gecko-dev/xpcom/components/nsServiceManager.cpp

365 lines
10 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "nsIServiceManager.h"
#include "nsVector.h"
#include "prcmon.h"
#include "prthread.h" /* XXX: only used for the NSPR initialization hack (rick) */
// XXX move to nsID.h or nsHashtable.h? (copied from nsRepository.cpp)
class IDKey: public nsHashKey {
private:
nsID id;
public:
IDKey(const nsID &aID) {
id = aID;
}
PRUint32 HashValue(void) const {
return id.m0;
}
PRBool Equals(const nsHashKey *aKey) const {
return (id.Equals(((const IDKey *) aKey)->id));
}
nsHashKey *Clone(void) const {
return new IDKey(id);
}
};
class nsServiceEntry {
public:
nsServiceEntry(const nsCID& cid, nsISupports* service);
~nsServiceEntry();
nsresult AddListener(nsIShutdownListener* listener);
nsresult RemoveListener(nsIShutdownListener* listener);
nsresult NotifyListeners(void);
const nsCID& mClassID;
nsISupports* mService;
nsVector* mListeners; // nsVector<nsIShutdownListener>
};
nsServiceEntry::nsServiceEntry(const nsCID& cid, nsISupports* service)
: mClassID(cid), mService(service), mListeners(NULL)
{
}
nsServiceEntry::~nsServiceEntry()
{
if (mListeners) {
NS_ASSERTION(mListeners->GetSize() == 0, "listeners not removed or notified");
#if 0
PRUint32 size = mListeners->GetSize();
for (PRUint32 i = 0; i < size; i++) {
nsIShutdownListener* listener = (nsIShutdownListener*)(*mListeners)[i];
listener->Release();
}
#endif
delete mListeners;
}
}
nsresult
nsServiceEntry::AddListener(nsIShutdownListener* listener)
{
if (listener == NULL)
return NS_OK;
if (mListeners == NULL) {
mListeners = new nsVector();
if (mListeners == NULL)
return NS_ERROR_OUT_OF_MEMORY;
}
PRInt32 err = mListeners->Add(listener);
listener->AddRef();
return err == -1 ? NS_ERROR_FAILURE : NS_OK;
}
nsresult
nsServiceEntry::RemoveListener(nsIShutdownListener* listener)
{
if (listener == NULL)
return NS_OK;
NS_ASSERTION(mListeners, "no listeners added yet");
PRUint32 size = mListeners->GetSize();
for (PRUint32 i = 0; i < size; i++) {
if ((*mListeners)[i] == listener) {
mListeners->Remove(i);
listener->Release();
return NS_OK;
}
}
NS_ASSERTION(0, "unregistered shutdown listener");
return NS_ERROR_FAILURE;
}
nsresult
nsServiceEntry::NotifyListeners(void)
{
if (mListeners) {
PRUint32 size = mListeners->GetSize();
for (PRUint32 i = 0; i < size; i++) {
nsIShutdownListener* listener = (nsIShutdownListener*)(*mListeners)[0];
nsresult err = listener->OnShutdown(mClassID, mService);
if (err) return err;
listener->Release();
mListeners->Remove(0);
}
NS_ASSERTION(mListeners->GetSize() == 0, "failed to notify all listeners");
delete mListeners;
mListeners = NULL;
}
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
class nsServiceManagerImpl : public nsIServiceManager {
public:
NS_IMETHOD
GetService(const nsCID& aClass, const nsIID& aIID,
nsISupports* *result,
nsIShutdownListener* shutdownListener = NULL);
NS_IMETHOD
ReleaseService(const nsCID& aClass, nsISupports* service,
nsIShutdownListener* shutdownListener = NULL);
NS_IMETHOD
ShutdownService(const nsCID& aClass);
nsServiceManagerImpl(void);
NS_DECL_ISUPPORTS
protected:
virtual ~nsServiceManagerImpl(void);
nsHashtable* mServices; // nsHashtable<nsServiceEntry>
};
nsServiceManagerImpl::nsServiceManagerImpl(void)
{
NS_INIT_REFCNT();
mServices = new nsHashtable();
NS_ASSERTION(mServices, "out of memory already?");
}
static PRBool
DeleteEntry(nsHashKey *aKey, void *aData, void* closure)
{
nsServiceEntry* entry = (nsServiceEntry*)aData;
entry->mService->Release();
delete entry;
return PR_TRUE;
}
nsServiceManagerImpl::~nsServiceManagerImpl(void)
{
mServices->Enumerate(DeleteEntry);
delete mServices;
}
static NS_DEFINE_IID(kIServiceManagerIID, NS_ISERVICEMANAGER_IID);
static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);
NS_IMPL_ADDREF(nsServiceManagerImpl);
NS_IMPL_RELEASE(nsServiceManagerImpl);
nsresult
nsServiceManagerImpl::QueryInterface(const nsIID& aIID, void* *aInstancePtr)
{
if (NULL == aInstancePtr) {
