| /* |
| * 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 <sstream> |
| |
| #include "arch/context.h" |
| #include "art_method-inl.h" |
| #include "atomic.h" |
| #include "class_linker.h" |
| #include "debugger.h" |
| #include "dex_file-inl.h" |
| #include "entrypoints/quick/quick_entrypoints.h" |
| #include "entrypoints/quick/quick_alloc_entrypoints.h" |
| #include "entrypoints/runtime_asm_entrypoints.h" |
| #include "gc_root-inl.h" |
| #include "interpreter/interpreter.h" |
| #include "jit/jit.h" |
| #include "jit/jit_code_cache.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/dex_cache.h" |
| #include "mirror/object_array-inl.h" |
| #include "mirror/object-inl.h" |
| #include "nth_caller_visitor.h" |
| #include "oat_quick_method_header.h" |
| #include "thread.h" |
| #include "thread_list.h" |
| |
| namespace art { |
| namespace instrumentation { |
| |
| constexpr bool kVerboseInstrumentation = false; |
| |
| // 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()(mirror::Class* klass) OVERRIDE REQUIRES(Locks::mutator_lock_) { |
| instrumentation_->InstallStubsForClass(klass); |
| return true; // we visit all classes. |
| } |
| |
| private: |
| Instrumentation* const instrumentation_; |
| }; |
| |
| |
| Instrumentation::Instrumentation() |
| : instrumentation_stubs_installed_(false), |
| entry_exit_stubs_installed_(false), |
| interpreter_stubs_installed_(false), |
| interpret_only_(false), |
| 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_caught_listeners_(false), |
| have_branch_listeners_(false), |
| have_invoke_virtual_or_interface_listeners_(false), |
| deoptimized_methods_lock_("deoptimized methods lock", kDeoptimizedMethodsLock), |
| deoptimization_enabled_(false), |
| interpreter_handler_table_(kMainHandlerTable), |
| quick_alloc_entry_points_instrumentation_counter_(0), |
| alloc_entrypoints_instrumented_(false) { |
| } |
| |
| void Instrumentation::InstallStubsForClass(mirror::Class* klass) { |
| if (klass->IsErroneous()) { |
| // We can't execute code in a erroneous class: do nothing. |
| } else 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 { |
| for (ArtMethod& method : klass->GetMethods(sizeof(void*))) { |
| InstallStubsForMethod(&method); |
| } |
| } |
| } |
| |
| static void UpdateEntrypoints(ArtMethod* method, const void* quick_code) |
| SHARED_REQUIRES(Locks::mutator_lock_) { |
| method->SetEntryPointFromQuickCompiledCode(quick_code); |
| } |
| |
| bool Instrumentation::NeedDebugVersionForBootImageCode(ArtMethod* method, const void* code) const |
| SHARED_REQUIRES(Locks::mutator_lock_) { |
| return Dbg::IsDebuggerActive() && |
| Runtime::Current()->GetHeap()->IsInBootImageOatFile(code) && |
| !method->IsNative() && |
| !method->IsProxyMethod(); |
| } |
| |
| 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. |
| if (method->IsConstructor() && |
| method->GetDeclaringClass()->DescriptorEquals("Ljava/lang/reflect/Proxy;")) { |
| return; |
| } |
| const void* new_quick_code; |
| bool uninstall = !entry_exit_stubs_installed_ && !interpreter_stubs_installed_; |
| Runtime* const runtime = Runtime::Current(); |
| ClassLinker* const class_linker = runtime->GetClassLinker(); |
| bool is_class_initialized = method->GetDeclaringClass()->IsInitialized(); |
| if (uninstall) { |
| if ((forced_interpret_only_ || IsDeoptimized(method)) && !method->IsNative()) { |
| new_quick_code = GetQuickToInterpreterBridge(); |
| } else if (is_class_initialized || !method->IsStatic() || method->IsConstructor()) { |
| new_quick_code = class_linker->GetQuickOatCodeFor(method); |
| if (NeedDebugVersionForBootImageCode(method, new_quick_code)) { |
| new_quick_code = GetQuickToInterpreterBridge(); |
| } |
| } else { |
| new_quick_code = GetQuickResolutionStub(); |
| } |
| } else { // !uninstall |
| if ((interpreter_stubs_installed_ || forced_interpret_only_ || IsDeoptimized(method)) && |
| !method->IsNative()) { |
