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
13namespace tracked_objects {
14
15enum TimeSourceType {
16  TIME_SOURCE_TYPE_WALL_TIME,
17  TIME_SOURCE_TYPE_TCMALLOC
18};
19
20// Provide type for an alternate timer function.
21typedef 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.
26BASE_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.
32BASE_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.
37NowFunction* GetAlternateTimeSource();
38
39// Returns the type of the currently set time source.
40BASE_EXPORT TimeSourceType GetTimeSourceType();
41
42}  // namespace tracked_objects
43
44#endif  // BASE_PROFILER_ALTERNATE_TIMER_H_
45