return NS_ERROR_NULL_POINTER;
}
*aInstancePtr = NULL;
if (aIID.Equals(kIServiceManagerIID) ||
aIID.Equals(kISupportsIID)) {
*aInstancePtr = (void*) this;
AddRef();
return NS_OK;
}
return NS_NOINTERFACE;
}
nsresult
nsServiceManagerImpl::GetService(const nsCID& aClass, const nsIID& aIID,
nsISupports* *result,
nsIShutdownListener* shutdownListener)
{
nsresult err = NS_OK;
/* XXX: This is a hack to force NSPR initialization.. This should be
* removed once PR_CEnterMonitor(...) initializes NSPR... (rick)
*/
(void)PR_GetCurrentThread();
PR_CEnterMonitor(this);
IDKey key(aClass);
nsServiceEntry* entry = (nsServiceEntry*)mServices->Get(&key);
if (entry) {
nsISupports* service;
err = entry->mService->QueryInterface(aIID, (void**)&service);
if (err == NS_OK) {
err = entry->AddListener(shutdownListener);
if (err == NS_OK) {
*result = service;
}
}
}
else {
nsISupports* service;
err = nsRepository::CreateInstance(aClass, NULL, aIID, (void**)&service);
if (err == NS_OK) {
entry = new nsServiceEntry(aClass, service);
if (entry == NULL) {
service->Release();
err = NS_ERROR_OUT_OF_MEMORY;
}
else {
err = entry->AddListener(shutdownListener);
if (err == NS_OK) {
mServices->Put(&key, entry);
*result = service;
}
else {
service->Release();
delete entry;
}
}
}
}
PR_CExitMonitor(this);
return err;
}
nsresult
nsServiceManagerImpl::ReleaseService(const nsCID& aClass, nsISupports* service,
nsIShutdownListener* shutdownListener)
{
nsresult err = NS_OK;
PR_CEnterMonitor(this);
IDKey key(aClass);
nsServiceEntry* entry = (nsServiceEntry*)mServices->Get(&key);
NS_ASSERTION(entry, "service not found");
NS_ASSERTION(entry->mService == service, "service looked failed");
if (entry) {
err = entry->RemoveListener(shutdownListener);
// XXX Is this too aggressive? Maybe we should have a memory
// pressure API that releases services if they're not in use so
// that we don't thrash.
nsrefcnt cnt = service->Release();
if (err == NS_OK && cnt == 0) {
mServices->Remove(&key);
delete entry;
}
}
PR_CExitMonitor(this);
return err;
}
nsresult
nsServiceManagerImpl::ShutdownService(const nsCID& aClass)
{
nsresult err = NS_OK;
PR_CEnterMonitor(this);
IDKey key(aClass);
nsServiceEntry* entry = (nsServiceEntry*)mServices->Get(&key);
if (entry == NULL) {
err = NS_ERROR_SERVICE_NOT_FOUND;
}
else {
entry->mService->AddRef();
err = entry->NotifyListeners();
nsrefcnt cnt = entry->mService->Release();
if (err == NS_OK && cnt == 0) {
mServices->Remove(&key);
err = nsRepository::FreeLibraries();
}
else
err = NS_ERROR_SERVICE_IN_USE;
}
PR_CExitMonitor(this);
return err;
}
////////////////////////////////////////////////////////////////////////////////
// Global service manager interface (see nsIServiceManager.h)
nsIServiceManager* nsServiceManager::globalServiceManager = NULL;
nsresult
nsServiceManager::GetGlobalServiceManager(nsIServiceManager* *result)
{
if (globalServiceManager == NULL) {
globalServiceManager = new nsServiceManagerImpl();
if (globalServiceManager == NULL)
return NS_ERROR_OUT_OF_MEMORY;
globalServiceManager->AddRef();
}
*result = globalServiceManager;
return NS_OK;
}
nsresult
nsServiceManager::GetService(const nsCID& aClass, const nsIID& aIID,
nsISupports* *result,
nsIShutdownListener* shutdownListener)
{
nsIServiceManager* mgr;
nsresult rslt = GetGlobalServiceManager(&mgr);
if (rslt != NS_OK) return rslt;
return mgr->GetService(aClass, aIID, result, shutdownListener);
}
nsresult
nsServiceManager::ReleaseService(const nsCID& aClass, nsISupports* service,
nsIShutdownListener* shutdownListener)
{
nsIServiceManager* mgr;
nsresult rslt = GetGlobalServiceManager(&mgr);
if (rslt != NS_OK) return rslt;
return mgr->ReleaseService(aClass, service, shutdownListener);
}
nsresult
nsServiceManager::ShutdownService(const nsCID& aClass)
{
nsIServiceManager* mgr;
nsresult rslt = GetGlobalServiceManager(&mgr);
if (rslt != NS_OK) return rslt;
return mgr->ShutdownService(aClass);
}
////////////////////////////////////////////////////////////////////////////////