base/logging_win.h

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