blob: 8fcf67d3d701c1765f99aec66b028829181772d7 [file] [log] [blame]
// Copyright (c) 2012 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/win/event_trace_provider.h"
#include <windows.h>
#include <cguid.h>
namespace base {
namespace win {
TRACE_GUID_REGISTRATION EtwTraceProvider::obligatory_guid_registration_ = {
&GUID_NULL,
NULL
};
EtwTraceProvider::EtwTraceProvider(const GUID& provider_name)
: provider_name_(provider_name), registration_handle_(NULL),
session_handle_(NULL), enable_flags_(0), enable_level_(0) {
}
EtwTraceProvider::EtwTraceProvider()
: provider_name_(GUID_NULL), registration_handle_(NULL),
session_handle_(NULL), enable_flags_(0), enable_level_(0) {
}
EtwTraceProvider::~EtwTraceProvider() {
Unregister();
}
ULONG EtwTraceProvider::EnableEvents(void* buffer) {
session_handle_ = ::GetTraceLoggerHandle(buffer);
if (NULL == session_handle_) {
return ::GetLastError();
}
enable_flags_ = ::GetTraceEnableFlags(session_handle_);
enable_level_ = ::GetTraceEnableLevel(session_handle_);
// Give subclasses a chance to digest the state change.
OnEventsEnabled();
return ERROR_SUCCESS;
}
ULONG EtwTraceProvider::DisableEvents() {
// Give subclasses a chance to digest the state change.
OnEventsDisabled();
enable_level_ = 0;
enable_flags_ = 0;
session_handle_ = NULL;
PostEventsDisabled();
return ERROR_SUCCESS;
}
ULONG EtwTraceProvider::Callback(WMIDPREQUESTCODE request, void* buffer) {
switch (request) {
case WMI_ENABLE_EVENTS:
return EnableEvents(buffer);
case WMI_DISABLE_EVENTS:
return DisableEvents();
default:
return ERROR_INVALID_PARAMETER;
}
// Not reached.
}
ULONG WINAPI EtwTraceProvider::ControlCallback(WMIDPREQUESTCODE request,
void* context, ULONG *reserved, void* buffer) {
EtwTraceProvider *provider = reinterpret_cast<EtwTraceProvider*>(context);
return provider->Callback(request, buffer);
}
ULONG EtwTraceProvider::Register() {
if (provider_name_ == GUID_NULL)
return ERROR_INVALID_NAME;
return ::RegisterTraceGuids(ControlCallback, this, &provider_name_,
1, &obligatory_guid_registration_, NULL, NULL, &registration_handle_);
}
ULONG EtwTraceProvider::Unregister() {
// If a session is active, notify subclasses that it's going away.
if (session_handle_ != NULL)
DisableEvents();
ULONG ret = ::UnregisterTraceGuids(registration_handle_);
registration_handle_ = NULL;
return ret;
}
ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
EtwEventType type, EtwEventLevel level, const char *message) {
if (NULL == session_handle_ || enable_level_ < level)
return ERROR_SUCCESS; // No one listening.
EtwMofEvent<1> event(event_class, type, level);
event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);
event.fields[0].Length = message ?
static_cast<ULONG>(sizeof(message[0]) * (1 + strlen(message))) : 0;
return ::TraceEvent(session_handle_, &event.header);
}
ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
EtwEventType type, EtwEventLevel level, const wchar_t *message) {
if (NULL == session_handle_ || enable_level_ < level)
return ERROR_SUCCESS; // No one listening.
EtwMofEvent<1> event(event_class, type, level);
event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);
event.fields[0].Length = message ?
static_cast<ULONG>(sizeof(message[0]) * (1 + wcslen(message))) : 0;
return ::TraceEvent(session_handle_, &event.header);
}
ULONG EtwTraceProvider::Log(EVENT_TRACE_HEADER* event) {
if (enable_level_ < event->Class.Level)
return ERROR_SUCCESS;
return ::TraceEvent(session_handle_, event);
}
} // namespace win
} // namespace base