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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_INSTRUMENTATION_H_
#define ART_RUNTIME_INSTRUMENTATION_H_
#include <stdint.h>
#include <functional>
#include <list>
#include <memory>
#include <optional>
#include <queue>
#include <unordered_set>
#include "arch/instruction_set.h"
#include "base/enums.h"
#include "base/locks.h"
#include "base/macros.h"
#include "base/safe_map.h"
#include "gc_root.h"
#include "jvalue.h"
#include "offsets.h"
namespace art {
namespace mirror {
class Class;
class Object;
class Throwable;
} // namespace mirror
class ArtField;
class ArtMethod;
template <typename T> class Handle;
template <typename T> class MutableHandle;
struct NthCallerVisitor;
union JValue;
class OatQuickMethodHeader;
class SHARED_LOCKABLE ReaderWriterMutex;
class ShadowFrame;
class Thread;
enum class DeoptimizationMethodType;
namespace instrumentation {
// Do we want to deoptimize for method entry and exit listeners or just try to intercept
// invocations? Deoptimization forces all code to run in the interpreter and considerably hurts the
// application's performance.
static constexpr bool kDeoptimizeForAccurateMethodEntryExitListeners = true;
// an optional frame is either Some(const ShadowFrame& current_frame) or None depending on if the
// method being exited has a shadow-frame associed with the current stack frame. In cases where
// there is no shadow-frame associated with this stack frame this will be None.
using OptionalFrame = std::optional<std::reference_wrapper<const ShadowFrame>>;
// Instrumentation event listener API. Registered listeners will get the appropriate call back for
// the events they are listening for. The call backs supply the thread, method and dex_pc the event
// occurred upon. The thread may or may not be Thread::Current().
struct InstrumentationListener {
InstrumentationListener() {}
virtual ~InstrumentationListener() {}
// Call-back for when a method is entered.
virtual void MethodEntered(Thread* thread, ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
virtual void MethodExited(Thread* thread,
ArtMethod* method,
OptionalFrame frame,
MutableHandle<mirror::Object>& return_value)
REQUIRES_SHARED(Locks::mutator_lock_);
// Call-back for when a method is exited. The implementor should either handler-ize the return
// value (if appropriate) or use the alternate MethodExited callback instead if they need to
// go through a suspend point.
virtual void MethodExited(Thread* thread,
ArtMethod* method,
OptionalFrame frame,
JValue& return_value)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back for when a method is popped due to an exception throw. A method will either cause a
// MethodExited call-back or a MethodUnwind call-back when its activation is removed.
virtual void MethodUnwind(Thread* thread,
ArtMethod* method,
uint32_t dex_pc)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back for when the dex pc moves in a method.
virtual void DexPcMoved(Thread* thread,
Handle<mirror::Object> this_object,
ArtMethod* method,
uint32_t new_dex_pc)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back for when we read from a field.
virtual void FieldRead(Thread* thread,
Handle<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field) = 0;
virtual void FieldWritten(Thread* thread,
Handle<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field,
Handle<mirror::Object> field_value)
REQUIRES_SHARED(Locks::mutator_lock_);
// Call-back for when we write into a field.
virtual void FieldWritten(Thread* thread,
Handle<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field,
const JValue& field_value)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back when an exception is thrown.
virtual void ExceptionThrown(Thread* thread,
Handle<mirror::Throwable> exception_object)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back when an exception is caught/handled by java code.
virtual void ExceptionHandled(Thread* thread, Handle<mirror::Throwable> exception_object)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back for when we execute a branch.
virtual void Branch(Thread* thread,
ArtMethod* method,
uint32_t dex_pc,
int32_t dex_pc_offset)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Call-back when a shadow_frame with the needs_notify_pop_ boolean set is popped off the stack by
// either return or exceptions. Normally instrumentation listeners should ensure that there are
// shadow-frames by deoptimizing stacks.
virtual void WatchedFramePop(Thread* thread ATTRIBUTE_UNUSED,
const ShadowFrame& frame ATTRIBUTE_UNUSED)
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
};
class Instrumentation;
// A helper to send instrumentation events while popping the stack in a safe way.
