1 // Copyright (c) 2012 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.
5 #include "base/win/event_trace_provider.h"
12 TRACE_GUID_REGISTRATION EtwTraceProvider::obligatory_guid_registration_ = {
17 EtwTraceProvider::EtwTraceProvider(const GUID& provider_name)
18 : provider_name_(provider_name), registration_handle_(NULL),
19 session_handle_(NULL), enable_flags_(0), enable_level_(0) {
22 EtwTraceProvider::EtwTraceProvider()
23 : provider_name_(GUID_NULL), registration_handle_(NULL),
24 session_handle_(NULL), enable_flags_(0), enable_level_(0) {
27 EtwTraceProvider::~EtwTraceProvider() {
31 ULONG EtwTraceProvider::EnableEvents(void* buffer) {
32 session_handle_ = ::GetTraceLoggerHandle(buffer);
33 if (NULL == session_handle_) {
34 return ::GetLastError();
37 enable_flags_ = ::GetTraceEnableFlags(session_handle_);
38 enable_level_ = ::GetTraceEnableLevel(session_handle_);
40 // Give subclasses a chance to digest the state change.
46 ULONG EtwTraceProvider::DisableEvents() {
47 // Give subclasses a chance to digest the state change.
52 session_handle_ = NULL;
59 ULONG EtwTraceProvider::Callback(WMIDPREQUESTCODE request, void* buffer) {
61 case WMI_ENABLE_EVENTS:
62 return EnableEvents(buffer);
63 case WMI_DISABLE_EVENTS:
64 return DisableEvents();
66 return ERROR_INVALID_PARAMETER;
71 ULONG WINAPI EtwTraceProvider::ControlCallback(WMIDPREQUESTCODE request,
72 void* context, ULONG *reserved, void* buffer) {
73 EtwTraceProvider *provider = reinterpret_cast<EtwTraceProvider*>(context);
75 return provider->Callback(request, buffer);
78 ULONG EtwTraceProvider::Register() {
79 if (provider_name_ == GUID_NULL)
80 return ERROR_INVALID_NAME;
82 return ::RegisterTraceGuids(ControlCallback, this, &provider_name_,
83 1, &obligatory_guid_registration_, NULL, NULL, ®istration_handle_);
86 ULONG EtwTraceProvider::Unregister() {
87 // If a session is active, notify subclasses that it's going away.
88 if (session_handle_ != NULL)
91 ULONG ret = ::UnregisterTraceGuids(registration_handle_);
93 registration_handle_ = NULL;
98 ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
99 EtwEventType type, EtwEventLevel level, const char *message) {
100 if (NULL == session_handle_ || enable_level_ < level)
101 return ERROR_SUCCESS; // No one listening.
103 EtwMofEvent<1> event(event_class, type, level);
105 event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);
106 event.fields[0].Length = message ?
107 static_cast<ULONG>(sizeof(message[0]) * (1 + strlen(message))) : 0;
109 return ::TraceEvent(session_handle_, &event.header);
112 ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
113 EtwEventType type, EtwEventLevel level, const wchar_t *message) {
114 if (NULL == session_handle_ || enable_level_ < level)
115 return ERROR_SUCCESS; // No one listening.
117 EtwMofEvent<1> event(event_class, type, level);
119 event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);
120 event.fields[0].Length = message ?
121 static_cast<ULONG>(sizeof(message[0]) * (1 + wcslen(message))) : 0;
123 return ::TraceEvent(session_handle_, &event.header);
126 ULONG EtwTraceProvider::Log(EVENT_TRACE_HEADER* event) {
127 if (enable_level_ < event->Class.Level)
128 return ERROR_SUCCESS;
130 return ::TraceEvent(session_handle_, event);