system/kernel/Notifications.cpp

/*
 * Copyright 2007-2009, Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		Axel Dörfler, axeld@pinc-software.de
 *		Ingo Weinhold, bonefish@cs.tu-berlin.de
 */


#include <Notifications.h>

#include <new>

#include <team.h>


#ifdef _KERNEL_MODE

static const char* kEventMaskString = "event mask";

NotificationManager NotificationManager::sManager;

#endif


// #pragma mark - NotificationListener


NotificationListener::~NotificationListener()
{
}


void
NotificationListener::EventOccurred(NotificationService& service,
	const KMessage* event)
{
}


void
NotificationListener::AllListenersNotified(NotificationService& service)
{
}


bool
NotificationListener::operator==(const NotificationListener& other) const
{
	return &other == this;
}


// #pragma mark - UserMessagingMessageSender


#ifdef _KERNEL_MODE


UserMessagingMessageSender::UserMessagingMessageSender()
	:
	fMessage(NULL),
	fTargetCount(0)
{
}


void
UserMessagingMessageSender::SendMessage(const KMessage* message, port_id port,
	int32 token)
{
	if ((message != fMessage && fMessage != NULL)
		|| fTargetCount == MAX_MESSAGING_TARGET_COUNT) {
		FlushMessage();
	}

	fMessage = message;
	fTargets[fTargetCount].port = port;
	fTargets[fTargetCount].token = token;
	fTargetCount++;
}


void
UserMessagingMessageSender::FlushMessage()
{
	if (fMessage != NULL && fTargetCount > 0) {
		send_message(fMessage->Buffer(), fMessage->ContentSize(),
			fTargets, fTargetCount);
	}

	fMessage = NULL;
	fTargetCount = 0;
}


// #pragma mark - UserMessagingListener


UserMessagingListener::UserMessagingListener(UserMessagingMessageSender& sender,
		port_id port, int32 token)
	:
	fSender(sender),
	fPort(port),
	fToken(token)
{
}


UserMessagingListener::~UserMessagingListener()
{
}


void
UserMessagingListener::EventOccurred(NotificationService& service,
	const KMessage* event)
{
	fSender.SendMessage(event, fPort, fToken);
}


void
UserMessagingListener::AllListenersNotified(NotificationService& service)
{
	fSender.FlushMessage();
}


//	#pragma mark - NotificationService


NotificationService::~NotificationService()
{
}


//	#pragma mark - default_listener


default_listener::~default_listener()
{
	// Only delete the listener if it's one of ours
	if (dynamic_cast<UserMessagingListener*>(listener) != NULL) {
		delete listener;
	}
}


//	#pragma mark - DefaultNotificationService


DefaultNotificationService::DefaultNotificationService(const char* name)
	:
	fName(name)
{
	recursive_lock_init(&fLock, name);
	NotificationManager::Manager().RegisterService(*this);
}


DefaultNotificationService::~DefaultNotificationService()
{
	NotificationManager::Manager().UnregisterService(*this);
	recursive_lock_destroy(&fLock);
}


/*!	\brief Notifies all registered listeners.
	\param event The message defining the event
	\param eventMask Only listeners with an event mask sharing at least one
		common bit with this mask will receive the event.
*/
void
DefaultNotificationService::NotifyLocked(const KMessage& event, uint32 eventMask)
{
	// Note: The following iterations support that the listener removes itself
	// in the hook method. That's a property of the DoublyLinkedList iterator.

	// notify all listeners about the event
	DefaultListenerList::Iterator iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if ((eventMask & listener->eventMask) != 0)
			listener->listener->EventOccurred(*this, &event);
	}

	// notify all listeners that all listeners have been notified
	iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if ((eventMask & listener->eventMask) != 0)
			listener->listener->AllListenersNotified(*this);
	}
}


status_t
DefaultNotificationService::AddListener(const KMessage* eventSpecifier,
	NotificationListener& notificationListener)
{
	if (eventSpecifier == NULL)
		return B_BAD_VALUE;

	uint32 eventMask;
	status_t status = ToEventMask(*eventSpecifier, eventMask);
	if (status != B_OK)
		return status;

	default_listener* listener = new(std::nothrow) default_listener;
	if (listener == NULL)
		return B_NO_MEMORY;

	listener->eventMask = eventMask;
	listener->team = -1;
	listener->listener = &notificationListener;

