michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "prlog.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "nsIObserverService.h"
michael@0: #include "nsIObserver.h"
michael@0: #include "nsObserverService.h"
michael@0: #include "nsObserverList.h"
michael@0: #include "nsThreadUtils.h"
michael@0: #include "nsEnumeratorUtils.h"
michael@0: #include "mozilla/net/NeckoCommon.h"
michael@0: #include "mozilla/Services.h"
michael@0: 
michael@0: #define NOTIFY_GLOBAL_OBSERVERS
michael@0: 
michael@0: #if defined(PR_LOGGING)
michael@0: // Log module for nsObserverService logging...
michael@0: //
michael@0: // To enable logging (see prlog.h for full details):
michael@0: //
michael@0: //    set NSPR_LOG_MODULES=ObserverService:5
michael@0: //    set NSPR_LOG_FILE=nspr.log
michael@0: //
michael@0: // this enables PR_LOG_DEBUG level information and places all output in
michael@0: // the file nspr.log
michael@0: static PRLogModuleInfo*
michael@0: GetObserverServiceLog()
michael@0: {
michael@0:     static PRLogModuleInfo *sLog;
michael@0:     if (!sLog)
michael@0:         sLog = PR_NewLogModule("ObserverService");
michael@0:     return sLog;
michael@0: }
michael@0:   #define LOG(x)  PR_LOG(GetObserverServiceLog(), PR_LOG_DEBUG, x)
michael@0: #else
michael@0:   #define LOG(x)
michael@0: #endif /* PR_LOGGING */
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: struct SuspectObserver {
michael@0:     SuspectObserver(const char* aTopic, size_t aReferentCount)
michael@0:         : topic(aTopic), referentCount(aReferentCount) {}
michael@0:     const char* topic;
michael@0:     size_t referentCount;
michael@0: };
michael@0: 
michael@0: struct ObserverServiceReferentCount {
michael@0:     ObserverServiceReferentCount()
michael@0:         : numStrong(0), numWeakAlive(0), numWeakDead(0) {}
michael@0:     size_t numStrong;
michael@0:     size_t numWeakAlive;
michael@0:     size_t numWeakDead;
michael@0:     nsTArray<SuspectObserver> suspectObservers;
michael@0: };
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: using namespace mozilla;
michael@0: 
michael@0: PLDHashOperator
michael@0: nsObserverService::CountReferents(nsObserverList* aObserverList,
michael@0:                                   void* aClosure)
michael@0: {
michael@0:     if (!aObserverList) {
michael@0:         return PL_DHASH_NEXT;
michael@0:     }
michael@0: 
michael@0:     ObserverServiceReferentCount* referentCount =
michael@0:         static_cast<ObserverServiceReferentCount*>(aClosure);
michael@0: 
michael@0:     size_t numStrong = 0;
michael@0:     size_t numWeakAlive = 0;
michael@0:     size_t numWeakDead = 0;
michael@0: 
michael@0:     nsTArray<ObserverRef>& observers = aObserverList->mObservers;
michael@0:     for (uint32_t i = 0; i < observers.Length(); i++) {
michael@0:         if (observers[i].isWeakRef) {
michael@0:             nsCOMPtr<nsIObserver> observerRef(
michael@0:                 do_QueryReferent(observers[i].asWeak()));
michael@0:             if (observerRef) {
michael@0:                 numWeakAlive++;
michael@0:             } else {
michael@0:                 numWeakDead++;
michael@0:             }
michael@0:         } else {
michael@0:             numStrong++;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     referentCount->numStrong += numStrong;
michael@0:     referentCount->numWeakAlive += numWeakAlive;
michael@0:     referentCount->numWeakDead += numWeakDead;
michael@0: 
michael@0:     // Keep track of topics that have a suspiciously large number
michael@0:     // of referents (symptom of leaks).
