/* * Copyright 2014 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 "jit.h" #include #include "art_method-inl.h" #include "base/enums.h" #include "base/file_utils.h" #include "base/logging.h" // For VLOG. #include "base/memfd.h" #include "base/memory_tool.h" #include "base/runtime_debug.h" #include "base/scoped_flock.h" #include "base/utils.h" #include "class_root-inl.h" #include "compilation_kind.h" #include "debugger.h" #include "dex/type_lookup_table.h" #include "gc/space/image_space.h" #include "entrypoints/entrypoint_utils-inl.h" #include "entrypoints/runtime_asm_entrypoints.h" #include "image-inl.h" #include "interpreter/interpreter.h" #include "jit-inl.h" #include "jit_code_cache.h" #include "jni/java_vm_ext.h" #include "mirror/method_handle_impl.h" #include "mirror/var_handle.h" #include "oat_file.h" #include "oat_file_manager.h" #include "oat_quick_method_header.h" #include "profile/profile_boot_info.h" #include "profile/profile_compilation_info.h" #include "profile_saver.h" #include "runtime.h" #include "runtime_options.h" #include "stack.h" #include "stack_map.h" #include "thread-inl.h" #include "thread_list.h" using android::base::unique_fd; namespace art { namespace jit { static constexpr bool kEnableOnStackReplacement = true; // Maximum permitted threshold value. static constexpr uint32_t kJitMaxThreshold = std::numeric_limits::max(); static constexpr uint32_t kJitDefaultOptimizeThreshold = 0xffff; // Different optimization threshold constants. These default to the equivalent optimization // thresholds divided by 2, but can be overridden at the command-line. static constexpr uint32_t kJitStressDefaultOptimizeThreshold = kJitDefaultOptimizeThreshold / 2; static constexpr uint32_t kJitSlowStressDefaultOptimizeThreshold = kJitStressDefaultOptimizeThreshold / 2; static constexpr uint32_t kJitDefaultWarmupThreshold = 0xffff; // Different warm-up threshold constants. These default to the equivalent warmup thresholds divided // by 2, but can be overridden at the command-line. static constexpr uint32_t kJitStressDefaultWarmupThreshold = kJitDefaultWarmupThreshold / 2; static constexpr uint32_t kJitSlowStressDefaultWarmupThreshold = kJitStressDefaultWarmupThreshold / 2; DEFINE_RUNTIME_DEBUG_FLAG(Jit, kSlowMode); // JIT compiler void* Jit::jit_library_handle_ = nullptr; JitCompilerInterface* Jit::jit_compiler_ = nullptr; JitCompilerInterface* (*Jit::jit_load_)(void) = nullptr; JitOptions* JitOptions::CreateFromRuntimeArguments(const RuntimeArgumentMap& options) { auto* jit_options = new JitOptions; jit_options->use_jit_compilation_ = options.GetOrDefault(RuntimeArgumentMap::UseJitCompilation); jit_options->use_profiled_jit_compilation_ = options.GetOrDefault(RuntimeArgumentMap::UseProfiledJitCompilation); jit_options->code_cache_initial_capacity_ = options.GetOrDefault(RuntimeArgumentMap::JITCodeCacheInitialCapacity); jit_options->code_cache_max_capacity_ = options.GetOrDefault(RuntimeArgumentMap::JITCodeCacheMaxCapacity); jit_options->dump_info_on_shutdown_ = options.Exists(RuntimeArgumentMap::DumpJITInfoOnShutdown); jit_options->profile_saver_options_ = options.GetOrDefault(RuntimeArgumentMap::ProfileSaverOpts); jit_options->thread_pool_pthread_priority_ = options.GetOrDefault(RuntimeArgumentMap::JITPoolThreadPthreadPriority); jit_options->zygote_thread_pool_pthread_priority_ = options.GetOrDefault(RuntimeArgumentMap::JITZygotePoolThreadPthreadPriority); // Set default optimize threshold to aid with checking defaults. jit_options->optimize_threshold_ = kIsDebugBuild ? (Jit::kSlowMode ? kJitSlowStressDefaultOptimizeThreshold : kJitStressDefaultOptimizeThreshold) : kJitDefaultOptimizeThreshold; // Set default warm-up threshold to aid with checking defaults. jit_options->warmup_threshold_ = kIsDebugBuild ? (Jit::kSlowMode ? kJitSlowStressDefaultWarmupThreshold : kJitStressDefaultWarmupThreshold) : kJitDefaultWarmupThreshold; if (options.Exists(RuntimeArgumentMap::JITOptimizeThreshold)) { jit_options->optimize_threshold_ = *options.Get(RuntimeArgumentMap::JITOptimizeThreshold); } DCHECK_LE(jit_options->optimize_threshold_, kJitMaxThreshold); if (options.Exists(RuntimeArgumentMap::JITWarmupThreshold)) { jit_options->warmup_threshold_ = *options.Get(RuntimeArgumentMap::JITWarmupThreshold); } DCHECK_LE(jit_options->warmup_threshold_, kJitMaxThreshold); if (options.Exists(RuntimeArgumentMap::JITPriorityThreadWeight)) { jit_options->priority_thread_weight_ = *options.Get(RuntimeArgumentMap::JITPriorityThreadWeight); if (jit_options->priority_thread_weight_ > jit_options->warmup_threshold_) { LOG(FATAL) << "Priority thread weight is above the warmup threshold."; } else if (jit_options->priority_thread_weight_ == 0) { LOG(FATAL) << "Priority thread weight cannot be 0."; } } else { jit_options->priority_thread_weight_ = std::max( jit_options->warmup_threshold_ / Jit::kDefaultPriorityThreadWeightRatio, static_cast(1)); } if (options.Exists(RuntimeArgumentMap::JITInvokeTransitionWeight)) { jit_options->invoke_transition_weight_ = *options.Get(RuntimeArgumentMap::JITInvokeTransitionWeight); if (jit_options->invoke_transition_weight_ > jit_options->warmup_threshold_) { LOG(FATAL) << "Invoke transition weight is above the warmup threshold."; } else if (jit_options->invoke_transition_weight_ == 0) { LOG(FATAL) << "Invoke transition weight cannot be 0."; } } else { jit_options->invoke_transition_weight_ = std::max( jit_options->warmup_threshold_ / Jit::kDefaultInvokeTransitionWeightRatio, static_cast(1)); } return jit_options; } void Jit::DumpInfo(std::ostream& os) { code_cache_->Dump(os); cumulative_timings_.Dump(os); MutexLock mu(Thread::Current(), lock_); memory_use_.PrintMemoryUse(os); } void Jit::DumpForSigQuit(std::ostream& os) { DumpInfo(os); ProfileSaver::DumpInstanceInfo(os); } void Jit::AddTimingLogger(const TimingLogger& logger) { cumulative_timings_.AddLogger(logger); } Jit::Jit(JitCodeCache* code_cache, JitOptions* options) : code_cache_(code_cache), options_(options), boot_completed_lock_("Jit::boot_completed_lock_"), cumulative_timings_("JIT timings"), memory_use_("Memory used for compilation", 16), lock_("JIT memory use lock"), zygote_mapping_methods_(), fd_methods_(-1), fd_methods_size_(0) {} Jit* Jit::Create(JitCodeCache* code_cache, JitOptions* options) { if (jit_load_ == nullptr) { LOG(WARNING) << "Not creating JIT: library not loaded"; return nullptr; } jit_compiler_ = (jit_load_)(); if (jit_compiler_ == nullptr) { LOG(WARNING) << "Not creating JIT: failed to allocate a compiler"; return nullptr; } std::unique_ptr jit(new Jit(code_cache, options)); // If the code collector is enabled, check if that still holds: // With 'perf', we want a 1-1 mapping between an address and a method. // We aren't able to keep method pointers live during the instrumentation method entry trampoline // so we will just disable jit-gc if we are doing that. // JitAtFirstUse compiles the methods synchronously on mutator threads. While this should work // in theory it is causing deadlocks in some jvmti tests related to Jit GC. Hence, disabling // Jit GC for now (b/147208992). if (code_cache->GetGarbageCollectCode()) { code_cache->SetGarbageCollectCode(!jit_compiler_->GenerateDebugInfo() && !jit->JitAtFirstUse()); } VLOG(jit) << "JIT created with initial_capacity=" << PrettySize(options->GetCodeCacheInitialCapacity()) << ", max_capacity=" << PrettySize(options->GetCodeCacheMaxCapacity()) << ", warmup_threshold=" << options->GetWarmupThreshold() << ", optimize_threshold=" << options->GetOptimizeThreshold() << ", profile_saver_options=" << options->GetProfileSaverOptions(); // We