src/libplatform/default-platform.h

// Copyright 2013 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_LIBPLATFORM_DEFAULT_PLATFORM_H_
#define V8_LIBPLATFORM_DEFAULT_PLATFORM_H_

#include <map>
#include <memory>

#include "include/libplatform/libplatform-export.h"
#include "include/libplatform/libplatform.h"
#include "include/libplatform/v8-tracing.h"
#include "include/v8-platform.h"
#include "src/base/compiler-specific.h"
#include "src/base/platform/mutex.h"
#include "src/libplatform/default-thread-isolated-allocator.h"

namespace v8 {
namespace platform {

class Thread;
class WorkerThread;
class DefaultForegroundTaskRunner;
class DefaultWorkerThreadsTaskRunner;
class DefaultPageAllocator;

class V8_PLATFORM_EXPORT DefaultPlatform : public NON_EXPORTED_BASE(Platform) {
 public:
  explicit DefaultPlatform(
      int thread_pool_size = 0,
      IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
      std::unique_ptr<v8::TracingController> tracing_controller = {},
      PriorityMode priority_mode = PriorityMode::kDontApply);

  ~DefaultPlatform() override;

  DefaultPlatform(const DefaultPlatform&) = delete;
  DefaultPlatform& operator=(const DefaultPlatform&) = delete;

  void EnsureBackgroundTaskRunnerInitialized();

  bool PumpMessageLoop(
      v8::Isolate* isolate,
      MessageLoopBehavior behavior = MessageLoopBehavior::kDoNotWait);

  void RunIdleTasks(v8::Isolate* isolate, double idle_time_in_seconds);

  void SetTracingController(
      std::unique_ptr<v8::TracingController> tracing_controller);

  using TimeFunction = double (*)();

  void SetTimeFunctionForTesting(TimeFunction time_function);

  // v8::Platform implementation.
  int NumberOfWorkerThreads() override;
  std::shared_ptr<TaskRunner> GetForegroundTaskRunner(
      v8::Isolate* isolate) override;
  void PostTaskOnWorkerThreadImpl(TaskPriority priority,
                                  std::unique_ptr<Task> task,
                                  const SourceLocation& location) override;
  void PostDelayedTaskOnWorkerThreadImpl(
      TaskPriority priority, std::unique_ptr<Task> task,
      double delay_in_seconds, const SourceLocation& location) override;
  bool IdleTasksEnabled(Isolate* isolate) override;
  std::unique_ptr<JobHandle> CreateJobImpl(
      TaskPriority priority, std::unique_ptr<JobTask> job_state,
      const SourceLocation& location) override;
  double MonotonicallyIncreasingTime() override;
  double CurrentClockTimeMillis() override;
  v8::TracingController* GetTracingController() override;
  StackTracePrinter GetStackTracePrinter() override;
  v8::PageAllocator* GetPageAllocator() override;
  v8::ThreadIsolatedAllocator* GetThreadIsolatedAllocator() override;

  void NotifyIsolateShutdown(Isolate* isolate);

 private:
  base::Thread::Priority priority_from_index(int i) const {
    if (priority_mode_ == PriorityMode::kDontApply) {
      return base::Thread::Priority::kDefault;
    }
    switch (static_cast<TaskPriority>(i)) {
      case TaskPriority::kUserBlocking:
        return base::Thread::Priority::kUserBlocking;
      case TaskPriority::kUserVisible:
        return base::Thread::Priority::kUserVisible;
      case TaskPriority::kBestEffort:
        return base::Thread::Priority::kBestEffort;
    }
  }

  int priority_to_index(TaskPriority priority) const {
    if (priority_mode_ == PriorityMode::kDontApply) {
      return 0;
    }
    return static_cast<int>(priority);
  }

  int num_worker_runners() const {
    return priority_to_index(TaskPriority::kMaxPriority) + 1;
  }

  base::Mutex lock_;
  const int thread_pool_size_;
  IdleTaskSupport idle_task_support_;
  std::shared_ptr<DefaultWorkerThreadsTaskRunner> worker_threads_task_runners_
      [static_cast<int>(TaskPriority::kMaxPriority) + 1] = {0};
  std::map<v8::Isolate*, std::shared_ptr<DefaultForegroundTaskRunner>>
      foreground_task_runner_map_;

  std::unique_ptr<TracingController> tracing_controller_;
  std::unique_ptr<PageAllocator> page_allocator_;
  DefaultThreadIsolatedAllocator thread_isolated_allocator_;

  const PriorityMode priority_mode_;
  TimeFunction time_function_for_testing_ = nullptr;
};

}  // namespace platform
}  // namespace v8


#endif  // V8_LIBPLATFORM_DEFAULT_PLATFORM_H_