| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/optimizing-compiler-thread.h" |
| |
| #include "src/v8.h" |
| |
| #include "src/base/atomicops.h" |
| #include "src/full-codegen.h" |
| #include "src/hydrogen.h" |
| #include "src/isolate.h" |
| #include "src/v8threads.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class OptimizingCompilerThread::CompileTask : public v8::Task { |
| public: |
| CompileTask(Isolate* isolate, OptimizedCompileJob* job) |
| : isolate_(isolate), job_(job) {} |
| |
| virtual ~CompileTask() {} |
| |
| private: |
| // v8::Task overrides. |
| virtual void Run() OVERRIDE { |
| DisallowHeapAllocation no_allocation; |
| DisallowHandleAllocation no_handles; |
| DisallowHandleDereference no_deref; |
| |
| // The function may have already been optimized by OSR. Simply continue. |
| OptimizedCompileJob::Status status = job_->OptimizeGraph(); |
| USE(status); // Prevent an unused-variable error in release mode. |
| DCHECK(status != OptimizedCompileJob::FAILED); |
| |
| // The function may have already been optimized by OSR. Simply continue. |
| // Use a mutex to make sure that functions marked for install |
| // are always also queued. |
| { |
| base::LockGuard<base::Mutex> lock_guard( |
| &isolate_->optimizing_compiler_thread()->output_queue_mutex_); |
| isolate_->optimizing_compiler_thread()->output_queue_.Enqueue(job_); |
| } |
| isolate_->stack_guard()->RequestInstallCode(); |
| { |
| base::LockGuard<base::Mutex> lock_guard( |
| &isolate_->optimizing_compiler_thread()->input_queue_mutex_); |
| isolate_->optimizing_compiler_thread()->input_queue_length_--; |
| } |
| isolate_->optimizing_compiler_thread()->input_queue_semaphore_.Signal(); |
| } |
| |
| Isolate* isolate_; |
| OptimizedCompileJob* job_; |
| |
| DISALLOW_COPY_AND_ASSIGN(CompileTask); |
| }; |
| |
| |
| OptimizingCompilerThread::~OptimizingCompilerThread() { |
| DCHECK_EQ(0, input_queue_length_); |
| DeleteArray(input_queue_); |
| if (FLAG_concurrent_osr) { |
| #ifdef DEBUG |
| for (int i = 0; i < osr_buffer_capacity_; i++) { |
| CHECK_EQ(NULL, osr_buffer_[i]); |
| } |
| #endif |
| DeleteArray(osr_buffer_); |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::Run() { |
| #ifdef DEBUG |
| { base::LockGuard<base::Mutex> lock_guard(&thread_id_mutex_); |
| thread_id_ = ThreadId::Current().ToInteger(); |
| } |
| #endif |
| DisallowHeapAllocation no_allocation; |
| DisallowHandleAllocation no_handles; |
| DisallowHandleDereference no_deref; |
| |
| if (job_based_recompilation_) { |
| return; |
| } |
| |
| base::ElapsedTimer total_timer; |
| if (tracing_enabled_) total_timer.Start(); |
| |
| while (true) { |
| input_queue_semaphore_.Wait(); |
| TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_); |
| |
| if (FLAG_concurrent_recompilation_delay != 0) { |
| base::OS::Sleep(FLAG_concurrent_recompilation_delay); |
| } |
| |
| switch (static_cast<StopFlag>(base::Acquire_Load(&stop_thread_))) { |
| case CONTINUE: |
| break; |
| case STOP: |
| if (tracing_enabled_) { |
| time_spent_total_ = total_timer.Elapsed(); |
| } |
| stop_semaphore_.Signal(); |
| return; |
| case FLUSH: |
| // The main thread is blocked, waiting for the stop semaphore. |
| { AllowHandleDereference allow_handle_dereference; |
| FlushInputQueue(true); |
| } |
| base::Release_Store(&stop_thread_, |
| static_cast<base::AtomicWord>(CONTINUE)); |
| stop_semaphore_.Signal(); |
| // Return to start of consumer loop. |
| continue; |