class InstrumentationStackPopper {
public:
explicit InstrumentationStackPopper(Thread* self);
~InstrumentationStackPopper() REQUIRES_SHARED(Locks::mutator_lock_);
// Increase the number of frames being popped up to `stack_pointer`. Return true if the
// frames were popped without any exceptions, false otherwise. The exception that caused
// the pop is 'exception'.
bool PopFramesTo(uintptr_t stack_pointer, /*in-out*/MutableHandle<mirror::Throwable>& exception)
REQUIRES_SHARED(Locks::mutator_lock_);
private:
Thread* self_;
Instrumentation* instrumentation_;
// The stack pointer limit for frames to pop.
uintptr_t pop_until_;
};
// Instrumentation is a catch-all for when extra information is required from the runtime. The
// typical use for instrumentation is for profiling and debugging. Instrumentation may add stubs
// to method entry and exit, it may also force execution to be switched to the interpreter and
// trigger deoptimization.
class Instrumentation {
public:
enum InstrumentationEvent {
kMethodEntered = 0x1,
kMethodExited = 0x2,
kMethodUnwind = 0x4,
kDexPcMoved = 0x8,
kFieldRead = 0x10,
kFieldWritten = 0x20,
kExceptionThrown = 0x40,
kBranch = 0x80,
kWatchedFramePop = 0x200,
kExceptionHandled = 0x400,
};
enum class InstrumentationLevel {
kInstrumentNothing, // execute without instrumentation
kInstrumentWithEntryExitHooks, // execute with entry/exit hooks
kInstrumentWithInterpreter // execute with interpreter
};
Instrumentation();
static constexpr MemberOffset RunExitHooksOffset() {
// Assert that run_entry_exit_hooks_ is 8bits wide. If the size changes
// update the compare instructions in the code generator when generating checks for
// MethodEntryExitHooks.
static_assert(sizeof(run_exit_hooks_) == 1, "run_exit_hooks_ isn't expected size");
return MemberOffset(OFFSETOF_MEMBER(Instrumentation, run_exit_hooks_));
}
static constexpr MemberOffset HaveMethodEntryListenersOffset() {
// Assert that have_method_entry_listeners_ is 8bits wide. If the size changes
// update the compare instructions in the code generator when generating checks for
// MethodEntryExitHooks.
static_assert(sizeof(have_method_entry_listeners_) == 1,
"have_method_entry_listeners_ isn't expected size");
return MemberOffset(OFFSETOF_MEMBER(Instrumentation, have_method_entry_listeners_));
}
static constexpr MemberOffset HaveMethodExitListenersOffset() {
// Assert that have_method_exit_listeners_ is 8bits wide. If the size changes
// update the compare instructions in the code generator when generating checks for
// MethodEntryExitHooks.
static_assert(sizeof(have_method_exit_listeners_) == 1,
"have_method_exit_listeners_ isn't expected size");
return MemberOffset(OFFSETOF_MEMBER(Instrumentation, have_method_exit_listeners_));
}
// Add a listener to be notified of the masked together sent of instrumentation events. This
// suspend the runtime to install stubs. You are expected to hold the mutator lock as a proxy
// for saying you should have suspended all threads (installing stubs while threads are running
// will break).
void AddListener(InstrumentationListener* listener, uint32_t events)
REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_);
// Removes listeners for the specified events.
void RemoveListener(InstrumentationListener* listener, uint32_t events)
REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_);
// Calls UndeoptimizeEverything which may visit class linker classes through ConfigureStubs.
// try_switch_to_non_debuggable specifies if we can switch the runtime back to non-debuggable.
