1 // Copyright (c) 2009 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.
4 //
5 #include "base/win/event_trace_provider.h"
6 #include <windows.h>
7 #include <cguid.h>
8
9 namespace base {
10 namespace win {
11
12 TRACE_GUID_REGISTRATION EtwTraceProvider::obligatory_guid_registration_ = {
13 &GUID_NULL,
14 NULL
15 };
16
EtwTraceProvider(const GUID & provider_name)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) {
20 }
21
EtwTraceProvider()22 EtwTraceProvider::EtwTraceProvider()
23 : provider_name_(GUID_NULL), registration_handle_(NULL),
24 session_handle_(NULL), enable_flags_(0), enable_level_(0) {
25 }
26
~EtwTraceProvider()27 EtwTraceProvider::~EtwTraceProvider() {
28 Unregister();
29 }
30
EnableEvents(void * buffer)31 ULONG EtwTraceProvider::EnableEvents(void* buffer) {
32 session_handle_ = ::GetTraceLoggerHandle(buffer);
33 if (NULL == session_handle_) {
34 return ::GetLastError();
35 }
36
37 enable_flags_ = ::GetTraceEnableFlags(session_handle_);
38 enable_level_ = ::GetTraceEnableLevel(session_handle_);
39
40 // Give subclasses a chance to digest the state change.
41 OnEventsEnabled();
42
43 return ERROR_SUCCESS;
44 }
45
DisableEvents()46 ULONG EtwTraceProvider::DisableEvents() {
47 // Give subclasses a chance to digest the state change.
48 OnEventsDisabled();
49
50 enable_level_ = 0;
51 enable_flags_ = 0;
52 session_handle_ = NULL;
53
54 PostEventsDisabled();
55
56 return ERROR_SUCCESS;
57 }
58
Callback(WMIDPREQUESTCODE request,void * buffer)59 ULONG EtwTraceProvider::Callback(WMIDPREQUESTCODE request, void* buffer) {
60 switch (request) {
61 case WMI_ENABLE_EVENTS:
62 return EnableEvents(buffer);
63 case WMI_DISABLE_EVENTS:
64 return DisableEvents();
65 default:
66 return ERROR_INVALID_PARAMETER;
67 }
68 // Not reached.
69 }
70
ControlCallback(WMIDPREQUESTCODE request,void * context,ULONG * reserved,void * buffer)71 ULONG WINAPI EtwTraceProvider::ControlCallback(WMIDPREQUESTCODE request,
72 void* context, ULONG *reserved, void* buffer) {
73 EtwTraceProvider *provider = reinterpret_cast<EtwTraceProvider*>(context);
74
75 return provider->Callback(request, buffer);
76 }
77
Register()78 ULONG EtwTraceProvider::Register() {
79 if (provider_name_ == GUID_NULL)
80 return ERROR_INVALID_NAME;
81
82 return ::RegisterTraceGuids(ControlCallback, this, &provider_name_,
83 1, &obligatory_guid_registration_, NULL, NULL, ®istration_handle_);
84 }
85
Unregister()86 ULONG EtwTraceProvider::Unregister() {
87 ULONG ret = ::UnregisterTraceGuids(registration_handle_);
88
89 // Make sure we don't log anything from here on.
90 enable_level_ = 0;
91 enable_flags_ = 0;
92 session_handle_ = NULL;
93 registration_handle_ = NULL;
94
95 return ret;
96 }
97
Log(const EtwEventClass & event_class,EtwEventType type,EtwEventLevel level,const char * message)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.
102
103 EtwMofEvent<1> event(event_class, type, level);
104
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;
108
109 return ::TraceEvent(session_handle_, &event.header);
110 }
111
Log(const EtwEventClass & event_class,EtwEventType type,EtwEventLevel level,const wchar_t * message)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.
116
117 EtwMofEvent<1> event(event_class, type, level);
118
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;
122
123 return ::TraceEvent(session_handle_, &event.header);
124 }
125
Log(EVENT_TRACE_HEADER * event)126 ULONG EtwTraceProvider::Log(EVENT_TRACE_HEADER* event) {
127 if (enable_level_ < event->Class.Level)
128 return ERROR_SUCCESS;
129
130 return ::TraceEvent(session_handle_, event);
131 }
132
133 } // namespace win
134 } // namespace base
135