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android / platform / art / 5f3c7ebf331e336b88842b8ce5ff2bf56f75307a / . / runtime / instrumentation.cc
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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "instrumentation.h"
#include <functional>
#include <optional>
#include <sstream>
#include <android-base/logging.h>
#include "arch/context.h"
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/atomic.h"
#include "base/callee_save_type.h"
#include "class_linker.h"
#include "debugger.h"
#include "dex/dex_file-inl.h"
#include "dex/dex_file_types.h"
#include "dex/dex_instruction-inl.h"
#include "entrypoints/quick/quick_alloc_entrypoints.h"
#include "entrypoints/quick/quick_entrypoints.h"
#include "entrypoints/runtime_asm_entrypoints.h"
#include "gc_root-inl.h"
#include "interpreter/interpreter.h"
#include "interpreter/interpreter_common.h"
#include "jit/jit.h"
#include "jit/jit_code_cache.h"
#include "jvalue-inl.h"
#include "jvalue.h"
#include "mirror/class-inl.h"
#include "mirror/dex_cache.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "nterp_helpers.h"
#include "nth_caller_visitor.h"
#include "oat_file_manager.h"
#include "oat_quick_method_header.h"
#include "runtime-inl.h"
#include "thread.h"
#include "thread_list.h"
namespace art {
extern "C" NO_RETURN void artDeoptimize(Thread* self);
extern "C" NO_RETURN void artDeliverPendingExceptionFromCode(Thread* self);
namespace instrumentation {
constexpr bool kVerboseInstrumentation = false;
void InstrumentationListener::MethodExited(
Thread* thread,
ArtMethod* method,
OptionalFrame frame,
MutableHandle<mirror::Object>& return_value) {
DCHECK_EQ(method->GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetReturnTypePrimitive(),
Primitive::kPrimNot);
const void* original_ret = return_value.Get();
JValue v;
v.SetL(return_value.Get());
MethodExited(thread, method, frame, v);
DCHECK(original_ret == v.GetL()) << "Return value changed";
}
void InstrumentationListener::FieldWritten(Thread* thread,
Handle<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field,
Handle<mirror::Object> field_value) {
DCHECK(!field->IsPrimitiveType());
JValue v;
v.SetL(field_value.Get());
FieldWritten(thread, this_object, method, dex_pc, field, v);
}
// Instrumentation works on non-inlined frames by updating returned PCs
// of compiled frames.
static constexpr StackVisitor::StackWalkKind kInstrumentationStackWalk =
StackVisitor::StackWalkKind::kSkipInlinedFrames;
class InstallStubsClassVisitor : public ClassVisitor {
public:
explicit InstallStubsClassVisitor(Instrumentation* instrumentation)
: instrumentation_(instrumentation) {}
bool operator()(ObjPtr<mirror::Class> klass) override REQUIRES(Locks::mutator_lock_) {
instrumentation_->InstallStubsForClass(klass.Ptr());
return true; // we visit all classes.
}
private:
Instrumentation* const instrumentation_;
};
Instrumentation::Instrumentation()
: current_force_deopt_id_(0),
instrumentation_stubs_installed_(false),
instrumentation_level_(InstrumentationLevel::kInstrumentNothing),
forced_interpret_only_(false),
have_method_entry_listeners_(false),
have_method_exit_listeners_(false),
have_method_unwind_listeners_(false),
have_dex_pc_listeners_(false),
have_field_read_listeners_(false),
have_field_write_listeners_(false),
have_exception_thrown_listeners_(false),
have_watched_frame_pop_listeners_(false),
have_branch_listeners_(false),
have_exception_handled_listeners_(false),
quick_alloc_entry_points_instrumentation_counter_(0),
alloc_entrypoints_instrumented_(false) {
}
bool Instrumentation::ProcessMethodUnwindCallbacks(Thread* self,
std::queue<ArtMethod*>& methods,
MutableHandle<mirror::Throwable>& exception) {
DCHECK(!self->IsExceptionPending());
if (!HasMethodUnwindListeners()) {
return true;
}
if (kVerboseInstrumentation) {
LOG(INFO) << "Popping frames for exception " << exception->Dump();
}
// The instrumentation events expect the exception to be set.
self->SetException(exception.Get());
bool new_exception_thrown = false;
// Process callbacks for all methods that would be unwound until a new exception is thrown.
while (!methods.empty()) {
ArtMethod* method = methods.front();
methods.pop();
if (kVerboseInstrumentation) {
LOG(INFO) << "Popping for unwind " << method->PrettyMethod();
}
if (method->IsRuntimeMethod()) {
continue;
}
// Notify listeners of method unwind.
// TODO: improve the dex_pc information here.
uint32_t dex_pc = dex::kDexNoIndex;
MethodUnwindEvent(self, method, dex_pc);
new_exception_thrown = self->GetException() != exception.Get();
if (new_exception_thrown) {
break;
}
}
exception.Assign(self->GetException());
self->ClearException();
if (kVerboseInstrumentation && new_exception_thrown) {
LOG(INFO) << "Did partial pop of frames due to new exception";
}
return !new_exception_thrown;
}
void Instrumentation::InstallStubsForClass(ObjPtr<mirror::Class> klass) {
if (!klass->IsResolved()) {
// We need the class to be resolved to install/uninstall stubs. Otherwise its methods
// could not be initialized or linked with regards to class inheritance.
} else if (klass->IsErroneousResolved()) {
// We can't execute code in a erroneous class: do nothing.
} else {
for (ArtMethod& method : klass->GetMethods(kRuntimePointerSize)) {
InstallStubsForMethod(&method);
}
}
}
static bool CanHandleInitializationCheck(const void* code) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
return class_linker->IsQuickResolutionStub(code) ||
class_linker->IsQuickToInterpreterBridge(code) ||
class_linker->IsQuickGenericJniStub(code) ||
(code == interpreter::GetNterpWithClinitEntryPoint()) ||
(code == GetQuickInstrumentationEntryPoint());
}
static bool IsProxyInit(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) {
// Annoyingly this can be called before we have actually initialized WellKnownClasses so therefore
// we also need to check this based on the declaring-class descriptor. The check is valid because
// Proxy only has a single constructor.
ArtMethod* well_known_proxy_init = WellKnownClasses::java_lang_reflect_Proxy_init;
if (well_known_proxy_init == method) {
return true;
}
if (well_known_proxy_init != nullptr) {
return false;
}
return method->IsConstructor() && !method->IsStatic() &&
method->GetDeclaringClass()->DescriptorEquals("Ljava/lang/reflect/Proxy;");
}
// Returns true if we need entry exit stub to call entry hooks. JITed code
// directly call entry / exit hooks and don't need the stub.
static bool CodeNeedsEntryExitStub(const void* entry_point, ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) {
// Proxy.init should never have entry/exit stubs.
if (IsProxyInit(method)) {
return false;
}
// In some tests runtime isn't setup fully and hence the entry points could
// be nullptr.
if (entry_point == nullptr) {
return true;
}
// Code running in the interpreter doesn't need entry/exit stubs.
if (Runtime::Current()->GetClassLinker()->IsQuickToInterpreterBridge(entry_point)) {
return false;
}
// When jiting code for debuggable runtimes / instrumentation is active we generate the code to
// call method entry / exit hooks when required. Hence it is not required to update to
// instrumentation entry point for JITed code in debuggable mode.
jit::Jit* jit = Runtime::Current()->GetJit();
if (jit != nullptr && jit->GetCodeCache()->ContainsPc(entry_point)) {
// If JITed code was compiled with instrumentation support we don't need entry / exit stub.