want to know whether the compiler is compiling baseline, as this // affects how we GC ProfilingInfos. for (const std::string& option : Runtime::Current()->GetCompilerOptions()) { if (option == "--baseline") { options->SetUseBaselineCompiler(); break; } } // Notify native debugger about the classes already loaded before the creation of the jit. jit->DumpTypeInfoForLoadedTypes(Runtime::Current()->GetClassLinker()); return jit.release(); } template bool Jit::LoadSymbol(T* address, const char* name, std::string* error_msg) { *address = reinterpret_cast(dlsym(jit_library_handle_, name)); if (*address == nullptr) { *error_msg = std::string("JIT couldn't find ") + name + std::string(" entry point"); return false; } return true; } bool Jit::LoadCompilerLibrary(std::string* error_msg) { jit_library_handle_ = dlopen( kIsDebugBuild ? "libartd-compiler.so" : "libart-compiler.so", RTLD_NOW); if (jit_library_handle_ == nullptr) { std::ostringstream oss; oss << "JIT could not load libart-compiler.so: " << dlerror(); *error_msg = oss.str(); return false; } if (!LoadSymbol(&jit_load_, "jit_load", error_msg)) { dlclose(jit_library_handle_); return false; } return true; } bool Jit::CompileMethodInternal(ArtMethod* method, Thread* self, CompilationKind compilation_kind, bool prejit) { if (kIsDebugBuild) { MutexLock mu(self, *Locks::jit_lock_); CHECK(GetCodeCache()->IsMethodBeingCompiled(method, compilation_kind)); } DCHECK(Runtime::Current()->UseJitCompilation()); DCHECK(!method->IsRuntimeMethod()); // If the baseline flag was explicitly passed in the compiler options, change the compilation kind // from optimized to baseline. if (jit_compiler_->IsBaselineCompiler() && compilation_kind == CompilationKind::kOptimized) { compilation_kind = CompilationKind::kBaseline; } // If we're asked to compile baseline, but we cannot allocate profiling infos, // change the compilation kind to optimized. if ((compilation_kind == CompilationKind::kBaseline) && !GetCodeCache()->CanAllocateProfilingInfo()) { compilation_kind = CompilationKind::kOptimized; } // Don't compile the method if it has breakpoints. if (Runtime::Current()->GetInstrumentation()->IsDeoptimized(method)) { VLOG(jit) << "JIT not compiling " << method->PrettyMethod() << " due to not being safe to jit according to runtime-callbacks. For example, there" << " could be breakpoints in this method."; return false; } if (!method->IsCompilable()) { DCHECK(method->GetDeclaringClass()->IsObsoleteObject() || method->IsProxyMethod()) << method->PrettyMethod(); VLOG(jit) << "JIT not compiling " << method->PrettyMethod() << " due to method being made " << "obsolete while waiting for JIT task to run. This probably happened due to " << "concurrent structural class redefinition."; return false; } // Don't compile the method if we are supposed to be deoptimized. instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation(); if (instrumentation->AreAllMethodsDeoptimized() || instrumentation->IsDeoptimized(method)) { VLOG(jit) << "JIT not compiling " << method->PrettyMethod() << " due to deoptimization"; return false; } JitMemoryRegion* region = GetCodeCache()->GetCurrentRegion(); if ((compilation_kind == CompilationKind::kOsr) && GetCodeCache()->IsSharedRegion(*region)) { VLOG(jit) << "JIT not osr compiling " << method->PrettyMethod() << " due to using shared region"; return false; } // If we get a request to compile a proxy method, we pass the actual Java method // of that proxy method, as the compiler does not expect a proxy method. ArtMethod* method_to_compile = method->GetInterfaceMethodIfProxy(kRuntimePointerSize); if (!code_cache_->NotifyCompilationOf(method_to_compile, self, compilation_kind, prejit)) { return false; } VLOG(jit) << "Compiling method " << ArtMethod::PrettyMethod(method_to_compile) << " kind=" << compilation_kind; bool success = jit_compiler_->CompileMethod(self, region, method_to_compile, compilation_kind); code_cache_->DoneCompiling(method_to_compile, self); if (!success) { VLOG(jit) << "Failed to compile method " << ArtMethod::PrettyMethod(method_to_compile) << " kind=" << compilation_kind; } if (kIsDebugBuild) { if (self->IsExceptionPending()) { mirror::Throwable* exception = self->GetException(); LOG(FATAL) << "No pending exception expected after compiling " << ArtMethod::PrettyMethod(method) << ": " << exception->Dump(); } } return success; } void Jit::WaitForWorkersToBeCreated() { if (thread_pool_ != nullptr) { thread_pool_->WaitForWorkersToBeCreated(); } } void Jit::DeleteThreadPool() { Thread* self = Thread::Current(); if (thread_pool_ != nullptr) { std::unique_ptr pool; { ScopedSuspendAll ssa(__FUNCTION__); // Clear thread_pool_ field while the threads are suspended. // A mutator in the 'AddSamples' method will check against it. pool = std::move(thread_pool_); } // When running sanitized, let all tasks finish to not leak. Otherwise just clear the queue. if (!kRunningOnMemoryTool) { pool->StopWorkers(self); pool->RemoveAllTasks(self); } // We could just suspend all threads, but we know those threads // will finish in a short period, so it's not worth adding a suspend logic // here. Besides, this is only done for shutdown. pool->Wait(self, false, false); } } void Jit::StartProfileSaver(const std::string& profile_filename, const std::vector& code_paths, const std::string& ref_profile_filename) { if (options_->GetSaveProfilingInfo()) { ProfileSaver::Start(options_->GetProfileSaverOptions(), profile_filename, code_cache_, code_paths, ref_profile_filename); } } void Jit::StopProfileSaver() { if (options_->GetSaveProfilingInfo() && ProfileSaver::IsStarted()) { ProfileSaver::Stop(options_->DumpJitInfoOnShutdown()); } } bool Jit::JitAtFirstUse() { return HotMethodThreshold() == 0; } bool Jit::CanInvokeCompiledCode(ArtMethod* method) { return code_cache_->ContainsPc(method->GetEntryPointFromQuickCompiledCode()); } Jit::~Jit() { DCHECK_IMPLIES(options_->GetSaveProfilingInfo(), !ProfileSaver::IsStarted()); if (options_->DumpJitInfoOnShutdown()) { DumpInfo(LOG_STREAM(INFO)); Runtime::Current()->DumpDeoptimizations(LOG_STREAM(INFO)); } DeleteThreadPool(); if (jit_compiler_ != nullptr) { delete jit_compiler_; jit_compiler_ = nullptr; } if (jit_library_handle_ != nullptr) { dlclose(jit_library_handle_); jit_library_handle_ = nullptr; } } void Jit::NewTypeLoadedIfUsingJit(mirror::Class* type) { if (!Runtime::Current()->UseJitCompilation()) { // No need to notify if we only use the JIT to save profiles. return; } jit::Jit* jit = Runtime::Current()->GetJit(); if (jit->jit_compiler_->GenerateDebugInfo()) { jit_compiler_->TypesLoaded(&type, 1); } } void Jit::DumpTypeInfoForLoadedTypes(ClassLinker* linker) { struct CollectClasses : public ClassVisitor { bool operator()(ObjPtr klass) override REQUIRES_SHARED(Locks::mutator_lock_) { classes_.push_back(klass.Ptr()); return true; } std::vector classes_; }; if (jit_compiler_->GenerateDebugInfo()) { ScopedObjectAccess so(Thread::Current()); CollectClasses visitor; linker->VisitClasses(&visitor); jit_compiler_->TypesLoaded(visitor.classes_.data(), visitor.classes_.size()); } } extern "C" void art_quick_osr_stub(void** stack, size_t stack_size_in_bytes, const uint8_t* native_pc, JValue* result, const char* shorty, Thread* self); OsrData* Jit::PrepareForOsr(ArtMethod* method, uint32_t