blob: 864c07ea0fb3ef03e02aef5f5d58ae3f294b4cce [file] [log] [blame]
// Copyright 2016 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.
#include "base/task/task_scheduler/task_scheduler.h"
#include <algorithm>
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/sys_info.h"
#include "base/task/task_scheduler/scheduler_worker_pool_params.h"
#include "base/task/task_scheduler/task_scheduler_impl.h"
#include "base/threading/platform_thread.h"
#include "base/time/time.h"
namespace base {
namespace {
// |g_task_scheduler| is intentionally leaked on shutdown.
TaskScheduler* g_task_scheduler = nullptr;
} // namespace
TaskScheduler::InitParams::InitParams(
const SchedulerWorkerPoolParams& background_worker_pool_params_in,
const SchedulerWorkerPoolParams& background_blocking_worker_pool_params_in,
const SchedulerWorkerPoolParams& foreground_worker_pool_params_in,
const SchedulerWorkerPoolParams& foreground_blocking_worker_pool_params_in,
SharedWorkerPoolEnvironment shared_worker_pool_environment_in)
: background_worker_pool_params(background_worker_pool_params_in),
background_blocking_worker_pool_params(
background_blocking_worker_pool_params_in),
foreground_worker_pool_params(foreground_worker_pool_params_in),
foreground_blocking_worker_pool_params(
foreground_blocking_worker_pool_params_in),
shared_worker_pool_environment(shared_worker_pool_environment_in) {}
TaskScheduler::InitParams::~InitParams() = default;
TaskScheduler::ScopedExecutionFence::ScopedExecutionFence() {
DCHECK(g_task_scheduler);
g_task_scheduler->SetExecutionFenceEnabled(true);
}
TaskScheduler::ScopedExecutionFence::~ScopedExecutionFence() {
DCHECK(g_task_scheduler);
g_task_scheduler->SetExecutionFenceEnabled(false);
}
#if !defined(OS_NACL)
// static
void TaskScheduler::CreateAndStartWithDefaultParams(StringPiece name) {
Create(name);
GetInstance()->StartWithDefaultParams();
}
void TaskScheduler::StartWithDefaultParams() {
// Values were chosen so that:
// * There are few background threads.
// * Background threads never outnumber foreground threads.
// * The system is utilized maximally by foreground threads.
// * The main thread is assumed to be busy, cap foreground workers at
// |num_cores - 1|.
const int num_cores = SysInfo::NumberOfProcessors();
constexpr int kBackgroundMaxThreads = 1;
constexpr int kBackgroundBlockingMaxThreads = 2;
const int kForegroundMaxThreads = std::max(1, num_cores - 1);
const int kForegroundBlockingMaxThreads = std::max(2, num_cores - 1);
constexpr TimeDelta kSuggestedReclaimTime = TimeDelta::FromSeconds(30);
Start({{kBackgroundMaxThreads, kSuggestedReclaimTime},
{kBackgroundBlockingMaxThreads, kSuggestedReclaimTime},
{kForegroundMaxThreads, kSuggestedReclaimTime},
{kForegroundBlockingMaxThreads, kSuggestedReclaimTime}});
}
#endif // !defined(OS_NACL)
void TaskScheduler::Create(StringPiece name) {
SetInstance(std::make_unique<internal::TaskSchedulerImpl>(name));
}
// static
void TaskScheduler::SetInstance(std::unique_ptr<TaskScheduler> task_scheduler) {
delete g_task_scheduler;
g_task_scheduler = task_scheduler.release();
}
// static
TaskScheduler* TaskScheduler::GetInstance() {
return g_task_scheduler;
}
} // namespace base