OatQuickMethodHeader* header = OatQuickMethodHeader::FromEntryPoint(entry_point);
return !CodeInfo::IsDebuggable(header->GetOptimizedCodeInfoPtr());
}
// GenericJni trampoline can handle entry / exit hooks in debuggable runtimes.
if (Runtime::Current()->GetClassLinker()->IsQuickGenericJniStub(entry_point) &&
Runtime::Current()->IsJavaDebuggable()) {
return false;
}
return true;
}
static void UpdateEntryPoints(ArtMethod* method, const void* quick_code)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (kIsDebugBuild) {
if (NeedsClinitCheckBeforeCall(method) &&
!method->GetDeclaringClass()->IsVisiblyInitialized()) {
CHECK(CanHandleInitializationCheck(quick_code));
}
jit::Jit* jit = Runtime::Current()->GetJit();
if (jit != nullptr && jit->GetCodeCache()->ContainsPc(quick_code)) {
// Ensure we always have the thumb entrypoint for JIT on arm32.
if (kRuntimeISA == InstructionSet::kArm) {
CHECK_EQ(reinterpret_cast<uintptr_t>(quick_code) & 1, 1u);
}
}
if (IsProxyInit(method)) {
CHECK_NE(quick_code, GetQuickInstrumentationEntryPoint());
}
const Instrumentation* instr = Runtime::Current()->GetInstrumentation();
if (instr->EntryExitStubsInstalled()) {
DCHECK(quick_code == GetQuickInstrumentationEntryPoint() ||
!CodeNeedsEntryExitStub(quick_code, method));
}
}
// If the method is from a boot image, don't dirty it if the entrypoint
// doesn't change.
if (method->GetEntryPointFromQuickCompiledCode() != quick_code) {
method->SetEntryPointFromQuickCompiledCode(quick_code);
}
}
bool Instrumentation::NeedsDexPcEvents(ArtMethod* method, Thread* thread) {
return (InterpretOnly(method) || thread->IsForceInterpreter()) && HasDexPcListeners();
}
bool Instrumentation::InterpretOnly(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) {
if (method->IsNative()) {
return false;
}
return InterpretOnly() || IsDeoptimized(method);
}
static bool CanUseAotCode(const void* quick_code)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (quick_code == nullptr) {
return false;
}
Runtime* runtime = Runtime::Current();
// For simplicity, we never use AOT code for debuggable.
if (runtime->IsJavaDebuggable()) {
return false;
}
if (runtime->IsNativeDebuggable()) {
DCHECK(runtime->UseJitCompilation() && runtime->GetJit()->JitAtFirstUse());
// If we are doing native debugging, ignore application's AOT code,
// since we want to JIT it (at first use) with extra stackmaps for native
// debugging. We keep however all AOT code from the boot image,
// since the JIT-at-first-use is blocking and would result in non-negligible
// startup performance impact.
return runtime->GetHeap()->IsInBootImageOatFile(quick_code);
}
return true;
}
static bool CanUseNterp(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) {
return interpreter::CanRuntimeUseNterp() &&
CanMethodUseNterp(method) &&
method->GetDeclaringClass()->IsVerified();
}
static const void* GetOptimizedCodeFor(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(!Runtime::Current()->GetInstrumentation()->InterpretOnly(method));
CHECK(method->IsInvokable()) << method->PrettyMethod();
if (method->IsProxyMethod()) {
return GetQuickProxyInvokeHandler();
}
// In debuggable mode, we can only use AOT code for native methods.
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
const void* aot_code = method->GetOatMethodQuickCode(class_linker->GetImagePointerSize());
if (CanUseAotCode(aot_code)) {
return aot_code;
}
// If the method has been precompiled, there can be a JIT version.
jit::Jit* jit = Runtime::Current()->GetJit();
if (jit != nullptr) {
const void* code = jit->GetCodeCache()->GetSavedEntryPointOfPreCompiledMethod(method);
if (code != nullptr) {
return code;
}
}
// We need to check if the class has been verified for setting up nterp, as
// the verifier could punt the method to the switch interpreter in case we
// need to do lock counting.
if (CanUseNterp(method)) {
return interpreter::GetNterpEntryPoint();
}
return method->IsNative() ? GetQuickGenericJniStub() : GetQuickToInterpreterBridge();
}
void Instrumentation::InitializeMethodsCode(ArtMethod* method, const void* aot_code)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (!method->IsInvokable()) {
DCHECK(method->GetEntryPointFromQuickCompiledCode() == nullptr ||
Runtime::Current()->GetClassLinker()->IsQuickToInterpreterBridge(
method->GetEntryPointFromQuickCompiledCode()));
UpdateEntryPoints(method, GetQuickToInterpreterBridge());
return;
}
// Use instrumentation entrypoints if instrumentation is installed.
if (UNLIKELY(EntryExitStubsInstalled()) && !IsProxyInit(method)) {
if (!method->IsNative() && InterpretOnly(method)) {
UpdateEntryPoints(method, GetQuickToInterpreterBridge());
} else {
UpdateEntryPoints(method, GetQuickInstrumentationEntryPoint());
}
return;
}
if (UNLIKELY(IsForcedInterpretOnly() || IsDeoptimized(method))) {
UpdateEntryPoints(
method, method->IsNative() ? GetQuickGenericJniStub() : GetQuickToInterpreterBridge());
return;
}
// Special case if we need an initialization check.
if (NeedsClinitCheckBeforeCall(method) && !method->GetDeclaringClass()->IsVisiblyInitialized()) {
// If we have code but the method needs a class initialization check before calling
// that code, install the resolution stub that will perform the check.
// It will be replaced by the proper entry point by ClassLinker::FixupStaticTrampolines
// after initializing class (see ClassLinker::InitializeClass method).
// Note: this mimics the logic in image_writer.cc that installs the resolution
// stub only if we have compiled code or we can execute nterp, and the method needs a class
// initialization check.
if (aot_code != nullptr || method->IsNative() || CanUseNterp(method)) {
if (kIsDebugBuild && CanUseNterp(method)) {
// Adds some test coverage for the nterp clinit entrypoint.
UpdateEntryPoints(method, interpreter::GetNterpWithClinitEntryPoint());
} else {
UpdateEntryPoints(method, GetQuickResolutionStub());
}
} else {
UpdateEntryPoints(method, GetQuickToInterpreterBridge());
}
return;
}
// Use the provided AOT code if possible.
if (CanUseAotCode(aot_code)) {
UpdateEntryPoints(method, aot_code);
return;
}
// We check if the class is verified as we need the slow interpreter for lock verification.
// If the class is not verified, This will be updated in
// ClassLinker::UpdateClassAfterVerification.
if (CanUseNterp(method)) {
UpdateEntryPoints(method, interpreter::GetNterpEntryPoint());
return;
}
// Use default entrypoints.
UpdateEntryPoints(
method, method->IsNative() ? GetQuickGenericJniStub() : GetQuickToInterpreterBridge());
}
void Instrumentation::InstallStubsForMethod(ArtMethod* method) {
if (!method->IsInvokable() || method->IsProxyMethod()) {
// Do not change stubs for these methods.
return;
}
// Don't stub Proxy.<init>. Note that the Proxy class itself is not a proxy class.
// TODO We should remove the need for this since it means we cannot always correctly detect calls
// to Proxy.<init>
if (IsProxyInit(method)) {
return;
}
// If the instrumentation needs to go through the interpreter, just update the
// entrypoint to interpreter.
if (InterpretOnly(method)) {
UpdateEntryPoints(method, GetQuickToInterpreterBridge());
return;
}
if (EntryExitStubsInstalled()) {
// Install the instrumentation entry point if needed.
if (CodeNeedsEntryExitStub(method->GetEntryPointFromQuickCompiledCode(), method)) {
UpdateEntryPoints(method, GetQuickInstrumentationEntryPoint());
}
return;
}
// We're being asked to restore the entrypoints after instrumentation.
CHECK_EQ(instrumentation_level_, InstrumentationLevel::kInstrumentNothing);
// We need to have the resolution stub still if the class is not initialized.
if (NeedsClinitCheckBeforeCall(method) && !method->GetDeclaringClass()->IsVisiblyInitialized()) {
UpdateEntryPoints(method, GetQuickResolutionStub());
return;
}
UpdateEntryPoints(method, GetOptimizedCodeFor(method));
}
void Instrumentation::UpdateEntrypointsForDebuggable() {
Runtime* runtime = Runtime::Current();
// If we are transitioning from non-debuggable to debuggable, we patch
// entry points of methods to remove any aot / JITed entry points.
InstallStubsClassVisitor visitor(this);
runtime->GetClassLinker()->VisitClasses(&visitor);
}
// Places the instrumentation exit pc as the return PC for every quick frame. This also allows
// deoptimization of quick frames to interpreter frames. When force_deopt is
// true the frames have to be deoptimized. If the frame has a deoptimization
// stack slot (all Jited frames), it is set to true to indicate this. For frames
// that do not have this slot, the force_deopt_id on the InstrumentationStack is
// used to check if the frame needs to be deoptimized. When force_deopt is false
// we just instrument the stack for method entry / exit hooks.
