gecko/xpcom/glue/nsThreadUtils.h
Ehsan Akhgari b6e35bb4b4 Bug 1118486 - Part 1: Use = delete instead of MOZ_DELETE directly; r=Waldo
Most of this patch (with the exception of dom/bindings/Codegen.py) was
generated by the following bash script:

#!/bin/bash

function convert() {
echo "Converting $1 to $2..."
find . ! -wholename "*nsprpub*" \
       ! -wholename "*security/nss*" \
       ! -wholename "*/.hg*" \
       ! -wholename "*/.git*" \
       ! -wholename "obj-*" \
         -type f \
      \( -iname "*.cpp" \
         -o -iname "*.h" \
         -o -iname "*.cc" \
         -o -iname "*.idl" \
         -o -iname "*.ipdl" \
         -o -iname "*.ipdlh" \
         -o -iname "*.mm" \) | \
    xargs -n 1 sed -i -e "s/\b$1\b/$2/g"
}

convert MOZ_DELETE '= delete'
2015-01-08 23:19:05 -05:00

582 lines
15 KiB
C++

/* -*- 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsThreadUtils_h__
#define nsThreadUtils_h__
#include "prthread.h"
#include "prinrval.h"
#include "MainThreadUtils.h"
#include "nsIThreadManager.h"
#include "nsIThread.h"
#include "nsIRunnable.h"
#include "nsICancelableRunnable.h"
#include "nsStringGlue.h"
#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "mozilla/Likely.h"
//-----------------------------------------------------------------------------
// These methods are alternatives to the methods on nsIThreadManager, provided
// for convenience.
/**
* Set name of the target thread. This operation is asynchronous.
*/
extern void NS_SetThreadName(nsIThread* aThread, const nsACString& aName);
/**
* Static length version of the above function checking length of the
* name at compile time.
*/
template<size_t LEN>
inline void
NS_SetThreadName(nsIThread* aThread, const char (&aName)[LEN])
{
static_assert(LEN <= 16,
"Thread name must be no more than 16 characters");
NS_SetThreadName(aThread, nsDependentCString(aName));
}
/**
* Create a new thread, and optionally provide an initial event for the thread.
*
* @param aResult
* The resulting nsIThread object.
* @param aInitialEvent
* The initial event to run on this thread. This parameter may be null.
* @param aStackSize
* The size in bytes to reserve for the thread's stack.
*
* @returns NS_ERROR_INVALID_ARG
* Indicates that the given name is not unique.
*/
extern NS_METHOD
NS_NewThread(nsIThread** aResult,
nsIRunnable* aInitialEvent = nullptr,
uint32_t aStackSize = nsIThreadManager::DEFAULT_STACK_SIZE);
/**
* Creates a named thread, otherwise the same as NS_NewThread
*/
template<size_t LEN>
inline NS_METHOD
NS_NewNamedThread(const char (&aName)[LEN],
nsIThread** aResult,
nsIRunnable* aInitialEvent = nullptr,
uint32_t aStackSize = nsIThreadManager::DEFAULT_STACK_SIZE)
{
// Hold a ref while dispatching the initial event to match NS_NewThread()
nsCOMPtr<nsIThread> thread;
nsresult rv = NS_NewThread(getter_AddRefs(thread), nullptr, aStackSize);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
NS_SetThreadName<LEN>(thread, aName);
if (aInitialEvent) {
rv = thread->Dispatch(aInitialEvent, NS_DISPATCH_NORMAL);
NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "Initial event dispatch failed");
}
*aResult = nullptr;
thread.swap(*aResult);
return rv;
}
/**
* Get a reference to the current thread.
*
* @param aResult
* The resulting nsIThread object.
*/
extern NS_METHOD NS_GetCurrentThread(nsIThread** aResult);
/**
* Dispatch the given event to the current thread.
*
* @param aEvent
* The event to dispatch.
*
* @returns NS_ERROR_INVALID_ARG
* If event is null.
*/
extern NS_METHOD NS_DispatchToCurrentThread(nsIRunnable* aEvent);
/**
* Dispatch the given event to the main thread.
*
* @param aEvent
* The event to dispatch.
* @param aDispatchFlags
* The flags to pass to the main thread's dispatch method.
*
* @returns NS_ERROR_INVALID_ARG
* If event is null.