// When a debugger is attached to a non-debuggable app, we switch the runtime to debuggable and
// when we are detaching the debugger we move back to non-debuggable. If we are disabling
// deoptimization for other reasons (ex: removing the last breakpoint) while the debugger is still
// connected, we pass false to stay in debuggable. Switching runtimes is expensive so we only want
// to switch when we know debug features aren't needed anymore.
void DisableDeoptimization(const char* key, bool try_switch_to_non_debuggable)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_);
// Enables entry exit hooks support. This is called in preparation for debug requests that require
// calling method entry / exit hooks.
void EnableEntryExitHooks(const char* key)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_);
bool AreAllMethodsDeoptimized() const {
return InterpreterStubsInstalled();
}
bool ShouldNotifyMethodEnterExitEvents() const REQUIRES_SHARED(Locks::mutator_lock_);
// Executes everything with interpreter.
void DeoptimizeEverything(const char* key)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
REQUIRES(!Locks::thread_list_lock_,
!Locks::classlinker_classes_lock_);
// Executes everything with compiled code (or interpreter if there is no code). May visit class
// linker classes through ConfigureStubs.
void UndeoptimizeEverything(const char* key)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
REQUIRES(!Locks::thread_list_lock_,
!Locks::classlinker_classes_lock_);
// Deoptimize a method by forcing its execution with the interpreter. Nevertheless, a static
// method (except a class initializer) set to the resolution trampoline will be deoptimized only
// once its declaring class is initialized.
void Deoptimize(ArtMethod* method) REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_);
// Undeoptimze the method by restoring its entrypoints. Nevertheless, a static method
// (except a class initializer) set to the resolution trampoline will be updated only once its
// declaring class is initialized.
void Undeoptimize(ArtMethod* method) REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_);
// Indicates whether the method has been deoptimized so it is executed with the interpreter.
bool IsDeoptimized(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_);
// Indicates if any method needs to be deoptimized. This is used to avoid walking the stack to
// determine if a deoptimization is required.
bool IsDeoptimizedMethodsEmpty() const REQUIRES_SHARED(Locks::mutator_lock_);
// Enable method tracing by installing instrumentation entry/exit stubs or interpreter.
void EnableMethodTracing(const char* key,
InstrumentationListener* listener,
bool needs_interpreter = kDeoptimizeForAccurateMethodEntryExitListeners)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
REQUIRES(!Locks::thread_list_lock_, !Locks::classlinker_classes_lock_);
// Disable method tracing by uninstalling instrumentation entry/exit stubs or interpreter.
void DisableMethodTracing(const char* key)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
REQUIRES(!Locks::thread_list_lock_,
!Locks::classlinker_classes_lock_);
void InstrumentQuickAllocEntryPoints() REQUIRES(!Locks::instrument_entrypoints_lock_);
void UninstrumentQuickAllocEntryPoints() REQUIRES(!Locks::instrument_entrypoints_lock_);
void InstrumentQuickAllocEntryPointsLocked()
REQUIRES(Locks::instrument_entrypoints_lock_, !Locks::thread_list_lock_,
!Locks::runtime_shutdown_lock_);
void UninstrumentQuickAllocEntryPointsLocked()
REQUIRES(Locks::instrument_entrypoints_lock_, !Locks::thread_list_lock_,
!Locks::runtime_shutdown_lock_);
void ResetQuickAllocEntryPoints() REQUIRES(Locks::runtime_shutdown_lock_);
// Returns a string representation of the given entry point.
static std::string EntryPointString(const void* code);
// Initialize the entrypoint of the method .`aot_code` is the AOT code.
void InitializeMethodsCode(ArtMethod* method, const void* aot_code)
REQUIRES_SHARED(Locks::mutator_lock_);
// Update the code of a method respecting any installed stubs.
void UpdateMethodsCode(ArtMethod* method, const void* new_code)
REQUIRES_SHARED(Locks::mutator_lock_);
// Update the code of a native method to a JITed stub.
void UpdateNativeMethodsCodeToJitCode(ArtMethod* method, const void* new_code)
REQUIRES_SHARED(Locks::mutator_lock_);
// Return the code that we can execute for an invoke including from the JIT.
const void* GetCodeForInvoke(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_);
// Return the code that we can execute considering the current instrumentation level.
