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