*/
extern NS_METHOD
NS_DispatchToMainThread(nsIRunnable* aEvent,
uint32_t aDispatchFlags = NS_DISPATCH_NORMAL);
#ifndef XPCOM_GLUE_AVOID_NSPR
/**
* Process all pending events for the given thread before returning. This
* method simply calls ProcessNextEvent on the thread while HasPendingEvents
* continues to return true and the time spent in NS_ProcessPendingEvents
* does not exceed the given timeout value.
*
* @param aThread
* The thread object for which to process pending events. If null, then
* events will be processed for the current thread.
* @param aTimeout
* The maximum number of milliseconds to spend processing pending events.
* Events are not pre-empted to honor this timeout. Rather, the timeout
* value is simply used to determine whether or not to process another event.
* Pass PR_INTERVAL_NO_TIMEOUT to specify no timeout.
*/
extern NS_METHOD
NS_ProcessPendingEvents(nsIThread* aThread,
PRIntervalTime aTimeout = PR_INTERVAL_NO_TIMEOUT);
#endif
/**
* Shortcut for nsIThread::HasPendingEvents.
*
* It is an error to call this function when the given thread is not the
* current thread. This function will return false if called from some
* other thread.
*
* @param aThread
* The current thread or null.
*
* @returns
* A boolean value that if "true" indicates that there are pending events
* in the current thread's event queue.
*/
extern bool NS_HasPendingEvents(nsIThread* aThread = nullptr);
/**
* Shortcut for nsIThread::ProcessNextEvent.
*
* It is an error to call this function when the given thread is not the
* current thread. This function will simply return false if called
* from some other thread.
*
* @param aThread
* The current thread or null.
* @param aMayWait
* A boolean parameter that if "true" indicates that the method may block
* the calling thread to wait for a pending event.
*
* @returns
* A boolean value that if "true" indicates that an event from the current
* thread's event queue was processed.
*/
extern bool NS_ProcessNextEvent(nsIThread* aThread = nullptr,
bool aMayWait = true);
//-----------------------------------------------------------------------------
// Helpers that work with nsCOMPtr:
inline already_AddRefed<nsIThread>
do_GetCurrentThread()
{
nsIThread* thread = nullptr;
NS_GetCurrentThread(&thread);
return already_AddRefed<nsIThread>(thread);
}
inline already_AddRefed<nsIThread>
do_GetMainThread()
{
nsIThread* thread = nullptr;
NS_GetMainThread(&thread);
return already_AddRefed<nsIThread>(thread);
}
//-----------------------------------------------------------------------------
#ifdef MOZILLA_INTERNAL_API
// Fast access to the current thread. Do not release the returned pointer! If
// you want to use this pointer from some other thread, then you will need to
// AddRef it. Otherwise, you should only consider this pointer valid from code
// running on the current thread.
extern nsIThread* NS_GetCurrentThread();
#endif
//-----------------------------------------------------------------------------
#ifndef XPCOM_GLUE_AVOID_NSPR
// This class is designed to be subclassed.
class nsRunnable : public nsIRunnable
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIRUNNABLE
nsRunnable() {}
protected:
virtual ~nsRunnable() {}
};
// This class is designed to be subclassed.
class nsCancelableRunnable : public nsICancelableRunnable
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIRUNNABLE
NS_DECL_NSICANCELABLERUNNABLE
nsCancelableRunnable() {}
protected:
virtual ~nsCancelableRunnable() {}
};
// An event that can be used to call a method on a class. The class type must
// support reference counting. This event supports Revoke for use
// with nsRevocableEventPtr.
template<class ClassType,
typename ReturnType = void,
bool Owning = true>
class nsRunnableMethod : public nsRunnable
{
public:
virtual void Revoke() = 0;
// These ReturnTypeEnforcer classes set up a blacklist for return types that
// we know are not safe. The default ReturnTypeEnforcer compiles just fine but
// already_AddRefed will not.
template<typename OtherReturnType>
class ReturnTypeEnforcer
{
public:
typedef int ReturnTypeIsSafe;
};
template<class T>
class ReturnTypeEnforcer<already_AddRefed<T>>
{
// No ReturnTypeIsSafe makes this illegal!