// If interpreter stubs are installed return interpreter bridge. If the entry exit stubs
// are installed return an instrumentation entry point. Otherwise, return the code that
// can be executed including from the JIT.
const void* GetMaybeInstrumentedCodeForInvoke(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_);
void ForceInterpretOnly() {
forced_interpret_only_ = true;
}
bool EntryExitStubsInstalled() const {
return instrumentation_level_ == InstrumentationLevel::kInstrumentWithEntryExitHooks ||
instrumentation_level_ == InstrumentationLevel::kInstrumentWithInterpreter;
}
bool InterpreterStubsInstalled() const {
return instrumentation_level_ == InstrumentationLevel::kInstrumentWithInterpreter;
}
// Called by ArtMethod::Invoke to determine dispatch mechanism.
bool InterpretOnly() const {
return forced_interpret_only_ || InterpreterStubsInstalled();
}
bool InterpretOnly(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_);
bool IsForcedInterpretOnly() const {
return forced_interpret_only_;
}
bool RunExitHooks() const {
return run_exit_hooks_;
}
bool HasMethodEntryListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_method_entry_listeners_;
}
bool HasMethodExitListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_method_exit_listeners_;
}
bool HasMethodUnwindListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_method_unwind_listeners_;
}
bool HasDexPcListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_dex_pc_listeners_;
}
bool HasFieldReadListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_field_read_listeners_;
}
bool HasFieldWriteListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_field_write_listeners_;
}
bool HasExceptionThrownListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_exception_thrown_listeners_;
}
bool HasBranchListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_branch_listeners_;
}
bool HasWatchedFramePopListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_watched_frame_pop_listeners_;
}
bool HasExceptionHandledListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_exception_handled_listeners_;
}
// Returns if dex pc events need to be reported for the specified method.
// These events are reported when DexPCListeners are installed and at least one of the
// following conditions hold:
// 1. The method is deoptimized. This is done when there is a breakpoint on method.
// 2. When the thread is deoptimized. This is used when single stepping a single thread.
// 3. When interpreter stubs are installed. In this case no additional information is maintained
// about which methods need dex pc move events. This is usually used for features which need
// them for several methods across threads or need expensive processing. So it is OK to not
// further optimize this case.
// DexPCListeners are installed when there is a breakpoint on any method / single stepping
// on any of thread. These are removed when the last breakpoint was removed. See AddListener and
// RemoveListener for more details.
bool NeedsDexPcEvents(ArtMethod* method, Thread* thread) REQUIRES_SHARED(Locks::mutator_lock_);
bool NeedsSlowInterpreterForListeners() const REQUIRES_SHARED(Locks::mutator_lock_) {
return have_field_read_listeners_ ||
have_field_write_listeners_ ||
have_watched_frame_pop_listeners_ ||
have_exception_handled_listeners_;
}
// Inform listeners that a method has been entered. A dex PC is provided as we may install
// listeners into executing code and get method enter events for methods already on the stack.
void MethodEnterEvent(Thread* thread, ArtMethod* method) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasMethodEntryListeners())) {
MethodEnterEventImpl(thread, method);
}
}
// Inform listeners that a method has been exited.
template<typename T>
void MethodExitEvent(Thread* thread,
ArtMethod* method,
OptionalFrame frame,
T& return_value) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasMethodExitListeners())) {
MethodExitEventImpl(thread, method, frame, return_value);
}
}
// Inform listeners that a method has been exited due to an exception.
void MethodUnwindEvent(Thread* thread,
ArtMethod* method,
uint32_t dex_pc) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Inform listeners that the dex pc has moved (only supported by the interpreter).
void DexPcMovedEvent(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasDexPcListeners())) {
DexPcMovedEventImpl(thread, this_object, method, dex_pc);
}
}
// Inform listeners that a branch has been taken (only supported by the interpreter).
void Branch(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t offset) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasBranchListeners())) {
BranchImpl(thread, method, dex_pc, offset);
}
}
// Inform listeners that we read a field (only supported by the interpreter).
void FieldReadEvent(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasFieldReadListeners())) {
FieldReadEventImpl(thread, this_object, method, dex_pc, field);
}
}
// Inform listeners that we write a field (only supported by the interpreter).
