test_simple_task_runner.h | Explore in Territory

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_
#define BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_

#include "base/compiler_specific.h"
#include "base/containers/circular_deque.h"
#include "base/functional/callback.h"
#include "base/synchronization/lock.h"
#include "base/task/single_thread_task_runner.h"
#include "base/test/test_pending_task.h"
#include "base/threading/platform_thread.h"

namespace base {

class TimeDelta;

// ATTENTION: Prefer using base::test::TaskEnvironment and a task runner
// obtained from base/task/thread_pool.h over this class. This class isn't as
// "simple" as it seems specifically because it runs tasks in a surprising order
// (delays aren't respected and nesting doesn't behave as usual). Should you
// prefer to flush all tasks regardless of delays,
// TaskEnvironment::TimeSource::MOCK_TIME and
// TaskEnvironment::FastForwardUntilNoTasksRemain() have you covered.
//
// TestSimpleTaskRunner is a simple TaskRunner implementation that can
// be used for testing.  It implements SingleThreadTaskRunner as that
// interface implements SequencedTaskRunner, which in turn implements
// TaskRunner, so TestSimpleTaskRunner can be passed in to a function
// that accepts any *TaskRunner object.
//
// TestSimpleTaskRunner has the following properties which make it simple:
//
//   - Tasks are simply stored in a queue in FIFO order, ignoring delay
//     and nestability.
//   - Tasks aren't guaranteed to be destroyed immediately after
//     they're run.
//
// However, TestSimpleTaskRunner allows for reentrancy, in that it
// handles the running of tasks that in turn call back into itself
// (e.g., to post more tasks).
//
// Note that, like any TaskRunner, TestSimpleTaskRunner is
// ref-counted.
class TestSimpleTaskRunner : public SingleThreadTaskRunner { … };

}  // namespace base

#endif  // BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_
chromium/base/test/test_simple_task_runner.h
