pjs/xpcom/proxy/public/nsProxyRelease.h

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/* -*- Mode: C++; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 3 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Netscape Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the NPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef nsProxyRelease_h_
#define nsProxyRelease_h__
#include "nsIEventQueueService.h"
#include "pratom.h"
#include "prmem.h"
// Ensures that the delete of a nsISupports object occurs on the main thread.
static NS_DEFINE_CID(kEventQueueServiceCID, NS_EVENTQUEUESERVICE_CID);
static void* PR_CALLBACK
ReleaseDestructorEventHandler(PLEvent *self)
{
nsISupports* owner = (nsISupports*) PL_GetEventOwner(self);
NS_RELEASE(owner);
return nsnull;
}
static void PR_CALLBACK
ReleaseDestructorDestroyHandler(PLEvent *self)
{
delete self;
}
static void
NS_ProxyRelease(nsIEventQueue *eventQ, nsISupports *doomed, PRBool alwaysProxy=PR_FALSE)
{
if (!doomed)
return;
if (!eventQ) {
NS_RELEASE(doomed);
return;
}
if (!alwaysProxy) {
PRBool onCurrentThread = PR_FALSE;
eventQ->IsQueueOnCurrentThread(&onCurrentThread);
if (onCurrentThread) {
NS_RELEASE(doomed);
return;
}
}
PLEvent *ev = new PLEvent;
if (!ev) {
NS_ERROR("failed to allocate PLEvent");
// we do not release doomed here since it may cause a delete on the the
// wrong thread. better to leak than crash.
return;
}
PL_InitEvent(ev,
(void *) doomed,
ReleaseDestructorEventHandler,
ReleaseDestructorDestroyHandler);
PRStatus rv = eventQ->PostEvent(ev);
NS_ASSERTION(rv == PR_SUCCESS, "PostEvent failed");
}
#define NS_IMPL_PROXY_RELEASE(_class) \
NS_IMETHODIMP_(nsrefcnt) _class::Release(void) \
{ \
NS_PRECONDITION(0 != mRefCnt, "dup release"); \
nsrefcnt count = PR_AtomicDecrement((PRInt32 *)&mRefCnt); \
NS_LOG_RELEASE(this, count, #_class); \
\
if (count == 0) \
{ \
mRefCnt = 1; /* stabilize */ \
PRBool callDirectly = PR_TRUE; \
nsCOMPtr<nsIEventQueueService> eventQService \
= do_GetService(kEventQueueServiceCID); \
NS_ASSERTION(eventQService, "event queue service is unavailable"); \
\
nsCOMPtr<nsIEventQueue> eventQ; \
if (eventQService) { \
eventQService->GetThreadEventQueue(NS_UI_THREAD, getter_AddRefs(eventQ)); \
if (eventQ) \
eventQ->IsQueueOnCurrentThread(&callDirectly); \
} \
\
if (callDirectly) \
{ \
NS_RELEASE(this); \
return 0; \
} \
PLEvent *event = new PLEvent; \
if (event == nsnull) \
{ \
NS_ASSERTION(0, "Could not create a plevent. Deleting on wrong thread!"); \
NS_DELETEXPCOM(this); \
return 0; \
} \
\
PL_InitEvent(event, \
NS_STATIC_CAST(nsISupports*, this), \
ReleaseDestructorEventHandler, \
ReleaseDestructorDestroyHandler); \
\
eventQ->PostEvent(event); \
return 0; \
} \
return count; \
} \
#endif