void FieldWriteEvent(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field,
const JValue& field_value) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasFieldWriteListeners())) {
FieldWriteEventImpl(thread, this_object, method, dex_pc, field, field_value);
}
}
// Inform listeners that a branch has been taken (only supported by the interpreter).
void WatchedFramePopped(Thread* thread, const ShadowFrame& frame) const
REQUIRES_SHARED(Locks::mutator_lock_) {
if (UNLIKELY(HasWatchedFramePopListeners())) {
WatchedFramePopImpl(thread, frame);
}
}
// Inform listeners that an exception was thrown.
void ExceptionThrownEvent(Thread* thread, ObjPtr<mirror::Throwable> exception_object) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Inform listeners that an exception has been handled. This is not sent for native code or for
// exceptions which reach the end of the thread's stack.
void ExceptionHandledEvent(Thread* thread, ObjPtr<mirror::Throwable> exception_object) const
REQUIRES_SHARED(Locks::mutator_lock_);
JValue GetReturnValue(ArtMethod* method, bool* is_ref, uint64_t* gpr_result, uint64_t* fpr_result)
REQUIRES_SHARED(Locks::mutator_lock_);
bool PushDeoptContextIfNeeded(Thread* self,
DeoptimizationMethodType deopt_type,
bool is_ref,
const JValue& result) REQUIRES_SHARED(Locks::mutator_lock_);
void DeoptimizeIfNeeded(Thread* self,
ArtMethod** sp,
DeoptimizationMethodType type,
JValue result,
bool is_ref) REQUIRES_SHARED(Locks::mutator_lock_);
// This returns if the caller of runtime method requires a deoptimization. This checks both if the
// method requires a deopt or if this particular frame needs a deopt because of a class
// redefinition.
bool ShouldDeoptimizeCaller(Thread* self, ArtMethod** sp) REQUIRES_SHARED(Locks::mutator_lock_);
bool ShouldDeoptimizeCaller(Thread* self, ArtMethod** sp, size_t frame_size)
REQUIRES_SHARED(Locks::mutator_lock_);
// This returns if the specified method requires a deoptimization. This doesn't account if a stack
// frame involving this method requires a deoptimization.
bool NeedsSlowInterpreterForMethod(Thread* self, ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_);
DeoptimizationMethodType GetDeoptimizationMethodType(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_);
// Call back for configure stubs.
void InstallStubsForClass(ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_);
void InstallStubsForMethod(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_);
void UpdateEntrypointsForDebuggable() REQUIRES(art::Locks::mutator_lock_);
// Install instrumentation exit stub on every method of the stack of the given thread.
// This is used by:
// - the debugger to cause a deoptimization of the all frames in thread's stack (for
// example, after updating local variables)
// - to call method entry / exit hooks for tracing. For this we instrument
// the stack frame to run entry / exit hooks but we don't need to deoptimize.
// deopt_all_frames indicates whether the frames need to deoptimize or not.
void InstrumentThreadStack(Thread* thread, bool deopt_all_frames) REQUIRES(Locks::mutator_lock_);
void InstrumentAllThreadStacks(bool deopt_all_frames) REQUIRES(Locks::mutator_lock_)
REQUIRES(!Locks::thread_list_lock_);
// Force all currently running frames to be deoptimized back to interpreter. This should only be
// used in cases where basically all compiled code has been invalidated.
void DeoptimizeAllThreadFrames() REQUIRES(art::Locks::mutator_lock_);
static size_t ComputeFrameId(Thread* self,
size_t frame_depth,
size_t inlined_frames_before_frame)
REQUIRES_SHARED(Locks::mutator_lock_);
// Does not hold lock, used to check if someone changed from not instrumented to instrumented
// during a GC suspend point.
bool AllocEntrypointsInstrumented() const REQUIRES_SHARED(Locks::mutator_lock_) {
return alloc_entrypoints_instrumented_;
}
bool ProcessMethodUnwindCallbacks(Thread* self,
std::queue<ArtMethod*>& methods,
MutableHandle<mirror::Throwable>& exception)
REQUIRES_SHARED(Locks::mutator_lock_);
InstrumentationLevel GetCurrentInstrumentationLevel() const;
bool MethodSupportsExitEvents(ArtMethod* method, const OatQuickMethodHeader* header)
REQUIRES_SHARED(Locks::mutator_lock_);
private:
// Update the current instrumentation_level_.
void UpdateInstrumentationLevel(InstrumentationLevel level);
// Does the job of installing or removing instrumentation code within methods.
