base/tracking_info.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 // This is a simple struct with tracking information that is stored
   6 // with a PendingTask (when message_loop is handling the task).
   7 // Only the information that is shared with the profiler in tracked_objects
   8 // are included in this structure.
   9
  10
  11 #ifndef BASE_TRACKING_INFO_H_
  12 #define BASE_TRACKING_INFO_H_
  13
  14 #include "base/base_export.h"
  15 #include "base/profiler/tracked_time.h"
  16 #include "base/time/time.h"
  17
  18 namespace tracked_objects {
  19 class Location;
  20 class Births;
  21 }
  22
  23 namespace base {
  24
  25 // This structure is copied around by value.
  26 struct BASE_EXPORT TrackingInfo {
  27   TrackingInfo();
  28   TrackingInfo(const tracked_objects::Location& posted_from,
  29                base::TimeTicks delayed_run_time);
  30   ~TrackingInfo();
  31
  32   // To avoid conflating our stats with the delay duration in a PostDelayedTask,
  33   // we identify such tasks, and replace their post_time with the time they
  34   // were scheduled (requested?) to emerge from the delayed task queue. This
  35   // means that queuing delay for such tasks will show how long they went
  36   // unserviced, after they *could* be serviced.  This is the same stat as we
  37   // have for non-delayed tasks, and we consistently call it queuing delay.
  38   tracked_objects::TrackedTime EffectiveTimePosted() const {
  39     return delayed_run_time.is_null()
  40                ? time_posted
  41                : tracked_objects::TrackedTime(delayed_run_time);
  42   }
  43
  44   // Record of location and thread that the task came from.
  45   tracked_objects::Births* birth_tally;
  46
  47   // Time when the related task was posted. Note that this value may be empty
  48   // if task profiling is disabled, and should only be used in conjunction with
  49   // profiling-related reporting.
  50   tracked_objects::TrackedTime time_posted;
  51
  52   // The time when the task should be run.
  53   base::TimeTicks delayed_run_time;
  54 };
  55
  56 }  // namespace base
  57
  58 #endif  // BASE_TRACKING_INFO_H_