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// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/logging_win.h"
#include "base/atomicops.h"
#include "base/singleton.h"
#include <initguid.h> // NOLINT
namespace {
struct LogEventProviderTraits {
// WARNING: User has to deal with get() returning NULL.
static logging::LogEventProvider* New() {
if (base::subtle::NoBarrier_AtomicExchange(&dead_, 1))
return NULL;
logging::LogEventProvider* ptr =
reinterpret_cast<logging::LogEventProvider*>(buffer_);
// We are protected by a memory barrier.
new(ptr) logging::LogEventProvider();
return ptr;
}
static void Delete(logging::LogEventProvider* p) {
base::subtle::NoBarrier_Store(&dead_, 1);
MemoryBarrier();
p->logging::LogEventProvider::~LogEventProvider();
}
static const bool kRegisterAtExit = true;
private:
static const size_t kBufferSize = (sizeof(logging::LogEventProvider) +
sizeof(intptr_t) - 1) / sizeof(intptr_t);
static intptr_t buffer_[kBufferSize];
// Signal the object was already deleted, so it is not revived.
static base::subtle::Atomic32 dead_;
};
intptr_t LogEventProviderTraits::buffer_[kBufferSize];
base::subtle::Atomic32 LogEventProviderTraits::dead_ = 0;
Singleton<logging::LogEventProvider, LogEventProviderTraits> log_provider;
} // namespace
namespace logging {
DEFINE_GUID(kLogEventId,
0x7fe69228, 0x633e, 0x4f06, 0x80, 0xc1, 0x52, 0x7f, 0xea, 0x23, 0xe3, 0xa7);
LogEventProvider::LogEventProvider() : old_log_level_(LOG_NONE) {
}
bool LogEventProvider::LogMessage(int severity, const std::string& message) {
EtwEventLevel level = TRACE_LEVEL_NONE;
// Convert the log severity to the most appropriate ETW trace level.
switch (severity) {
case LOG_INFO:
level = TRACE_LEVEL_INFORMATION;
break;
case LOG_WARNING:
level = TRACE_LEVEL_WARNING;
break;
case LOG_ERROR:
case LOG_ERROR_REPORT:
level = TRACE_LEVEL_ERROR;
break;
case LOG_FATAL:
level = TRACE_LEVEL_FATAL;
break;
};
// Bail if we're not logging, not at that level,
// or if we're post-atexit handling.
LogEventProvider* provider = log_provider.get();
if (provider == NULL || level > provider->enable_level())
return false;
// And now log the event, with stack trace if one is
// requested per our enable flags.
if (provider->enable_flags() & ENABLE_STACK_TRACE_CAPTURE) {
const size_t kMaxBacktraceDepth = 32;
void* backtrace[kMaxBacktraceDepth];
DWORD depth = CaptureStackBackTrace(2, kMaxBacktraceDepth, backtrace, NULL);
EtwMofEvent<3> event(kLogEventId, LOG_MESSAGE_WITH_STACKTRACE, level);
event.SetField(0, sizeof(depth), &depth);
event.SetField(1, sizeof(backtrace[0]) * depth, &backtrace);
event.SetField(2, message.length() + 1, message.c_str());
provider->Log(event.get());
} else {
EtwMofEvent<1> event(kLogEventId, LOG_MESSAGE, level);
event.SetField(0, message.length() + 1, message.c_str());
provider->Log(event.get());
}
// Don't increase verbosity in other log destinations.
if (severity >= provider->old_log_level_)
return true;
return false;
}
void LogEventProvider::Initialize(const GUID& provider_name) {
LogEventProvider* provider = log_provider.get();
provider->set_provider_name(provider_name);
provider->Register();
// Register our message handler with logging.
SetLogMessageHandler(LogMessage);
}
void LogEventProvider::Uninitialize() {
log_provider.get()->Unregister();
}
void LogEventProvider::OnEventsEnabled() {
// Grab the old log level so we can restore it later.
old_log_level_ = GetMinLogLevel();
// Convert the new trace level to a logging severity
// and enable logging at that level.
EtwEventLevel level = enable_level();
switch (level) {
case TRACE_LEVEL_NONE:
case TRACE_LEVEL_FATAL:
SetMinLogLevel(LOG_FATAL);
break;
case TRACE_LEVEL_ERROR:
SetMinLogLevel(LOG_ERROR);
break;
case TRACE_LEVEL_WARNING:
SetMinLogLevel(LOG_WARNING);
break;
case TRACE_LEVEL_INFORMATION:
case TRACE_LEVEL_VERBOSE:
SetMinLogLevel(LOG_INFO);
break;
}
}
void LogEventProvider::OnEventsDisabled() {
// Restore the old log level.
SetMinLogLevel(old_log_level_);
}
} // namespace logging
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