// Copyright 2017 The Chromium Authors. All rights reserved.
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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_scheduler/environment_config.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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size_t GetEnvironmentIndexForTraits(const TaskTraits& traits) {
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const bool is_background =
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traits.priority() == base::TaskPriority::BACKGROUND;
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if (traits.may_block() || traits.with_base_sync_primitives())
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return is_background ? BACKGROUND_BLOCKING : FOREGROUND_BLOCKING;
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return is_background ? BACKGROUND : FOREGROUND;
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}
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bool CanUseBackgroundPriorityForSchedulerWorker() {
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// When Lock doesn't handle multiple thread priorities, run all
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// SchedulerWorker 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 !defined(OS_ANDROID)
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// When thread priority can't be increased, run all threads with a normal
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// priority to avoid priority inversions on shutdown (TaskScheduler increases
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// background threads priority to normal on shutdown while resolving remaining
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// 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::CanIncreaseCurrentThreadPriority())
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return false;
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#endif // defined(OS_ANDROID)
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return true;
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}
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} // namespace internal
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} // namespace base
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