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         level = TRACE_LEVEL_ERROR;
  41         break;
  42       case LOG_FATAL:
  43         level = TRACE_LEVEL_FATAL;
  44         break;
  45     }
  46   } else {  // severity < 0 is VLOG verbosity levels.
  47     level = static_cast<EtwEventLevel>(TRACE_LEVEL_INFORMATION - severity);
  48   }
  49
  50   // Bail if we're not logging, not at that level,
  51   // or if we're post-atexit handling.
  52   LogEventProvider* provider = LogEventProvider::GetInstance();
  53   if (provider == NULL || level > provider->enable_level())
  54     return false;
  55
  56   // And now log the event.
  57   if (provider->enable_flags() & ENABLE_LOG_MESSAGE_ONLY) {
  58     EtwMofEvent<1> event(kLogEventId, LOG_MESSAGE, level);
  59     event.SetField(0, message.length() + 1 - message_start,
  60         message.c_str() + message_start);
  61
  62     provider->Log(event.get());
  63   } else {
  64     const size_t kMaxBacktraceDepth = 32;
  65     void* backtrace[kMaxBacktraceDepth];
  66     DWORD depth = 0;
  67
  68     // Capture a stack trace if one is requested.
  69     // requested per our enable flags.
  70     if (provider->enable_flags() & ENABLE_STACK_TRACE_CAPTURE)
  71       depth = CaptureStackBackTrace(2, kMaxBacktraceDepth, backtrace, NULL);
  72
  73     EtwMofEvent<5> event(kLogEventId, LOG_MESSAGE_FULL, level);
  74     if (file == NULL)
  75       file = "";
  76
  77     // Add the stack trace.
  78     event.SetField(0, sizeof(depth), &depth);
  79     event.SetField(1, sizeof(backtrace[0]) * depth, &backtrace);
  80     // The line.
  81     event.SetField(2, sizeof(line), &line);
  82     // The file.
  83     event.SetField(3, strlen(file) + 1, file);
  84     // And finally the message.
  85     event.SetField(4, message.length() + 1 - message_start,
  86         message.c_str() + message_start);
  87
  88     provider->Log(event.get());
  89   }
  90
  91   // Don't increase verbosity in other log destinations.
  92   if (severity < provider->old_log_level_)
  93     return true;
  94
  95   return false;
  96 }
  97
  98 void LogEventProvider::Initialize(const GUID& provider_name) {
  99   LogEventProvider* provider = LogEventProvider::GetInstance();
 100
 101   provider->set_provider_name(provider_name);
 102   provider->Register();
 103
 104   // Register our message handler with logging.
 105   SetLogMessageHandler(LogMessage);
 106 }
 107
 108 void LogEventProvider::Uninitialize() {
 109   LogEventProvider::GetInstance()->Unregister();
 110 }
 111
 112 void LogEventProvider::OnEventsEnabled() {
 113   // Grab the old log level so we can restore it later.
 114   old_log_level_ = GetMinLogLevel();
 115
 116   // Convert the new trace level to a logging severity
 117   // and enable logging at that level.
 118   EtwEventLevel level = enable_level();
 119   if (level == TRACE_LEVEL_NONE || level == TRACE_LEVEL_FATAL) {
 120     SetMinLogLevel(LOG_FATAL);
 121   } else if (level == TRACE_LEVEL_ERROR) {
 122     SetMinLogLevel(LOG_ERROR);
 123   } else if (level == TRACE_LEVEL_WARNING) {
 124     SetMinLogLevel(LOG_WARNING);
 125   } else if (level == TRACE_LEVEL_INFORMATION) {
 126     SetMinLogLevel(LOG_INFO);
 127   } else if (level >= TRACE_LEVEL_VERBOSE) {
 128     // Above INFO, we enable verbose levels with negative severities.
 129     SetMinLogLevel(TRACE_LEVEL_INFORMATION - level);
 130   }
 131 }
 132
 133 void LogEventProvider::OnEventsDisabled() {
 134   // Restore the old log level.
 135   SetMinLogLevel(old_log_level_);
 136 }
 137
 138 }  // namespace logging