dex_pc, uint32_t* vregs) { if (!kEnableOnStackReplacement) { return nullptr; } // Cheap check if the method has been compiled already. That's an indicator that we should // osr into it. if (!GetCodeCache()->ContainsPc(method->GetEntryPointFromQuickCompiledCode())) { return nullptr; } // Fetch some data before looking up for an OSR method. We don't want thread // suspension once we hold an OSR method, as the JIT code cache could delete the OSR // method while we are being suspended. CodeItemDataAccessor accessor(method->DexInstructionData()); const size_t number_of_vregs = accessor.RegistersSize(); std::string method_name(VLOG_IS_ON(jit) ? method->PrettyMethod() : ""); OsrData* osr_data = nullptr; { ScopedAssertNoThreadSuspension sts("Holding OSR method"); const OatQuickMethodHeader* osr_method = GetCodeCache()->LookupOsrMethodHeader(method); if (osr_method == nullptr) { // No osr method yet, just return to the interpreter. return nullptr; } CodeInfo code_info(osr_method); // Find stack map starting at the target dex_pc. StackMap stack_map = code_info.GetOsrStackMapForDexPc(dex_pc); if (!stack_map.IsValid()) { // There is no OSR stack map for this dex pc offset. Just return to the interpreter in the // hope that the next branch has one. return nullptr; } // We found a stack map, now fill the frame with dex register values from the interpreter's // shadow frame. DexRegisterMap vreg_map = code_info.GetDexRegisterMapOf(stack_map); DCHECK_EQ(vreg_map.size(), number_of_vregs); size_t frame_size = osr_method->GetFrameSizeInBytes(); // Allocate memory to put shadow frame values. The osr stub will copy that memory to // stack. // Note that we could pass the shadow frame to the stub, and let it copy the values there, // but that is engineering complexity not worth the effort for something like OSR. osr_data = reinterpret_cast(malloc(sizeof(OsrData) + frame_size)); if (osr_data == nullptr) { return nullptr; } memset(osr_data, 0, sizeof(OsrData) + frame_size); osr_data->frame_size = frame_size; // Art ABI: ArtMethod is at the bottom of the stack. osr_data->memory[0] = method; if (vreg_map.empty()) { // If we don't have a dex register map, then there are no live dex registers at // this dex pc. } else { for (uint16_t vreg = 0; vreg < number_of_vregs; ++vreg) { DexRegisterLocation::Kind location = vreg_map[vreg].GetKind(); if (location == DexRegisterLocation::Kind::kNone) { // Dex register is dead or uninitialized. continue; } if (location == DexRegisterLocation::Kind::kConstant) { // We skip constants because the compiled code knows how to handle them. continue; } DCHECK_EQ(location, DexRegisterLocation::Kind::kInStack); int32_t vreg_value = vregs[vreg]; int32_t slot_offset = vreg_map[vreg].GetStackOffsetInBytes(); DCHECK_LT(slot_offset, static_cast(frame_size)); DCHECK_GT(slot_offset, 0); (reinterpret_cast(osr_data->memory))[slot_offset / sizeof(int32_t)] = vreg_value; } } osr_data->native_pc = stack_map.GetNativePcOffset(kRuntimeISA) + osr_method->GetEntryPoint(); VLOG(jit) << "Jumping to " << method_name << "@" << std::hex << reinterpret_cast(osr_data->native_pc); } return osr_data; } bool Jit::MaybeDoOnStackReplacement(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t dex_pc_offset, JValue* result) { Jit* jit = Runtime::Current()->GetJit(); if (jit == nullptr) { return false; } if (UNLIKELY(__builtin_frame_address(0) < thread->GetStackEnd())) { // Don't attempt to do an OSR if we are close to the stack limit. Since // the interpreter frames are still on stack, OSR has the potential // to stack overflow even for a simple loop. // b/27094810. return false; } // Get the actual Java method if this method is from a proxy class. The compiler // and the JIT code cache do not expect methods from proxy classes. method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize); // Before allowing the jump, make sure no code is actively inspecting the method to avoid // jumping from interpreter to OSR while e.g. single stepping. Note that we could selectively // disable OSR when single stepping, but that's currently hard to know at this point. // Currently, HaveLocalsChanged is not frame specific. It is possible to make it frame specific // to allow OSR of frames that don't have any locals changed but it isn't worth the additional // complexity. if (Runtime::Current()->GetInstrumentation()->NeedsSlowInterpreterForMethod(thread, method) || Runtime::Current()->GetRuntimeCallbacks()->HaveLocalsChanged()) { return false; } ShadowFrame* shadow_frame = thread->GetManagedStack()->GetTopShadowFrame(); OsrData* osr_data = jit->PrepareForOsr(method, dex_pc + dex_pc_offset, shadow_frame->GetVRegArgs(0)); if (osr_data == nullptr) { return false; } { thread->PopShadowFrame(); ManagedStack fragment; thread->PushManagedStackFragment(&fragment); (*art_quick_osr_stub)(osr_data->memory, osr_data->frame_size, osr_data->native_pc, result, method->GetShorty(), thread); if (UNLIKELY(thread->GetException() == Thread::GetDeoptimizationException())) { thread->DeoptimizeWithDeoptimizationException(result); } thread->PopManagedStackFragment(fragment); } free(osr_data); thread->PushShadowFrame(shadow_frame); VLOG(jit) << "Done running OSR code for " << method->PrettyMethod(); return true; } void Jit::AddMemoryUsage(ArtMethod* method, size_t bytes) { if (bytes > 4 * MB) { LOG(INFO) << "Compiler allocated " << PrettySize(bytes) << " to compile " << ArtMethod::PrettyMethod(method); } MutexLock mu(Thread::Current(), lock_); memory_use_.AddValue(bytes); } void Jit::NotifyZygoteCompilationDone() { if (fd_methods_ == -1) { return; } size_t offset = 0; for (gc::space::ImageSpace* space : Runtime::Current()->GetHeap()->GetBootImageSpaces()) { const ImageHeader& header = space->GetImageHeader(); const ImageSection& section = header.GetMethodsSection(); // Because mremap works at page boundaries, we can only handle methods // within a page range. For methods that falls above or below the range, // the child processes will copy their contents to their private mapping // in `child_mapping_methods`. See `MapBootImageMethods`. uint8_t* page_start = AlignUp(header.GetImageBegin() + section.Offset(), kPageSize); uint8_t* page_end = AlignDown(header.GetImageBegin() + section.Offset() + section.Size(), kPageSize); if (page_end > page_start) { uint64_t capacity = page_end - page_start; memcpy(zygote_mapping_methods_.Begin() + offset, page_start, capacity); offset += capacity; } } // Do an msync to ensure we are not affected by writes still being in caches. if (msync(zygote_mapping_methods_.Begin(), fd_methods_size_, MS_SYNC) != 0) { PLOG(WARNING) << "Failed to sync boot image methods memory"; code_cache_->GetZygoteMap()->SetCompilationState(ZygoteCompilationState::kNotifiedFailure); return; } // We don't need the shared mapping anymore, and we need to drop it in case // the file hasn't been sealed writable. zygote_mapping_methods_ = MemMap::Invalid(); // Seal writes now. Zygote and children will map the memory private in order // to write to it. if (fcntl(fd_methods_, F_ADD_SEALS, F_SEAL_SEAL | F_SEAL_WRITE) == -1) { PLOG(WARNING) << "Failed to seal boot image methods file descriptor"; code_cache_->GetZygoteMap()->SetCompilationState(ZygoteCompilationState::kNotifiedFailure); return; } std::string error_str; MemMap child_mapping_methods = MemMap::MapFile( fd_methods_size_, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd_methods_, /* start= */ 0, /* low_4gb= */ false, "boot-image-methods", &error_str); if (!child_mapping_methods.IsValid()) { LOG(WARNING) << "Failed to create child mapping of boot image methods: " << error_str; code_cache_->GetZygoteMap()->SetCompilationState(ZygoteCompilationState::kNotifiedFailure); return; } // Ensure the contents are the same as before: there was a window between // the memcpy and the sealing where other processes could have changed the // contents. // Note this would not be needed if we could have used F_SEAL_FUTURE_WRITE, // see b/143833776. offset = 0; for (gc::space::ImageSpace* space : Runtime::Current()->GetHeap()->GetBootImageSpaces()) { const ImageHeader& header = space->GetImageHeader(); const ImageSection& section = header.GetMethodsSection(); // Because mremap works at page boundaries, we can only handle methods // within a page range. For methods that falls above or below the range, // the child processes will copy their contents to their private mapping // in `child_mapping_methods`. See `MapBootImageMethods`. uint8_t* page_start = AlignUp(header.GetImageBegin() + section.Offset(), kPageSize); uint8_t* page_end = AlignDown(header.GetImageBegin() + section.Offset() + section.Size(), kPageSize); if (page_end > page_start) { uint64_t capacity = page_end - page_start; if (memcmp(child_mapping_methods.Begin() + offset, page_start, capacity) != 0) { LOG(WARNING) << "Contents differ in boot image methods data"; code_cache_->GetZygoteMap()->SetCompilationState( ZygoteCompilationState::kNotifiedFailure); return; } offset += capacity; } } // Future spawned processes don't need the fd anymore. fd_methods_.reset(); // In order to have the zygote and children share the memory, we also remap // the memory into the zygote process. offset = 0; for (gc::space::ImageSpace* space : Runtime::Current()->GetHeap()->GetBootImageSpaces()) { const ImageHeader& header = space->GetImageHeader(); const ImageSection& section = header.GetMethodsSection(); // Because mremap works at page boundaries, we can only handle methods // within a page range. For methods that falls above or below the range, // the child processes will copy their contents to their private mapping // in `child_mapping_methods`. See `MapBootImageMethods`. uint8_t* page_start = AlignUp(header.GetImageBegin() + section.Offset(), kPageSize); uint8_t* page_end = AlignDown(header.GetImageBegin() + section.Offset() + section.Size(), kPageSize); if (page_end > page_start) { uint64_t capacity = page_end - page_start; if (mremap(child_mapping_methods.Begin() + offset, capacity, capacity, MREMAP_FIXED | MREMAP_MAYMOVE, page_start) == MAP_FAILED) { // Failing to remap is safe as the process will just use the old // contents. PLOG(WARNING) << "Failed mremap of boot image methods of " << space->GetImageFilename(); } offset += capacity; } } LOG(INFO) << "Successfully notified child processes on sharing boot image methods"; // Mark that compilation of boot classpath is done, and memory can now be // shared. Other processes will pick up this information. code_cache_->GetZygoteMap()->SetCompilationState(ZygoteCompilationState::kNotifiedOk); // The private mapping created for this process has been mremaped. We can // reset it. child_mapping_methods.Reset(); } class ScopedCompilation { public: ScopedCompilation(ScopedCompilation&& other) noexcept : jit_(other.jit_), method_(other.method_), compilation_kind_(other.compilation_kind_), owns_compilation_(other.owns_compilation_) { other.owns_compilation_ = false; } ScopedCompilation(Jit* jit, ArtMethod* method, CompilationKind compilation_kind) : jit_(jit), method_(method), compilation_kind_(compilation_kind), owns_compilation_(true) { MutexLock mu(Thread::Current(), *Locks::jit_lock_); // We don't want to enqueue any new tasks when thread pool has stopped. This simplifies // the implementation of redefinition feature in jvmti. if (jit_->GetThreadPool() == nullptr || !jit_->GetThreadPool()->HasStarted(Thread::Current()) || jit_->GetCodeCache()->IsMethodBeingCompiled(method_, compilation_kind_)) { owns_compilation_ = false; return; } jit_->GetCodeCache()->AddMethodBeingCompiled(method_, compilation_kind_); } bool OwnsCompilation() const { return owns_compilation_; } ~ScopedCompilation() { if (owns_compilation_) { MutexLock mu(Thread::Current(), *Locks::jit_lock_); jit_->GetCodeCache()->RemoveMethodBeingCompiled(method_, compilation_kind_); } } private: Jit* const jit_; ArtMethod* const method_; const CompilationKind compilation_kind_; bool owns_compilation_; }; class JitCompileTask final : public Task { public: enum class TaskKind { kCompile, kPreCompile, }; JitCompileTask(ArtMethod* method, TaskKind task_kind, CompilationKind compilation_kind, ScopedCompilation&& sc) : method_(method), kind_(task_kind), compilation_kind_(compilation_kind), scoped_compilation_(std::move(sc)) { DCHECK(scoped_compilation_.OwnsCompilation()); DCHECK(!sc.OwnsCompilation()); } void Run(Thread* self) override { { ScopedObjectAccess soa(self); switch (kind_) { case TaskKind::kCompile: case TaskKind::kPreCompile: { Runtime::Current()->GetJit()->CompileMethodInternal( method_, self, compilation_kind_, /* prejit= */ (kind_ == TaskKind::kPreCompile)); break; } } } ProfileSaver::NotifyJitActivity(); } void Finalize() override { delete this; } private: ArtMethod* const method_; const TaskKind kind_; const CompilationKind compilation_kind_; ScopedCompilation scoped_compilation_; DISALLOW_IMPLICIT_CONSTRUCTORS(JitCompileTask); }; static std::string GetProfileFile(const std::string& dex_location) { // Hardcoded assumption where the profile file is. // TODO(ngeoffray): this is brittle and we would need to change change if we // wanted to do more eager JITting of methods in a profile. This is // currently only for system server. return dex_location + ".prof"; } static std::string GetBootProfileFile(const std::string& profile) { // The boot profile can be found next to the compilation profile, with a // different extension. return ReplaceFileExtension(profile, "bprof"); } /** * A JIT task to run after all profile compilation is done. */ class JitDoneCompilingProfileTask final : public SelfDeletingTask { public: explicit JitDoneCompilingProfileTask(const std::vector& dex_files) : dex_files_(dex_files) {} void Run(Thread* self ATTRIBUTE_UNUSED) override { // Madvise DONTNEED dex files now that we're done compiling methods. for (const DexFile* dex_file : dex_files_) { if (IsAddressKnownBackedByFileOrShared(dex_file->Begin())) { int result = madvise(const_cast(AlignDown(dex_file->Begin(), kPageSize)), RoundUp(dex_file->Size(), kPageSize), MADV_DONTNEED); if (result == -1) { PLOG(WARNING) << "Madvise failed"; } } } } private: std::vector dex_files_; DISALLOW_COPY_AND_ASSIGN(JitDoneCompilingProfileTask); }; class JitZygoteDoneCompilingTask final : public SelfDeletingTask { public: JitZygoteDoneCompilingTask() {} void Run(Thread* self ATTRIBUTE_UNUSED) override { DCHECK(Runtime::Current()->IsZygote()); Runtime::Current()->GetJit()->GetCodeCache()->GetZygoteMap()->SetCompilationState( ZygoteCompilationState::kDone); } private: DISALLOW_COPY_AND_ASSIGN(JitZygoteDoneCompilingTask); }; /** * A JIT task to run Java verification of boot classpath classes that were not * verified at compile-time. */ class ZygoteVerificationTask final : public Task { public: ZygoteVerificationTask() {} void Run(Thread* self) override { // We are going to load class and run verification, which may also need to load // classes. If