michael@0:     size_t total = numStrong + numWeakAlive + numWeakDead;
michael@0:     if (total > kSuspectReferentCount) {
michael@0:         SuspectObserver suspect(aObserverList->GetKey(), total);
michael@0:         referentCount->suspectObservers.AppendElement(suspect);
michael@0:     }
michael@0: 
michael@0:     return PL_DHASH_NEXT;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsObserverService::CollectReports(nsIHandleReportCallback* aHandleReport,
michael@0:                                   nsISupports* aData)
michael@0: {
michael@0:     ObserverServiceReferentCount referentCount;
michael@0:     mObserverTopicTable.EnumerateEntries(CountReferents, &referentCount);
michael@0: 
michael@0:     nsresult rv;
michael@0:     for (uint32_t i = 0; i < referentCount.suspectObservers.Length(); i++) {
michael@0:         SuspectObserver& suspect = referentCount.suspectObservers[i];
michael@0:         nsPrintfCString suspectPath("observer-service-suspect/"
michael@0:                                     "referent(topic=%s)",
michael@0:                                     suspect.topic);
michael@0:         rv = aHandleReport->Callback(/* process */ EmptyCString(),
michael@0:             suspectPath, KIND_OTHER, UNITS_COUNT, suspect.referentCount,
michael@0:             NS_LITERAL_CSTRING("A topic with a suspiciously large number of "
michael@0:                                "referents.  This may be symptomatic of a leak "
michael@0:                                "if the number of referents is high with "
michael@0:                                "respect to the number of windows."),
michael@0:             aData);
michael@0: 
michael@0:       if (NS_WARN_IF(NS_FAILED(rv)))
michael@0:           return rv;
michael@0:     }
michael@0: 
michael@0:     rv = aHandleReport->Callback(/* process */ EmptyCString(),
michael@0:         NS_LITERAL_CSTRING("observer-service/referent/strong"),
michael@0:         KIND_OTHER, UNITS_COUNT, referentCount.numStrong,
michael@0:         NS_LITERAL_CSTRING("The number of strong references held by the "
michael@0:                            "observer service."),
michael@0:         aData);
michael@0: 
michael@0:     if (NS_WARN_IF(NS_FAILED(rv)))
michael@0:         return rv;
michael@0: 
michael@0:     rv = aHandleReport->Callback(/* process */ EmptyCString(),
michael@0:         NS_LITERAL_CSTRING("observer-service/referent/weak/alive"),
michael@0:         KIND_OTHER, UNITS_COUNT, referentCount.numWeakAlive,
michael@0:         NS_LITERAL_CSTRING("The number of weak references held by the "
michael@0:                            "observer service that are still alive."),
michael@0:         aData);
michael@0: 
michael@0:     if (NS_WARN_IF(NS_FAILED(rv)))
michael@0:         return rv;
michael@0: 
michael@0:     rv = aHandleReport->Callback(/* process */ EmptyCString(),
michael@0:         NS_LITERAL_CSTRING("observer-service/referent/weak/dead"),
michael@0:         KIND_OTHER, UNITS_COUNT, referentCount.numWeakDead,
michael@0:         NS_LITERAL_CSTRING("The number of weak references held by the "
michael@0:                            "observer service that are dead."),
michael@0:         aData);
michael@0: 
michael@0:     if (NS_WARN_IF(NS_FAILED(rv)))
michael@0:         return rv;
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // nsObserverService Implementation
michael@0: 
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(
michael@0:     nsObserverService,
michael@0:     nsIObserverService,
michael@0:     nsObserverService,
michael@0:     nsIMemoryReporter)
michael@0: 
michael@0: nsObserverService::nsObserverService() :
michael@0:     mShuttingDown(false)
michael@0: {
michael@0: }
michael@0: 
michael@0: nsObserverService::~nsObserverService(void)
michael@0: {
michael@0:     Shutdown();
michael@0: }
michael@0: 
michael@0: void
michael@0: nsObserverService::RegisterReporter()
michael@0: {
michael@0:     RegisterWeakMemoryReporter(this);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsObserverService::Shutdown()
michael@0: {
michael@0:     UnregisterWeakMemoryReporter(this);
michael@0: 
michael@0:     mShuttingDown = true;
michael@0: 
michael@0:     mObserverTopicTable.Clear();
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsObserverService::Create(nsISupports* outer, const nsIID& aIID, void* *aInstancePtr)
michael@0: {
michael@0:     LOG(("nsObserverService::Create()"));
michael@0: 
michael@0:     nsRefPtr<nsObserverService> os = new nsObserverService();
michael@0: 
michael@0:     if (!os)
michael@0:         return NS_ERROR_OUT_OF_MEMORY;
michael@0: 
michael@0:     // The memory reporter can not be immediately registered here because
michael@0:     // the nsMemoryReporterManager may attempt to get the nsObserverService
michael@0:     // during initialization, causing a recursive GetService.
