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, 107 insertions, 0 deletions

diff --git a/base/event_trace_provider_win_unittest.cc b/base/event_trace_provider_win_unittest.cc
new file mode 100644
index 0000000..2ffae82
--- /dev/null
+++ b/base/event_trace_provider_win_unittest.cc
@@ -0,0 +1,107 @@
+// 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.
+//
+// Unit tests for event trace provider.
+#include "base/event_trace_provider_win.h"
+#include <new>
+#include "testing/gtest/include/gtest/gtest.h"
+#include <initguid.h>  // NOLINT - has to be last
+
+namespace {
+
+// {7F0FD37F-FA3C-4cd6-9242-DF60967A2CB2}
+DEFINE_GUID(kTestProvider,
+  0x7f0fd37f, 0xfa3c, 0x4cd6, 0x92, 0x42, 0xdf, 0x60, 0x96, 0x7a, 0x2c, 0xb2);
+
+// {7F0FD37F-FA3C-4cd6-9242-DF60967A2CB2}
+DEFINE_GUID(kTestEventClass,
+  0x7f0fd37f, 0xfa3c, 0x4cd6, 0x92, 0x42, 0xdf, 0x60, 0x96, 0x7a, 0x2c, 0xb2);
+
+}  // namespace
+
+TEST(EtwTraceProviderTest, ToleratesPreCreateInvocations) {
+  // Because the trace provider is used in logging, it's important that
+  // it be possible to use static provider instances without regard to
+  // whether they've been constructed or destructed.
+  // The interface of the class is designed to tolerate this usage.
+  char buf[sizeof(EtwTraceProvider)] = {0};
+  EtwTraceProvider& provider = reinterpret_cast<EtwTraceProvider&>(buf);
+
+  EXPECT_EQ(NULL, provider.registration_handle());
+  EXPECT_EQ(NULL, provider.session_handle());
+  EXPECT_EQ(0, provider.enable_flags());
+  EXPECT_EQ(0, provider.enable_level());
+
+  EXPECT_FALSE(provider.ShouldLog(TRACE_LEVEL_FATAL, 0xfffffff));
+
+  // We expect these not to crash.
+  provider.Log(kTestEventClass, 0, TRACE_LEVEL_FATAL, "foo");
+  provider.Log(kTestEventClass, 0, TRACE_LEVEL_FATAL, L"foo");
+
+  EtwMofEvent<1> dummy(kTestEventClass, 0, TRACE_LEVEL_FATAL);
+  DWORD data = 0;
+  dummy.SetField(0, sizeof(data), &data);
+  provider.Log(dummy.get());
+
+  // Placement-new the provider into our buffer.
+  new (buf) EtwTraceProvider(kTestProvider);
+
+  // Registration is now safe.
+  EXPECT_EQ(ERROR_SUCCESS, provider.Register());
+
+  // Destruct the instance, this should unregister it.
+  provider.EtwTraceProvider::~EtwTraceProvider();
+
+  // And post-destruction, all of the above should still be safe.
+  EXPECT_EQ(NULL, provider.registration_handle());
+  EXPECT_EQ(NULL, provider.session_handle());
+  EXPECT_EQ(0, provider.enable_flags());
+  EXPECT_EQ(0, provider.enable_level());
+
+  EXPECT_FALSE(provider.ShouldLog(TRACE_LEVEL_FATAL, 0xfffffff));
+
+  // We expect these not to crash.
+  provider.Log(kTestEventClass, 0, TRACE_LEVEL_FATAL, "foo");
+  provider.Log(kTestEventClass, 0, TRACE_LEVEL_FATAL, L"foo");
+  provider.Log(dummy.get());
+}
+
+TEST(EtwTraceProviderTest, Initialize) {
+  EtwTraceProvider provider(kTestProvider);
+
+  EXPECT_EQ(NULL, provider.registration_handle());
+  EXPECT_EQ(NULL, provider.session_handle());
+  EXPECT_EQ(0, provider.enable_flags());
+  EXPECT_EQ(0, provider.enable_level());
+}
+
+TEST(EtwTraceProviderTest, Register) {
+  EtwTraceProvider provider(kTestProvider);
+
+  ASSERT_EQ(ERROR_SUCCESS, provider.Register());
+  EXPECT_NE(NULL, provider.registration_handle());
+  ASSERT_EQ(ERROR_SUCCESS, provider.Unregister());
+  EXPECT_EQ(NULL, provider.registration_handle());
+}
+
+TEST(EtwTraceProviderTest, RegisterWithNoNameFails) {
+  EtwTraceProvider provider;
+
+  EXPECT_NE(ERROR_SUCCESS, provider.Register());
+}
+
+TEST(EtwTraceProviderTest, Enable) {
+  EtwTraceProvider provider(kTestProvider);
+
+  ASSERT_EQ(ERROR_SUCCESS, provider.Register());
+  EXPECT_NE(NULL, provider.registration_handle());
+
+  // No session so far.
+  EXPECT_EQ(NULL, provider.session_handle());
+  EXPECT_EQ(0, provider.enable_flags());
+  EXPECT_EQ(0, provider.enable_level());
+
+  ASSERT_EQ(ERROR_SUCCESS, provider.Unregister());
+  EXPECT_EQ(NULL, provider.registration_handle());
+}