gecko-dev/xpcom/build/perfprobe.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
/* 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* 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 "prlog.h"
#include "nsTArray.h"
#include "nsAutoPtr.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();
~Probe() {};
protected:
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 uid The unique ID of the probe. Under Windows, this unique
* ID must have been previously registered using an external tool.
* See MyCategory on http://msdn.microsoft.com/en-us/library/aa364100.aspx
* @param name 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 &applicationUID,
const nsACString &applicationName);
/**
* 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 eventUID The unique ID of the probe. Under Windows, this unique
* ID must have been previously registered using an external tool.
* See MyCategory on http://msdn.microsoft.com/en-us/library/aa364100.aspx
* @param eventMame 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 &eventUID,
const nsACString &eventName);
/**
* 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();
~ProbeManager();
protected:
nsresult StartSession(nsTArray<nsRefPtr<Probe> > &probes);
nsresult Init(const nsCID &applicationUID, const nsACString &applicationName);
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<nsRefPtr<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 RequestCode,
PVOID Context,
ULONG *Reserved,
PVOID Buffer
);//Sets |mSessionHandle|
};
}
}
#endif //mozilla_perfprobe_h