// Since we may already have done this previously, we need to push new instrumentation frame before
// existing instrumentation frames.
void InstrumentationInstallStack(Thread* thread, void* arg, bool deopt_all_frames)
REQUIRES(Locks::mutator_lock_) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
struct InstallStackVisitor final : public StackVisitor {
InstallStackVisitor(Thread* thread_in,
Context* context,
uintptr_t instrumentation_exit_pc,
uint64_t force_deopt_id,
bool deopt_all_frames)
: StackVisitor(thread_in, context, kInstrumentationStackWalk),
instrumentation_stack_(thread_in->GetInstrumentationStack()),
instrumentation_exit_pc_(instrumentation_exit_pc),
reached_existing_instrumentation_frames_(false),
force_deopt_id_(force_deopt_id),
deopt_all_frames_(deopt_all_frames),
runtime_methods_need_deopt_check_(false) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* m = GetMethod();
if (m == nullptr || m->IsRuntimeMethod()) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Skipping upcall / runtime method. Frame " << GetFrameId();
}
return true; // Ignore upcalls and runtime methods.
}
if (GetCurrentQuickFrame() == nullptr) {
// Since we are updating the instrumentation related information we have to recalculate
// NeedsDexPcEvents. For example, when a new method or thread is deoptimized / interpreter
// stubs are installed the NeedsDexPcEvents could change for the shadow frames on the stack.
// If we don't update it here we would miss reporting dex pc events which is incorrect.
ShadowFrame* shadow_frame = GetCurrentShadowFrame();
DCHECK(shadow_frame != nullptr);
shadow_frame->SetNotifyDexPcMoveEvents(
Runtime::Current()->GetInstrumentation()->NeedsDexPcEvents(GetMethod(), GetThread()));
if (kVerboseInstrumentation) {
LOG(INFO) << "Pushing shadow frame method " << m->PrettyMethod();
}
stack_methods_.push_back(m);
return true; // Continue.
}
uintptr_t return_pc = GetReturnPc();
if (kVerboseInstrumentation) {
LOG(INFO) << " Installing exit stub in " << DescribeLocation();
}
if (return_pc == instrumentation_exit_pc_) {
auto it = instrumentation_stack_->find(GetReturnPcAddr());
CHECK(it != instrumentation_stack_->end());
const InstrumentationStackFrame& frame = it->second;
// We've reached a frame which has already been installed with instrumentation exit stub.
// We should have already installed instrumentation or be interpreter on previous frames.
reached_existing_instrumentation_frames_ = true;
// Trampolines get replaced with their actual method in the stack,
// so don't do the check below for runtime methods.
if (!frame.method_->IsRuntimeMethod()) {
CHECK_EQ(m->GetNonObsoleteMethod(), frame.method_->GetNonObsoleteMethod())
<< "Expected " << ArtMethod::PrettyMethod(m)
<< ", Found " << ArtMethod::PrettyMethod(frame.method_);
}
return_pc = frame.return_pc_;
if (kVerboseInstrumentation) {
LOG(INFO) << "Ignoring already instrumented " << frame.Dump();
}
} else {
if (!m->IsRuntimeMethod()) {
// Record the method so we can call method entry callbacks for all non-runtime methods on
// the stack. Runtime methods don't need method entry callbacks.
// TODO(232212577): Add tests to check the validity of the tracefiles generated.
// Currently the tracing tests only check a trace file is generated.
stack_methods_.push_back(m);
}
if (m->IsNative() && Runtime::Current()->IsJavaDebuggable()) {
// Native methods in debuggable runtimes don't use instrumentation stubs.
return true;
}
// If it is a JITed frame then just set the deopt bit if required
// otherwise continue
const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
if (method_header != nullptr && method_header->HasShouldDeoptimizeFlag()) {
if (deopt_all_frames_) {
runtime_methods_need_deopt_check_ = true;
SetShouldDeoptimizeFlag(DeoptimizeFlagValue::kForceDeoptForRedefinition);
}
SetShouldDeoptimizeFlag(DeoptimizeFlagValue::kCheckCallerForDeopt);
return true;
}
CHECK_NE(return_pc, 0U);
DCHECK(!m->IsRuntimeMethod());
if (UNLIKELY(reached_existing_instrumentation_frames_)) {
// We already saw an existing instrumentation frame so this should be a runtime-method
// inserted by the interpreter or runtime.
std::string thread_name;
GetThread()->GetThreadName(thread_name);
LOG(FATAL) << "While walking " << thread_name << " found unexpected non-runtime method"
<< " without instrumentation exit return or interpreter frame."
<< " method is " << GetMethod()->PrettyMethod()
<< " return_pc is " << std::hex << return_pc;
UNREACHABLE();
}
InstrumentationStackFrame instrumentation_frame(
GetThisObject().Ptr(), m, return_pc, false, force_deopt_id_);
if (kVerboseInstrumentation) {
LOG(INFO) << "Pushing frame " << instrumentation_frame.Dump();
}
instrumentation_stack_->insert({GetReturnPcAddr(), instrumentation_frame});
SetReturnPc(instrumentation_exit_pc_);
}
return true; // Continue.
}
std::map<uintptr_t, InstrumentationStackFrame>* const instrumentation_stack_;
std::vector<ArtMethod*> stack_methods_;
const uintptr_t instrumentation_exit_pc_;
bool reached_existing_instrumentation_frames_;
uint64_t force_deopt_id_;
bool deopt_all_frames_;
bool runtime_methods_need_deopt_check_;
};
if (kVerboseInstrumentation) {
std::string thread_name;
thread->GetThreadName(thread_name);
LOG(INFO) << "Installing exit stubs in " << thread_name;
}
Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
std::unique_ptr<Context> context(Context::Create());
uintptr_t instrumentation_exit_pc = reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc());
InstallStackVisitor visitor(thread,
context.get(),
instrumentation_exit_pc,
instrumentation->current_force_deopt_id_,
deopt_all_frames);
visitor.WalkStack(true);
if (visitor.runtime_methods_need_deopt_check_) {
thread->SetDeoptCheckRequired(true);
}
if (instrumentation->ShouldNotifyMethodEnterExitEvents()) {
// Create method enter events for all methods currently on the thread's stack. We only do this
// if we haven't already processed the method enter events.
for (auto smi = visitor.stack_methods_.rbegin(); smi != visitor.stack_methods_.rend(); smi++) {
instrumentation->MethodEnterEvent(thread, *smi);
}
}
thread->VerifyStack();
}
void UpdateNeedsDexPcEventsOnStack(Thread* thread) REQUIRES(Locks::mutator_lock_) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
struct InstallStackVisitor final : public StackVisitor {
InstallStackVisitor(Thread* thread_in, Context* context)
: StackVisitor(thread_in, context, kInstrumentationStackWalk) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
ShadowFrame* shadow_frame = GetCurrentShadowFrame();
if (shadow_frame != nullptr) {
shadow_frame->SetNotifyDexPcMoveEvents(
Runtime::Current()->GetInstrumentation()->NeedsDexPcEvents(GetMethod(), GetThread()));
}
return true;
}
};
if (kVerboseInstrumentation) {
std::string thread_name;
thread->GetThreadName(thread_name);
LOG(INFO) << "Updating DexPcMoveEvents on shadow frames on stack " << thread_name;
}
std::unique_ptr<Context> context(Context::Create());
InstallStackVisitor visitor(thread, context.get());
visitor.WalkStack(true);
}
void Instrumentation::InstrumentThreadStack(Thread* thread, bool force_deopt) {
instrumentation_stubs_installed_ = true;
InstrumentationInstallStack(thread, this, force_deopt);
}
// Removes the instrumentation exit pc as the return PC for every quick frame.
static void InstrumentationRestoreStack(Thread* thread, void* arg)
REQUIRES(Locks::mutator_lock_) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
struct RestoreStackVisitor final : public StackVisitor {
RestoreStackVisitor(Thread* thread_in,
uintptr_t instrumentation_exit_pc,
Instrumentation* instrumentation)
: StackVisitor(thread_in, nullptr, kInstrumentationStackWalk),
thread_(thread_in),
instrumentation_exit_pc_(instrumentation_exit_pc),
instrumentation_(instrumentation),
instrumentation_stack_(thread_in->GetInstrumentationStack()),
frames_removed_(0),
runtime_methods_need_deopt_check_(false) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* m = GetMethod();
if (GetCurrentQuickFrame() == nullptr) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Ignoring a shadow frame. Frame " << GetFrameId()
<< " Method=" << ArtMethod::PrettyMethod(m);
}
return true; // Ignore shadow frames.
}
if (m == nullptr) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Skipping upcall. Frame " << GetFrameId();
}
return true; // Ignore upcalls and runtime methods.