// In order to support multiple clients using instrumentation at the same time,
// the caller must pass a unique key (a string) identifying it so we remind which
// instrumentation level it needs. Therefore the current instrumentation level
// becomes the highest instrumentation level required by a client.
void ConfigureStubs(const char* key,
InstrumentationLevel desired_instrumentation_level,
bool try_switch_to_non_debuggable)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
REQUIRES(!Locks::thread_list_lock_, !Locks::classlinker_classes_lock_);
void UpdateStubs(bool try_switch_to_non_debuggable)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
REQUIRES(!Locks::thread_list_lock_, !Locks::classlinker_classes_lock_);
// If there are no pending deoptimizations restores the stack to the normal state by updating the
// return pcs to actual return addresses from the instrumentation stack and clears the
// instrumentation stack.
void MaybeRestoreInstrumentationStack() REQUIRES(Locks::mutator_lock_);
// Switches the runtime state to non-java debuggable if entry / exit hooks are no longer required
// and the runtime did not start off as java debuggable.
void MaybeSwitchRuntimeDebugState(Thread* self)
REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_);
// No thread safety analysis to get around SetQuickAllocEntryPointsInstrumented requiring
// exclusive access to mutator lock which you can't get if the runtime isn't started.
void SetEntrypointsInstrumented(bool instrumented) NO_THREAD_SAFETY_ANALYSIS;
void MethodEnterEventImpl(Thread* thread, ArtMethod* method) const
REQUIRES_SHARED(Locks::mutator_lock_);
template <typename T>
void MethodExitEventImpl(Thread* thread,
ArtMethod* method,
OptionalFrame frame,
T& return_value) const
REQUIRES_SHARED(Locks::mutator_lock_);
void DexPcMovedEventImpl(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc) const
REQUIRES_SHARED(Locks::mutator_lock_);
void BranchImpl(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t offset) const
REQUIRES_SHARED(Locks::mutator_lock_);
void WatchedFramePopImpl(Thread* thread, const ShadowFrame& frame) const
REQUIRES_SHARED(Locks::mutator_lock_);
void FieldReadEventImpl(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field) const
REQUIRES_SHARED(Locks::mutator_lock_);
void FieldWriteEventImpl(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field,
const JValue& field_value) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Read barrier-aware utility functions for accessing deoptimized_methods_
bool AddDeoptimizedMethod(ArtMethod* method) REQUIRES(Locks::mutator_lock_);
bool IsDeoptimizedMethod(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_);
bool RemoveDeoptimizedMethod(ArtMethod* method) REQUIRES(Locks::mutator_lock_);
void UpdateMethodsCodeImpl(ArtMethod* method, const void* new_code)
REQUIRES_SHARED(Locks::mutator_lock_);
// We need to run method exit hooks for two reasons:
// 1. When method exit listeners are installed
// 2. When we need to check if the caller of this method needs a deoptimization. This is needed
// only for deoptimizing the currently active invocations on stack when we deoptimize a method or
// invalidate the JITed code when redefining the classes. So future invocations don't need to do
// this check.
//
// For JITed code of non-native methods we already have a stack slot reserved for deoptimizing
// on demand and we use that stack slot to check if the caller needs a deoptimization. JITed code
// checks if there are any method exit listeners or if the stack slot is set to determine if
// method exit hooks need to be executed.
//
// For JITed JNI stubs there is no reserved stack slot for this and we just use this variable to
// check if we need to run method entry / exit hooks. This variable would be set when either of
// the above conditions are true. If we need method exit hooks only for case 2, we would call exit
// hooks for any future invocations which aren't necessary.
