Integrate the base logging with Event Tracing for Windows. This allows ETW to control the log level and log feature flags from outside the process, and all log messages can be transported into ETW trace sessions.As is this provides an event trace provider class thatmanages the log level on control callbacks and shunts the formatted log messages to ETW when warranted.The provider observes one feature flag, which when turned on causes it to capture and log a stack trace at the log site, which can be helpful when diagnosing errors from logs.This CL also initializes ETW logging for chrome.dll, but only if the environment variable "CHROME_ETW_LOGGING" is set. The ETW machinery may create a thread in every process registering a trace provider, and the environment variable makes this overhead optional.

TEST=Unittests in this change
BUG=none

Review URL: http://codereview.chromium.org/413006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33066 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 152 insertions, 0 deletions

diff --git a/base/logging_win.cc b/base/logging_win.cc
new file mode 100644
index 0000000..b3702aa
--- /dev/null
+++ b/base/logging_win.cc
@@ -0,0 +1,152 @@
+// 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