	RecursiveLocker _(fLock);
	if (fListeners.IsEmpty())
		FirstAdded();
	fListeners.Add(listener);

	return B_OK;
}


status_t
DefaultNotificationService::UpdateListener(const KMessage* eventSpecifier,
	NotificationListener& notificationListener)
{
	return B_NOT_SUPPORTED;
}


status_t
DefaultNotificationService::RemoveListener(const KMessage* eventSpecifier,
	NotificationListener& notificationListener)
{
	RecursiveLocker _(fLock);

	DefaultListenerList::Iterator iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if (listener->listener == &notificationListener) {
			iterator.Remove();
			delete listener;

			if (fListeners.IsEmpty())
				LastRemoved();
			return B_OK;
		}
	}

	return B_ENTRY_NOT_FOUND;
}


status_t
DefaultNotificationService::ToEventMask(const KMessage& eventSpecifier,
	uint32& eventMask)
{
	return eventSpecifier.FindInt32("event mask", (int32*)&eventMask);
}


void
DefaultNotificationService::FirstAdded()
{
}


void
DefaultNotificationService::LastRemoved()
{
}


//	#pragma mark - DefaultUserNotificationService


DefaultUserNotificationService::DefaultUserNotificationService(const char* name)
	: DefaultNotificationService(name)
{
	NotificationManager::Manager().AddListener("teams", TEAM_REMOVED, *this);
}


DefaultUserNotificationService::~DefaultUserNotificationService()
{
	NotificationManager::Manager().RemoveListener("teams", NULL, *this);
}


status_t
DefaultUserNotificationService::AddListener(const KMessage* eventSpecifier,
	NotificationListener& listener)
{
	if (eventSpecifier == NULL)
		return B_BAD_VALUE;

	uint32 eventMask = eventSpecifier->GetInt32(kEventMaskString, 0);

	return _AddListener(eventMask, listener);
}


status_t
DefaultUserNotificationService::UpdateListener(const KMessage* eventSpecifier,
	NotificationListener& notificationListener)
{
	if (eventSpecifier == NULL)
		return B_BAD_VALUE;

	uint32 eventMask = eventSpecifier->GetInt32(kEventMaskString, 0);
	bool addEvents = eventSpecifier->GetBool("add events", false);

	RecursiveLocker _(fLock);

	DefaultListenerList::Iterator iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if (*listener->listener == notificationListener) {
			if (addEvents)
				listener->eventMask |= eventMask;
			else
				listener->eventMask = eventMask;
			return B_OK;
		}
	}

	return B_ENTRY_NOT_FOUND;
}


status_t
DefaultUserNotificationService::RemoveListener(const KMessage* eventSpecifier,
	NotificationListener& notificationListener)
{
	RecursiveLocker _(fLock);

	DefaultListenerList::Iterator iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if (listener->listener == &notificationListener) {
			iterator.Remove();
			delete listener;
			return B_OK;
		}
	}

	return B_ENTRY_NOT_FOUND;
}


status_t
DefaultUserNotificationService::RemoveUserListeners(port_id port, uint32 token)
{
	UserMessagingListener userListener(fSender, port, token);

	RecursiveLocker _(fLock);

	DefaultListenerList::Iterator iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if (*listener->listener == userListener) {
			iterator.Remove();
			delete listener;

			if (fListeners.IsEmpty())
				LastRemoved();
			return B_OK;
		}
	}

	return B_ENTRY_NOT_FOUND;
}


status_t
DefaultUserNotificationService::UpdateUserListener(uint32 eventMask,
	port_id port, uint32 token)
{
	UserMessagingListener userListener(fSender, port, token);

	RecursiveLocker _(fLock);

	DefaultListenerList::Iterator iterator = fListeners.GetIterator();
	while (default_listener* listener = iterator.Next()) {
		if (*listener->listener == userListener) {
			listener->eventMask |= eventMask;
			return B_OK;
		}
	}

	UserMessagingListener* copiedListener
		= new(std::nothrow) UserMessagingListener(userListener);
	if (copiedListener == NULL)
		return B_NO_MEMORY;

	status_t status = _AddListener(eventMask, *copiedListener);
	if (status != B_OK)
		delete copiedListener;

	return status;
}


void
DefaultUserNotificationService::EventOccurred(NotificationService& service,
	const KMessage* event)
{
	int32 eventCode = event->GetInt32("event", -1);
	team_id team = event->GetInt32("team", -1);

	if (eventCode == TEAM_REMOVED && team >= B_OK) {
		// check if we have any listeners from that team, and remove them
		RecursiveLocker _(fLock);