| new_quick_code = GetQuickToInterpreterBridge(); |
| } else { |
| // Do not overwrite resolution trampoline. When the trampoline initializes the method's |
| // class, all its static methods code will be set to the instrumentation entry point. |
| // For more details, see ClassLinker::FixupStaticTrampolines. |
| if (is_class_initialized || !method->IsStatic() || method->IsConstructor()) { |
| new_quick_code = class_linker->GetQuickOatCodeFor(method); |
| if (NeedDebugVersionForBootImageCode(method, new_quick_code)) { |
| // Oat code should not be used. Don't install instrumentation stub and |
| // use interpreter for instrumentation. |
| new_quick_code = GetQuickToInterpreterBridge(); |
| } else if (entry_exit_stubs_installed_) { |
| new_quick_code = GetQuickInstrumentationEntryPoint(); |
| } |
| } else { |
| new_quick_code = GetQuickResolutionStub(); |
| } |
| } |
| } |
| UpdateEntrypoints(method, new_quick_code); |
| } |
| |
| // Places the instrumentation exit pc as the return PC for every quick frame. This also allows |
| // deoptimization of quick frames to interpreter frames. |
| // Since we may already have done this previously, we need to push new instrumentation frame before |
| // existing instrumentation frames. |
| static void InstrumentationInstallStack(Thread* thread, void* arg) |
| SHARED_REQUIRES(Locks::mutator_lock_) { |
| struct InstallStackVisitor FINAL : public StackVisitor { |
| InstallStackVisitor(Thread* thread_in, Context* context, uintptr_t instrumentation_exit_pc) |
| : StackVisitor(thread_in, context, kInstrumentationStackWalk), |
| instrumentation_stack_(thread_in->GetInstrumentationStack()), |
| instrumentation_exit_pc_(instrumentation_exit_pc), |
| reached_existing_instrumentation_frames_(false), instrumentation_stack_depth_(0), |
| last_return_pc_(0) { |
| } |
| |
| bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { |
| ArtMethod* m = GetMethod(); |
| if (m == nullptr) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Skipping upcall. Frame " << GetFrameId(); |
| } |
| last_return_pc_ = 0; |
| return true; // Ignore upcalls. |
| } |
| if (GetCurrentQuickFrame() == nullptr) { |
| bool interpreter_frame = true; |
| InstrumentationStackFrame instrumentation_frame(GetThisObject(), m, 0, GetFrameId(), |
| interpreter_frame); |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Pushing shadow frame " << instrumentation_frame.Dump(); |
| } |
| shadow_stack_.push_back(instrumentation_frame); |
| return true; // Continue. |
| } |
| uintptr_t return_pc = GetReturnPc(); |
| if (m->IsRuntimeMethod()) { |
| if (return_pc == instrumentation_exit_pc_) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Handling quick to interpreter transition. Frame " << GetFrameId(); |
| } |
| CHECK_LT(instrumentation_stack_depth_, instrumentation_stack_->size()); |
| const InstrumentationStackFrame& frame = |
| instrumentation_stack_->at(instrumentation_stack_depth_); |
| CHECK(frame.interpreter_entry_); |
| // This is an interpreter frame so method enter event must have been reported. However we |
| // need to push a DEX pc into the dex_pcs_ list to match size of instrumentation stack. |
| // Since we won't report method entry here, we can safely push any DEX pc. |
| dex_pcs_.push_back(0); |
| last_return_pc_ = frame.return_pc_; |
| ++instrumentation_stack_depth_; |
| return true; |
| } else { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Skipping runtime method. Frame " << GetFrameId(); |
| } |
| last_return_pc_ = GetReturnPc(); |
| return true; // Ignore unresolved methods since they will be instrumented after resolution. |
| } |
| } |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Installing exit stub in " << DescribeLocation(); |
| } |
| if (return_pc == instrumentation_exit_pc_) { |
| // We've reached a frame which has already been installed with instrumentation exit stub. |
