/* * 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 #include #include #include #include #include #include #include "arch/instruction_set.h" #include "base/locks.h" #include "base/macros.h" #include "base/pointer_size.h" #include "base/safe_map.h" #include "gc_root.h" #include "jvalue.h" #include "offsets.h" namespace art HIDDEN { namespace mirror { class Class; class Object; class Throwable; } // namespace mirror class ArtField; class ArtMethod; class Context; template class Handle; template 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>; // 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& 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 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 this_object, ArtMethod* method, uint32_t dex_pc, ArtField* field) = 0; virtual void FieldWritten(Thread* thread, Handle this_object, ArtMethod* method, uint32_t dex_pc, ArtField* field, Handle field_value) REQUIRES_SHARED(Locks::mutator_lock_); // Call-back for when we write into a field. virtual void FieldWritten(Thread* thread, Handle 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 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 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([[maybe_unused]] Thread* thread, [[maybe_unused]] const ShadowFrame& frame) 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& 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 }; static constexpr uint8_t kFastTraceListeners = 0b01; static constexpr uint8_t kSlowMethodEntryExitListeners = 0b10; 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_slow_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). EXPORT void AddListener(InstrumentationListener* listener, uint32_t events, bool is_trace_listener = false) REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_); // Removes listeners for the specified events. EXPORT void RemoveListener(InstrumentationListener* listener, uint32_t events, bool is_trace_listener = false) 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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. EXPORT 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_ != 0; } bool HasMethodExitListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { return have_method_exit_listeners_ != 0; } bool HasFastMethodEntryListenersOnly() const REQUIRES_SHARED(Locks::mutator_lock_) { return have_method_entry_listeners_ == kFastTraceListeners; } bool HasFastMethodExitListenersOnly() const REQUIRES_SHARED(Locks::mutator_lock_) { return have_method_exit_listeners_ == kFastTraceListeners; } 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 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 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 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 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 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 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_); // Deoptimize upon pending exception or if the caller requires it. Returns a long jump context if // a deoptimization is needed and taken. std::unique_ptr 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 klass) REQUIRES_SHARED(Locks::mutator_lock_); void InstallStubsForMethod(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_); EXPORT 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. // force_deopt indicates whether the frames need to deoptimize or not. EXPORT void InstrumentThreadStack(Thread* thread, bool force_deopt) REQUIRES(Locks::mutator_lock_); void InstrumentAllThreadStacks(bool force_deopt) 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. EXPORT 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& methods, MutableHandle& exception) REQUIRES_SHARED(Locks::mutator_lock_); EXPORT 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 void MethodExitEventImpl(Thread* thread, ArtMethod* method, OptionalFrame frame, T& return_value) const REQUIRES_SHARED(Locks::mutator_lock_); void DexPcMovedEventImpl(Thread* thread, ObjPtr 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 this_object, ArtMethod* method, uint32_t dex_pc, ArtField* field) const REQUIRES_SHARED(Locks::mutator_lock_); void FieldWriteEventImpl(Thread* thread, ObjPtr 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_; // For method entry / exit events, we maintain fast trace listeners in a separate list to make // implementation of fast trace listeners more efficient by JITing the code to handle fast trace // events. We use a uint8_t (and not bool) to encode if there are none / fast / slow listeners. // Do we have any listeners for method entry events. uint8_t have_method_entry_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any listeners for method exit events. uint8_t have_method_exit_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any listeners for method unwind events? bool have_method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any listeners for dex move events? bool have_dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any listeners for field read events? bool have_field_read_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any listeners for field write events? bool have_field_write_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any exception thrown listeners? bool have_exception_thrown_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any frame pop listeners? bool have_watched_frame_pop_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any branch listeners? bool have_branch_listeners_ GUARDED_BY(Locks::mutator_lock_); // Do we have any exception handled listeners? 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; 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 method_entry_slow_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list method_entry_fast_trace_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list method_exit_slow_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list method_exit_fast_trace_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list branch_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list field_read_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list field_write_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list exception_thrown_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list watched_frame_pop_listeners_ GUARDED_BY(Locks::mutator_lock_); std::list 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 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_