}
const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
if (method_header != nullptr && method_header->HasShouldDeoptimizeFlag()) {
if (ShouldForceDeoptForRedefinition()) {
runtime_methods_need_deopt_check_ = true;
}
UnsetShouldDeoptimizeFlag(DeoptimizeFlagValue::kCheckCallerForDeopt);
}
auto it = instrumentation_stack_->find(GetReturnPcAddr());
if (it != instrumentation_stack_->end()) {
const InstrumentationStackFrame& instrumentation_frame = it->second;
if (kVerboseInstrumentation) {
LOG(INFO) << " Removing exit stub in " << DescribeLocation();
}
if (instrumentation_frame.interpreter_entry_) {
CHECK(m == Runtime::Current()->GetCalleeSaveMethod(CalleeSaveType::kSaveRefsAndArgs));
} else {
CHECK_EQ(m->GetNonObsoleteMethod(),
instrumentation_frame.method_->GetNonObsoleteMethod())
<< ArtMethod::PrettyMethod(m)
<< " and " << instrumentation_frame.method_->GetNonObsoleteMethod()->PrettyMethod();
}
SetReturnPc(instrumentation_frame.return_pc_);
if (instrumentation_->ShouldNotifyMethodEnterExitEvents() &&
!m->IsRuntimeMethod()) {
// Create the method exit events. As the methods didn't really exit the result is 0.
// We only do this if no debugger is attached to prevent from posting events twice.
JValue val;
instrumentation_->MethodExitEvent(thread_, m, OptionalFrame{}, val);
}
frames_removed_++;
} else {
if (kVerboseInstrumentation) {
LOG(INFO) << " No exit stub in " << DescribeLocation();
}
}
return true; // Continue.
}
Thread* const thread_;
const uintptr_t instrumentation_exit_pc_;
Instrumentation* const instrumentation_;
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* const instrumentation_stack_;
size_t frames_removed_;
bool runtime_methods_need_deopt_check_;
};
if (kVerboseInstrumentation) {
std::string thread_name;
thread->GetThreadName(thread_name);
LOG(INFO) << "Removing exit stubs in " << thread_name;
}
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* stack =
thread->GetInstrumentationStack();
Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
uintptr_t instrumentation_exit_pc =
reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc());
RestoreStackVisitor visitor(thread, instrumentation_exit_pc, instrumentation);
visitor.WalkStack(true);
DCHECK_IMPLIES(visitor.runtime_methods_need_deopt_check_, thread->IsDeoptCheckRequired());
if (!visitor.runtime_methods_need_deopt_check_) {
thread->SetDeoptCheckRequired(false);
}
CHECK_EQ(visitor.frames_removed_, stack->size());
stack->clear();
}
void Instrumentation::DeoptimizeAllThreadFrames() {
Thread* self = Thread::Current();
MutexLock mu(self, *Locks::thread_list_lock_);
ThreadList* tl = Runtime::Current()->GetThreadList();
tl->ForEach([&](Thread* t) {
Locks::mutator_lock_->AssertExclusiveHeld(self);
InstrumentThreadStack(t, /* deopt_all_frames= */ true);
});
current_force_deopt_id_++;
}
static bool HasEvent(Instrumentation::InstrumentationEvent expected, uint32_t events) {
return (events & expected) != 0;
}
static void PotentiallyAddListenerTo(Instrumentation::InstrumentationEvent event,
uint32_t events,
std::list<InstrumentationListener*>& list,
InstrumentationListener* listener,
bool* has_listener)
REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
if (!HasEvent(event, events)) {
return;
}
// If there is a free slot in the list, we insert the listener in that slot.
// Otherwise we add it to the end of the list.
auto it = std::find(list.begin(), list.end(), nullptr);
if (it != list.end()) {
*it = listener;
} else {
list.push_back(listener);
}
*has_listener = true;
}
void Instrumentation::AddListener(InstrumentationListener* listener, uint32_t events) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
PotentiallyAddListenerTo(kMethodEntered,
events,
method_entry_listeners_,
listener,
&have_method_entry_listeners_);
PotentiallyAddListenerTo(kMethodExited,
events,
method_exit_listeners_,
listener,
&have_method_exit_listeners_);
PotentiallyAddListenerTo(kMethodUnwind,
events,
method_unwind_listeners_,
listener,
&have_method_unwind_listeners_);
PotentiallyAddListenerTo(kBranch,
events,
branch_listeners_,
listener,
&have_branch_listeners_);
PotentiallyAddListenerTo(kDexPcMoved,
events,
dex_pc_listeners_,
listener,
&have_dex_pc_listeners_);
PotentiallyAddListenerTo(kFieldRead,
events,
field_read_listeners_,
listener,
&have_field_read_listeners_);
PotentiallyAddListenerTo(kFieldWritten,
events,
field_write_listeners_,
listener,
&have_field_write_listeners_);
PotentiallyAddListenerTo(kExceptionThrown,
events,
exception_thrown_listeners_,
listener,
&have_exception_thrown_listeners_);
PotentiallyAddListenerTo(kWatchedFramePop,
events,
watched_frame_pop_listeners_,
listener,
&have_watched_frame_pop_listeners_);
PotentiallyAddListenerTo(kExceptionHandled,
events,
exception_handled_listeners_,
listener,
&have_exception_handled_listeners_);
if (HasEvent(kDexPcMoved, events)) {
MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
for (Thread* thread : Runtime::Current()->GetThreadList()->GetList()) {
UpdateNeedsDexPcEventsOnStack(thread);
}
}
}
static void PotentiallyRemoveListenerFrom(Instrumentation::InstrumentationEvent event,
uint32_t events,
std::list<InstrumentationListener*>& list,
InstrumentationListener* listener,
bool* has_listener)
REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
if (!HasEvent(event, events)) {
return;
}
auto it = std::find(list.begin(), list.end(), listener);
if (it != list.end()) {
// Just update the entry, do not remove from the list. Removing entries in the list
// is unsafe when mutators are iterating over it.
*it = nullptr;
}
// Check if the list contains any non-null listener, and update 'has_listener'.
for (InstrumentationListener* l : list) {
if (l != nullptr) {
*has_listener = true;
return;
}
}
*has_listener = false;
}
void Instrumentation::RemoveListener(InstrumentationListener* listener, uint32_t events) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
PotentiallyRemoveListenerFrom(kMethodEntered,
events,
method_entry_listeners_,
listener,
&have_method_entry_listeners_);
PotentiallyRemoveListenerFrom(kMethodExited,
events,
method_exit_listeners_,
listener,
&have_method_exit_listeners_);
PotentiallyRemoveListenerFrom(kMethodUnwind,
events,
method_unwind_listeners_,
listener,
&have_method_unwind_listeners_);
PotentiallyRemoveListenerFrom(kBranch,
events,
branch_listeners_,
listener,
&have_branch_listeners_);
PotentiallyRemoveListenerFrom(kDexPcMoved,
events,
dex_pc_listeners_,
listener,
&have_dex_pc_listeners_);
PotentiallyRemoveListenerFrom(kFieldRead,
events,
field_read_listeners_,
listener,
&have_field_read_listeners_);
PotentiallyRemoveListenerFrom(kFieldWritten,
events,
field_write_listeners_,
listener,
&have_field_write_listeners_);
PotentiallyRemoveListenerFrom(kExceptionThrown,
events,
exception_thrown_listeners_,
listener,
&have_exception_thrown_listeners_);
PotentiallyRemoveListenerFrom(kWatchedFramePop,
events,
watched_frame_pop_listeners_,
listener,
&have_watched_frame_pop_listeners_);
PotentiallyRemoveListenerFrom(kExceptionHandled,
events,
exception_handled_listeners_,
listener,
&have_exception_handled_listeners_);
if (HasEvent(kDexPcMoved, events)) {
MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
for (Thread* thread : Runtime::Current()->GetThreadList()->GetList()) {
UpdateNeedsDexPcEventsOnStack(thread);
}
}
}
Instrumentation::InstrumentationLevel Instrumentation::GetCurrentInstrumentationLevel() const {
return instrumentation_level_;
}
bool Instrumentation::RequiresInstrumentationInstallation(InstrumentationLevel new_level) const {
// We need to reinstall instrumentation if we go to a different level.
return GetCurrentInstrumentationLevel() != new_level;
}
void Instrumentation::ConfigureStubs(const char* key, InstrumentationLevel desired_level) {
// Store the instrumentation level for this key or remove it.
if (desired_level == InstrumentationLevel::kInstrumentNothing) {
// The client no longer needs instrumentation.
requested_instrumentation_levels_.erase(key);
} else {
// The client needs instrumentation.
requested_instrumentation_levels_.Overwrite(key, desired_level);
}
UpdateStubs();
}
void Instrumentation::UpdateInstrumentationLevel(InstrumentationLevel requested_level) {
instrumentation_level_ = requested_level;
}
void Instrumentation::MaybeRestoreInstrumentationStack() {
// Restore stack only if there is no method currently deoptimized.
if (!IsDeoptimizedMethodsEmpty()) {
return;
}
Thread* self = Thread::Current();
MutexLock mu(self, *Locks::thread_list_lock_);
bool no_remaining_deopts = true;
// Check that there are no other forced deoptimizations. Do it here so we only need to lock
// thread_list_lock once.
