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[chromium-blink-merge.git] / base / test / test_simple_task_runner.h
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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_
6 #define BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_
8 #include <deque>
10 #include "base/basictypes.h"
11 #include "base/compiler_specific.h"
12 #include "base/single_thread_task_runner.h"
13 #include "base/test/test_pending_task.h"
14 #include "base/threading/thread_checker.h"
16 namespace base {
18 class TimeDelta;
20 // TestSimpleTaskRunner is a simple TaskRunner implementation that can
21 // be used for testing. It implements SingleThreadTaskRunner as that
22 // interface implements SequencedTaskRunner, which in turn implements
23 // TaskRunner, so TestSimpleTaskRunner can be passed in to a function
24 // that accepts any *TaskRunner object.
26 // TestSimpleTaskRunner has the following properties which make it simple:
28 // - It is non-thread safe; all member functions must be called on
29 // the same thread.
30 // - Tasks are simply stored in a queue in FIFO order, ignoring delay
31 // and nestability.
32 // - Tasks aren't guaranteed to be destroyed immediately after
33 // they're run.
35 // However, TestSimpleTaskRunner allows for reentrancy, in that it
36 // handles the running of tasks that in turn call back into itself
37 // (e.g., to post more tasks).
39 // If you need more complicated properties, consider using this class
40 // as a template for writing a test TaskRunner implementation using
41 // TestPendingTask.
43 // Note that, like any TaskRunner, TestSimpleTaskRunner is
44 // ref-counted.
45 class TestSimpleTaskRunner : public SingleThreadTaskRunner {
46 public:
47 TestSimpleTaskRunner();
49 // SingleThreadTaskRunner implementation.
50 bool PostDelayedTask(const tracked_objects::Location& from_here,
51 const Closure& task,
52 TimeDelta delay) override;
53 bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
54 const Closure& task,
55 TimeDelta delay) override;
57 bool RunsTasksOnCurrentThread() const override;
59 const std::deque<TestPendingTask>& GetPendingTasks() const;
60 bool HasPendingTask() const;
61 base::TimeDelta NextPendingTaskDelay() const;
63 // Clears the queue of pending tasks without running them.
64 void ClearPendingTasks();
66 // Runs each current pending task in order and clears the queue.
67 // Any tasks posted by the tasks are not run.
68 virtual void RunPendingTasks();
70 // Runs pending tasks until the queue is empty.
71 void RunUntilIdle();
73 protected:
74 ~TestSimpleTaskRunner() override;
76 std::deque<TestPendingTask> pending_tasks_;
77 ThreadChecker thread_checker_;
79 private:
80 DISALLOW_COPY_AND_ASSIGN(TestSimpleTaskRunner);
83 } // namespace base
85 #endif // BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_