gecko/xpcom/ds/nsObserverService.cpp
2012-05-21 12:12:37 +01:00

178 lines
5.2 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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/. */
#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(false)
{
mObserverTopicTable.Init();
}
nsObserverService::~nsObserverService(void)
{
Shutdown();
}
void
nsObserverService::Shutdown()
{
mShuttingDown = true;
if (mObserverTopicTable.IsInitialized())
mObserverTopicTable.Clear();
}
nsresult
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,
bool 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;
}
static PLDHashOperator
UnmarkGrayObserverEntry(nsObserverList* aObserverList, void* aClosure)
{
if (aObserverList) {
aObserverList->UnmarkGrayStrongObservers();
}
return PL_DHASH_NEXT;
}
NS_IMETHODIMP
nsObserverService::UnmarkGrayStrongObservers()
{
NS_ENSURE_VALIDCALL
mObserverTopicTable.EnumerateEntries(UnmarkGrayObserverEntry, nsnull);
return NS_OK;
}