| // We should have already installed instrumentation on previous frames. |
| reached_existing_instrumentation_frames_ = true; |
| |
| CHECK_LT(instrumentation_stack_depth_, instrumentation_stack_->size()); |
| const InstrumentationStackFrame& frame = |
| instrumentation_stack_->at(instrumentation_stack_depth_); |
| CHECK_EQ(m, frame.method_) << "Expected " << PrettyMethod(m) |
| << ", Found " << PrettyMethod(frame.method_); |
| return_pc = frame.return_pc_; |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Ignoring already instrumented " << frame.Dump(); |
| } |
| } else { |
| CHECK_NE(return_pc, 0U); |
| CHECK(!reached_existing_instrumentation_frames_); |
| InstrumentationStackFrame instrumentation_frame(GetThisObject(), m, return_pc, GetFrameId(), |
| false); |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Pushing frame " << instrumentation_frame.Dump(); |
| } |
| |
| // Insert frame at the right position so we do not corrupt the instrumentation stack. |
| // Instrumentation stack frames are in descending frame id order. |
| auto it = instrumentation_stack_->begin(); |
| for (auto end = instrumentation_stack_->end(); it != end; ++it) { |
| const InstrumentationStackFrame& current = *it; |
| if (instrumentation_frame.frame_id_ >= current.frame_id_) { |
| break; |
| } |
| } |
| instrumentation_stack_->insert(it, instrumentation_frame); |
| SetReturnPc(instrumentation_exit_pc_); |
| } |
| dex_pcs_.push_back((GetCurrentOatQuickMethodHeader() == nullptr) |
| ? DexFile::kDexNoIndex |
| : GetCurrentOatQuickMethodHeader()->ToDexPc(m, last_return_pc_)); |
| last_return_pc_ = return_pc; |
| ++instrumentation_stack_depth_; |
| return true; // Continue. |
| } |
| std::deque<InstrumentationStackFrame>* const instrumentation_stack_; |
| std::vector<InstrumentationStackFrame> shadow_stack_; |
| std::vector<uint32_t> dex_pcs_; |
| const uintptr_t instrumentation_exit_pc_; |
| bool reached_existing_instrumentation_frames_; |
| size_t instrumentation_stack_depth_; |
| uintptr_t last_return_pc_; |
| }; |
| 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); |
| visitor.WalkStack(true); |
| CHECK_EQ(visitor.dex_pcs_.size(), thread->GetInstrumentationStack()->size()); |
| |
| if (instrumentation->ShouldNotifyMethodEnterExitEvents()) { |
| // Create method enter events for all methods currently on the thread's stack. We only do this |
| // if no debugger is attached to prevent from posting events twice. |
| auto ssi = visitor.shadow_stack_.rbegin(); |
| for (auto isi = thread->GetInstrumentationStack()->rbegin(), |
| end = thread->GetInstrumentationStack()->rend(); isi != end; ++isi) { |
| while (ssi != visitor.shadow_stack_.rend() && (*ssi).frame_id_ < (*isi).frame_id_) { |
| instrumentation->MethodEnterEvent(thread, (*ssi).this_object_, (*ssi).method_, 0); |
| ++ssi; |
| } |
| uint32_t dex_pc = visitor.dex_pcs_.back(); |
| visitor.dex_pcs_.pop_back(); |
| if (!isi->interpreter_entry_) { |
| instrumentation->MethodEnterEvent(thread, (*isi).this_object_, (*isi).method_, dex_pc); |
| } |
| } |
| } |
| thread->VerifyStack(); |
| } |
| |
| void Instrumentation::InstrumentThreadStack(Thread* thread) { |
| instrumentation_stubs_installed_ = true; |
| InstrumentationInstallStack(thread, this); |
| } |
| |
| // 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) {} |
| |
| bool VisitFrame() OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { |
| if (instrumentation_stack_->size() == 0) { |
| return false; // Stop. |
| } |
| ArtMethod* m = GetMethod(); |
| if (GetCurrentQuickFrame() == nullptr) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Ignoring a shadow frame. Frame " << GetFrameId() |
| << " Method=" << PrettyMethod(m); |
| } |
| return true; // Ignore shadow frames. |
| } |
| if (m == nullptr) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Skipping upcall. Frame " << GetFrameId(); |
| } |
| return true; // Ignore upcalls. |
| } |
| bool removed_stub = false; |