// The compiler gets confused on the thread annotations, so use
// NO_THREAD_SAFETY_ANALYSIS. Note that we hold the mutator lock
// exclusively at this point.
Locks::mutator_lock_->AssertExclusiveHeld(self);
Runtime::Current()->GetThreadList()->ForEach([&](Thread* t) NO_THREAD_SAFETY_ANALYSIS {
no_remaining_deopts =
no_remaining_deopts &&
!t->IsForceInterpreter() &&
!t->HasDebuggerShadowFrames() &&
std::all_of(t->GetInstrumentationStack()->cbegin(),
t->GetInstrumentationStack()->cend(),
[&](const auto& frame) REQUIRES_SHARED(Locks::mutator_lock_) {
return frame.second.force_deopt_id_ == current_force_deopt_id_;
});
});
if (no_remaining_deopts) {
Runtime::Current()->GetThreadList()->ForEach(InstrumentationRestoreStack, this);
// Only do this after restoring, as walking the stack when restoring will see
// the instrumentation exit pc.
instrumentation_stubs_installed_ = false;
}
}
void Instrumentation::UpdateStubs() {
// Look for the highest required instrumentation level.
InstrumentationLevel requested_level = InstrumentationLevel::kInstrumentNothing;
for (const auto& v : requested_instrumentation_levels_) {
requested_level = std::max(requested_level, v.second);
}
if (!RequiresInstrumentationInstallation(requested_level)) {
// We're already set.
return;
}
Thread* const self = Thread::Current();
Runtime* runtime = Runtime::Current();
Locks::mutator_lock_->AssertExclusiveHeld(self);
Locks::thread_list_lock_->AssertNotHeld(self);
UpdateInstrumentationLevel(requested_level);
InstallStubsClassVisitor visitor(this);
runtime->GetClassLinker()->VisitClasses(&visitor);
if (requested_level > InstrumentationLevel::kInstrumentNothing) {
instrumentation_stubs_installed_ = true;
MutexLock mu(self, *Locks::thread_list_lock_);
for (Thread* thread : Runtime::Current()->GetThreadList()->GetList()) {
InstrumentThreadStack(thread, /* deopt_all_frames= */ false);
}
} else {
MaybeRestoreInstrumentationStack();
}
}
static void ResetQuickAllocEntryPointsForThread(Thread* thread, void* arg ATTRIBUTE_UNUSED) {
thread->ResetQuickAllocEntryPointsForThread();
}
void Instrumentation::SetEntrypointsInstrumented(bool instrumented) {
Thread* self = Thread::Current();
Runtime* runtime = Runtime::Current();
Locks::mutator_lock_->AssertNotHeld(self);
Locks::instrument_entrypoints_lock_->AssertHeld(self);
if (runtime->IsStarted()) {
ScopedSuspendAll ssa(__FUNCTION__);
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
SetQuickAllocEntryPointsInstrumented(instrumented);
ResetQuickAllocEntryPoints();
alloc_entrypoints_instrumented_ = instrumented;
} else {
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
SetQuickAllocEntryPointsInstrumented(instrumented);
// Note: ResetQuickAllocEntryPoints only works when the runtime is started. Manually run the
// update for just this thread.
// Note: self may be null. One of those paths is setting instrumentation in the Heap
// constructor for gcstress mode.
if (self != nullptr) {
ResetQuickAllocEntryPointsForThread(self, nullptr);
}
alloc_entrypoints_instrumented_ = instrumented;
}
}
void Instrumentation::InstrumentQuickAllocEntryPoints() {
MutexLock mu(Thread::Current(), *Locks::instrument_entrypoints_lock_);
InstrumentQuickAllocEntryPointsLocked();
}
void Instrumentation::UninstrumentQuickAllocEntryPoints() {
MutexLock mu(Thread::Current(), *Locks::instrument_entrypoints_lock_);
UninstrumentQuickAllocEntryPointsLocked();
}
void Instrumentation::InstrumentQuickAllocEntryPointsLocked() {
Locks::instrument_entrypoints_lock_->AssertHeld(Thread::Current());
if (quick_alloc_entry_points_instrumentation_counter_ == 0) {
SetEntrypointsInstrumented(true);
}
++quick_alloc_entry_points_instrumentation_counter_;
}
void Instrumentation::UninstrumentQuickAllocEntryPointsLocked() {
Locks::instrument_entrypoints_lock_->AssertHeld(Thread::Current());
CHECK_GT(quick_alloc_entry_points_instrumentation_counter_, 0U);
--quick_alloc_entry_points_instrumentation_counter_;
if (quick_alloc_entry_points_instrumentation_counter_ == 0) {
SetEntrypointsInstrumented(false);
}
}
void Instrumentation::ResetQuickAllocEntryPoints() {
Runtime* runtime = Runtime::Current();
if (runtime->IsStarted()) {
MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
runtime->GetThreadList()->ForEach(ResetQuickAllocEntryPointsForThread, nullptr);
}
}
std::string Instrumentation::EntryPointString(const void* code) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
jit::Jit* jit = Runtime::Current()->GetJit();
if (class_linker->IsQuickToInterpreterBridge(code)) {
return "interpreter";
} else if (class_linker->IsQuickResolutionStub(code)) {
return "resolution";
} else if (code == GetQuickInstrumentationEntryPoint()) {
return "instrumentation";
} else if (jit != nullptr && jit->GetCodeCache()->ContainsPc(code)) {
return "jit";
} else if (code == GetInvokeObsoleteMethodStub()) {
return "obsolete";
} else if (code == interpreter::GetNterpEntryPoint()) {
return "nterp";
} else if (code == interpreter::GetNterpWithClinitEntryPoint()) {
return "nterp with clinit";
} else if (class_linker->IsQuickGenericJniStub(code)) {
return "generic jni";
} else if (Runtime::Current()->GetOatFileManager().ContainsPc(code)) {
return "oat";
}
return "unknown";
}
void Instrumentation::UpdateMethodsCodeImpl(ArtMethod* method, const void* new_code) {
if (!AreExitStubsInstalled()) {
// Fast path: no instrumentation.
DCHECK(!IsDeoptimized(method));
UpdateEntryPoints(method, new_code);
return;
}
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
if (class_linker->IsQuickToInterpreterBridge(new_code)) {
// It's always OK to update to the interpreter.
UpdateEntryPoints(method, new_code);
return;
}
if (IsDeoptimized(method)) {
DCHECK(class_linker->IsQuickToInterpreterBridge(method->GetEntryPointFromQuickCompiledCode()))
<< EntryPointString(method->GetEntryPointFromQuickCompiledCode());
// Don't update, stay deoptimized.
return;
}
if (EntryExitStubsInstalled() && CodeNeedsEntryExitStub(new_code, method)) {
DCHECK(method->GetEntryPointFromQuickCompiledCode() == GetQuickInstrumentationEntryPoint() ||
class_linker->IsQuickToInterpreterBridge(method->GetEntryPointFromQuickCompiledCode()))
<< EntryPointString(method->GetEntryPointFromQuickCompiledCode())
<< " " << method->PrettyMethod();
// If the code we want to update the method with still needs entry/exit stub, just skip.
return;
}
// At this point, we can update as asked.
