base/profiler/alternate_timer.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 glue file, which allows third party code to call into our profiler
   6 // without having to include most any functions from base.
   7
   8 #ifndef BASE_PROFILER_ALTERNATE_TIMER_H_
   9 #define BASE_PROFILER_ALTERNATE_TIMER_H_
  10
  11 #include "base/base_export.h"
  12
  13 namespace tracked_objects {
  14
  15 enum TimeSourceType {
  16   TIME_SOURCE_TYPE_WALL_TIME,
  17   TIME_SOURCE_TYPE_TCMALLOC
  18 };
  19
  20 // Provide type for an alternate timer function.
  21 typedef unsigned int NowFunction();
  22
  23 // Environment variable name that is used to activate alternate timer profiling
  24 // (such as using TCMalloc allocations to provide a pseudo-timer) for tasks
  25 // instead of wall clock profiling.
  26 BASE_EXPORT extern const char kAlternateProfilerTime[];
  27
  28 // Set an alternate timer function to replace the OS time function when
  29 // profiling.  Typically this is called by an allocator that is providing a
  30 // function that indicates how much memory has been allocated on any given
  31 // thread.
  32 BASE_EXPORT void SetAlternateTimeSource(NowFunction* now_function,
  33                                         TimeSourceType type);
  34
  35 // Gets the pointer to a function that was set via SetAlternateTimeSource().
  36 // Returns NULL if no set was done prior to calling GetAlternateTimeSource.
  37 NowFunction* GetAlternateTimeSource();
  38
  39 // Returns the type of the currently set time source.
  40 BASE_EXPORT TimeSourceType GetTimeSourceType();
  41
  42 }  // namespace tracked_objects
  43
  44 #endif  // BASE_PROFILER_ALTERNATE_TIMER_H_