| // TODO: make this search more efficient? |
| const size_t frameId = GetFrameId(); |
| for (const InstrumentationStackFrame& instrumentation_frame : *instrumentation_stack_) { |
| if (instrumentation_frame.frame_id_ == frameId) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << " Removing exit stub in " << DescribeLocation(); |
| } |
| if (instrumentation_frame.interpreter_entry_) { |
| CHECK(m == Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs)); |
| } else { |
| CHECK(m == instrumentation_frame.method_) << PrettyMethod(m); |
| } |
| SetReturnPc(instrumentation_frame.return_pc_); |
| if (instrumentation_->ShouldNotifyMethodEnterExitEvents()) { |
| // 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. |
| instrumentation_->MethodExitEvent(thread_, instrumentation_frame.this_object_, m, |
| GetDexPc(), JValue()); |
| } |
| frames_removed_++; |
| removed_stub = true; |
| break; |
| } |
| } |
| if (!removed_stub) { |
| 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::deque<instrumentation::InstrumentationStackFrame>* const instrumentation_stack_; |
| size_t frames_removed_; |
| }; |
| if (kVerboseInstrumentation) { |
| std::string thread_name; |
| thread->GetThreadName(thread_name); |
| LOG(INFO) << "Removing exit stubs in " << thread_name; |
| } |
| std::deque<instrumentation::InstrumentationStackFrame>* stack = thread->GetInstrumentationStack(); |
| if (stack->size() > 0) { |
| 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); |
| CHECK_EQ(visitor.frames_removed_, stack->size()); |
| while (stack->size() > 0) { |
| stack->pop_front(); |
| } |
| } |
| } |
| |
| 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(kInvokeVirtualOrInterface, |
| events, |
| invoke_virtual_or_interface_listeners_, |
| listener, |
| &have_invoke_virtual_or_interface_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(kExceptionCaught, |
| events, |
| exception_caught_listeners_, |
| listener, |
| &have_exception_caught_listeners_); |
| UpdateInterpreterHandlerTable(); |
| } |
| |
| 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(kInvokeVirtualOrInterface, |
| events, |
| invoke_virtual_or_interface_listeners_, |
| listener, |
| &have_invoke_virtual_or_interface_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(kExceptionCaught, |
| events, |
| exception_caught_listeners_, |
| listener, |
| &have_exception_caught_listeners_); |
| UpdateInterpreterHandlerTable(); |
| } |
| |
| Instrumentation::InstrumentationLevel Instrumentation::GetCurrentInstrumentationLevel() const { |
| if (interpreter_stubs_installed_) { |
| return InstrumentationLevel::kInstrumentWithInterpreter; |
| } else if (entry_exit_stubs_installed_) { |
| return InstrumentationLevel::kInstrumentWithInstrumentationStubs; |
| } else { |
| return InstrumentationLevel::kInstrumentNothing; |
| } |
| } |
| |
| 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); |
| } |
| |
| // 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); |
| } |
| |
| interpret_only_ = (requested_level == InstrumentationLevel::kInstrumentWithInterpreter) || |
| forced_interpret_only_; |
| |
| InstrumentationLevel current_level = GetCurrentInstrumentationLevel(); |
| if (requested_level == current_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); |
| if (requested_level > InstrumentationLevel::kInstrumentNothing) { |
| if (requested_level == InstrumentationLevel::kInstrumentWithInterpreter) { |
| interpreter_stubs_installed_ = true; |
| entry_exit_stubs_installed_ = true; |
| } else { |
| CHECK_EQ(requested_level, InstrumentationLevel::kInstrumentWithInstrumentationStubs); |
| entry_exit_stubs_installed_ = true; |
| interpreter_stubs_installed_ = false; |
| } |
| InstallStubsClassVisitor visitor(this); |
| runtime->GetClassLinker()->VisitClasses(&visitor); |
| instrumentation_stubs_installed_ = true; |
| MutexLock mu(self, *Locks::thread_list_lock_); |