		DefaultListenerList::Iterator iterator = fListeners.GetIterator();
		while (default_listener* listener = iterator.Next()) {
			if (listener->team == team) {
				iterator.Remove();
				delete listener;
			}
		}
	}
}


void
DefaultUserNotificationService::AllListenersNotified(
	NotificationService& service)
{
}


status_t
DefaultUserNotificationService::_AddListener(uint32 eventMask,
	NotificationListener& notificationListener)
{
	default_listener* listener = new(std::nothrow) default_listener;
	if (listener == NULL)
		return B_NO_MEMORY;

	listener->eventMask = eventMask;
	listener->team = team_get_current_team_id();
	listener->listener = &notificationListener;

	RecursiveLocker _(fLock);
	if (fListeners.IsEmpty())
		FirstAdded();
	fListeners.Add(listener);

	return B_OK;
}


//	#pragma mark - NotificationManager


/*static*/ NotificationManager&
NotificationManager::Manager()
{
	return sManager;
}


/*static*/ status_t
NotificationManager::CreateManager()
{
	new(&sManager) NotificationManager;
	return sManager._Init();
}


NotificationManager::NotificationManager()
{
}


NotificationManager::~NotificationManager()
{
}


status_t
NotificationManager::_Init()
{
	mutex_init(&fLock, "notification manager");

	return fServiceHash.Init();
}


NotificationService*
NotificationManager::_ServiceFor(const char* name)
{
	return fServiceHash.Lookup(name);
}


status_t
NotificationManager::RegisterService(NotificationService& service)
{
	MutexLocker _(fLock);

	if (_ServiceFor(service.Name()))
		return B_NAME_IN_USE;

	status_t status = fServiceHash.Insert(&service);
	if (status == B_OK)
		service.AcquireReference();

	return status;
}


void
NotificationManager::UnregisterService(NotificationService& service)
{
	MutexLocker _(fLock);
	fServiceHash.Remove(&service);
	service.ReleaseReference();
}


status_t
NotificationManager::AddListener(const char* serviceName,
	uint32 eventMask, NotificationListener& listener)
{
	char buffer[96];
	KMessage specifier;
	specifier.SetTo(buffer, sizeof(buffer), 0);
	specifier.AddInt32(kEventMaskString, eventMask);

	return AddListener(serviceName, &specifier, listener);
}


status_t
NotificationManager::AddListener(const char* serviceName,
	const KMessage* eventSpecifier, NotificationListener& listener)
{
	MutexLocker locker(fLock);
	NotificationService* service = _ServiceFor(serviceName);
	if (service == NULL)
		return B_NAME_NOT_FOUND;

	BReference<NotificationService> reference(service);
	locker.Unlock();

	return service->AddListener(eventSpecifier, listener);
}


status_t
NotificationManager::UpdateListener(const char* serviceName,
	uint32 eventMask, NotificationListener& listener)
{
	char buffer[96];
	KMessage specifier;
	specifier.SetTo(buffer, sizeof(buffer), 0);
	specifier.AddInt32(kEventMaskString, eventMask);

	return UpdateListener(serviceName, &specifier, listener);
}


status_t
NotificationManager::UpdateListener(const char* serviceName,
	const KMessage* eventSpecifier, NotificationListener& listener)
{
	MutexLocker locker(fLock);
	NotificationService* service = _ServiceFor(serviceName);
	if (service == NULL)
		return B_NAME_NOT_FOUND;

	BReference<NotificationService> reference(service);
	locker.Unlock();

	return service->UpdateListener(eventSpecifier, listener);
}


status_t
NotificationManager::RemoveListener(const char* serviceName,
	const KMessage* eventSpecifier, NotificationListener& listener)
{
	MutexLocker locker(fLock);
	NotificationService* service = _ServiceFor(serviceName);
	if (service == NULL)
		return B_NAME_NOT_FOUND;

	BReference<NotificationService> reference(service);
	locker.Unlock();

	return service->RemoveListener(eventSpecifier, listener);
}


//	#pragma mark -


extern "C" void
notifications_init(void)
{
	status_t status = NotificationManager::CreateManager();
	if (status < B_OK) {
		panic("Creating the notification manager failed: %s\n",
			strerror(status));
	}
}


#endif	// _KERNEL_MODE