UpdateEntryPoints(method, new_code);
}
void Instrumentation::UpdateNativeMethodsCodeToJitCode(ArtMethod* method, const void* new_code) {
// We don't do any read barrier on `method`'s declaring class in this code, as the JIT might
// enter here on a soon-to-be deleted ArtMethod. Updating the entrypoint is OK though, as
// the ArtMethod is still in memory.
if (EntryExitStubsInstalled() && CodeNeedsEntryExitStub(new_code, method)) {
// If stubs are installed don't update.
return;
}
UpdateEntryPoints(method, new_code);
}
void Instrumentation::UpdateMethodsCode(ArtMethod* method, const void* new_code) {
DCHECK(method->GetDeclaringClass()->IsResolved());
UpdateMethodsCodeImpl(method, new_code);
}
bool Instrumentation::AddDeoptimizedMethod(ArtMethod* method) {
if (IsDeoptimizedMethod(method)) {
// Already in the map. Return.
return false;
}
// Not found. Add it.
deoptimized_methods_.insert(method);
return true;
}
bool Instrumentation::IsDeoptimizedMethod(ArtMethod* method) {
return deoptimized_methods_.find(method) != deoptimized_methods_.end();
}
bool Instrumentation::RemoveDeoptimizedMethod(ArtMethod* method) {
auto it = deoptimized_methods_.find(method);
if (it == deoptimized_methods_.end()) {
return false;
}
deoptimized_methods_.erase(it);
return true;
}
void Instrumentation::Deoptimize(ArtMethod* method) {
CHECK(!method->IsNative());
CHECK(!method->IsProxyMethod());
CHECK(method->IsInvokable());
Thread* self = Thread::Current();
{
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
bool has_not_been_deoptimized = AddDeoptimizedMethod(method);
CHECK(has_not_been_deoptimized) << "Method " << ArtMethod::PrettyMethod(method)
<< " is already deoptimized";
}
if (!InterpreterStubsInstalled()) {
UpdateEntryPoints(method, GetQuickToInterpreterBridge());
// Install instrumentation exit stub and instrumentation frames. We may already have installed
// these previously so it will only cover the newly created frames.
instrumentation_stubs_installed_ = true;
MutexLock mu(self, *Locks::thread_list_lock_);
for (Thread* thread : Runtime::Current()->GetThreadList()->GetList()) {
// This isn't a strong deopt. We deopt this method if it is still in the
// deopt methods list. If by the time we hit this frame we no longer need
// a deopt it is safe to continue. So we don't mark the frame.
InstrumentThreadStack(thread, /* deopt_all_frames= */ false);
}
}
}
void Instrumentation::Undeoptimize(ArtMethod* method) {
CHECK(!method->IsNative());
CHECK(!method->IsProxyMethod());
CHECK(method->IsInvokable());
{
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
bool found_and_erased = RemoveDeoptimizedMethod(method);
CHECK(found_and_erased) << "Method " << ArtMethod::PrettyMethod(method)
<< " is not deoptimized";
}
// If interpreter stubs are still needed nothing to do.
if (InterpreterStubsInstalled()) {
return;
}
if (method->IsObsolete()) {
// Don't update entry points for obsolete methods. The entrypoint should
// have been set to InvokeObsoleteMethoStub.
DCHECK_EQ(method->GetEntryPointFromQuickCompiledCodePtrSize(kRuntimePointerSize),
GetInvokeObsoleteMethodStub());
return;
}
// We are not using interpreter stubs for deoptimization. Restore the code of the method.
// We still retain interpreter bridge if we need it for other reasons.
if (InterpretOnly(method)) {
UpdateEntryPoints(method, GetQuickToInterpreterBridge());
} else if (NeedsClinitCheckBeforeCall(method) &&
!method->GetDeclaringClass()->IsVisiblyInitialized()) {
if (EntryExitStubsInstalled()) {
UpdateEntryPoints(method, GetQuickInstrumentationEntryPoint());
} else {
UpdateEntryPoints(method, GetQuickResolutionStub());
}
} else {
UpdateEntryPoints(method, GetMaybeInstrumentedCodeForInvoke(method));
}
// If there is no deoptimized method left, we can restore the stack of each thread.
if (!EntryExitStubsInstalled()) {
MaybeRestoreInstrumentationStack();
}
}
bool Instrumentation::IsDeoptimizedMethodsEmpty() const {
return deoptimized_methods_.empty();
}
bool Instrumentation::IsDeoptimized(ArtMethod* method) {
DCHECK(method != nullptr);
return IsDeoptimizedMethod(method);
}
void Instrumentation::DisableDeoptimization(const char* key) {
// Remove any instrumentation support added for deoptimization.
ConfigureStubs(key, InstrumentationLevel::kInstrumentNothing);
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
// Undeoptimized selected methods.
while (true) {
ArtMethod* method;
{
if (deoptimized_methods_.empty()) {
break;
}
method = *deoptimized_methods_.begin();
CHECK(method != nullptr);
}
Undeoptimize(method);
}
}
// Indicates if instrumentation should notify method enter/exit events to the listeners.
bool Instrumentation::ShouldNotifyMethodEnterExitEvents() const {
if (!HasMethodEntryListeners() && !HasMethodExitListeners()) {
return false;
}
return !InterpreterStubsInstalled();
}
void Instrumentation::DeoptimizeEverything(const char* key) {
ConfigureStubs(key, InstrumentationLevel::kInstrumentWithInterpreter);
}
void Instrumentation::UndeoptimizeEverything(const char* key) {
CHECK(InterpreterStubsInstalled());
ConfigureStubs(key, InstrumentationLevel::kInstrumentNothing);
}
void Instrumentation::EnableMethodTracing(const char* key, bool needs_interpreter) {
InstrumentationLevel level;
if (needs_interpreter) {
level = InstrumentationLevel::kInstrumentWithInterpreter;
} else {
level = InstrumentationLevel::kInstrumentWithInstrumentationStubs;
}
ConfigureStubs(key, level);
}
void Instrumentation::DisableMethodTracing(const char* key) {
ConfigureStubs(key, InstrumentationLevel::kInstrumentNothing);
}
const void* Instrumentation::GetCodeForInvoke(ArtMethod* method) {
// This is called by instrumentation and resolution trampolines
// and that should never be getting proxy methods.
DCHECK(!method->IsProxyMethod()) << method->PrettyMethod();
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
const void* code = method->GetEntryPointFromQuickCompiledCodePtrSize(kRuntimePointerSize);
// If we don't have the instrumentation, the resolution stub, or the
// interpreter, just return the current entrypoint,
// assuming it's the most optimized.
if (code != GetQuickInstrumentationEntryPoint() &&
!class_linker->IsQuickResolutionStub(code) &&
!class_linker->IsQuickToInterpreterBridge(code)) {
return code;
}
if (InterpretOnly(method)) {
// If we're forced into interpreter just use it.
return GetQuickToInterpreterBridge();
}
return GetOptimizedCodeFor(method);
}
const void* Instrumentation::GetMaybeInstrumentedCodeForInvoke(ArtMethod* method) {
// This is called by resolution trampolines and that should never be getting proxy methods.
