cc/test/ordered_simple_task_runner.h

   1 // Copyright 2014 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 CC_TEST_ORDERED_SIMPLE_TASK_RUNNER_H_
   6 #define CC_TEST_ORDERED_SIMPLE_TASK_RUNNER_H_
   7
   8 #include <limits>
   9 #include <set>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/logging.h"
  15 #include "base/test/simple_test_tick_clock.h"
  16 #include "base/test/test_simple_task_runner.h"
  17 #include "base/trace_event/trace_event.h"
  18
  19 namespace cc {
  20
  21 // Subclass of TestPendingTask which has a unique ID for every task, supports
  22 // being used inside a std::set and has debug tracing support.
  23 class TestOrderablePendingTask : public base::TestPendingTask {
  24  public:
  25   TestOrderablePendingTask();
  26   TestOrderablePendingTask(const tracked_objects::Location& location,
  27                            const base::Closure& task,
  28                            base::TimeTicks post_time,
  29                            base::TimeDelta delay,
  30                            TestNestability nestability);
  31   ~TestOrderablePendingTask();
  32
  33   // operators needed by std::set and comparison
  34   bool operator==(const TestOrderablePendingTask& other) const;
  35   bool operator<(const TestOrderablePendingTask& other) const;
  36
  37   // base::trace_event tracing functionality
  38   scoped_refptr<base::trace_event::ConvertableToTraceFormat> AsValue() const;
  39   void AsValueInto(base::trace_event::TracedValue* state) const;
  40
  41  private:
  42   static size_t task_id_counter;
  43   const size_t task_id_;
  44 };
  45
  46 // This runs pending tasks based on task's post_time + delay.
  47 // We should not execute a delayed task sooner than some of the queued tasks
  48 // which don't have a delay even though it is queued early.
  49 class OrderedSimpleTaskRunner : public base::SingleThreadTaskRunner {
  50  public:
  51   OrderedSimpleTaskRunner(base::SimpleTestTickClock* now_src, bool advance_now);
  52
  53   // base::TestSimpleTaskRunner implementation:
  54   bool PostDelayedTask(const tracked_objects::Location& from_here,
  55                        const base::Closure& task,
  56                        base::TimeDelta delay) override;
  57   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
  58                                   const base::Closure& task,
  59                                   base::TimeDelta delay) override;
  60
  61   bool RunsTasksOnCurrentThread() const override;
  62
  63   static base::TimeTicks AbsoluteMaxNow();
  64
  65   // Set a maximum number of tasks to run at once. Useful as a timeout to
  66   // prevent infinite task loops.
  67   static const size_t kAbsoluteMaxTasks;
  68   void SetRunTaskLimit(size_t max_tasks) { max_tasks_ = max_tasks; }
  69   void ClearRunTaskLimit() { max_tasks_ = kAbsoluteMaxTasks; }
  70
  71   // Allow task runner to advance now when running tasks.
  72   void SetAutoAdvanceNowToPendingTasks(bool advance_now) {
  73     advance_now_ = advance_now;
  74   }
  75
  76   size_t NumPendingTasks() const;
  77   bool HasPendingTasks() const;
  78   base::TimeTicks NextTaskTime();
  79   base::TimeDelta DelayToNextTaskTime();
  80
  81   // Run tasks while the callback returns true or too many tasks have been run.
  82   // Returns true if there are still pending tasks left.
  83   bool RunTasksWhile(base::Callback<bool(void)> condition);
  84
  85   // Run tasks while *all* of the callbacks return true or too many tasks have
  86   // been run. Exits on the *first* condition which returns false, skipping
  87   // calling all remaining conditions. Conditions can have side effects,
  88   // including modifying the task queue.
  89   // Returns true if there are still pending tasks left.
  90   bool RunTasksWhile(const std::vector<base::Callback<bool(void)>>& conditions);
  91
  92   // Convenience functions to run tasks with common conditions.
  93
  94   // Run tasks which existed at the start of this call.
  95   // Return code indicates tasks still exist to run.
  96   bool RunPendingTasks();
  97   // Keep running tasks until no tasks are left.
  98   // Return code indicates tasks still exist to run which also indicates if
  99   // runner reached idle.
 100   bool RunUntilIdle();
 101   // Keep running tasks until given time period.
 102   // Return code indicates tasks still exist to run.
 103   bool RunUntilTime(base::TimeTicks time);
 104   bool RunForPeriod(base::TimeDelta period);
 105
 106   // base::trace_event tracing functionality
 107   scoped_refptr<base::trace_event::ConvertableToTraceFormat> AsValue() const;
 108   virtual void AsValueInto(base::trace_event::TracedValue* state) const;
 109
 110   // Common conditions to run for, exposed publicly to allow external users to
 111   // use their own combinations.
 112   // -------------------------------------------------------------------------
 113
 114   // Keep running until the given number of tasks have run.
 115   // You generally shouldn't use this check as it will cause your tests to fail
 116   // when code is changed adding a new task. It is useful as a "timeout" type
 117   // solution.
 118   base::Callback<bool(void)> TaskRunCountBelow(size_t max_tasks);
 119
 120   // Keep running until a task which didn't exist initially would run.
 121   base::Callback<bool(void)> TaskExistedInitially();
 122
 123   // Stop running tasks when NextTaskTime() >= stop_at
 124   base::Callback<bool(void)> NowBefore(base::TimeTicks stop_at);
 125
 126   // Advance Now() to the next task to run.
 127   base::Callback<bool(void)> AdvanceNow();
 128
 129  protected:
 130   static bool TaskRunCountBelowCallback(size_t max_tasks, size_t* task_run);
 131   bool TaskExistedInitiallyCallback(
 132       const std::set<TestOrderablePendingTask>& existing_tasks);
 133   bool NowBeforeCallback(base::TimeTicks stop_at);
 134   bool AdvanceNowCallback();
 135
 136   ~OrderedSimpleTaskRunner() override;
 137
 138   base::ThreadChecker thread_checker_;
 139
 140   bool advance_now_;
 141   // Not owned.
 142   base::SimpleTestTickClock* now_src_;
 143
 144   size_t max_tasks_;
 145
 146   bool inside_run_tasks_until_;
 147   std::set<TestOrderablePendingTask> pending_tasks_;
 148
 149  private:
 150   DISALLOW_COPY_AND_ASSIGN(OrderedSimpleTaskRunner);
 151 };
 152
 153 }  // namespace cc
 154
 155 #endif  // CC_TEST_ORDERED_SIMPLE_TASK_RUNNER_H_