| } |
| |
| base::ElapsedTimer compiling_timer; |
| if (tracing_enabled_) compiling_timer.Start(); |
| |
| CompileNext(); |
| |
| if (tracing_enabled_) { |
| time_spent_compiling_ += compiling_timer.Elapsed(); |
| } |
| } |
| } |
| |
| |
| OptimizedCompileJob* OptimizingCompilerThread::NextInput() { |
| base::LockGuard<base::Mutex> access_input_queue_(&input_queue_mutex_); |
| DCHECK(!job_based_recompilation_); |
| if (input_queue_length_ == 0) return NULL; |
| OptimizedCompileJob* job = input_queue_[InputQueueIndex(0)]; |
| DCHECK_NE(NULL, job); |
| input_queue_shift_ = InputQueueIndex(1); |
| input_queue_length_--; |
| return job; |
| } |
| |
| |
| void OptimizingCompilerThread::CompileNext() { |
| OptimizedCompileJob* job = NextInput(); |
| DCHECK_NE(NULL, job); |
| |
| // The function may have already been optimized by OSR. Simply continue. |
| OptimizedCompileJob::Status status = job->OptimizeGraph(); |
| USE(status); // Prevent an unused-variable error in release mode. |
| DCHECK(status != OptimizedCompileJob::FAILED); |
| |
| // The function may have already been optimized by OSR. Simply continue. |
| // Use a mutex to make sure that functions marked for install |
| // are always also queued. |
| output_queue_.Enqueue(job); |
| isolate_->stack_guard()->RequestInstallCode(); |
| } |
| |
| |
| static void DisposeOptimizedCompileJob(OptimizedCompileJob* job, |
| bool restore_function_code) { |
| // The recompile job is allocated in the CompilationInfo's zone. |
| CompilationInfo* info = job->info(); |
| if (restore_function_code) { |
| if (info->is_osr()) { |
| if (!job->IsWaitingForInstall()) { |
| // Remove stack check that guards OSR entry on original code. |
| Handle<Code> code = info->unoptimized_code(); |
| uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id()); |
| BackEdgeTable::RemoveStackCheck(code, offset); |
| } |
| } else { |
| Handle<JSFunction> function = info->closure(); |
| function->ReplaceCode(function->shared()->code()); |
| } |
| } |
| delete info; |
| } |
| |
| |
| void OptimizingCompilerThread::FlushInputQueue(bool restore_function_code) { |
| DCHECK(!job_based_recompilation_); |
| OptimizedCompileJob* job; |
| while ((job = NextInput())) { |
| // This should not block, since we have one signal on the input queue |
| // semaphore corresponding to each element in the input queue. |
| input_queue_semaphore_.Wait(); |
| // OSR jobs are dealt with separately. |
| if (!job->info()->is_osr()) { |
| DisposeOptimizedCompileJob(job, restore_function_code); |
| } |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::FlushOutputQueue(bool restore_function_code) { |
| OptimizedCompileJob* job; |
| while (output_queue_.Dequeue(&job)) { |
| // OSR jobs are dealt with separately. |
| if (!job->info()->is_osr()) { |
| DisposeOptimizedCompileJob(job, restore_function_code); |
| } |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::FlushOsrBuffer(bool restore_function_code) { |
| for (int i = 0; i < osr_buffer_capacity_; i++) { |
| if (osr_buffer_[i] != NULL) { |
| DisposeOptimizedCompileJob(osr_buffer_[i], restore_function_code); |
| osr_buffer_[i] = NULL; |
| } |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::Flush() { |
| DCHECK(!IsOptimizerThread()); |
| base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(FLUSH)); |
| if (FLAG_block_concurrent_recompilation) Unblock(); |
| if (!job_based_recompilation_) { |
| input_queue_semaphore_.Signal(); |