// QuickToInterpreterBridge and GenericJniStub also use this for same reasons.
// If calling entry / exit hooks becomes expensive we could do the same optimization we did for
// JITed code by having a reserved stack slot.
bool run_exit_hooks_;
// The required level of instrumentation. This could be one of the following values:
// kInstrumentNothing: no instrumentation support is needed
// kInstrumentWithEntryExitHooks: needs support to call method entry/exit stubs.
// kInstrumentWithInterpreter: only execute with interpreter
Instrumentation::InstrumentationLevel instrumentation_level_;
// Did the runtime request we only run in the interpreter? ie -Xint mode.
bool forced_interpret_only_;
// Do we have any listeners for method entry events? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_method_entry_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any listeners for method exit events? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_method_exit_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any listeners for method unwind events? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any listeners for dex move events? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any listeners for field read events? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_field_read_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any listeners for field write events? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_field_write_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any exception thrown listeners? Short-cut to avoid taking the instrumentation_lock_.
bool have_exception_thrown_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any frame pop listeners? Short-cut to avoid taking the instrumentation_lock_.
bool have_watched_frame_pop_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any branch listeners? Short-cut to avoid taking the instrumentation_lock_.
bool have_branch_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Do we have any exception handled listeners? Short-cut to avoid taking the
// instrumentation_lock_.
bool have_exception_handled_listeners_ GUARDED_BY(Locks::mutator_lock_);
// Contains the instrumentation level required by each client of the instrumentation identified
// by a string key.
using InstrumentationLevelTable = SafeMap<const char*, InstrumentationLevel>;
InstrumentationLevelTable requested_instrumentation_levels_ GUARDED_BY(Locks::mutator_lock_);
// The event listeners, written to with the mutator_lock_ exclusively held.
// Mutators must be able to iterate over these lists concurrently, that is, with listeners being
// added or removed while iterating. The modifying thread holds exclusive lock,
// so other threads cannot iterate (i.e. read the data of the list) at the same time but they
// do keep iterators that need to remain valid. This is the reason these listeners are std::list
// and not for example std::vector: the existing storage for a std::list does not move.
// Note that mutators cannot make a copy of these lists before iterating, as the instrumentation
// listeners can also be deleted concurrently.
// As a result, these lists are never trimmed. That's acceptable given the low number of
// listeners we have.
std::list<InstrumentationListener*> method_entry_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> method_exit_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> branch_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> field_read_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> field_write_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> exception_thrown_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> watched_frame_pop_listeners_ GUARDED_BY(Locks::mutator_lock_);
std::list<InstrumentationListener*> exception_handled_listeners_ GUARDED_BY(Locks::mutator_lock_);
// The set of methods being deoptimized (by the debugger) which must be executed with interpreter
// only.
std::unordered_set<ArtMethod*> deoptimized_methods_ GUARDED_BY(Locks::mutator_lock_);
// Current interpreter handler table. This is updated each time the thread state flags are
// modified.
// Greater than 0 if quick alloc entry points instrumented.
size_t quick_alloc_entry_points_instrumentation_counter_;
// alloc_entrypoints_instrumented_ is only updated with all the threads suspended, this is done
// to prevent races with the GC where the GC relies on thread suspension only see
// alloc_entrypoints_instrumented_ change during suspend points.
bool alloc_entrypoints_instrumented_;
friend class InstrumentationTest; // For GetCurrentInstrumentationLevel and ConfigureStubs.
friend class InstrumentationStackPopper; // For popping instrumentation frames.
friend void InstrumentationInstallStack(Thread*, bool);
DISALLOW_COPY_AND_ASSIGN(Instrumentation);
};
std::ostream& operator<<(std::ostream& os, Instrumentation::InstrumentationEvent rhs);
std::ostream& operator<<(std::ostream& os, Instrumentation::InstrumentationLevel rhs);
} // namespace instrumentation
} // namespace art
#endif // ART_RUNTIME_INSTRUMENTATION_H_