack<mirror::Object>* thread_local_mark_stack;
// The pending async-exception or null.
mirror::Throwable* async_exception;
// Top of the linked-list for reflective-handle scopes or null if none.
BaseReflectiveHandleScope* top_reflective_handle_scope;
} tlsPtr_;
// Small thread-local cache to be used from the interpreter.
// It is keyed by dex instruction pointer.
// The value is opcode-depended (e.g. field offset).
InterpreterCache interpreter_cache_;
// All fields below this line should not be accessed by native code. This means these fields can
// be modified, rearranged, added or removed without having to modify asm_support.h
// Guards the 'wait_monitor_' members.
Mutex* wait_mutex_ DEFAULT_MUTEX_ACQUIRED_AFTER;
// Condition variable waited upon during a wait.
ConditionVariable* wait_cond_ GUARDED_BY(wait_mutex_);
// Pointer to the monitor lock we're currently waiting on or null if not waiting.
Monitor* wait_monitor_ GUARDED_BY(wait_mutex_);
// Debug disable read barrier count, only is checked for debug builds and only in the runtime.
uint8_t debug_disallow_read_barrier_ = 0;
// Note that it is not in the packed struct, may not be accessed for cross compilation.
uintptr_t poison_object_cookie_ = 0;
// Pending extra checkpoints if checkpoint_function_ is already used.
std::list<Closure*> checkpoint_overflow_ GUARDED_BY(Locks::thread_suspend_count_lock_);
// Custom TLS field that can be used by plugins or the runtime. Should not be accessed directly by
// compiled code or entrypoints.
SafeMap<std::string, std::unique_ptr<TLSData>, std::less<>> custom_tls_
GUARDED_BY(Locks::custom_tls_lock_);
#if !defined(__BIONIC__)
#if !defined(ANDROID_HOST_MUSL)
__attribute__((tls_model("initial-exec")))
#endif
static thread_local Thread* self_tls_;
#endif
// True if the thread is some form of runtime thread (ex, GC or JIT).
bool is_runtime_thread_;
// Set during execution of JNI methods that get field and method id's as part of determining if
// the caller is allowed to access all fields and methods in the Core Platform API.
uint32_t core_platform_api_cookie_ = 0;
friend class gc::collector::SemiSpace; // For getting stack traces.
friend class Runtime; // For CreatePeer.
friend class QuickExceptionHandler; // For dumping the stack.
friend class ScopedThreadStateChange;
friend class StubTest; // For accessing entrypoints.
friend class ThreadList; // For ~Thread and Destroy.
friend class EntrypointsOrderTest; // To test the order of tls entries.
friend class JniCompilerTest; // For intercepting JNI entrypoint calls.
DISALLOW_COPY_AND_ASSIGN(Thread);
};
class SCOPED_CAPABILITY ScopedAssertNoThreadSuspension {
public:
ALWAYS_INLINE ScopedAssertNoThreadSuspension(const char* cause,
bool enabled = true)
ACQUIRE(Roles::uninterruptible_)
: enabled_(enabled) {
if (!enabled_) {
return;
}
if (kIsDebugBuild) {
self_ = Thread::Current();
old_cause_ = self_->StartAssertNoThreadSuspension(cause);
} else {
Roles::uninterruptible_.Acquire(); // No-op.
}
}
ALWAYS_INLINE ~ScopedAssertNoThreadSuspension() RELEASE(Roles::uninterruptible_) {
if (!enabled_) {
return;
}
if (kIsDebugBuild) {
self_->EndAssertNoThreadSuspension(old_cause_);
} else {
Roles::uninterruptible_.Release(); // No-op.
}
}
private:
Thread* self_;
const bool enabled_;
const char* old_cause_;
};
class ScopedAllowThreadSuspension {
public:
ALWAYS_INLINE ScopedAllowThreadSuspension() RELEASE(Roles::uninterruptible_) {
if (kIsDebugBuild) {
self_ = Thread::Current();
old_cause_ = self_->EndAssertNoThreadSuspension();
} else {
Roles::uninterruptible_.Release(); // No-op.
}
}
ALWAYS_INLINE ~ScopedAllowThreadSuspension() ACQUIRE(Roles::uninterruptible_) {
if (kIsDebugBuild) {
CHECK(self_->StartAssertNoThreadSuspension(old_cause_) == nullptr);
} else {
Roles::uninterruptible_.Acquire(); // No-op.
}
}
private:
Thread* self_;
const char* old_cause_;
};
class ScopedStackedShadowFramePusher {
public:
ScopedStackedShadowFramePusher(Thread* self, ShadowFrame* sf) : self_(self), sf_(sf) {
DCHECK_EQ(sf->GetLink(), nullptr);
self_->PushStackedShadowFrame(sf, StackedShadowFrameType::kShadowFrameUnderConstruction);
}
~ScopedStackedShadowFramePusher() {
ShadowFrame* sf = self_->PopStackedShadowFrame();
DCHECK_EQ(sf, sf_);
}
private:
Thread* const self_;
ShadowFrame* const sf_;
DISALLOW_COPY_AND_ASSIGN(ScopedStackedShadowFramePusher);
};
// Only works for debug builds.
class ScopedDebugDisallowReadBarriers {
public:
explicit ScopedDebugDisallowReadBarriers(Thread* self) : self_(self) {
self_->ModifyDebugDisallowReadBarrier(1);
}
~ScopedDebugDisallowReadBarriers() {
self_->ModifyDebugDisallowReadBarrier(-1);
}
private:
Thread* const self_;
};
class ScopedTransitioningToRunnable : public ValueObject {
public:
explicit ScopedTransitioningToRunnable(Thread* self)
: self_(self) {
DCHECK_EQ(self, Thread::Current());
if (gUseReadBarrier) {
self_->SetIsTransitioningToRunnable(true);
}
}
~ScopedTransitioningToRunnable() {
if (gUseReadBarrier) {
self_->SetIsTransitioningToRunnable(false);
}
}
private:
Thread* const self_;
};
class ThreadLifecycleCallback {
public:
virtual ~ThreadLifecycleCallback() {}
virtual void ThreadStart(Thread* self) REQUIRES_SHARED(Locks::mutator_lock_) = 0;
virtual void ThreadDeath(Thread* self) REQUIRES_SHARED(Locks::mutator_lock_) = 0;
};
// Store an exception from the thread and suppress it for the duration of this object.
class ScopedExceptionStorage {
public:
explicit ScopedExceptionStorage(Thread* self) REQUIRES_SHARED(Locks::mutator_lock_);
void SuppressOldException(const char* message = "") REQUIRES_SHARED(Locks::mutator_lock_);
~ScopedExceptionStorage() REQUIRES_SHARED(Locks::mutator_lock_);
private:
Thread* self_;
StackHandleScope<1> hs_;
MutableHandle<mirror::Throwable> excp_;
};
std::ostream& operator<<(std::ostream& os, const Thread& thread);
std::ostream& operator<<(std::ostream& os, StackedShadowFrameType thread);
} // namespace art
#endif // ART_RUNTIME_THREAD_H_