53 lines
1.6 KiB
C++
53 lines
1.6 KiB
C++
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// Copyright 2015 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/threading/sequenced_task_runner_handle.h"
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#include <utility>
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#include "base/lazy_instance.h"
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#include "base/logging.h"
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#include "base/threading/thread_local.h"
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namespace base {
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namespace {
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LazyInstance<ThreadLocalPointer<SequencedTaskRunnerHandle>>::Leaky
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sequenced_task_runner_tls = LAZY_INSTANCE_INITIALIZER;
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} // namespace
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// static
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const scoped_refptr<SequencedTaskRunner>& SequencedTaskRunnerHandle::Get() {
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const SequencedTaskRunnerHandle* current =
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sequenced_task_runner_tls.Pointer()->Get();
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CHECK(current)
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<< "Error: This caller requires a sequenced context (i.e. the current "
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"task needs to run from a SequencedTaskRunner). If you're in a test "
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"refer to //docs/threading_and_tasks_testing.md.";
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return current->task_runner_;
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}
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// static
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bool SequencedTaskRunnerHandle::IsSet() {
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return !!sequenced_task_runner_tls.Pointer()->Get();
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}
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SequencedTaskRunnerHandle::SequencedTaskRunnerHandle(
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scoped_refptr<SequencedTaskRunner> task_runner)
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: task_runner_(std::move(task_runner)) {
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DCHECK(task_runner_->RunsTasksInCurrentSequence());
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DCHECK(!SequencedTaskRunnerHandle::IsSet());
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sequenced_task_runner_tls.Pointer()->Set(this);
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}
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SequencedTaskRunnerHandle::~SequencedTaskRunnerHandle() {
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DCHECK(task_runner_->RunsTasksInCurrentSequence());
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DCHECK_EQ(sequenced_task_runner_tls.Pointer()->Get(), this);
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sequenced_task_runner_tls.Pointer()->Set(nullptr);
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}
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} // namespace base
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