| runtime->GetThreadList()->ForEach(InstrumentationInstallStack, this); |
| } else { |
| interpreter_stubs_installed_ = false; |
| entry_exit_stubs_installed_ = false; |
| InstallStubsClassVisitor visitor(this); |
| runtime->GetClassLinker()->VisitClasses(&visitor); |
| // Restore stack only if there is no method currently deoptimized. |
| bool empty; |
| { |
| ReaderMutexLock mu(self, deoptimized_methods_lock_); |
| empty = IsDeoptimizedMethodsEmpty(); // Avoid lock violation. |
| } |
| if (empty) { |
| MutexLock mu(self, *Locks::thread_list_lock_); |
| 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; |
| } |
| } |
| } |
| |
| 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); |
| ResetQuickAllocEntryPoints(); |
| 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); |
| } |
| } |
| |
| void Instrumentation::UpdateMethodsCode(ArtMethod* method, const void* quick_code) { |
| DCHECK(method->GetDeclaringClass()->IsResolved()); |
| const void* new_quick_code; |
| if (LIKELY(!instrumentation_stubs_installed_)) { |
| new_quick_code = quick_code; |
| } else { |
| if ((interpreter_stubs_installed_ || IsDeoptimized(method)) && !method->IsNative()) { |
| new_quick_code = GetQuickToInterpreterBridge(); |
| } else { |
| ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); |
| if (class_linker->IsQuickResolutionStub(quick_code) || |
| class_linker->IsQuickToInterpreterBridge(quick_code)) { |
| new_quick_code = quick_code; |
| } else if (entry_exit_stubs_installed_) { |
| new_quick_code = GetQuickInstrumentationEntryPoint(); |
| } else { |
| new_quick_code = quick_code; |
| } |
| } |
| } |
| UpdateEntrypoints(method, new_quick_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(); |
| } |
| |
| ArtMethod* Instrumentation::BeginDeoptimizedMethod() { |
| if (deoptimized_methods_.empty()) { |
| // Empty. |
| return nullptr; |
| } |
| return *deoptimized_methods_.begin(); |
| } |
| |
| bool Instrumentation::RemoveDeoptimizedMethod(ArtMethod* method) { |
| auto it = deoptimized_methods_.find(method); |
| if (it == deoptimized_methods_.end()) { |
| return false; |
| } |
| deoptimized_methods_.erase(it); |
| return true; |
| } |
| |
| bool Instrumentation::IsDeoptimizedMethodsEmpty() const { |
| return deoptimized_methods_.empty(); |
| } |
| |
| void Instrumentation::Deoptimize(ArtMethod* method) { |
| CHECK(!method->IsNative()); |
| CHECK(!method->IsProxyMethod()); |
| CHECK(method->IsInvokable()); |
| |
| Thread* self = Thread::Current(); |
| { |
| WriterMutexLock mu(self, deoptimized_methods_lock_); |
| bool has_not_been_deoptimized = AddDeoptimizedMethod(method); |
| CHECK(has_not_been_deoptimized) << "Method " << PrettyMethod(method) |
| << " is already deoptimized"; |
| } |
| if (!interpreter_stubs_installed_) { |
| UpdateEntrypoints(method, GetQuickInstrumentationEntryPoint()); |
| |
| // 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_); |
| Runtime::Current()->GetThreadList()->ForEach(InstrumentationInstallStack, this); |
| } |
| } |
| |
| void Instrumentation::Undeoptimize(ArtMethod* method) { |
| CHECK(!method->IsNative()); |
| CHECK(!method->IsProxyMethod()); |
| CHECK(method->IsInvokable()); |
| |
| Thread* self = Thread::Current(); |
| bool empty; |
| { |
| WriterMutexLock mu(self, deoptimized_methods_lock_); |
| bool found_and_erased = RemoveDeoptimizedMethod(method); |
| CHECK(found_and_erased) << "Method " << PrettyMethod(method) |
| << " is not deoptimized"; |
| empty = IsDeoptimizedMethodsEmpty(); |
| } |
| |
| // Restore code and possibly stack only if we did not deoptimize everything. |
| if (!interpreter_stubs_installed_) { |
| // Restore its code or resolution trampoline. |
| ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); |
| if (method->IsStatic() && !method->IsConstructor() && |
| !method->GetDeclaringClass()->IsInitialized()) { |
| UpdateEntrypoints(method, GetQuickResolutionStub()); |
| } else { |
