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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*****************************
Windows implementation of probes, using xperf
*****************************/
#include <windows.h>
#include <wmistr.h>
#include <evntrace.h>
#include "perfprobe.h"
namespace mozilla {
namespace probes {
#if defined(MOZ_LOGGING)
static LazyLogModule sProbeLog("SysProbe");
# define LOG(x) MOZ_LOG(sProbeLog, mozilla::LogLevel::Debug, x)
#else
# define LOG(x)
#endif
// Utility function
GUID CID_to_GUID(const nsCID& aCID) {
GUID result;
result.Data1 = aCID.m0;
result.Data2 = aCID.m1;
result.Data3 = aCID.m2;
for (int i = 0; i < 8; ++i) {
result.Data4[i] = aCID.m3[i];
}
return result;
}
// Implementation of Probe
Probe::Probe(const nsCID& aGUID, const nsACString& aName,
ProbeManager* aManager)
: mGUID(CID_to_GUID(aGUID)), mName(aName), mManager(aManager) {}
nsresult Probe::Trigger() {
if (!(mManager->mIsActive)) {
// Do not trigger if there is no session
return NS_OK;
}
_EVENT_TRACE_HEADER event;
ZeroMemory(&event, sizeof(event));
event.Size = sizeof(event);
event.Flags = WNODE_FLAG_TRACED_GUID;
event.Guid = (const GUID)mGUID;
event.Class.Type = 1;
event.Class.Version = 0;
event.Class.Level = TRACE_LEVEL_INFORMATION;
ULONG result = TraceEvent(mManager->mSessionHandle, &event);
LOG(("Probes: Triggered %s, %s, %ld", mName.Data(),
result == ERROR_SUCCESS ? "success" : "failure", result));
nsresult rv;
switch (result) {
case ERROR_SUCCESS:
rv = NS_OK;
break;
case ERROR_INVALID_FLAG_NUMBER:
case ERROR_MORE_DATA:
case ERROR_INVALID_PARAMETER:
rv = NS_ERROR_INVALID_ARG;
break;
case ERROR_INVALID_HANDLE:
rv = NS_ERROR_FAILURE;
break;
case ERROR_NOT_ENOUGH_MEMORY:
case ERROR_OUTOFMEMORY:
rv = NS_ERROR_OUT_OF_MEMORY;
break;
default:
rv = NS_ERROR_UNEXPECTED;
}
return rv;
}
// Implementation of ProbeManager
ProbeManager::~ProbeManager() {
// If the manager goes out of scope, stop the session.
if (mIsActive && mRegistrationHandle) {
StopSession();
}
}
ProbeManager::ProbeManager(const nsCID& aApplicationUID,
const nsACString& aApplicationName)
: mIsActive(false),
mApplicationUID(aApplicationUID),
mApplicationName(aApplicationName),
mSessionHandle(0),
mRegistrationHandle(0),
mInitialized(false) {
#if defined(MOZ_LOGGING)
char cidStr[NSID_LENGTH];
aApplicationUID.ToProvidedString(cidStr);
LOG(("ProbeManager::Init for application %s, %s", aApplicationName.Data(),
cidStr));
#endif
}
// Note: The Windows API is just a little bit scary there.
// The only way to obtain the session handle is to
//- ignore the session handle obtained from RegisterTraceGuids
//- pass a callback
//- in that callback, request the session handle through
// GetTraceLoggerHandle and some opaque value received by the callback
ULONG WINAPI ControlCallback(WMIDPREQUESTCODE aRequestCode, PVOID aContext,
ULONG* aReserved, PVOID aBuffer) {
ProbeManager* context = (ProbeManager*)aContext;
switch (aRequestCode) {
case WMI_ENABLE_EVENTS: {
context->mIsActive = true;
TRACEHANDLE sessionHandle = GetTraceLoggerHandle(aBuffer);
// Note: We only accept one handle
if ((HANDLE)sessionHandle == INVALID_HANDLE_VALUE) {
ULONG result = GetLastError();
LOG(("Probes: ControlCallback failed, %lu", result));
return result;
} else if (context->mIsActive && context->mSessionHandle &&
context->mSessionHandle != sessionHandle) {
LOG(
("Probes: Can only handle one context at a time, "
"ignoring activation"));
return ERROR_SUCCESS;
} else {
context->mSessionHandle = sessionHandle;
LOG(("Probes: ControlCallback activated"));
return ERROR_SUCCESS;
}
}
case WMI_DISABLE_EVENTS:
context->mIsActive = false;
context->mSessionHandle = 0;
LOG(("Probes: ControlCallback deactivated"));
return ERROR_SUCCESS;
default:
LOG(("Probes: ControlCallback does not know what to do with %d",
aRequestCode));
return ERROR_INVALID_PARAMETER;
}
}
already_AddRefed<Probe> ProbeManager::GetProbe(const nsCID& aEventUID,
const nsACString& aEventName) {
RefPtr<Probe> result(new Probe(aEventUID, aEventName, this));
mAllProbes.AppendElement(result);
return result.forget();
}
nsresult ProbeManager::StartSession() { return StartSession(mAllProbes); }
nsresult ProbeManager::StartSession(nsTArray<RefPtr<Probe>>& aProbes) {
const size_t probesCount = aProbes.Length();
_TRACE_GUID_REGISTRATION* probes = new _TRACE_GUID_REGISTRATION[probesCount];
for (unsigned int i = 0; i < probesCount; ++i) {
const Probe* probe = aProbes[i];
const Probe* probeX = static_cast<const Probe*>(probe);
probes[i].Guid = (LPCGUID)&probeX->mGUID;
}
ULONG result =
RegisterTraceGuids(&ControlCallback
/*RequestAddress: Sets mSessions appropriately.*/,
this
/*RequestContext: Passed to ControlCallback*/,
(LPGUID)&mApplicationUID
/*ControlGuid: Tracing GUID
the cast comes from MSDN examples*/
,
probesCount
/*GuidCount: Number of probes*/,
probes
/*TraceGuidReg: Probes registration*/,
nullptr
/*MofImagePath: Must be nullptr, says MSDN*/,
nullptr
/*MofResourceName:Must be nullptr, says MSDN*/,
&mRegistrationHandle
/*RegistrationHandle: Handler.
used only for unregistration*/
);
delete[] probes;
if (NS_WARN_IF(result != ERROR_SUCCESS)) {
return NS_ERROR_UNEXPECTED;
}
return NS_OK;
}
nsresult ProbeManager::StopSession() {
LOG(("Probes: Stopping measures"));
if (mSessionHandle != 0) {
ULONG result = UnregisterTraceGuids(mSessionHandle);
mSessionHandle = 0;
if (result != ERROR_SUCCESS) {
return NS_ERROR_INVALID_ARG;
}
}
return NS_OK;
}
} // namespace probes
} // namespace mozilla