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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
/**
* A mechanism for interacting with operating system-provided
* debugging/profiling tools such as Microsoft EWT/Windows Performance Toolkit.
*/
#ifndef mozilla_perfprobe_h
#define mozilla_perfprobe_h
#if !defined(XP_WIN)
# error "For the moment, perfprobe.h is defined only for Windows platforms"
#endif
#include "nsError.h"
#include "nsString.h"
#include "mozilla/Logging.h"
#include "nsTArray.h"
#include <windows.h>
#undef GetStartupInfo // Prevent Windows from polluting global namespace
#include <wmistr.h>
#include <evntrace.h>
namespace mozilla {
namespace probes {
class ProbeManager;
/**
* A data structure supporting a trigger operation that can be used to
* send information to the operating system.
*/
class Probe {
public:
NS_INLINE_DECL_REFCOUNTING(Probe)
/**
* Trigger the event.
*
* Note: Can be called from any thread.
*/
nsresult Trigger();
protected:
~Probe(){};
Probe(const nsCID& aGUID, const nsACString& aName, ProbeManager* aManager);
friend class ProbeManager;
protected:
/**
* The system GUID associated to this probe. See the documentation
* of |ProbeManager::Make| for more details.
*/
const GUID mGUID;
/**
* The name of this probe. See the documentation
* of |ProbeManager::Make| for more details.
*/
const nsCString mName;
/**
* The ProbeManager managing this probe.
*
* Note: This is a weak reference to avoid a useless cycle.
*/
class ProbeManager* mManager;
};
/**
* A manager for a group of probes.
*
* You can have several managers in one application, provided that they all
* have distinct IDs and names. However, having more than 2 is considered a bad
* practice.
*/
class ProbeManager {
public:
NS_INLINE_DECL_REFCOUNTING(ProbeManager)
/**
* Create a new probe manager.
*
* This constructor should be called from the main thread.
*
* @param aApplicationUID The unique ID of the probe. Under Windows, this
* unique ID must have been previously registered using an external tool.
* @param aApplicationName A name for the probe. Currently used only for
* logging purposes. In the future, may be attached to the data sent to the
* operating system.
*
* Note: If two ProbeManagers are constructed with the same uid and/or name,
* behavior is unspecified.
*/
ProbeManager(const nsCID& aApplicationUID,
const nsACString& aApplicationName);
/**
* Acquire a probe.
*
* Note: Only probes acquired before the call to SetReady are taken into
* account
* Note: Can be called only from the main thread.
*
* @param aEventUID The unique ID of the probe. Under Windows, this unique
* ID must have been previously registered using an external tool.
* @param aEventName A name for the probe. Currently used only for logging
* purposes. In the
* future, may be attached to the data sent to the operating system.
* @return Either |null| in case of error or a valid |Probe*|.
*
* Note: If this method is called twice with the same uid and/or name,
* behavior is undefined.
*/
already_AddRefed<Probe> GetProbe(const nsCID& aEventUID,
const nsACString& aEventName);
/**
* Start/stop the measuring session.
*
* This method should be called from the main thread.
*
* Note that starting an already started probe manager has no effect,
* nor does stopping an already stopped probe manager.
*/
nsresult StartSession();
nsresult StopSession();
/**
* @return true If measures are currently on, i.e. if triggering probes is any
* is useful. You do not have to check this before triggering a probe, unless
* this can avoid complex computations.
*/
bool IsActive();
protected:
~ProbeManager();
nsresult StartSession(nsTArray<RefPtr<Probe>>& aProbes);
nsresult Init(const nsCID& aApplicationUID,
const nsACString& aApplicationName);
protected:
/**
* `true` if a session is in activity, `false` otherwise.
*/
bool mIsActive;
/**
* The UID of this manager.
* See documentation above for registration steps that you
* may have to take.
*/
nsCID mApplicationUID;
/**
* The name of the application.
*/
nsCString mApplicationName;
/**
* All the probes that have been created for this manager.
*/
nsTArray<RefPtr<Probe>> mAllProbes;
/**
* Handle used for triggering events
*/
TRACEHANDLE mSessionHandle;
/**
* Handle used for registration/unregistration
*/
TRACEHANDLE mRegistrationHandle;
/**
* `true` if initialization has been performed, `false` until then.
*/
bool mInitialized;
friend class Probe; // Needs to access |mSessionHandle|
friend ULONG WINAPI ControlCallback(WMIDPREQUESTCODE aRequestCode,
PVOID aContext, ULONG* aReserved,
PVOID aBuffer); // Sets |mSessionHandle|
};
} // namespace probes
} // namespace mozilla
#endif // mozilla_perfprobe_h