DCHECK(!method->IsProxyMethod()) << method->PrettyMethod();
const void* code = GetCodeForInvoke(method);
if (EntryExitStubsInstalled() && CodeNeedsEntryExitStub(code, method)) {
return GetQuickInstrumentationEntryPoint();
}
return code;
}
void Instrumentation::MethodEnterEventImpl(Thread* thread, ArtMethod* method) const {
DCHECK(!method->IsRuntimeMethod());
if (HasMethodEntryListeners()) {
for (InstrumentationListener* listener : method_entry_listeners_) {
if (listener != nullptr) {
listener->MethodEntered(thread, method);
}
}
}
}
template <>
void Instrumentation::MethodExitEventImpl(Thread* thread,
ArtMethod* method,
OptionalFrame frame,
MutableHandle<mirror::Object>& return_value) const {
if (HasMethodExitListeners()) {
for (InstrumentationListener* listener : method_exit_listeners_) {
if (listener != nullptr) {
listener->MethodExited(thread, method, frame, return_value);
}
}
}
}
template<> void Instrumentation::MethodExitEventImpl(Thread* thread,
ArtMethod* method,
OptionalFrame frame,
JValue& return_value) const {
if (HasMethodExitListeners()) {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
if (method->GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetReturnTypePrimitive() !=
Primitive::kPrimNot) {
for (InstrumentationListener* listener : method_exit_listeners_) {
if (listener != nullptr) {
listener->MethodExited(thread, method, frame, return_value);
}
}
} else {
MutableHandle<mirror::Object> ret(hs.NewHandle(return_value.GetL()));
MethodExitEventImpl(thread, method, frame, ret);
return_value.SetL(ret.Get());
}
}
}
void Instrumentation::MethodUnwindEvent(Thread* thread,
ArtMethod* method,
uint32_t dex_pc) const {
if (HasMethodUnwindListeners()) {
for (InstrumentationListener* listener : method_unwind_listeners_) {
if (listener != nullptr) {
listener->MethodUnwind(thread, method, dex_pc);
}
}
}
}
void Instrumentation::DexPcMovedEventImpl(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc) const {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Object> thiz(hs.NewHandle(this_object));
for (InstrumentationListener* listener : dex_pc_listeners_) {
if (listener != nullptr) {
listener->DexPcMoved(thread, thiz, method, dex_pc);
}
}
}
void Instrumentation::BranchImpl(Thread* thread,
ArtMethod* method,
uint32_t dex_pc,
int32_t offset) const {
for (InstrumentationListener* listener : branch_listeners_) {
if (listener != nullptr) {
listener->Branch(thread, method, dex_pc, offset);
}
}
}
void Instrumentation::WatchedFramePopImpl(Thread* thread, const ShadowFrame& frame) const {
for (InstrumentationListener* listener : watched_frame_pop_listeners_) {
if (listener != nullptr) {
listener->WatchedFramePop(thread, frame);
}
}
}
void Instrumentation::FieldReadEventImpl(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field) const {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Object> thiz(hs.NewHandle(this_object));
for (InstrumentationListener* listener : field_read_listeners_) {
if (listener != nullptr) {
listener->FieldRead(thread, thiz, method, dex_pc, field);
}
}
}
void Instrumentation::FieldWriteEventImpl(Thread* thread,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uint32_t dex_pc,
ArtField* field,
const JValue& field_value) const {
Thread* self = Thread::Current();
StackHandleScope<2> hs(self);
Handle<mirror::Object> thiz(hs.NewHandle(this_object));
if (field->IsPrimitiveType()) {
for (InstrumentationListener* listener : field_write_listeners_) {
if (listener != nullptr) {
listener->FieldWritten(thread, thiz, method, dex_pc, field, field_value);
}
}
} else {
Handle<mirror::Object> val(hs.NewHandle(field_value.GetL()));
for (InstrumentationListener* listener : field_write_listeners_) {
if (listener != nullptr) {
listener->FieldWritten(thread, thiz, method, dex_pc, field, val);
}
}
}
}
void Instrumentation::ExceptionThrownEvent(Thread* thread,
ObjPtr<mirror::Throwable> exception_object) const {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Throwable> h_exception(hs.NewHandle(exception_object));
if (HasExceptionThrownListeners()) {
DCHECK_EQ(thread->GetException(), h_exception.Get());
thread->ClearException();
for (InstrumentationListener* listener : exception_thrown_listeners_) {
if (listener != nullptr) {
listener->ExceptionThrown(thread, h_exception);
}
}
// See b/65049545 for discussion about this behavior.
thread->AssertNoPendingException();
thread->SetException(h_exception.Get());
}
}
void Instrumentation::ExceptionHandledEvent(Thread* thread,
ObjPtr<mirror::Throwable> exception_object) const {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Throwable> h_exception(hs.NewHandle(exception_object));
if (HasExceptionHandledListeners()) {
// We should have cleared the exception so that callers can detect a new one.
DCHECK(thread->GetException() == nullptr);
for (InstrumentationListener* listener : exception_handled_listeners_) {
if (listener != nullptr) {
listener->ExceptionHandled(thread, h_exception);
}
}
}
}
void Instrumentation::PushInstrumentationStackFrame(Thread* self,
ObjPtr<mirror::Object> this_object,
ArtMethod* method,
uintptr_t stack_ptr,
uintptr_t lr,
bool interpreter_entry) {
DCHECK(!self->IsExceptionPending());
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* stack =
self->GetInstrumentationStack();
if (kVerboseInstrumentation) {
LOG(INFO) << "Entering " << ArtMethod::PrettyMethod(method) << " from PC "
<< reinterpret_cast<void*>(lr);
}
// We send the enter event before pushing the instrumentation frame to make cleanup easier. If the
// event causes an exception we can simply send the unwind event and return.
StackHandleScope<1> hs(self);
Handle<mirror::Object> h_this(hs.NewHandle(this_object));
if (!interpreter_entry) {
MethodEnterEvent(self, method);
if (self->IsExceptionPending()) {
MethodUnwindEvent(self, method, 0);
return;
}
}
// We have a callee-save frame meaning this value is guaranteed to never be 0.
DCHECK(!self->IsExceptionPending());
instrumentation::InstrumentationStackFrame instrumentation_frame(
h_this.Get(), method, lr, interpreter_entry, current_force_deopt_id_);
stack->insert({stack_ptr, instrumentation_frame});
}
DeoptimizationMethodType Instrumentation::GetDeoptimizationMethodType(ArtMethod* method) {
if (method->IsRuntimeMethod()) {
// Certain methods have strict requirement on whether the dex instruction
// should be re-executed upon deoptimization.
if (method == Runtime::Current()->GetCalleeSaveMethod(
CalleeSaveType::kSaveEverythingForClinit)) {
return DeoptimizationMethodType::kKeepDexPc;
}
if (method == Runtime::Current()->GetCalleeSaveMethod(
CalleeSaveType::kSaveEverythingForSuspendCheck)) {
return DeoptimizationMethodType::kKeepDexPc;
}
}
return DeoptimizationMethodType::kDefault;
}
JValue Instrumentation::GetReturnValue(ArtMethod* method,
bool* is_ref,
uint64_t* gpr_result,
uint64_t* fpr_result) {
uint32_t length;
const PointerSize pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
// Runtime method does not call into MethodExitEvent() so there should not be
// suspension point below.
ScopedAssertNoThreadSuspension ants(__FUNCTION__, method->IsRuntimeMethod());
DCHECK(!method->IsRuntimeMethod());
char return_shorty = method->GetInterfaceMethodIfProxy(pointer_size)->GetShorty(&length)[0];
*is_ref = return_shorty == '[' || return_shorty == 'L';
JValue return_value;
if (return_shorty == 'V') {
return_value.SetJ(0);
} else if (return_shorty == 'F' || return_shorty == 'D') {
return_value.SetJ(*fpr_result);
} else {
return_value.SetJ(*gpr_result);
}
return return_value;
}
bool Instrumentation::PushDeoptContextIfNeeded(Thread* self,
DeoptimizationMethodType deopt_type,
bool is_ref,
const JValue& return_value)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (self->IsExceptionPending()) {
return false;
}
ArtMethod** sp = self->GetManagedStack()->GetTopQuickFrame();
DCHECK(sp != nullptr && (*sp)->IsRuntimeMethod());
if (!ShouldDeoptimizeCaller(self, sp)) {
return false;
}
// TODO(mythria): The current deopt behaviour is we just re-execute the
// alloc instruction so we don't need the return value. For instrumentation
// related deopts, we actually don't need to and can use the result we got
// here. Since this is a debug only feature it is not very important but
// consider reusing the result in future.
self->PushDeoptimizationContext(
return_value, is_ref, nullptr, /* from_code= */ false, deopt_type);
self->SetException(Thread::GetDeoptimizationException());
return true;
}
void Instrumentation::DeoptimizeIfNeeded(Thread* self,
ArtMethod** sp,
DeoptimizationMethodType type,
JValue return_value,
bool is_reference) {
if (self->IsAsyncExceptionPending() || ShouldDeoptimizeCaller(self, sp)) {
self->PushDeoptimizationContext(return_value,
is_reference,
nullptr,
/* from_code= */ false,
type);
artDeoptimize(self);
}
}
bool Instrumentation::NeedsSlowInterpreterForMethod(Thread* self, ArtMethod* method) {
return (method != nullptr) &&
(InterpreterStubsInstalled() ||
IsDeoptimized(method) ||
self->IsForceInterpreter() ||
// NB Since structurally obsolete compiled methods might have the offsets of
// methods/fields compiled in we need to go back to interpreter whenever we hit
// them.
method->GetDeclaringClass()->IsObsoleteObject() ||
Dbg::IsForcedInterpreterNeededForUpcall(self, method));
}
bool Instrumentation::ShouldDeoptimizeCaller(Thread* self, ArtMethod** sp) {
// When exit stubs aren't installed we don't need to check for any instrumentation related
// deoptimizations.