michael@0:     nsRefPtr<nsRunnableMethod<nsObserverService> > registerRunnable =
michael@0:         NS_NewRunnableMethod(os, &nsObserverService::RegisterReporter);
michael@0:     NS_DispatchToCurrentThread(registerRunnable);
michael@0: 
michael@0:     return os->QueryInterface(aIID, aInstancePtr);
michael@0: }
michael@0: 
michael@0: #define NS_ENSURE_VALIDCALL \
michael@0:     if (!NS_IsMainThread()) {                                     \
michael@0:         MOZ_CRASH("Using observer service off the main thread!"); \
michael@0:         return NS_ERROR_UNEXPECTED;                               \
michael@0:     }                                                             \
michael@0:     if (mShuttingDown) {                                          \
michael@0:         NS_ERROR("Using observer service after XPCOM shutdown!"); \
michael@0:         return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;                  \
michael@0:     }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsObserverService::AddObserver(nsIObserver* anObserver, const char* aTopic,
michael@0:                                bool ownsWeak)
michael@0: {
michael@0:     LOG(("nsObserverService::AddObserver(%p: %s)",
michael@0:          (void*) anObserver, aTopic));
michael@0: 
michael@0:     NS_ENSURE_VALIDCALL
michael@0:     if (NS_WARN_IF(!anObserver) || NS_WARN_IF(!aTopic))
michael@0:         return NS_ERROR_INVALID_ARG;
michael@0: 
michael@0:     if (mozilla::net::IsNeckoChild() && !strncmp(aTopic, "http-on-", 8)) {
michael@0:       return NS_ERROR_NOT_IMPLEMENTED;
michael@0:     }
michael@0: 
michael@0:     nsObserverList *observerList = mObserverTopicTable.PutEntry(aTopic);
michael@0:     if (!observerList)
michael@0:         return NS_ERROR_OUT_OF_MEMORY;
michael@0: 
michael@0:     return observerList->AddObserver(anObserver, ownsWeak);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsObserverService::RemoveObserver(nsIObserver* anObserver, const char* aTopic)
michael@0: {
michael@0:     LOG(("nsObserverService::RemoveObserver(%p: %s)",
michael@0:          (void*) anObserver, aTopic));
michael@0:     NS_ENSURE_VALIDCALL
michael@0:     if (NS_WARN_IF(!anObserver) || NS_WARN_IF(!aTopic))
michael@0:         return NS_ERROR_INVALID_ARG;
michael@0: 
michael@0:     nsObserverList *observerList = mObserverTopicTable.GetEntry(aTopic);
michael@0:     if (!observerList)
michael@0:         return NS_ERROR_FAILURE;
michael@0: 
michael@0:     /* This death grip is to protect against stupid consumers who call
michael@0:        RemoveObserver from their Destructor, see bug 485834/bug 325392. */
michael@0:     nsCOMPtr<nsIObserver> kungFuDeathGrip(anObserver);
michael@0:     return observerList->RemoveObserver(anObserver);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsObserverService::EnumerateObservers(const char* aTopic,
michael@0:                                       nsISimpleEnumerator** anEnumerator)
michael@0: {
michael@0:     NS_ENSURE_VALIDCALL
michael@0:     if (NS_WARN_IF(!anEnumerator) || NS_WARN_IF(!aTopic))
michael@0:         return NS_ERROR_INVALID_ARG;
michael@0: 
michael@0:     nsObserverList *observerList = mObserverTopicTable.GetEntry(aTopic);
michael@0:     if (!observerList)
michael@0:         return NS_NewEmptyEnumerator(anEnumerator);
michael@0: 
michael@0:     return observerList->GetObserverList(anEnumerator);
michael@0: }
michael@0: 
michael@0: // Enumerate observers of aTopic and call Observe on each.
michael@0: NS_IMETHODIMP nsObserverService::NotifyObservers(nsISupports *aSubject,
michael@0:                                                  const char *aTopic,
michael@0:                                                  const char16_t *someData)
michael@0: {
michael@0:     LOG(("nsObserverService::NotifyObservers(%s)", aTopic));
michael@0: 
michael@0:     NS_ENSURE_VALIDCALL
michael@0:     if (NS_WARN_IF(!aTopic))
michael@0:         return NS_ERROR_INVALID_ARG;
michael@0: 
michael@0:     nsObserverList *observerList = mObserverTopicTable.GetEntry(aTopic);
michael@0:     if (observerList)
michael@0:         observerList->NotifyObservers(aSubject, aTopic, someData);
michael@0: 
michael@0: #ifdef NOTIFY_GLOBAL_OBSERVERS
michael@0:     observerList = mObserverTopicTable.GetEntry("*");
michael@0:     if (observerList)
michael@0:         observerList->NotifyObservers(aSubject, aTopic, someData);
michael@0: #endif
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: static PLDHashOperator
michael@0: UnmarkGrayObserverEntry(nsObserverList* aObserverList, void* aClosure)
michael@0: {
michael@0:     if (aObserverList) {
michael@0:         aObserverList->UnmarkGrayStrongObservers();
michael@0:     }
michael@0:     return PL_DHASH_NEXT;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsObserverService::UnmarkGrayStrongObservers()
michael@0: {
michael@0:     NS_ENSURE_VALIDCALL
michael@0: 
michael@0:     mObserverTopicTable.EnumerateEntries(UnmarkGrayObserverEntry, nullptr);
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: