76 lines
2.5 KiB
C++
76 lines
2.5 KiB
C++
// Copyright 2017 The Chromium Authors
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "base/task/thread_pool/environment_config.h"
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#include "base/base_switches.h"
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#include "base/command_line.h"
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#include "base/synchronization/lock.h"
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#include "base/threading/platform_thread.h"
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#include "build/build_config.h"
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namespace base {
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namespace internal {
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namespace {
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bool CanUseBackgroundThreadTypeForWorkerThreadImpl() {
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// Commandline flag overrides (e.g. for experiments). Note that it may not be
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// initialized yet, e.g. in cronet.
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if (CommandLine::InitializedForCurrentProcess() &&
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CommandLine::ForCurrentProcess()->HasSwitch(
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switches::kEnableBackgroundThreadPool)) {
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return true;
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}
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// When Lock doesn't handle multiple thread priorities, run all
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// WorkerThread with a normal priority to avoid priority inversion when a
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// thread running with a normal priority tries to acquire a lock held by a
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// thread running with a background priority.
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if (!Lock::HandlesMultipleThreadPriorities())
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return false;
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#if !BUILDFLAG(IS_ANDROID)
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// When thread type can't be increased to kNormal, run all threads with a
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// kNormal thread type to avoid priority inversions on shutdown
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// (ThreadPoolImpl increases kBackground threads type to kNormal on shutdown
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// while resolving remaining shutdown blocking tasks).
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//
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// This is ignored on Android, because it doesn't have a clean shutdown phase.
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if (!PlatformThread::CanChangeThreadType(ThreadType::kBackground,
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ThreadType::kDefault))
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return false;
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#endif // BUILDFLAG(IS_ANDROID)
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return true;
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}
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bool CanUseUtilityThreadTypeForWorkerThreadImpl() {
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#if !BUILDFLAG(IS_ANDROID)
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// Same as CanUseBackgroundThreadTypeForWorkerThreadImpl()
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if (!PlatformThread::CanChangeThreadType(ThreadType::kUtility,
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ThreadType::kDefault))
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return false;
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#endif // BUILDFLAG(IS_ANDROID)
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return true;
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}
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} // namespace
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bool CanUseBackgroundThreadTypeForWorkerThread() {
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static const bool can_use_background_thread_type_for_worker_thread =
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CanUseBackgroundThreadTypeForWorkerThreadImpl();
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return can_use_background_thread_type_for_worker_thread;
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}
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bool CanUseUtilityThreadTypeForWorkerThread() {
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static const bool can_use_utility_thread_type_for_worker_thread =
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CanUseUtilityThreadTypeForWorkerThreadImpl();
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return can_use_utility_thread_type_for_worker_thread;
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}
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} // namespace internal
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} // namespace base
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