| const void* quick_code = class_linker->GetQuickOatCodeFor(method); |
| if (NeedDebugVersionForBootImageCode(method, quick_code)) { |
| quick_code = GetQuickToInterpreterBridge(); |
| } |
| UpdateEntrypoints(method, quick_code); |
| } |
| |
| // If there is no deoptimized method left, we can restore the stack of each thread. |
| if (empty) { |
| MutexLock mu(self, *Locks::thread_list_lock_); |
| Runtime::Current()->GetThreadList()->ForEach(InstrumentationRestoreStack, this); |
| instrumentation_stubs_installed_ = false; |
| } |
| } |
| } |
| |
| bool Instrumentation::IsDeoptimized(ArtMethod* method) { |
| DCHECK(method != nullptr); |
| ReaderMutexLock mu(Thread::Current(), deoptimized_methods_lock_); |
| return IsDeoptimizedMethod(method); |
| } |
| |
| void Instrumentation::EnableDeoptimization() { |
| ReaderMutexLock mu(Thread::Current(), deoptimized_methods_lock_); |
| CHECK(IsDeoptimizedMethodsEmpty()); |
| CHECK_EQ(deoptimization_enabled_, false); |
| deoptimization_enabled_ = true; |
| } |
| |
| void Instrumentation::DisableDeoptimization(const char* key) { |
| CHECK_EQ(deoptimization_enabled_, true); |
| // If we deoptimized everything, undo it. |
| if (interpreter_stubs_installed_) { |
| UndeoptimizeEverything(key); |
| } |
| // Undeoptimized selected methods. |
| while (true) { |
| ArtMethod* method; |
| { |
| ReaderMutexLock mu(Thread::Current(), deoptimized_methods_lock_); |
| if (IsDeoptimizedMethodsEmpty()) { |
| break; |
| } |
| method = BeginDeoptimizedMethod(); |
| CHECK(method != nullptr); |
| } |
| Undeoptimize(method); |
| } |
| deoptimization_enabled_ = false; |
| } |
| |
| // Indicates if instrumentation should notify method enter/exit events to the listeners. |
| bool Instrumentation::ShouldNotifyMethodEnterExitEvents() const { |
| if (!HasMethodEntryListeners() && !HasMethodExitListeners()) { |
| return false; |
| } |
| return !deoptimization_enabled_ && !interpreter_stubs_installed_; |
| } |
| |
| void Instrumentation::DeoptimizeEverything(const char* key) { |
| CHECK(deoptimization_enabled_); |
| ConfigureStubs(key, InstrumentationLevel::kInstrumentWithInterpreter); |
| } |
| |
| void Instrumentation::UndeoptimizeEverything(const char* key) { |
| CHECK(interpreter_stubs_installed_); |
| CHECK(deoptimization_enabled_); |
| 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::GetQuickCodeFor(ArtMethod* method, size_t pointer_size) const { |
| Runtime* runtime = Runtime::Current(); |
| if (LIKELY(!instrumentation_stubs_installed_)) { |
| const void* code = method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size); |
| DCHECK(code != nullptr); |
| ClassLinker* class_linker = runtime->GetClassLinker(); |
| if (LIKELY(!class_linker->IsQuickResolutionStub(code) && |
| !class_linker->IsQuickToInterpreterBridge(code)) && |
| !class_linker->IsQuickResolutionStub(code) && |
| !class_linker->IsQuickToInterpreterBridge(code)) { |
| return code; |
| } |
| } |
| return runtime->GetClassLinker()->GetQuickOatCodeFor(method); |
| } |
| |
| void Instrumentation::MethodEnterEventImpl(Thread* thread, mirror::Object* this_object, |
| ArtMethod* method, |
| uint32_t dex_pc) const { |
| if (HasMethodEntryListeners()) { |
| for (InstrumentationListener* listener : method_entry_listeners_) { |
| if (listener != nullptr) { |
| listener->MethodEntered(thread, this_object, method, dex_pc); |
| } |
| } |
| } |
| } |
| |
| void Instrumentation::MethodExitEventImpl(Thread* thread, mirror::Object* this_object, |
| ArtMethod* method, |
| uint32_t dex_pc, const JValue& return_value) const { |
| if (HasMethodExitListeners()) { |
| for (InstrumentationListener* listener : method_exit_listeners_) { |
| if (listener != nullptr) { |
| listener->MethodExited(thread, this_object, method, dex_pc, return_value); |
| } |
| } |
| } |
| } |
| |
| void Instrumentation::MethodUnwindEvent(Thread* thread, mirror::Object* this_object, |
| ArtMethod* method, |
| uint32_t dex_pc) const { |
| if (HasMethodUnwindListeners()) { |
| for (InstrumentationListener* listener : method_unwind_listeners_) { |
| if (listener != nullptr) { |
| listener->MethodUnwind(thread, this_object, method, dex_pc); |
| } |
| } |
| } |
| } |
| |
| void Instrumentation::DexPcMovedEventImpl(Thread* thread, mirror::Object* this_object, |
| ArtMethod* method, |
| uint32_t dex_pc) const { |
| for (InstrumentationListener* listener : dex_pc_listeners_) { |
| if (listener != nullptr) { |
| listener->DexPcMoved(thread, this_object, 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::InvokeVirtualOrInterfaceImpl(Thread* thread, |
| mirror::Object* this_object, |
| ArtMethod* caller, |
| uint32_t dex_pc, |
| ArtMethod* callee) const { |
| // We cannot have thread suspension since that would cause the this_object parameter to |
| // potentially become a dangling pointer. An alternative could be to put it in a handle instead. |
| ScopedAssertNoThreadSuspension ants(thread, __FUNCTION__); |
| for (InstrumentationListener* listener : invoke_virtual_or_interface_listeners_) { |
| if (listener != nullptr) { |
| listener->InvokeVirtualOrInterface(thread, this_object, caller, dex_pc, callee); |
| } |
| } |
| } |
| |
| void Instrumentation::FieldReadEventImpl(Thread* thread, mirror::Object* this_object, |
| ArtMethod* method, uint32_t dex_pc, |
| ArtField* field) const { |
| for (InstrumentationListener* listener : field_read_listeners_) { |
| if (listener != nullptr) { |
| listener->FieldRead(thread, this_object, method, dex_pc, field); |
| } |
| } |
| } |
| |
| void Instrumentation::FieldWriteEventImpl(Thread* thread, mirror::Object* this_object, |
| ArtMethod* method, uint32_t dex_pc, |
| ArtField* field, const JValue& field_value) const { |
| for (InstrumentationListener* listener : field_write_listeners_) { |
| if (listener != nullptr) { |
| listener->FieldWritten(thread, this_object, method, dex_pc, field, field_value); |
| } |
| } |
| } |
| |
| void Instrumentation::ExceptionCaughtEvent(Thread* thread, |
| mirror::Throwable* exception_object) const { |
| if (HasExceptionCaughtListeners()) { |
| DCHECK_EQ(thread->GetException(), exception_object); |
| thread->ClearException(); |
| for (InstrumentationListener* listener : exception_caught_listeners_) { |
| if (listener != nullptr) { |
| listener->ExceptionCaught(thread, exception_object); |
| } |
| } |
| thread->SetException(exception_object); |
| } |
| } |
| |
| // Computes a frame ID by ignoring inlined frames. |
| size_t Instrumentation::ComputeFrameId(Thread* self, |
| size_t frame_depth, |
| size_t inlined_frames_before_frame) { |
| CHECK_GE(frame_depth, inlined_frames_before_frame); |
| size_t no_inline_depth = frame_depth - inlined_frames_before_frame; |
| return StackVisitor::ComputeNumFrames(self, kInstrumentationStackWalk) - no_inline_depth; |
| } |
| |
| static void CheckStackDepth(Thread* self, const InstrumentationStackFrame& instrumentation_frame, |
| int delta) |
| SHARED_REQUIRES(Locks::mutator_lock_) { |
| size_t frame_id = StackVisitor::ComputeNumFrames(self, kInstrumentationStackWalk) + delta; |
| if (frame_id != instrumentation_frame.frame_id_) { |
| LOG(ERROR) << "Expected frame_id=" << frame_id << " but found " |
| << instrumentation_frame.frame_id_; |
| StackVisitor::DescribeStack(self); |
| CHECK_EQ(frame_id, instrumentation_frame.frame_id_); |
| } |
| } |
| |
| void Instrumentation::PushInstrumentationStackFrame(Thread* self, mirror::Object* this_object, |
| ArtMethod* method, |
| uintptr_t lr, bool interpreter_entry) { |
| // We have a callee-save frame meaning this value is guaranteed to never be 0. |
| size_t frame_id = StackVisitor::ComputeNumFrames(self, kInstrumentationStackWalk); |
| std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack(); |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Entering " << PrettyMethod(method) << " from PC " << reinterpret_cast<void*>(lr); |