the thread cannot load classes (typically when the runtime is // debuggable), then just return. if (!self->CanLoadClasses()) { return; } Runtime* runtime = Runtime::Current(); ClassLinker* linker = runtime->GetClassLinker(); const std::vector& boot_class_path = runtime->GetClassLinker()->GetBootClassPath(); ScopedObjectAccess soa(self); StackHandleScope<1> hs(self); MutableHandle klass = hs.NewHandle(nullptr); uint64_t start_ns = ThreadCpuNanoTime(); uint64_t number_of_classes = 0; for (const DexFile* dex_file : boot_class_path) { for (uint32_t i = 0; i < dex_file->NumClassDefs(); ++i) { const dex::ClassDef& class_def = dex_file->GetClassDef(i); const char* descriptor = dex_file->GetClassDescriptor(class_def); klass.Assign(linker->LookupResolvedType(descriptor, /* class_loader= */ nullptr)); if (klass == nullptr) { // Class not loaded yet. DCHECK(!self->IsExceptionPending()); continue; } if (klass->IsVerified()) { continue; } if (linker->VerifyClass(self, /* verifier_deps= */ nullptr, klass) == verifier::FailureKind::kHardFailure) { CHECK(self->IsExceptionPending()); LOG(WARNING) << "Methods in the boot classpath failed to verify: " << self->GetException()->Dump(); self->ClearException(); } else { ++number_of_classes; } CHECK(!self->IsExceptionPending()); } } LOG(INFO) << "Background verification of " << number_of_classes << " classes from boot classpath took " << PrettyDuration(ThreadCpuNanoTime() - start_ns); } }; class ZygoteTask final : public Task { public: ZygoteTask() {} void Run(Thread* self) override { Runtime* runtime = Runtime::Current(); uint32_t added_to_queue = 0; for (gc::space::ImageSpace* space : Runtime::Current()->GetHeap()->GetBootImageSpaces()) { const std::vector& boot_class_path = runtime->GetClassLinker()->GetBootClassPath(); ScopedNullHandle null_handle; // We avoid doing compilation at boot for the secondary zygote, as apps forked from it are not // critical for boot. if (Runtime::Current()->IsPrimaryZygote()) { for (const std::string& profile_file : space->GetProfileFiles()) { std::string boot_profile = GetBootProfileFile(profile_file); LOG(INFO) << "JIT Zygote looking at boot profile " << boot_profile; // We add to the queue for zygote so that we can fork processes in-between compilations. added_to_queue += runtime->GetJit()->CompileMethodsFromBootProfile( self, boot_class_path, boot_profile, null_handle, /* add_to_queue= */ true); } } for (const std::string& profile_file : space->GetProfileFiles()) { LOG(INFO) << "JIT Zygote looking at profile " << profile_file; added_to_queue += runtime->GetJit()->CompileMethodsFromProfile( self, boot_class_path, profile_file, null_handle, /* add_to_queue= */ true); } } DCHECK(runtime->GetJit()->InZygoteUsingJit()); runtime->GetJit()->AddPostBootTask(self, new JitZygoteDoneCompilingTask()); JitCodeCache* code_cache = runtime->GetJit()->GetCodeCache(); code_cache->GetZygoteMap()->Initialize(added_to_queue); } void Finalize() override { delete this; } private: DISALLOW_COPY_AND_ASSIGN(ZygoteTask); }; class JitProfileTask final : public Task { public: JitProfileTask(const std::vector>& dex_files, jobject class_loader) { ScopedObjectAccess soa(Thread::Current()); StackHandleScope<1> hs(soa.Self()); Handle h_loader(hs.NewHandle( soa.Decode(class_loader))); ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); for (const auto& dex_file : dex_files) { dex_files_.push_back(dex_file.get()); // Register the dex file so that we can guarantee it doesn't get deleted // while reading it during the task. class_linker->RegisterDexFile(*dex_file.get(), h_loader.Get()); } // We also create our own global ref to use this class loader later. class_loader_ = soa.Vm()->AddGlobalRef(soa.Self(), h_loader.Get()); } void Run(Thread* self) override { ScopedObjectAccess soa(self); StackHandleScope<1> hs(self); Handle loader = hs.NewHandle( soa.Decode(class_loader_)); std::string profile = GetProfileFile(dex_files_[0]->GetLocation()); std::string boot_profile = GetBootProfileFile(profile); Jit* jit = Runtime::Current()->GetJit(); jit->CompileMethodsFromBootProfile( self, dex_files_, boot_profile, loader, /* add_to_queue= */ false); jit->CompileMethodsFromProfile( self, dex_files_, profile, loader, /* add_to_queue= */ true); } void Finalize() override { delete this; } ~JitProfileTask() { ScopedObjectAccess soa(Thread::Current()); soa.Vm()->DeleteGlobalRef(soa.Self(), class_loader_); } private: std::vector dex_files_; jobject class_loader_; DISALLOW_COPY_AND_ASSIGN(JitProfileTask); }; static void CopyIfDifferent(void* s1, const void* s2, size_t n) { if (memcmp(s1, s2, n) != 0) { memcpy(s1, s2, n); } } void Jit::MapBootImageMethods() { if (Runtime::Current()->IsJavaDebuggable()) { LOG(INFO) << "Not mapping boot image methods due to process being debuggable"; return; } CHECK_NE(fd_methods_.get(), -1); if (!code_cache_->GetZygoteMap()->CanMapBootImageMethods()) { LOG(WARNING) << "Not mapping boot image methods due to error from zygote"; // We don't need the fd anymore. fd_methods_.reset(); return; } std::string error_str; MemMap child_mapping_methods = MemMap::MapFile( fd_methods_size_, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd_methods_, /* start= */ 0, /* low_4gb= */ false, "boot-image-methods", &error_str); // We don't need the fd anymore. fd_methods_.reset(); if (!child_mapping_methods.IsValid()) { LOG(WARNING) << "Failed to create child mapping of boot image methods: " << error_str; return; } // We are going to mremap the child mapping into the image: // // ImageSection ChildMappingMethods // // section start --> ----------- // | | // | | // page_start --> | | <----- ----------- // | | | | // | | | | // | | | | // | | | | // | | | | // | | | | // | | | | // page_end --> | | <----- ----------- // | | // section end --> ----------- // size_t offset = 0; for (gc::space::ImageSpace* space : Runtime::Current()->GetHeap()->GetBootImageSpaces()) { const ImageHeader& header = space->GetImageHeader(); const ImageSection& section = header.GetMethodsSection(); uint8_t* page_start = AlignUp(header.GetImageBegin() + section.Offset(), kPageSize); uint8_t* page_end = AlignDown(header.GetImageBegin() + section.Offset() + section.Size(), kPageSize); if (page_end <= page_start) { // Section doesn't contain one aligned entire page. continue; } uint64_t capacity = page_end - page_start; // Walk over methods in the boot image, and check for: // 1) methods whose class is not initialized in the process, but are in the // zygote process. For such methods, we need their entrypoints to be stubs // that do the initialization check. // 2) native methods whose data pointer is different than the one in the // zygote. Such methods may have had custom native implementation provided // by JNI RegisterNatives. header.VisitPackedArtMethods([&](ArtMethod& method) NO_THREAD_SAFETY_ANALYSIS { // Methods in the boot image should never have their single // implementation flag set (and therefore never have a `data_` pointing // to an ArtMethod for single implementation). CHECK(method.IsIntrinsic() || !method.HasSingleImplementationFlag()); if (method.IsRuntimeMethod()) { return; } // Pointer to the method we're currently using. uint8_t* pointer = reinterpret_cast(&method); // The data pointer of that method that we want to keep. uint8_t* data_pointer = pointer + ArtMethod::DataOffset(kRuntimePointerSize).Int32Value(); if (method.IsNative() && data_pointer >= page_start && data_pointer < page_end) { // The