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. 4 5 #ifndef BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_ 6 #define BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_ 7 8 #include <deque> 9 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" 15 16 namespace base { 17 18 class TimeDelta; 19 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. 25 // 26 // TestSimpleTaskRunner has the following properties which make it simple: 27 // 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. 34 // 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). 38 // 39 // If you need more complicated properties, consider using this class 40 // as a template for writing a test TaskRunner implementation using 41 // TestPendingTask. 42 // 43 // Note that, like any TaskRunner, TestSimpleTaskRunner is 44 // ref-counted. 45 class TestSimpleTaskRunner : public SingleThreadTaskRunner { 46 public: 47 TestSimpleTaskRunner(); 48 49 // SingleThreadTaskRunner implementation. 50 virtual bool PostDelayedTask(const tracked_objects::Location& from_here, 51 const Closure& task, 52 TimeDelta delay) OVERRIDE; 53 virtual bool PostNonNestableDelayedTask( 54 const tracked_objects::Location& from_here, 55 const Closure& task, 56 TimeDelta delay) OVERRIDE; 57 58 virtual bool RunsTasksOnCurrentThread() const OVERRIDE; 59 60 const std::deque<TestPendingTask>& GetPendingTasks() const; 61 bool HasPendingTask() const; 62 base::TimeDelta NextPendingTaskDelay() const; 63 64 // Clears the queue of pending tasks without running them. 65 void ClearPendingTasks(); 66 67 // Runs each current pending task in order and clears the queue. 68 // Any tasks posted by the tasks are not run. 69 virtual void RunPendingTasks(); 70 71 // Runs pending tasks until the queue is empty. 72 void RunUntilIdle(); 73 74 protected: 75 virtual ~TestSimpleTaskRunner(); 76 77 std::deque<TestPendingTask> pending_tasks_; 78 ThreadChecker thread_checker_; 79 80 private: 81 DISALLOW_COPY_AND_ASSIGN(TestSimpleTaskRunner); 82 }; 83 84 } // namespace base 85 86 #endif // BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_ 87