| } |
| instrumentation::InstrumentationStackFrame instrumentation_frame(this_object, method, lr, |
| frame_id, interpreter_entry); |
| stack->push_front(instrumentation_frame); |
| |
| if (!interpreter_entry) { |
| MethodEnterEvent(self, this_object, method, 0); |
| } |
| } |
| |
| TwoWordReturn Instrumentation::PopInstrumentationStackFrame(Thread* self, uintptr_t* return_pc, |
| uint64_t gpr_result, |
| uint64_t fpr_result) { |
| // Do the pop. |
| std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack(); |
| CHECK_GT(stack->size(), 0U); |
| InstrumentationStackFrame instrumentation_frame = stack->front(); |
| stack->pop_front(); |
| |
| // Set return PC and check the sanity of the stack. |
| *return_pc = instrumentation_frame.return_pc_; |
| CheckStackDepth(self, instrumentation_frame, 0); |
| self->VerifyStack(); |
| |
| ArtMethod* method = instrumentation_frame.method_; |
| uint32_t length; |
| const size_t pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize(); |
| char return_shorty = method->GetInterfaceMethodIfProxy(pointer_size)->GetShorty(&length)[0]; |
| 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); |
| } |
| // TODO: improve the dex pc information here, requires knowledge of current PC as opposed to |
| // return_pc. |
| uint32_t dex_pc = DexFile::kDexNoIndex; |
| mirror::Object* this_object = instrumentation_frame.this_object_; |
| if (!instrumentation_frame.interpreter_entry_) { |
| MethodExitEvent(self, this_object, instrumentation_frame.method_, dex_pc, 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); |
| bool deoptimize = (visitor.caller != nullptr) && |
| (interpreter_stubs_installed_ || IsDeoptimized(visitor.caller) || |
| Dbg::IsForcedInterpreterNeededForUpcall(self, visitor.caller)); |
| if (deoptimize) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << StringPrintf("Deoptimizing %s by returning from %s with result %#" PRIx64 " in ", |
| PrettyMethod(visitor.caller).c_str(), |
| PrettyMethod(method).c_str(), |
| return_value.GetJ()) << *self; |
| } |
| self->PushDeoptimizationContext(return_value, |
| return_shorty == 'L', |
| false /* from_code */, |
| nullptr /* no pending exception */); |
| return GetTwoWordSuccessValue(*return_pc, |
| reinterpret_cast<uintptr_t>(GetQuickDeoptimizationEntryPoint())); |
| } else { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Returning from " << PrettyMethod(method) |
| << " to PC " << reinterpret_cast<void*>(*return_pc); |
| } |
| return GetTwoWordSuccessValue(0, *return_pc); |
| } |
| } |
| |
| void Instrumentation::PopMethodForUnwind(Thread* self, bool is_deoptimization) const { |
| // Do the pop. |
| std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack(); |
| CHECK_GT(stack->size(), 0U); |
| InstrumentationStackFrame instrumentation_frame = stack->front(); |
| // TODO: bring back CheckStackDepth(self, instrumentation_frame, 2); |
| stack->pop_front(); |
| |
| ArtMethod* method = instrumentation_frame.method_; |
| if (is_deoptimization) { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Popping for deoptimization " << PrettyMethod(method); |
| } |
| } else { |
| if (kVerboseInstrumentation) { |
| LOG(INFO) << "Popping for unwind " << PrettyMethod(method); |
| } |
| |
| // Notify listeners of method unwind. |
| // TODO: improve the dex pc information here, requires knowledge of current PC as opposed to |
| // return_pc. |
| uint32_t dex_pc = DexFile::kDexNoIndex; |
| MethodUnwindEvent(self, instrumentation_frame.this_object_, method, dex_pc); |
| } |
| } |
| |
| std::string InstrumentationStackFrame::Dump() const { |
| std::ostringstream os; |
| os << "Frame " << frame_id_ << " " << PrettyMethod(method_) << ":" |
| << reinterpret_cast<void*>(return_pc_) << " this=" << reinterpret_cast<void*>(this_object_); |
| return os.str(); |
| } |
| |
| } // namespace instrumentation |
| } // namespace art |