base/logging_win.cc

   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 #include "base/logging_win.h"
   6 #include "base/memory/singleton.h"
   7 #include <initguid.h>  // NOLINT
   8
   9 namespace logging {
  10
  11 using base::win::EtwEventLevel;
  12 using base::win::EtwMofEvent;
  13
  14 DEFINE_GUID(kLogEventId,
  15     0x7fe69228, 0x633e, 0x4f06, 0x80, 0xc1, 0x52, 0x7f, 0xea, 0x23, 0xe3, 0xa7);
  16
  17 LogEventProvider::LogEventProvider() : old_log_level_(LOG_NONE) {
  18 }
  19
  20 LogEventProvider* LogEventProvider::GetInstance() {
  21   return Singleton<LogEventProvider,
  22                    StaticMemorySingletonTraits<LogEventProvider> >::get();
  23 }
  24
  25 bool LogEventProvider::LogMessage(logging::LogSeverity severity,
  26     const char* file, int line, size_t message_start,
  27     const std::string& message) {
  28   EtwEventLevel level = TRACE_LEVEL_NONE;
  29
  30   // Convert the log severity to the most appropriate ETW trace level.
  31   if (severity >= 0) {
  32     switch (severity) {
  33       case LOG_INFO:
  34         level = TRACE_LEVEL_INFORMATION;
  35         break;
  36       case LOG_WARNING:
  37         level = TRACE_LEVEL_WARNING;
  38         break;
  39       case LOG_ERROR:
  40       case LOG_ERROR_REPORT:
  41         level = TRACE_LEVEL_ERROR;
  42         break;
  43       case LOG_FATAL:
  44         level = TRACE_LEVEL_FATAL;
  45         break;
  46     }
  47   } else {  // severity < 0 is VLOG verbosity levels.
  48     level = TRACE_LEVEL_INFORMATION - severity;
  49   }
  50
  51   // Bail if we're not logging, not at that level,
  52   // or if we're post-atexit handling.
  53   LogEventProvider* provider = LogEventProvider::GetInstance();
  54   if (provider == NULL || level > provider->enable_level())
  55     return false;
  56
  57   // And now log the event.
  58   if (provider->enable_flags() & ENABLE_LOG_MESSAGE_ONLY) {
  59     EtwMofEvent<1> event(kLogEventId, LOG_MESSAGE, level);
  60     event.SetField(0, message.length() + 1 - message_start,
  61         message.c_str() + message_start);
  62
  63     provider->Log(event.get());
  64   } else {
  65     const size_t kMaxBacktraceDepth = 32;
  66     void* backtrace[kMaxBacktraceDepth];
  67     DWORD depth = 0;
  68
  69     // Capture a stack trace if one is requested.
  70     // requested per our enable flags.
  71     if (provider->enable_flags() & ENABLE_STACK_TRACE_CAPTURE)
  72       depth = CaptureStackBackTrace(2, kMaxBacktraceDepth, backtrace, NULL);
  73
  74     EtwMofEvent<5> event(kLogEventId, LOG_MESSAGE_FULL, level);
  75     if (file == NULL)
  76       file = "";
  77
  78     // Add the stack trace.
  79     event.SetField(0, sizeof(depth), &depth);
  80     event.SetField(1, sizeof(backtrace[0]) * depth, &backtrace);
  81     // The line.
  82     event.SetField(2, sizeof(line), &line);
  83     // The file.
  84     event.SetField(3, strlen(file) + 1, file);
  85     // And finally the message.
  86     event.SetField(4, message.length() + 1 - message_start,
  87         message.c_str() + message_start);
  88
  89     provider->Log(event.get());
  90   }
  91
  92   // Don't increase verbosity in other log destinations.
  93   if (severity < provider->old_log_level_)
  94     return true;
  95
  96   return false;
  97 }
  98
  99 void LogEventProvider::Initialize(const GUID& provider_name) {
 100   LogEventProvider* provider = LogEventProvider::GetInstance();
 101
 102   provider->set_provider_name(provider_name);
 103   provider->Register();
 104
 105   // Register our message handler with logging.
 106   SetLogMessageHandler(LogMessage);
 107 }
 108
 109 void LogEventProvider::Uninitialize() {
 110   LogEventProvider::GetInstance()->Unregister();
 111 }
 112
 113 void LogEventProvider::OnEventsEnabled() {
 114   // Grab the old log level so we can restore it later.
 115   old_log_level_ = GetMinLogLevel();
 116
 117   // Convert the new trace level to a logging severity
 118   // and enable logging at that level.
 119   EtwEventLevel level = enable_level();
 120   if (level == TRACE_LEVEL_NONE || level == TRACE_LEVEL_FATAL) {
 121     SetMinLogLevel(LOG_FATAL);
 122   } else if (level == TRACE_LEVEL_ERROR) {
 123     SetMinLogLevel(LOG_ERROR);
 124   } else if (level == TRACE_LEVEL_WARNING) {
 125     SetMinLogLevel(LOG_WARNING);
 126   } else if (level == TRACE_LEVEL_INFORMATION) {
 127     SetMinLogLevel(LOG_INFO);
 128   } else if (level >= TRACE_LEVEL_VERBOSE) {
 129     // Above INFO, we enable verbose levels with negative severities.
 130     SetMinLogLevel(TRACE_LEVEL_INFORMATION - level);
 131   }
 132 }
 133
 134 void LogEventProvider::OnEventsDisabled() {
 135   // Restore the old log level.
 136   SetMinLogLevel(old_log_level_);
 137 }
 138
 139 }  // namespace logging