1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This file contains the Windows-specific exporting to ETW.
#ifndef BASE_TRACE_EVENT_TRACE_EVENT_ETW_EXPORT_WIN_H_
#define BASE_TRACE_EVENT_TRACE_EVENT_ETW_EXPORT_WIN_H_
#include <stdint.h>
#include <map>
#include "base/base_export.h"
#include "base/macros.h"
#include "base/strings/string_piece.h"
#include "base/trace_event/trace_event_impl.h"
namespace base {
template <typename Type>
struct StaticMemorySingletonTraits;
namespace trace_event {
class BASE_EXPORT TraceEventETWExport {
public:
~TraceEventETWExport();
// Retrieves the singleton.
// Note that this may return NULL post-AtExit processing.
static TraceEventETWExport* GetInstance();
// Enables/disables exporting of events to ETW. If disabled,
// AddEvent and AddCustomEvent will simply return when called.
static void EnableETWExport();
static void DisableETWExport();
// Returns true if ETW is enabled. For now, this is true if the command line
// flag is specified.
static bool IsETWExportEnabled();
// Exports an event to ETW. This is mainly used in
// TraceLog::AddTraceEventWithThreadIdAndTimestamp to export internal events.
static void AddEvent(
char phase,
const unsigned char* category_group_enabled,
const char* name,
unsigned long long id,
int num_args,
const char** arg_names,
const unsigned char* arg_types,
const unsigned long long* arg_values,
const scoped_refptr<ConvertableToTraceFormat>* convertable_values);
// Exports an ETW event that marks the end of a complete event.
static void AddCompleteEndEvent(const char* name);
// Returns true if any category in the group is enabled.
static bool IsCategoryGroupEnabled(const char* category_group_name);
private:
// Ensure only the provider can construct us.
friend struct StaticMemorySingletonTraits<TraceEventETWExport>;
// To have access to UpdateKeyword().
class ETWKeywordUpdateThread;
TraceEventETWExport();
// Updates the list of enabled categories by consulting the ETW keyword.
// Returns true if there was a change, false otherwise.
bool UpdateEnabledCategories();
// Returns true if the category is enabled.
bool IsCategoryEnabled(const char* category_name) const;
// Called back by the update thread to check for potential changes to the
// keyword.
static void UpdateETWKeyword();
// True if ETW is enabled. Allows hiding the exporting behind a flag.
bool etw_export_enabled_;
// Maps category names to their status (enabled/disabled).
std::map<StringPiece, bool> categories_status_;
// Local copy of the ETW keyword.
uint64_t etw_match_any_keyword_;
// Background thread that monitors changes to the ETW keyword and updates
// the enabled categories when a change occurs.
scoped_ptr<ETWKeywordUpdateThread> keyword_update_thread_;
PlatformThreadHandle keyword_update_thread_handle_;
DISALLOW_COPY_AND_ASSIGN(TraceEventETWExport);
};
} // namespace trace_event
} // namespace base
#endif // BASE_TRACE_EVENT_TRACE_EVENT_ETW_EXPORT_WIN_H_
|
