michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: //
michael@0: #include "base/win/event_trace_provider.h"
michael@0: #include <windows.h>
michael@0: #include <cguid.h>
michael@0: 
michael@0: namespace base {
michael@0: namespace win {
michael@0: 
michael@0: TRACE_GUID_REGISTRATION EtwTraceProvider::obligatory_guid_registration_ = {
michael@0:   &GUID_NULL,
michael@0:   NULL
michael@0: };
michael@0: 
michael@0: EtwTraceProvider::EtwTraceProvider(const GUID& provider_name)
michael@0:     : provider_name_(provider_name), registration_handle_(NULL),
michael@0:       session_handle_(NULL), enable_flags_(0), enable_level_(0) {
michael@0: }
michael@0: 
michael@0: EtwTraceProvider::EtwTraceProvider()
michael@0:     : provider_name_(GUID_NULL), registration_handle_(NULL),
michael@0:       session_handle_(NULL), enable_flags_(0), enable_level_(0) {
michael@0: }
michael@0: 
michael@0: EtwTraceProvider::~EtwTraceProvider() {
michael@0:   Unregister();
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::EnableEvents(void* buffer) {
michael@0:   session_handle_ = ::GetTraceLoggerHandle(buffer);
michael@0:   if (NULL == session_handle_) {
michael@0:     return ::GetLastError();
michael@0:   }
michael@0: 
michael@0:   enable_flags_ = ::GetTraceEnableFlags(session_handle_);
michael@0:   enable_level_ = ::GetTraceEnableLevel(session_handle_);
michael@0: 
michael@0:   // Give subclasses a chance to digest the state change.
michael@0:   OnEventsEnabled();
michael@0: 
michael@0:   return ERROR_SUCCESS;
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::DisableEvents() {
michael@0:   // Give subclasses a chance to digest the state change.
michael@0:   OnEventsDisabled();
michael@0: 
michael@0:   enable_level_ = 0;
michael@0:   enable_flags_ = 0;
michael@0:   session_handle_ = NULL;
michael@0: 
michael@0:   PostEventsDisabled();
michael@0: 
michael@0:   return ERROR_SUCCESS;
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::Callback(WMIDPREQUESTCODE request, void* buffer) {
michael@0:   switch (request) {
michael@0:     case WMI_ENABLE_EVENTS:
michael@0:       return EnableEvents(buffer);
michael@0:     case WMI_DISABLE_EVENTS:
michael@0:       return DisableEvents();
michael@0:     default:
michael@0:       return ERROR_INVALID_PARAMETER;
michael@0:   }
michael@0:   // Not reached.
michael@0: }
michael@0: 
michael@0: ULONG WINAPI EtwTraceProvider::ControlCallback(WMIDPREQUESTCODE request,
michael@0:     void* context, ULONG *reserved, void* buffer) {
michael@0:   EtwTraceProvider *provider = reinterpret_cast<EtwTraceProvider*>(context);
michael@0: 
michael@0:   return provider->Callback(request, buffer);
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::Register() {
michael@0:   if (provider_name_ == GUID_NULL)
michael@0:     return ERROR_INVALID_NAME;
michael@0: 
michael@0:   return ::RegisterTraceGuids(ControlCallback, this, &provider_name_,
michael@0:       1, &obligatory_guid_registration_, NULL, NULL, &registration_handle_);
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::Unregister() {
michael@0:   // If a session is active, notify subclasses that it's going away.
michael@0:   if (session_handle_ != NULL)
michael@0:     DisableEvents();
michael@0: 
michael@0:   ULONG ret = ::UnregisterTraceGuids(registration_handle_);
michael@0: 
michael@0:   registration_handle_ = NULL;
michael@0: 
michael@0:   return ret;
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
michael@0:     EtwEventType type, EtwEventLevel level, const char *message) {
michael@0:   if (NULL == session_handle_ || enable_level_ < level)
michael@0:     return ERROR_SUCCESS;  // No one listening.
michael@0: 
michael@0:   EtwMofEvent<1> event(event_class, type, level);
michael@0: 
michael@0:   event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);
michael@0:   event.fields[0].Length = message ?
michael@0:       static_cast<ULONG>(sizeof(message[0]) * (1 + strlen(message))) : 0;
michael@0: 
michael@0:   return ::TraceEvent(session_handle_, &event.header);
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
michael@0:     EtwEventType type, EtwEventLevel level, const wchar_t *message) {
michael@0:   if (NULL == session_handle_ || enable_level_ < level)
michael@0:     return ERROR_SUCCESS;  // No one listening.
michael@0: 
michael@0:   EtwMofEvent<1> event(event_class, type, level);
michael@0: 
michael@0:   event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);
michael@0:   event.fields[0].Length = message ?
michael@0:       static_cast<ULONG>(sizeof(message[0]) * (1 + wcslen(message))) : 0;
michael@0: 
michael@0:   return ::TraceEvent(session_handle_, &event.header);
michael@0: }
michael@0: 
michael@0: ULONG EtwTraceProvider::Log(EVENT_TRACE_HEADER* event) {
michael@0:   if (enable_level_ < event->Class.Level)
michael@0:     return ERROR_SUCCESS;
michael@0: 
michael@0:   return ::TraceEvent(session_handle_, event);
michael@0: }
michael@0: 
michael@0: }  // namespace win
michael@0: }  // namespace base