};
// Make sure this return type is safe.
typedef typename ReturnTypeEnforcer<ReturnType>::ReturnTypeIsSafe check;
};
template<class ClassType, typename Arg, bool Owning>
struct nsRunnableMethodReceiver
{
nsRefPtr<ClassType> mObj;
Arg mArg;
nsRunnableMethodReceiver(ClassType* aObj, Arg aArg)
: mObj(aObj)
, mArg(aArg)
{
}
~nsRunnableMethodReceiver() { Revoke(); }
void Revoke() { mObj = nullptr; }
};
template<class ClassType, bool Owning>
struct nsRunnableMethodReceiver<ClassType, void, Owning>
{
nsRefPtr<ClassType> mObj;
explicit nsRunnableMethodReceiver(ClassType* aObj)
: mObj(aObj)
{
}
~nsRunnableMethodReceiver() { Revoke(); }
void Revoke() { mObj = nullptr; }
};
template<class ClassType>
struct nsRunnableMethodReceiver<ClassType, void, false>
{
ClassType* MOZ_NON_OWNING_REF mObj;
explicit nsRunnableMethodReceiver(ClassType* aObj) : mObj(aObj) {}
void Revoke() { mObj = nullptr; }
};
template<typename Method, bool Owning> struct nsRunnableMethodTraits;
template<class C, typename R, typename A, bool Owning>
struct nsRunnableMethodTraits<R(C::*)(A), Owning>
{
typedef C class_type;
typedef R return_type;
typedef A arg_type;
typedef nsRunnableMethod<C, R, Owning> base_type;
};
template<class C, typename R, bool Owning>
struct nsRunnableMethodTraits<R(C::*)(), Owning>
{
typedef C class_type;
typedef R return_type;
typedef void arg_type;
typedef nsRunnableMethod<C, R, Owning> base_type;
};
#ifdef NS_HAVE_STDCALL
template<class C, typename R, typename A, bool Owning>
struct nsRunnableMethodTraits<R(__stdcall C::*)(A), Owning>
{
typedef C class_type;
typedef R return_type;
typedef A arg_type;
typedef nsRunnableMethod<C, R, Owning> base_type;
};
template<class C, typename R, bool Owning>
struct nsRunnableMethodTraits<R(NS_STDCALL C::*)(), Owning>
{
typedef C class_type;
typedef R return_type;
typedef void arg_type;
typedef nsRunnableMethod<C, R, Owning> base_type;
};
#endif
template<typename Method, typename Arg, bool Owning>
class nsRunnableMethodImpl
: public nsRunnableMethodTraits<Method, Owning>::base_type
{
typedef typename nsRunnableMethodTraits<Method, Owning>::class_type ClassType;
nsRunnableMethodReceiver<ClassType, Arg, Owning> mReceiver;
Method mMethod;
public:
nsRunnableMethodImpl(ClassType* aObj, Method aMethod, Arg aArg)
: mReceiver(aObj, aArg)
, mMethod(aMethod)
{
}
NS_IMETHOD Run()
{
if (MOZ_LIKELY(mReceiver.mObj)) {
((*mReceiver.mObj).*mMethod)(mReceiver.mArg);
}
return NS_OK;
}
void Revoke() { mReceiver.Revoke(); }
};
template<typename Method, bool Owning>
class nsRunnableMethodImpl<Method, void, Owning>
: public nsRunnableMethodTraits<Method, Owning>::base_type
{
typedef typename nsRunnableMethodTraits<Method, Owning>::class_type ClassType;
nsRunnableMethodReceiver<ClassType, void, Owning> mReceiver;
Method mMethod;
public:
nsRunnableMethodImpl(ClassType* aObj, Method aMethod)
: mReceiver(aObj)
, mMethod(aMethod)
{
}
NS_IMETHOD Run()
{
if (MOZ_LIKELY(mReceiver.mObj)) {
((*mReceiver.mObj).*mMethod)();
}
return NS_OK;
}
void Revoke() { mReceiver.Revoke(); }
};
// Use this template function like so:
//
// nsCOMPtr<nsIRunnable> event =
// NS_NewRunnableMethod(myObject, &MyClass::HandleEvent);
// NS_DispatchToCurrentThread(event);
//
// Statically enforced constraints:
// - myObject must be of (or implicitly convertible to) type MyClass
// - MyClass must defined AddRef and Release methods
//
template<typename PtrType, typename Method>
typename nsRunnableMethodTraits<Method, true>::base_type*
NS_NewRunnableMethod(PtrType aPtr, Method aMethod)
{
return new nsRunnableMethodImpl<Method, void, true>(aPtr, aMethod);
}
template<typename T>
struct dependent_type
{
typedef T type;
};
// Similar to NS_NewRunnableMethod. Call like so:
// Type myArg;
// nsCOMPtr<nsIRunnable> event =
// NS_NewRunnableMethodWithArg<Type>(myObject, &MyClass::HandleEvent, myArg);
template<typename Arg, typename Method, typename PtrType>
typename nsRunnableMethodTraits<Method, true>::base_type*
NS_NewRunnableMethodWithArg(PtrType&& aPtr, Method aMethod,
typename dependent_type<Arg>::type aArg)
{
return new nsRunnableMethodImpl<Method, Arg, true>(aPtr, aMethod, aArg);
}
template<typename PtrType, typename Method>
typename nsRunnableMethodTraits<Method, false>::base_type*
NS_NewNonOwningRunnableMethod(PtrType&& aPtr, Method aMethod)
{
return new nsRunnableMethodImpl<Method, void, false>(aPtr, aMethod);
}
#endif // XPCOM_GLUE_AVOID_NSPR
// This class is designed to be used when you have an event class E that has a
// pointer back to resource class R. If R goes away while E is still pending,
// then it is important to "revoke" E so that it does not try use R after R has
// been destroyed. nsRevocableEventPtr makes it easy for R to manage such
// situations:
//
// class R;
//
// class E : public nsRunnable {
// public:
// void Revoke() {
// mResource = nullptr;
// }
// private:
// R *mResource;
// };
//
// class R {
// public:
// void EventHandled() {
// mEvent.Forget();
// }
// private:
// nsRevocableEventPtr<E> mEvent;
// };
//
// void R::PostEvent() {
// // Make sure any pending event is revoked.
// mEvent->Revoke();
//
// nsCOMPtr<nsIRunnable> event = new E();
// if (NS_SUCCEEDED(NS_DispatchToCurrentThread(event))) {
// // Keep pointer to event so we can revoke it.
// mEvent = event;
// }
// }
//
// NS_IMETHODIMP E::Run() {
// if (!mResource)
// return NS_OK;
// ...
// mResource->EventHandled();
// return NS_OK;
// }
//
template<class T>
class nsRevocableEventPtr
{
public:
nsRevocableEventPtr() : mEvent(nullptr) {}
~nsRevocableEventPtr() { Revoke(); }
const nsRevocableEventPtr& operator=(T* aEvent)
{
if (mEvent != aEvent) {
Revoke();
mEvent = aEvent;
}
return *this;
}
void Revoke()
{
if (mEvent) {
mEvent->Revoke();
mEvent = nullptr;
}
}
void Forget() { mEvent = nullptr; }
bool IsPending() { return mEvent != nullptr; }
T* get() { return mEvent; }
private:
// Not implemented
nsRevocableEventPtr(const nsRevocableEventPtr&);
nsRevocableEventPtr& operator=(const nsRevocableEventPtr&);
nsRefPtr<T> mEvent;
};
/**
* A simple helper to suffix thread pool name
* with incremental numbers.
*/
class nsThreadPoolNaming
{
public:
nsThreadPoolNaming() : mCounter(0) {}
/**
* Creates and sets next thread name as "<aPoolName> #<n>"
* on the specified thread. If no thread is specified (aThread
* is null) then the name is synchronously set on the current thread.
*/
void SetThreadPoolName(const nsACString& aPoolName,
nsIThread* aThread = nullptr);
private:
volatile uint32_t mCounter;
nsThreadPoolNaming(const nsThreadPoolNaming&) = delete;
void operator=(const nsThreadPoolNaming&) = delete;
};
/**
* Thread priority in most operating systems affect scheduling, not IO. This
* helper is used to set the current thread to low IO priority for the lifetime
* of the created object. You can only use this low priority IO setting within
* the context of the current thread.
*/
class MOZ_STACK_CLASS nsAutoLowPriorityIO
{
public:
nsAutoLowPriorityIO();
~nsAutoLowPriorityIO();
private:
bool lowIOPrioritySet;
#if defined(XP_MACOSX)
int oldPriority;
#endif
};
void
NS_SetMainThread();
/**
* Helpers for thread to report their status when compiled with Nuwa.
*/
#ifdef MOZILLA_INTERNAL_API
#ifdef MOZ_NUWA_PROCESS
extern void
NS_SetIgnoreStatusOfCurrentThread();
#else // MOZ_NUWA_PROCESS
inline void
NS_SetIgnoreStatusOfCurrentThread()
{
}
#endif // MOZ_NUWA_PROCESS
#endif // MOZILLA_INTERNAL_API
#endif // nsThreadUtils_h__