data pointer of the ArtMethod in the shared memory we are going to remap into our // own mapping. This is the data that we will see after the remap. uint8_t* new_data_pointer = child_mapping_methods.Begin() + offset + (data_pointer - page_start); CopyIfDifferent(new_data_pointer, data_pointer, sizeof(void*)); } // The entrypoint of the method we're currently using and that we want to // keep. uint8_t* entry_point_pointer = pointer + ArtMethod::EntryPointFromQuickCompiledCodeOffset(kRuntimePointerSize).Int32Value(); if (!method.GetDeclaringClassUnchecked()->IsVisiblyInitialized() && method.IsStatic() && !method.IsConstructor() && entry_point_pointer >= page_start && entry_point_pointer < page_end) { // The entry point of the ArtMethod in the shared memory we are going to remap into our // own mapping. This is the entrypoint that we will see after the remap. uint8_t* new_entry_point_pointer = child_mapping_methods.Begin() + offset + (entry_point_pointer - page_start); CopyIfDifferent(new_entry_point_pointer, entry_point_pointer, sizeof(void*)); } }, space->Begin(), kRuntimePointerSize); // Map the memory in the boot image range. if (mremap(child_mapping_methods.Begin() + offset, capacity, capacity, MREMAP_FIXED | MREMAP_MAYMOVE, page_start) == MAP_FAILED) { PLOG(WARNING) << "Fail to mremap boot image methods for " << space->GetImageFilename(); } offset += capacity; } // The private mapping created for this process has been mremaped. We can // reset it. child_mapping_methods.Reset(); LOG(INFO) << "Successfully mapped boot image methods"; } bool Jit::InZygoteUsingJit() { Runtime* runtime = Runtime::Current(); return runtime->IsZygote() && runtime->HasImageWithProfile() && runtime->UseJitCompilation(); } void Jit::CreateThreadPool() { // There is a DCHECK in the 'AddSamples' method to ensure the tread pool // is not null when we instrument. // We need peers as we may report the JIT thread, e.g., in the debugger. constexpr bool kJitPoolNeedsPeers = true; thread_pool_.reset(new ThreadPool("Jit thread pool", 1, kJitPoolNeedsPeers)); Runtime* runtime = Runtime::Current(); thread_pool_->SetPthreadPriority( runtime->IsZygote() ? options_->GetZygoteThreadPoolPthreadPriority() : options_->GetThreadPoolPthreadPriority()); Start(); if (runtime->IsZygote()) { // To speed up class lookups, generate a type lookup table for // dex files not backed by oat file. for (const DexFile* dex_file : runtime->GetClassLinker()->GetBootClassPath()) { if (dex_file->GetOatDexFile() == nullptr) { TypeLookupTable type_lookup_table = TypeLookupTable::Create(*dex_file); type_lookup_tables_.push_back( std::make_unique(std::move(type_lookup_table))); dex_file->SetOatDexFile(type_lookup_tables_.back().get()); } } // Add a task that will verify boot classpath jars that were not // pre-compiled. thread_pool_->AddTask(Thread::Current(), new ZygoteVerificationTask()); } if (InZygoteUsingJit()) { // If we have an image with a profile, request a JIT task to // compile all methods in that profile. thread_pool_->AddTask(Thread::Current(), new ZygoteTask()); // And create mappings to share boot image methods memory from the zygote to // child processes. // Compute the total capacity required for the boot image methods. uint64_t total_capacity = 0; for (gc::space::ImageSpace* space : Runtime::Current()->GetHeap()->GetBootImageSpaces()) { const ImageHeader& header = space->GetImageHeader(); const ImageSection& section = header.GetMethodsSection(); // Mappings need to be at the page level. uint8_t* page_start = AlignUp(header.GetImageBegin() + section.Offset(), kPageSize); uint8_t* page_end = AlignDown(header.GetImageBegin() + section.Offset() + section.Size(), kPageSize); if (page_end > page_start) { total_capacity += (page_end - page_start); } } // Create the child and zygote mappings to the boot image methods. if (total_capacity > 0) { // Start with '/boot' and end with '.art' to match the pattern recognized // by android_os_Debug.cpp for boot images. const char* name = "/boot-image-methods.art"; unique_fd mem_fd = unique_fd(art::memfd_create(name, /* flags= */ MFD_ALLOW_SEALING | MFD_CLOEXEC)); if (mem_fd.get() == -1) { PLOG(WARNING) << "Could not create boot image methods file descriptor"; return; } if (ftruncate(mem_fd.get(), total_capacity) != 0) { PLOG(WARNING) << "Failed to truncate boot image methods file to " << total_capacity; return; } std::string error_str; // Create the shared mapping eagerly, as this prevents other processes // from adding the writable seal. zygote_mapping_methods_ = MemMap::MapFile( total_capacity, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, /* start= */ 0, /* low_4gb= */ false, "boot-image-methods", &error_str); if (!zygote_mapping_methods_.IsValid()) { LOG(WARNING) << "Failed to create zygote mapping of boot image methods: " << error_str; return; } if (zygote_mapping_methods_.MadviseDontFork() != 0) { LOG(WARNING) << "Failed to madvise dont fork boot image methods"; zygote_mapping_methods_ = MemMap(); return; } // We should use the F_SEAL_FUTURE_WRITE flag, but this has unexpected // behavior on private mappings after fork (the mapping becomes shared between // parent and children), see b/143833776. // We will seal the write once we are done writing to the shared mapping. if (fcntl(mem_fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW) == -1) { PLOG(WARNING) << "Failed to seal boot image methods file descriptor"; zygote_mapping_methods_ = MemMap(); return; } fd_methods_ = unique_fd(mem_fd.release()); fd_methods_size_ = total_capacity; } } } void Jit::RegisterDexFiles(const std::vector>& dex_files, jobject class_loader) { if (dex_files.empty()) { return; } Runtime* runtime = Runtime::Current(); // If the runtime is debuggable, don't bother precompiling methods. // If system server is being profiled, don't precompile as we are going to use // the JIT to count hotness. Note that --count-hotness-in-compiled-code is // only forced when we also profile the boot classpath, see // AndroidRuntime.cpp. if (runtime->IsSystemServer() && UseJitCompilation() && options_->UseProfiledJitCompilation() && runtime->HasImageWithProfile() && !runtime->IsSystemServerProfiled() && !runtime->IsJavaDebuggable()) { // Note: this precompilation is currently not running in production because: // - UseProfiledJitCompilation() is not set by default. // - System server dex files are registered *before* we set the runtime as // system server (though we are in the system server process). thread_pool_->AddTask(Thread::Current(), new JitProfileTask(dex_files, class_loader)); } } void Jit::AddCompileTask(Thread* self, ArtMethod* method, CompilationKind compilation_kind, bool precompile) { ScopedCompilation sc(this, method, compilation_kind); if (!sc.OwnsCompilation()) { return; } JitCompileTask::TaskKind task_kind = precompile ? JitCompileTask::TaskKind::kPreCompile : JitCompileTask::TaskKind::kCompile; thread_pool_->AddTask( self, new JitCompileTask(method, task_kind, compilation_kind, std::move(sc))); } bool Jit::CompileMethodFromProfile(Thread* self, ClassLinker* class_linker, uint32_t method_idx, Handle dex_cache, Handle class_loader, bool add_to_queue, bool compile_after_boot) { ArtMethod* method = class_linker->ResolveMethodWithoutInvokeType( method_idx, dex_cache, class_loader); if (method == nullptr) { self->ClearException(); return false; } if (!method->IsCompilable() || !method->IsInvokable()) { return false; } if (method->IsPreCompiled()) { // Already seen by another profile. return false; } CompilationKind compilation_kind = CompilationKind::kOptimized; const void* entry_point = method->GetEntryPointFromQuickCompiledCode(); if (class_linker->IsQuickToInterpreterBridge(entry_point) || class_linker->IsQuickGenericJniStub(entry_point) || class_linker->IsNterpEntryPoint(entry_point) || // We explicitly check for the resolution stub, and not the resolution trampoline. // The trampoline is for methods backed by a .oat file that has a compiled version of // the method. (entry_point == GetQuickResolutionStub())) { VLOG(jit) << "JIT Zygote processing method " << ArtMethod::PrettyMethod(method) << " from profile"; method->SetPreCompiled(); ScopedCompilation sc(this, method, compilation_kind); if (!sc.OwnsCompilation()) { return false; } if (!add_to_queue) { CompileMethodInternal(method, self, compilation_kind, /* prejit= */ true); } else { Task* task = new JitCompileTask( method, JitCompileTask::TaskKind::kPreCompile, compilation_kind, std::move(sc)); if (compile_after_boot) { AddPostBootTask(self, task); } else { thread_pool_->AddTask(self, task); } return true; } } return false; } uint32_t Jit::CompileMethodsFromBootProfile( Thread* self, const std::vector& dex_files, const std::string& profile_file, Handle class_loader, bool add_to_queue) { unix_file::FdFile profile(profile_file, O_RDONLY, true); if (profile.Fd() == -1) { PLOG(WARNING) << "No boot profile: " << profile_file; return 0u; } ProfileBootInfo profile_info; if (!profile_info.Load(profile.Fd(), dex_files)) { LOG(ERROR) << "Could not load profile file: " << profile_file; return 0u; } ScopedObjectAccess soa(self); VariableSizedHandleScope handles(self); std::vector> dex_caches; ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); for (const DexFile* dex_file : profile_info.GetDexFiles()) { dex_caches.push_back(handles.NewHandle(class_linker->FindDexCache(self, *dex_file))); } uint32_t added_to_queue = 0; for (const std::pair& pair : profile_info.GetMethods()) { if (CompileMethodFromProfile(self, class_linker, pair.second, dex_caches[pair.first], class_loader, add_to_queue, /*compile_after_boot=*/false)) { ++added_to_queue; } } return added_to_queue; } uint32_t Jit::CompileMethodsFromProfile( Thread* self, const std::vector& dex_files, const std::string& profile_file, Handle class_loader, bool add_to_queue) { if (profile_file.empty()) { LOG(WARNING) << "Expected a profile file in JIT zygote mode"; return 0u; } // We don't generate boot profiles on device, therefore we don't // need to lock the file. unix_file::FdFile profile(profile_file, O_RDONLY, true); if (profile.Fd() == -1) { PLOG(WARNING) << "No profile: " << profile_file; return 0u; } ProfileCompilationInfo profile_info(/* for_boot_image= */ class_loader.IsNull()); if (!profile_info.Load(profile.Fd())) { LOG(ERROR) << "Could not load profile file"; return 0u; } ScopedObjectAccess soa(self); StackHandleScope<1> hs(self); MutableHandle dex_cache = hs.NewHandle(nullptr); ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); uint32_t added_to_queue = 0u; for (const DexFile* dex_file : dex_files) { std::set class_types; std::set all_methods; if (!profile_info.GetClassesAndMethods(*dex_file, &class_types, &all_methods, &all_methods, &all_methods)) { // This means the profile file did not reference the dex file, which is the case // if there's no classes and methods of that dex file in the profile. continue; } dex_cache.Assign(class_linker->FindDexCache(self, *dex_file)); CHECK(dex_cache != nullptr) << "Could not find dex cache for " << dex_file->GetLocation(); for (uint16_t method_idx : all_methods) { if (CompileMethodFromProfile(self, class_linker, method_idx, dex_cache, class_loader, add_to_queue, /*compile_after_boot=*/true)) { ++added_to_queue; } } } // Add a task to run when all compilation is done. AddPostBootTask(self, new JitDoneCompilingProfileTask(dex_files)); return added_to_queue; } bool Jit::IgnoreSamplesForMethod(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) { if (method->IsClassInitializer() || !method->IsCompilable()) { // We do not want to compile such methods. return true; } if (method->IsNative()) { ObjPtr klass = method->GetDeclaringClass(); if (klass == GetClassRoot() || klass == GetClassRoot()) { // MethodHandle and VarHandle invocation methods are required to throw an // UnsupportedOperationException if invoked reflectively. We achieve this by having native // implementations that raise the exception. We need to disable JIT compilation of these JNI // methods as it can lead to transitioning between JIT compiled JNI stubs and generic JNI // stubs. Since these stubs have different stack representations we can then crash in stack // walking (b/78151261). return true; } } return false; } void Jit::EnqueueOptimizedCompilation(ArtMethod* method, Thread* self) { // Reset the hotness counter so the baseline compiled code doesn't call this // method repeatedly. GetCodeCache()->ResetHotnessCounter(method, self); if (thread_pool_ == nullptr) { return; } // We arrive here after a baseline compiled code has reached its baseline // hotness threshold. If we're not only using the baseline compiler, enqueue a compilation // task that will compile optimize the method. if (!options_->UseBaselineCompiler()) { AddCompileTask(self, method, CompilationKind::kOptimized); } } class ScopedSetRuntimeThread { public: explicit ScopedSetRuntimeThread(Thread* self) : self_(self), was_runtime_thread_(self_->IsRuntimeThread()) { self_->SetIsRuntimeThread(true); } ~ScopedSetRuntimeThread() { self_->SetIsRuntimeThread(was_runtime_thread_); } private: Thread* self_; bool was_runtime_thread_; }; void Jit::MethodEntered(Thread* self, ArtMethod* method) { Runtime* runtime = Runtime::Current(); if (UNLIKELY(runtime->UseJitCompilation() && JitAtFirstUse())) { ArtMethod* np_method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize); if (np_method->IsCompilable()) { CompileMethod(method, self, CompilationKind::kOptimized, /* prejit= */ false); } return; } AddSamples(self, method); } void Jit::WaitForCompilationToFinish(Thread* self) { if (thread_pool_ != nullptr) { thread_pool_->Wait(self, false, false); } } void Jit::Stop() { Thread* self = Thread::Current(); // TODO(ngeoffray): change API to not require calling WaitForCompilationToFinish twice. WaitForCompilationToFinish(self); GetThreadPool()->StopWorkers(self); WaitForCompilationToFinish(self); } void Jit::Start() { GetThreadPool()->StartWorkers(Thread::Current()); } ScopedJitSuspend::ScopedJitSuspend() { jit::Jit* jit = Runtime::Current()->GetJit(); was_on_ = (jit != nullptr) && (jit->GetThreadPool() != nullptr); if (was_on_) { jit->Stop(); } } ScopedJitSuspend::~ScopedJitSuspend() { if (was_on_) { DCHECK(Runtime::Current()->GetJit() != nullptr); DCHECK(Runtime::Current()->GetJit()->GetThreadPool() != nullptr); Runtime::Current()->GetJit()->Start(); } } static void* RunPollingThread(void* arg) { Jit* jit = reinterpret_cast(arg); do { sleep(10); } while (!jit->GetCodeCache()->GetZygoteMap()->IsCompilationNotified()); // We will suspend other threads: we can only do that if we're attached to the // runtime. Runtime* runtime = Runtime::Current(); bool thread_attached = runtime->AttachCurrentThread( "BootImagePollingThread", /* as_daemon= */ true, /* thread_group= */ nullptr, /* create_peer= */ false); CHECK(thread_attached); { // Prevent other threads from running while we are