// TODO(mythria): Once we remove instrumentation stubs rename AreExitStubsInstalled. This is
// used to check if any instrumentation related work needs to be done. For ex: calling method
// entry / exit hooks, checking for instrumentation related deopts in suspend points
if (!AreExitStubsInstalled()) {
return false;
}
ArtMethod* runtime_method = *sp;
DCHECK(runtime_method->IsRuntimeMethod());
QuickMethodFrameInfo frame_info = Runtime::Current()->GetRuntimeMethodFrameInfo(runtime_method);
return ShouldDeoptimizeCaller(self, sp, frame_info.FrameSizeInBytes());
}
bool Instrumentation::ShouldDeoptimizeCaller(Thread* self, ArtMethod** sp, size_t frame_size) {
uintptr_t caller_sp = reinterpret_cast<uintptr_t>(sp) + frame_size;
ArtMethod* caller = *(reinterpret_cast<ArtMethod**>(caller_sp));
uintptr_t caller_pc_addr = reinterpret_cast<uintptr_t>(sp) + (frame_size - sizeof(void*));
uintptr_t caller_pc = *reinterpret_cast<uintptr_t*>(caller_pc_addr);
return ShouldDeoptimizeCaller(self, caller, caller_pc, caller_sp);
}
bool Instrumentation::ShouldDeoptimizeCaller(Thread* self, const NthCallerVisitor& visitor) {
uintptr_t caller_sp = reinterpret_cast<uintptr_t>(visitor.GetCurrentQuickFrame());
// When the caller isn't executing quick code there is no need to deoptimize.
if (visitor.GetCurrentOatQuickMethodHeader() == nullptr) {
return false;
}
return ShouldDeoptimizeCaller(self, visitor.GetOuterMethod(), visitor.caller_pc, caller_sp);
}
bool Instrumentation::ShouldDeoptimizeCaller(Thread* self,
ArtMethod* caller,
uintptr_t caller_pc,
uintptr_t caller_sp) {
if (caller == nullptr ||
caller->IsNative() ||
caller->IsRuntimeMethod() ||
caller_pc == reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc())) {
// If caller_pc is QuickInstrumentationExit then deoptimization will be handled by the
// instrumentation exit trampoline so we don't need to handle deoptimizations here.
// We need to check for a deoptimization here because when a redefinition happens it is
// not safe to use any compiled code because the field offsets might change. For native
// methods, we don't embed any field offsets so no need to check for a deoptimization.
// If the caller is null we don't need to do anything. This can happen when the caller
// is being interpreted by the switch interpreter (when called from
// artQuickToInterpreterBridge) / during shutdown / early startup.
return false;
}
bool needs_deopt = NeedsSlowInterpreterForMethod(self, caller);
// Non java debuggable apps don't support redefinition and hence it isn't required to check if
// frame needs to be deoptimized. Even in debuggable apps, we only need this check when a
// redefinition has actually happened. This is indicated by IsDeoptCheckRequired flag. We also
// want to avoid getting method header when we need a deopt anyway.
if (Runtime::Current()->IsJavaDebuggable() && !needs_deopt && self->IsDeoptCheckRequired()) {
const OatQuickMethodHeader* header = caller->GetOatQuickMethodHeader(caller_pc);
if (header != nullptr && header->HasShouldDeoptimizeFlag()) {
DCHECK(header->IsOptimized());
uint8_t* should_deopt_flag_addr =
reinterpret_cast<uint8_t*>(caller_sp) + header->GetShouldDeoptimizeFlagOffset();
if ((*should_deopt_flag_addr &
static_cast<uint8_t>(DeoptimizeFlagValue::kForceDeoptForRedefinition)) != 0) {
needs_deopt = true;
}
}
}
if (needs_deopt) {
if (!Runtime::Current()->IsAsyncDeoptimizeable(caller, caller_pc)) {
LOG(WARNING) << "Got a deoptimization request on un-deoptimizable method "
<< caller->PrettyMethod();
return false;
}
return true;
}
return false;
}
TwoWordReturn Instrumentation::PopInstrumentationStackFrame(Thread* self,
uintptr_t* return_pc_addr,
uint64_t* gpr_result,
uint64_t* fpr_result) {
DCHECK(gpr_result != nullptr);
DCHECK(fpr_result != nullptr);
// Do the pop.
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* stack =
self->GetInstrumentationStack();
CHECK_GT(stack->size(), 0U);
auto it = stack->find(reinterpret_cast<uintptr_t>(return_pc_addr));
CHECK(it != stack->end());
InstrumentationStackFrame instrumentation_frame = it->second;
stack->erase(it);
// Set return PC and check the consistency of the stack.
// We don't cache the return pc value in a local as it may change after
// sending a method exit event.
*return_pc_addr = instrumentation_frame.return_pc_;
self->VerifyStack();
ArtMethod* method = instrumentation_frame.method_;
DCHECK(!method->IsRuntimeMethod());
bool is_ref;
JValue return_value = GetReturnValue(method, &is_ref, gpr_result, fpr_result);
StackHandleScope<1> hs(self);
MutableHandle<mirror::Object> res(hs.NewHandle<mirror::Object>(nullptr));
if (is_ref) {
// Take a handle to the return value so we won't lose it if we suspend.
DCHECK_ALIGNED(return_value.GetL(), kObjectAlignment);
res.Assign(return_value.GetL());
}
if (!instrumentation_frame.interpreter_entry_) {
DCHECK(!method->IsRuntimeMethod());
// Note that sending the event may change the contents of *return_pc_addr.
MethodExitEvent(self, instrumentation_frame.method_, OptionalFrame{}, return_value);
}
// Deoptimize if the caller needs to continue execution in the interpreter. Do nothing if we get
// back to an upcall.
NthCallerVisitor visitor(self, 1, true);
visitor.WalkStack(true);
// Check if we forced all threads to deoptimize in the time between this frame being created and
// now.
bool should_deoptimize_frame = instrumentation_frame.force_deopt_id_ != current_force_deopt_id_;
bool deoptimize = ShouldDeoptimizeCaller(self, visitor) || should_deoptimize_frame;
if (is_ref) {
// Restore the return value if it's a reference since it might have moved.
*reinterpret_cast<mirror::Object**>(gpr_result) = res.Get();
}
if (deoptimize) {
// NthCallerVisitor also takes inlined frames into consideration, so visitor.caller points to
// the inlined function. We need the actual method corresponding to the return_pc_addr to check
// if the method is deoptimizeable. So fetch the outer method.
if (Runtime::Current()->IsAsyncDeoptimizeable(visitor.GetOuterMethod(), *return_pc_addr)) {
if (kVerboseInstrumentation) {
LOG(INFO) << "Deoptimizing "
<< visitor.caller->PrettyMethod()
<< " by returning from "
<< method->PrettyMethod()
<< " with result "
<< std::hex << return_value.GetJ() << std::dec
<< " in "
<< *self;
}
DeoptimizationMethodType deopt_method_type = GetDeoptimizationMethodType(method);
self->PushDeoptimizationContext(return_value,
is_ref,
/* exception= */ nullptr,
/* from_code= */ false,
deopt_method_type);
return GetTwoWordSuccessValue(
*return_pc_addr, reinterpret_cast<uintptr_t>(GetQuickDeoptimizationEntryPoint()));
} else {
VLOG(deopt) << "Got a deoptimization request on un-deoptimizable "
<< visitor.caller->PrettyMethod() << " at PC "
<< reinterpret_cast<void*>(*return_pc_addr);
}
}
if (kVerboseInstrumentation) {
LOG(INFO) << "Returning from " << method->PrettyMethod() << " to PC "
<< reinterpret_cast<void*>(*return_pc_addr);
}
return GetTwoWordSuccessValue(0, *return_pc_addr);
}
uintptr_t Instrumentation::PopInstrumentationStackUntil(Thread* self, uintptr_t pop_until) const {
std::map<uintptr_t, instrumentation::InstrumentationStackFrame>* stack =
self->GetInstrumentationStack();
// Pop all instrumentation frames below `pop_until`.
uintptr_t return_pc = 0u;
for (auto i = stack->begin(); i != stack->end() && i->first <= pop_until;) {
if (kVerboseInstrumentation) {
LOG(INFO) << "Popping for deoptimization " << i->second.method_->PrettyMethod();
}
return_pc = i->second.return_pc_;
i = stack->erase(i);
}
return return_pc;
}
std::string InstrumentationStackFrame::Dump() const {
std::ostringstream os;
os << ArtMethod::PrettyMethod(method_) << ":"
<< reinterpret_cast<void*>(return_pc_) << " this=" << reinterpret_cast<void*>(this_object_)
<< " force_deopt_id=" << force_deopt_id_;
return os.str();
}
} // namespace instrumentation
} // namespace art