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