remapping the boot image // ArtMethod's. Native threads might still be running, but they cannot // change the contents of ArtMethod's. ScopedSuspendAll ssa(__FUNCTION__); runtime->GetJit()->MapBootImageMethods(); } Runtime::Current()->DetachCurrentThread(); return nullptr; } void Jit::PostForkChildAction(bool is_system_server, bool is_zygote) { // Clear the potential boot tasks inherited from the zygote. { MutexLock mu(Thread::Current(), boot_completed_lock_); tasks_after_boot_.clear(); } Runtime* const runtime = Runtime::Current(); // Check if we'll need to remap the boot image methods. if (!is_zygote && fd_methods_ != -1) { // Create a thread that will poll the status of zygote compilation, and map // the private mapping of boot image methods. // For child zygote, we instead query IsCompilationNotified() post zygote fork. zygote_mapping_methods_.ResetInForkedProcess(); pthread_t polling_thread; pthread_attr_t attr; CHECK_PTHREAD_CALL(pthread_attr_init, (&attr), "new thread"); CHECK_PTHREAD_CALL(pthread_attr_setdetachstate, (&attr, PTHREAD_CREATE_DETACHED), "PTHREAD_CREATE_DETACHED"); CHECK_PTHREAD_CALL( pthread_create, (&polling_thread, &attr, RunPollingThread, reinterpret_cast(this)), "Methods maps thread"); } if (is_zygote || runtime->IsSafeMode()) { // Delete the thread pool, we are not going to JIT. thread_pool_.reset(nullptr); return; } // At this point, the compiler options have been adjusted to the particular configuration // of the forked child. Parse them again. jit_compiler_->ParseCompilerOptions(); // Adjust the status of code cache collection: the status from zygote was to not collect. // JitAtFirstUse compiles the methods synchronously on mutator threads. While this should work // in theory it is causing deadlocks in some jvmti tests related to Jit GC. Hence, disabling // Jit GC for now (b/147208992). code_cache_->SetGarbageCollectCode( !jit_compiler_->GenerateDebugInfo() && !JitAtFirstUse()); if (is_system_server && runtime->HasImageWithProfile()) { // Disable garbage collection: we don't want it to delete methods we're compiling // through boot and system server profiles. // TODO(ngeoffray): Fix this so we still collect deoptimized and unused code. code_cache_->SetGarbageCollectCode(false); } // We do this here instead of PostZygoteFork, as NativeDebugInfoPostFork only // applies to a child. NativeDebugInfoPostFork(); } void Jit::PreZygoteFork() { if (thread_pool_ == nullptr) { return; } thread_pool_->DeleteThreads(); NativeDebugInfoPreFork(); } void Jit::PostZygoteFork() { Runtime* runtime = Runtime::Current(); if (thread_pool_ == nullptr) { // If this is a child zygote, check if we need to remap the boot image // methods. if (runtime->IsZygote() && fd_methods_ != -1 && code_cache_->GetZygoteMap()->IsCompilationNotified()) { ScopedSuspendAll ssa(__FUNCTION__); MapBootImageMethods(); } return; } if (runtime->IsZygote() && code_cache_->GetZygoteMap()->IsCompilationDoneButNotNotified()) { // Copy the boot image methods data to the mappings we created to share // with the children. We do this here as we are the only thread running and // we don't risk other threads concurrently updating the ArtMethod's. CHECK_EQ(GetTaskCount(), 1); NotifyZygoteCompilationDone(); CHECK(code_cache_->GetZygoteMap()->IsCompilationNotified()); } thread_pool_->CreateThreads(); thread_pool_->SetPthreadPriority( runtime->IsZygote() ? options_->GetZygoteThreadPoolPthreadPriority() : options_->GetThreadPoolPthreadPriority()); } void Jit::AddPostBootTask(Thread* self, Task* task) { MutexLock mu(self, boot_completed_lock_); if (boot_completed_) { thread_pool_->AddTask(self, task); } else { tasks_after_boot_.push_back(task); } } void Jit::BootCompleted() { Thread* self = Thread::Current(); std::deque tasks; { MutexLock mu(self, boot_completed_lock_); tasks = std::move(tasks_after_boot_); boot_completed_ = true; } for (Task* task : tasks) { thread_pool_->AddTask(self, task); } } bool Jit::CanEncodeMethod(ArtMethod* method, bool is_for_shared_region) const { return !is_for_shared_region || Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(method->GetDeclaringClass()); } bool Jit::CanEncodeClass(ObjPtr cls, bool is_for_shared_region) const { return !is_for_shared_region || Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(cls); } bool Jit::CanEncodeString(ObjPtr string, bool is_for_shared_region) const { return !is_for_shared_region || Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(string); } bool Jit::CanAssumeInitialized(ObjPtr cls, bool is_for_shared_region) const { if (!is_for_shared_region) { return cls->IsInitialized(); } else { // Look up the class status in the oat file. const DexFile& dex_file = *cls->GetDexCache()->GetDexFile(); const OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); // In case we run without an image there won't be a backing oat file. if (oat_dex_file == nullptr || oat_dex_file->GetOatFile() == nullptr) { return false; } uint16_t class_def_index = cls->GetDexClassDefIndex(); return oat_dex_file->GetOatClass(class_def_index).GetStatus() >= ClassStatus::kInitialized; } } void Jit::MaybeEnqueueCompilation(ArtMethod* method, Thread* self) { if (thread_pool_ == nullptr) { return; } if (JitAtFirstUse()) { // Tests might request JIT on first use (compiled synchronously in the interpreter). return; } if (!UseJitCompilation()) { return; } if (IgnoreSamplesForMethod(method)) { return; } if (GetCodeCache()->ContainsPc(method->GetEntryPointFromQuickCompiledCode())) { if (!method->IsNative() && !code_cache_->IsOsrCompiled(method)) { // If we already have compiled code for it, nterp may be stuck in a loop. // Compile OSR. AddCompileTask(self, method, CompilationKind::kOsr); } return; } // Check if we have precompiled this method. if (UNLIKELY(method->IsPreCompiled())) { if (!method->StillNeedsClinitCheck()) { const void* entry_point = code_cache_->GetSavedEntryPointOfPreCompiledMethod(method); if (entry_point != nullptr) { Runtime::Current()->GetInstrumentation()->UpdateMethodsCode(method, entry_point); } } return; } static constexpr size_t kIndividualSharedMethodHotnessThreshold = 0x3f; if (method->IsMemorySharedMethod()) { MutexLock mu(self, lock_); auto it = shared_method_counters_.find(method); if (it == shared_method_counters_.end()) { shared_method_counters_[method] = kIndividualSharedMethodHotnessThreshold; return; } else if (it->second != 0) { DCHECK_LE(it->second, kIndividualSharedMethodHotnessThreshold); shared_method_counters_[method] = it->second - 1; return; } else { shared_method_counters_[method] = kIndividualSharedMethodHotnessThreshold; } } if (!method->IsNative() && GetCodeCache()->CanAllocateProfilingInfo()) { AddCompileTask(self, method, CompilationKind::kBaseline); } else { AddCompileTask(self, method, CompilationKind::kOptimized); } } bool Jit::CompileMethod(ArtMethod* method, Thread* self, CompilationKind compilation_kind, bool prejit) { ScopedCompilation sc(this, method, compilation_kind); // TODO: all current users of this method expect us to wait if it is being compiled. if (!sc.OwnsCompilation()) { return false; } // Fake being in a runtime thread so that class-load behavior will be the same as normal jit. ScopedSetRuntimeThread ssrt(self); // TODO(ngeoffray): For JIT at first use, use kPreCompile. Currently we don't due to // conflicts with jitzygote optimizations. return CompileMethodInternal(method, self, compilation_kind, prejit); } } // namespace jit } // namespace art