base/task/thread_pool/platform_native_worker_pool_mac.h

// Copyright 2019 The Chromium 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 BASE_TASK_THREAD_POOL_PLATFORM_NATIVE_WORKER_POOL_MAC_H_
#define BASE_TASK_THREAD_POOL_PLATFORM_NATIVE_WORKER_POOL_MAC_H_

#include <dispatch/dispatch.h>

#include "base/base_export.h"
#include "base/mac/scoped_dispatch_object.h"
#include "base/task/thread_pool/platform_native_worker_pool.h"

namespace base {
namespace internal {

// A SchedulerWorkerPool implementation backed by libdispatch.
//
// libdispatch official documentation:
// https://developer.apple.com/documentation/dispatch
//
// Guides:
// https://apple.github.io/swift-corelibs-libdispatch/tutorial/
// https://developer.apple.com/library/archive/documentation/General/Conceptual/ConcurrencyProgrammingGuide/OperationQueues/OperationQueues.html
class BASE_EXPORT PlatformNativeWorkerPoolMac
    : public PlatformNativeWorkerPool {
 public:
  PlatformNativeWorkerPoolMac(TrackedRef<TaskTracker> task_tracker,
                              TrackedRef<Delegate> delegate,
                              SchedulerWorkerPool* predecessor_pool = nullptr);

  ~PlatformNativeWorkerPoolMac() override;

 private:
  // PlatformNativeWorkerPool:
  void JoinImpl() override;
  void StartImpl() override;
  void SubmitWork() override;

  // Dispatch queue on which work is scheduled. Backed by a shared thread pool
  // managed by libdispatch.
  ScopedDispatchObject<dispatch_queue_t> queue_;

  // Dispatch group to enable synchronization.
  ScopedDispatchObject<dispatch_group_t> group_;

  DISALLOW_COPY_AND_ASSIGN(PlatformNativeWorkerPoolMac);
};

using PlatformNativeWorkerPoolImpl = PlatformNativeWorkerPoolMac;

}  // namespace internal
}  // namespace base

#endif  // BASE_TASK_THREAD_POOL_PLATFORM_NATIVE_WORKER_POOL_MAC_H_