| stop_semaphore_.Wait(); |
| } |
| FlushOutputQueue(true); |
| if (FLAG_concurrent_osr) FlushOsrBuffer(true); |
| if (tracing_enabled_) { |
| PrintF(" ** Flushed concurrent recompilation queues.\n"); |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::Stop() { |
| DCHECK(!IsOptimizerThread()); |
| base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(STOP)); |
| if (FLAG_block_concurrent_recompilation) Unblock(); |
| if (!job_based_recompilation_) { |
| input_queue_semaphore_.Signal(); |
| stop_semaphore_.Wait(); |
| } |
| |
| if (job_based_recompilation_) { |
| while (true) { |
| { |
| base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_); |
| if (!input_queue_length_) break; |
| } |
| input_queue_semaphore_.Wait(); |
| } |
| } else if (FLAG_concurrent_recompilation_delay != 0) { |
| // At this point the optimizing compiler thread's event loop has stopped. |
| // There is no need for a mutex when reading input_queue_length_. |
| while (input_queue_length_ > 0) CompileNext(); |
| InstallOptimizedFunctions(); |
| } else { |
| FlushInputQueue(false); |
| FlushOutputQueue(false); |
| } |
| |
| if (FLAG_concurrent_osr) FlushOsrBuffer(false); |
| |
| if (tracing_enabled_) { |
| double percentage = time_spent_compiling_.PercentOf(time_spent_total_); |
| PrintF(" ** Compiler thread did %.2f%% useful work\n", percentage); |
| } |
| |
| if ((FLAG_trace_osr || tracing_enabled_) && FLAG_concurrent_osr) { |
| PrintF("[COSR hit rate %d / %d]\n", osr_hits_, osr_attempts_); |
| } |
| |
| Join(); |
| } |
| |
| |
| void OptimizingCompilerThread::InstallOptimizedFunctions() { |
| DCHECK(!IsOptimizerThread()); |
| HandleScope handle_scope(isolate_); |
| |
| OptimizedCompileJob* job; |
| while (output_queue_.Dequeue(&job)) { |
| CompilationInfo* info = job->info(); |
| Handle<JSFunction> function(*info->closure()); |
| if (info->is_osr()) { |
| if (FLAG_trace_osr) { |
| PrintF("[COSR - "); |
| function->ShortPrint(); |
| PrintF(" is ready for install and entry at AST id %d]\n", |
| info->osr_ast_id().ToInt()); |
| } |
| job->WaitForInstall(); |
| // Remove stack check that guards OSR entry on original code. |
| Handle<Code> code = info->unoptimized_code(); |
| uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id()); |
| BackEdgeTable::RemoveStackCheck(code, offset); |
| } else { |
| if (function->IsOptimized()) { |
| if (tracing_enabled_) { |
| PrintF(" ** Aborting compilation for "); |
| function->ShortPrint(); |
| PrintF(" as it has already been optimized.\n"); |
| } |
| DisposeOptimizedCompileJob(job, false); |
| } else { |
| Handle<Code> code = Compiler::GetConcurrentlyOptimizedCode(job); |
| function->ReplaceCode( |
| code.is_null() ? function->shared()->code() : *code); |
| } |
| } |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::QueueForOptimization(OptimizedCompileJob* job) { |
| DCHECK(IsQueueAvailable()); |
| DCHECK(!IsOptimizerThread()); |
| CompilationInfo* info = job->info(); |
| if (info->is_osr()) { |
| osr_attempts_++; |
| AddToOsrBuffer(job); |
| // Add job to the front of the input queue. |
| base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_); |
| DCHECK_LT(input_queue_length_, input_queue_capacity_); |
| // Move shift_ back by one. |
| input_queue_shift_ = InputQueueIndex(input_queue_capacity_ - 1); |
| input_queue_[InputQueueIndex(0)] = job; |
| input_queue_length_++; |
| } else { |
| // Add job to the back of the input queue. |
