gecko-dev/xpcom/ds/nsObserverService.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla 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/MPL/
*
* 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):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 MPL, 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 MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "prlog.h"
#include "nsAutoPtr.h"
#include "nsIFactory.h"
#include "nsIServiceManager.h"
#include "nsIComponentManager.h"
#include "nsIObserverService.h"
#include "nsIObserver.h"
#include "nsISimpleEnumerator.h"
#include "nsObserverService.h"
#include "nsObserverList.h"
#include "nsHashtable.h"
#include "nsThreadUtils.h"
#include "nsIWeakReference.h"
#include "nsEnumeratorUtils.h"
#define NOTIFY_GLOBAL_OBSERVERS
#if defined(PR_LOGGING)
// Log module for nsObserverService logging...
//
// To enable logging (see prlog.h for full details):
//
// set NSPR_LOG_MODULES=ObserverService:5
// set NSPR_LOG_FILE=nspr.log
//
// this enables PR_LOG_DEBUG level information and places all output in
// the file nspr.log
PRLogModuleInfo* observerServiceLog = PR_NewLogModule("ObserverService");
#define LOG(x) PR_LOG(observerServiceLog, PR_LOG_DEBUG, x)
#else
#define LOG(x)
#endif /* PR_LOGGING */
////////////////////////////////////////////////////////////////////////////////
// nsObserverService Implementation
NS_IMPL_THREADSAFE_ISUPPORTS2(nsObserverService, nsIObserverService, nsObserverService)
nsObserverService::nsObserverService() :
mShuttingDown(PR_FALSE)
{
mObserverTopicTable.Init();
}
nsObserverService::~nsObserverService(void)
{
Shutdown();
}
void
nsObserverService::Shutdown()
{
mShuttingDown = PR_TRUE;
if (mObserverTopicTable.IsInitialized())
mObserverTopicTable.Clear();
}
NS_METHOD
nsObserverService::Create(nsISupports* outer, const nsIID& aIID, void* *aInstancePtr)
{
LOG(("nsObserverService::Create()"));
nsRefPtr<nsObserverService> os = new nsObserverService();
if (!os || !os->mObserverTopicTable.IsInitialized())
return NS_ERROR_OUT_OF_MEMORY;
return os->QueryInterface(aIID, aInstancePtr);
}
#define NS_ENSURE_VALIDCALL \
if (!NS_IsMainThread()) { \
NS_ERROR("Using observer service off the main thread!"); \
return NS_ERROR_UNEXPECTED; \
} \
if (mShuttingDown) { \
NS_ERROR("Using observer service after XPCOM shutdown!"); \
return NS_ERROR_ILLEGAL_DURING_SHUTDOWN; \
}
NS_IMETHODIMP
nsObserverService::AddObserver(nsIObserver* anObserver, const char* aTopic,
PRBool ownsWeak)
{
LOG(("nsObserverService::AddObserver(%p: %s)",
(void*) anObserver, aTopic));
NS_ENSURE_VALIDCALL
NS_ENSURE_ARG(anObserver && aTopic);
nsObserverList *observerList = mObserverTopicTable.PutEntry(aTopic);
if (!observerList)
return NS_ERROR_OUT_OF_MEMORY;
return observerList->AddObserver(anObserver, ownsWeak);
}
NS_IMETHODIMP
nsObserverService::RemoveObserver(nsIObserver* anObserver, const char* aTopic)
{
LOG(("nsObserverService::RemoveObserver(%p: %s)",
(void*) anObserver, aTopic));
NS_ENSURE_VALIDCALL
NS_ENSURE_ARG(anObserver && aTopic);
nsObserverList *observerList = mObserverTopicTable.GetEntry(aTopic);
if (!observerList)
return NS_ERROR_FAILURE;
/* This death grip is to protect against stupid consumers who call
RemoveObserver from their Destructor, see bug 485834/bug 325392. */
nsCOMPtr<nsIObserver> kungFuDeathGrip(anObserver);
return observerList->RemoveObserver(anObserver);
}
NS_IMETHODIMP
nsObserverService::EnumerateObservers(const char* aTopic,
nsISimpleEnumerator** anEnumerator)
{
NS_ENSURE_VALIDCALL
NS_ENSURE_ARG(aTopic && anEnumerator);
nsObserverList *observerList = mObserverTopicTable.GetEntry(aTopic);
if (!observerList)
return NS_NewEmptyEnumerator(anEnumerator);
return observerList->GetObserverList(anEnumerator);
}
// Enumerate observers of aTopic and call Observe on each.
NS_IMETHODIMP nsObserverService::NotifyObservers(nsISupports *aSubject,
const char *aTopic,
const PRUnichar *someData)
{
LOG(("nsObserverService::NotifyObservers(%s)", aTopic));
NS_ENSURE_VALIDCALL
NS_ENSURE_ARG(aTopic);
nsObserverList *observerList = mObserverTopicTable.GetEntry(aTopic);
if (observerList)
observerList->NotifyObservers(aSubject, aTopic, someData);
#ifdef NOTIFY_GLOBAL_OBSERVERS
observerList = mObserverTopicTable.GetEntry("*");
if (observerList)
observerList->NotifyObservers(aSubject, aTopic, someData);
#endif
return NS_OK;
}