base/logging_win.h

   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
  16 template <typename Type>
  17 struct StaticMemorySingletonTraits;
  18
  19 namespace logging {
  20
  21 // Event ID for the log messages we generate.
  22 extern const GUID kLogEventId;
  23
  24 // Feature enable mask for LogEventProvider.
  25 enum 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.
  37 enum 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.
  53 class 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_