base/debug/task_annotator.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 BASE_DEBUG_TASK_ANNOTATOR_H_
   6 #define BASE_DEBUG_TASK_ANNOTATOR_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/basictypes.h"
  10
  11 namespace base {
  12 struct PendingTask;
  13 namespace debug {
  14
  15 // Implements common debug annotations for posted tasks. This includes data
  16 // such as task origins, queueing durations and memory usage.
  17 class BASE_EXPORT TaskAnnotator {
  18  public:
  19   TaskAnnotator();
  20   ~TaskAnnotator();
  21
  22   // Called to indicate that a task has been queued to run in the future.
  23   // |queue_function| is used as the trace flow event name.
  24   void DidQueueTask(const char* queue_function,
  25                     const PendingTask& pending_task);
  26
  27   // Run a previously queued task. |queue_function| should match what was
  28   // passed into |DidQueueTask| for this task. |run_function| is used as the
  29   // name for the trace event that surrounds the task's execution.
  30   void RunTask(const char* queue_function,
  31                const char* run_function,
  32                const PendingTask& pending_task);
  33
  34  private:
  35   // Creates a process-wide unique ID to represent this task in trace events.
  36   // This will be mangled with a Process ID hash to reduce the likelyhood of
  37   // colliding with TaskAnnotator pointers on other processes.
  38   uint64 GetTaskTraceID(const PendingTask& task) const;
  39
  40   DISALLOW_COPY_AND_ASSIGN(TaskAnnotator);
  41 };
  42
  43 }  // namespace debug
  44 }  // namespace base
  45
  46 #endif  // BASE_DEBUG_TASK_ANNOTATOR_H_