logging_win.h revision ddb351dbec246cf1fab5ec20d2d5520909041de1 
1// Copyright (c) 2011 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_LOGGING_WIN_H_
6#define BASE_LOGGING_WIN_H_
7#pragma once
8
9#include <string>
10
11#include "base/base_api.h"
12#include "base/basictypes.h"
13#include "base/win/event_trace_provider.h"
14#include "base/logging.h"
15
16template <typename Type>
17struct StaticMemorySingletonTraits;
18
19namespace logging {
20
21// Event ID for the log messages we generate.
22extern const GUID kLogEventId;
23
24// Feature enable mask for LogEventProvider.
25enum LogEnableMask {
26  // If this bit is set in our provider enable mask, we will include
27  // a stack trace with every log message.
28  ENABLE_STACK_TRACE_CAPTURE = 0x0001,
29  // If this bit is set in our provider enable mask, the provider will log
30  // a LOG message with only the textual content of the message, and no
31  // stack trace.
32  ENABLE_LOG_MESSAGE_ONLY = 0x0002,
33};
34
35// The message types our log event provider generates.
36// ETW likes user message types to start at 10.
37enum LogMessageTypes {
38  // A textual only log message, contains a zero-terminated string.
39  LOG_MESSAGE = 10,
40  // A message with a stack trace, followed by the zero-terminated
41  // message text.
42  LOG_MESSAGE_WITH_STACKTRACE = 11,
43  // A message with:
44  //  a stack trace,
45  //  the line number as a four byte integer,
46  //  the file as a zero terminated UTF8 string,
47  //  the zero-terminated UTF8 message text.
48  LOG_MESSAGE_FULL = 12,
49};
50
51// Trace provider class to drive log control and transport
52// with Event Tracing for Windows.
53class BASE_API LogEventProvider : public base::win::EtwTraceProvider {
54 public:
55  static LogEventProvider* GetInstance();
56
57  static bool LogMessage(logging::LogSeverity severity, const char* file,
58      int line, size_t message_start, const std::string& str);
59
60  static void Initialize(const GUID& provider_name);
61  static void Uninitialize();
62
63 protected:
64  // Overridden to manipulate the log level on ETW control callbacks.
65  virtual void OnEventsEnabled();
66  virtual void OnEventsDisabled();
67
68 private:
69  LogEventProvider();
70
71  // The log severity prior to OnEventsEnabled,
72  // restored in OnEventsDisabled.
73  logging::LogSeverity old_log_level_;
74
75  friend struct StaticMemorySingletonTraits<LogEventProvider>;
76  DISALLOW_COPY_AND_ASSIGN(LogEventProvider);
77};
78
79}  // namespace logging
80
81#endif  // BASE_LOGGING_WIN_H_
82