| base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_); |
| DCHECK_LT(input_queue_length_, input_queue_capacity_); |
| input_queue_[InputQueueIndex(input_queue_length_)] = job; |
| input_queue_length_++; |
| } |
| if (job_based_recompilation_) { |
| V8::GetCurrentPlatform()->CallOnBackgroundThread( |
| new CompileTask(isolate_, job), v8::Platform::kShortRunningTask); |
| } else if (FLAG_block_concurrent_recompilation) { |
| blocked_jobs_++; |
| } else { |
| input_queue_semaphore_.Signal(); |
| } |
| } |
| |
| |
| void OptimizingCompilerThread::Unblock() { |
| DCHECK(!IsOptimizerThread()); |
| if (job_based_recompilation_) { |
| return; |
| } |
| while (blocked_jobs_ > 0) { |
| input_queue_semaphore_.Signal(); |
| blocked_jobs_--; |
| } |
| } |
| |
| |
| OptimizedCompileJob* OptimizingCompilerThread::FindReadyOSRCandidate( |
| Handle<JSFunction> function, BailoutId osr_ast_id) { |
| DCHECK(!IsOptimizerThread()); |
| for (int i = 0; i < osr_buffer_capacity_; i++) { |
| OptimizedCompileJob* current = osr_buffer_[i]; |
| if (current != NULL && |
| current->IsWaitingForInstall() && |
| current->info()->HasSameOsrEntry(function, osr_ast_id)) { |
| osr_hits_++; |
| osr_buffer_[i] = NULL; |
| return current; |
| } |
| } |
| return NULL; |
| } |
| |
| |
| bool OptimizingCompilerThread::IsQueuedForOSR(Handle<JSFunction> function, |
| BailoutId osr_ast_id) { |
| DCHECK(!IsOptimizerThread()); |
| for (int i = 0; i < osr_buffer_capacity_; i++) { |
| OptimizedCompileJob* current = osr_buffer_[i]; |
| if (current != NULL && |
| current->info()->HasSameOsrEntry(function, osr_ast_id)) { |
| return !current->IsWaitingForInstall(); |
| } |
| } |
| return false; |
| } |
| |
| |
| bool OptimizingCompilerThread::IsQueuedForOSR(JSFunction* function) { |
| DCHECK(!IsOptimizerThread()); |
| for (int i = 0; i < osr_buffer_capacity_; i++) { |
| OptimizedCompileJob* current = osr_buffer_[i]; |
| if (current != NULL && *current->info()->closure() == function) { |
| return !current->IsWaitingForInstall(); |
| } |
| } |
| return false; |
| } |
| |
| |
| void OptimizingCompilerThread::AddToOsrBuffer(OptimizedCompileJob* job) { |
| DCHECK(!IsOptimizerThread()); |
| // Find the next slot that is empty or has a stale job. |
| OptimizedCompileJob* stale = NULL; |
| while (true) { |
| stale = osr_buffer_[osr_buffer_cursor_]; |
| if (stale == NULL || stale->IsWaitingForInstall()) break; |
| osr_buffer_cursor_ = (osr_buffer_cursor_ + 1) % osr_buffer_capacity_; |
| } |
| |
| // Add to found slot and dispose the evicted job. |
| if (stale != NULL) { |
| DCHECK(stale->IsWaitingForInstall()); |
| CompilationInfo* info = stale->info(); |
| if (FLAG_trace_osr) { |
| PrintF("[COSR - Discarded "); |
| info->closure()->PrintName(); |
| PrintF(", AST id %d]\n", info->osr_ast_id().ToInt()); |
| } |
| DisposeOptimizedCompileJob(stale, false); |
| } |
| osr_buffer_[osr_buffer_cursor_] = job; |
| osr_buffer_cursor_ = (osr_buffer_cursor_ + 1) % osr_buffer_capacity_; |
| } |
| |
| |
| #ifdef DEBUG |
| bool OptimizingCompilerThread::IsOptimizerThread(Isolate* isolate) { |
| return isolate->concurrent_recompilation_enabled() && |
| isolate->optimizing_compiler_thread()->IsOptimizerThread(); |
| } |
| |
| |
| bool OptimizingCompilerThread::IsOptimizerThread() { |
| base::LockGuard<base::Mutex> lock_guard(&thread_id_mutex_); |
| return ThreadId::Current().ToInteger() == thread_id_; |
| } |
| #endif |
| |
| |
| } } // namespace v8::internal |