// Copyright 2016 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. #ifndef V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_ #define V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_ #include <cstdint> #include <map> #include <memory> #include <unordered_set> #include <utility> #include "src/base/atomic-utils.h" #include "src/base/macros.h" #include "src/base/optional.h" #include "src/base/platform/condition-variable.h" #include "src/base/platform/mutex.h" #include "src/base/platform/semaphore.h" #include "src/globals.h" #include "src/identity-map.h" #include "src/maybe-handles.h" #include "testing/gtest/include/gtest/gtest_prod.h" // nogncheck namespace v8 { class Platform; enum class MemoryPressureLevel; namespace internal { class AstRawString; class AstValueFactory; class BackgroundCompileTask; class CancelableTaskManager; class UnoptimizedCompileJob; class CompilerDispatcherTracer; class DeferredHandles; class FunctionLiteral; class Isolate; class ParseInfo; class SharedFunctionInfo; class TimedHistogram; class WorkerThreadRuntimeCallStats; class Zone; template <typename T> class Handle; // The CompilerDispatcher uses a combination of idle tasks and background tasks // to parse and compile lazily parsed functions. // // As both parsing and compilation currently requires a preparation and // finalization step that happens on the main thread, every task has to be // advanced during idle time first. Depending on the properties of the task, it // can then be parsed or compiled on either background threads, or during idle // time. Last, it has to be finalized during idle time again. // // CompilerDispatcher::jobs_ maintains the list of all CompilerDispatcherJobs // the CompilerDispatcher knows about. // // CompilerDispatcher::pending_background_jobs_ contains the set of // CompilerDispatcherJobs that can be processed on a background thread. // // CompilerDispatcher::running_background_jobs_ contains the set of // CompilerDispatcherJobs that are currently being processed on a background // thread. // // CompilerDispatcher::DoIdleWork tries to advance as many jobs out of jobs_ as // possible during idle time. If a job can't be advanced, but is suitable for // background processing, it fires off background threads. // // CompilerDispatcher::DoBackgroundWork advances one of the pending jobs, and // then spins of another idle task to potentially do the final step on the main // thread. class V8_EXPORT_PRIVATE CompilerDispatcher { public: typedef uintptr_t JobId; CompilerDispatcher(Isolate* isolate, Platform* platform, size_t max_stack_size); ~CompilerDispatcher(); // Returns true if the compiler dispatcher is enabled. bool IsEnabled() const; base::Optional<JobId> Enqueue(const ParseInfo* outer_parse_info, const AstRawString* function_name, const FunctionLiteral* function_literal); // Registers the given |function| with the compilation job |job_id|. void RegisterSharedFunctionInfo(JobId job_id, SharedFunctionInfo function); // Returns true if there is a pending job with the given id. bool IsEnqueued(JobId job_id) const; // Returns true if there is a pending job registered for the given function. bool IsEnqueued(Handle<SharedFunctionInfo> function) const; // Blocks until the given function is compiled (and does so as fast as // possible). Returns true if the compile job was successful. bool FinishNow(Handle<SharedFunctionInfo> function); // Aborts compilation job |job_id|. void AbortJob(JobId job_id); // Aborts all jobs, blocking until all jobs are aborted. void AbortAll(); private: FRIEND_TEST(CompilerDispatcherTest, IdleTaskNoIdleTime); FRIEND_TEST(CompilerDispatcherTest, IdleTaskSmallIdleTime); FRIEND_TEST(CompilerDispatcherTest, FinishNowWithWorkerTask); FRIEND_TEST(CompilerDispatcherTest, AbortJobNotStarted); FRIEND_TEST(CompilerDispatcherTest, AbortJobAlreadyStarted); FRIEND_TEST(CompilerDispatcherTest, AsyncAbortAllPendingWorkerTask); FRIEND_TEST(CompilerDispatcherTest, AsyncAbortAllRunningWorkerTask); FRIEND_TEST(CompilerDispatcherTest, CompileMultipleOnBackgroundThread); struct Job { explicit Job(BackgroundCompileTask* task_arg); ~Job(); bool IsReadyToFinalize(const base::MutexGuard&) { return has_run && (!function.is_null() || aborted); } bool IsReadyToFinalize(base::Mutex* mutex) { base::MutexGuard lock(mutex); return IsReadyToFinalize(lock); } std::unique_ptr<BackgroundCompileTask> task; MaybeHandle<SharedFunctionInfo> function; bool has_run; bool aborted; }; typedef std::map<JobId, std::unique_ptr<Job>> JobMap; typedef IdentityMap<JobId, FreeStoreAllocationPolicy> SharedToJobIdMap; void WaitForJobIfRunningOnBackground(Job* job); JobMap::const_iterator GetJobFor(Handle<SharedFunctionInfo> shared) const; void ScheduleMoreWorkerTasksIfNeeded(); void ScheduleIdleTaskFromAnyThread(const base::MutexGuard&); void DoBackgroundWork(); void DoIdleWork(double deadline_in_seconds); // Returns iterator to the inserted job. JobMap::const_iterator InsertJob(std::unique_ptr<Job> job); // Returns iterator following the removed job. JobMap::const_iterator RemoveJob(JobMap::const_iterator job); Isolate* isolate_; AccountingAllocator* allocator_; WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats_; TimedHistogram* background_compile_timer_; std::shared_ptr<v8::TaskRunner> taskrunner_; Platform* platform_; size_t max_stack_size_; // Copy of FLAG_trace_compiler_dispatcher to allow for access from any thread. bool trace_compiler_dispatcher_; std::unique_ptr<CancelableTaskManager> task_manager_; // Id for next job to be added JobId next_job_id_; // Mapping from job_id to job. JobMap jobs_; // Mapping from SharedFunctionInfo to the corresponding unoptimized // compilation's JobId; SharedToJobIdMap shared_to_unoptimized_job_id_; // The following members can be accessed from any thread. Methods need to hold // the mutex |mutex_| while accessing them. base::Mutex mutex_; // True if an idle task is scheduled to be run. bool idle_task_scheduled_; // Number of scheduled or running WorkerTask objects. int num_worker_tasks_; // The set of jobs that can be run on a background thread. std::unordered_set<Job*> pending_background_jobs_; // The set of jobs currently being run on background threads. std::unordered_set<Job*> running_background_jobs_; // If not nullptr, then the main thread waits for the task processing // this job, and blocks on the ConditionVariable main_thread_blocking_signal_. Job* main_thread_blocking_on_job_; base::ConditionVariable main_thread_blocking_signal_; // Test support. base::AtomicValue<bool> block_for_testing_; base::Semaphore semaphore_for_testing_; DISALLOW_COPY_AND_ASSIGN(CompilerDispatcher); }; } // namespace internal } // namespace v8 #endif // V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_