base/test/test_pending_task.h

   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_PENDING_TASK_H_
   6 #define BASE_TEST_TEST_PENDING_TASK_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/location.h"
  12 #include "base/time/time.h"
  13 #include "base/trace_event/trace_event_argument.h"
  14
  15 namespace base {
  16
  17 // TestPendingTask is a helper class for test TaskRunner
  18 // implementations.  See test_simple_task_runner.h for example usage.
  19
  20 struct TestPendingTask {
  21   enum TestNestability { NESTABLE, NON_NESTABLE };
  22
  23   TestPendingTask();
  24   TestPendingTask(const tracked_objects::Location& location,
  25                   const Closure& task,
  26                   TimeTicks post_time,
  27                   TimeDelta delay,
  28                   TestNestability nestability);
  29   ~TestPendingTask();
  30
  31   // Returns post_time + delay.
  32   TimeTicks GetTimeToRun() const;
  33
  34   // Returns true if this task is nestable and |other| isn't, or if
  35   // this task's time to run is strictly earlier than |other|'s time
  36   // to run.
  37   //
  38   // Note that two tasks may both have the same nestability and delay.
  39   // In that case, the caller must use some other criterion (probably
  40   // the position in some queue) to break the tie.  Conveniently, the
  41   // following STL functions already do so:
  42   //
  43   //   - std::min_element
  44   //   - std::stable_sort
  45   //
  46   // but the following STL functions don't:
  47   //
  48   //   - std::max_element
  49   //   - std::sort.
  50   bool ShouldRunBefore(const TestPendingTask& other) const;
  51
  52   tracked_objects::Location location;
  53   Closure task;
  54   TimeTicks post_time;
  55   TimeDelta delay;
  56   TestNestability nestability;
  57
  58   // Functions for using test pending task with tracing, useful in unit
  59   // testing.
  60   void AsValueInto(base::trace_event::TracedValue* state) const;
  61   scoped_refptr<base::trace_event::ConvertableToTraceFormat> AsValue() const;
  62   std::string ToString() const;
  63 };
  64
  65 // gtest helpers which allow pretty printing of the tasks, very useful in unit
  66 // testing.
  67 std::ostream& operator<<(std::ostream& os, const TestPendingTask& task);
  68 void PrintTo(const TestPendingTask& task, std::ostream* os);
  69
  70 }  // namespace base
  71
  72 #endif  // BASE_TEST_TEST_PENDING_TASK_H_