bonefish+axeld: Implemented a robust notification framework for the kernel.

Will be used for node monitoring and other stuff, too (like the Registrar or the
VM low memory handler).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21768 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/Notifications.h

@@ -0,0 +1,196 @@
+/*
+ * Copyright 2007, 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
+ */
+#ifndef _KERNEL_NOTIFICATIONS_H
+#define _KERNEL_NOTIFICATIONS_H
+
+
+#include <SupportDefs.h>
+
+#include <Referenceable.h>
+
+#include <lock.h>
+#include <messaging.h>
+#include <util/AutoLock.h>
+#include <util/DoublyLinkedList.h>
+#include <util/khash.h>
+#include <util/KMessage.h>
+#include <util/OpenHashTable.h>
+
+
+#ifdef __cplusplus
+
+class NotificationService;
+
+class NotificationListener
+	: public DoublyLinkedListLinkImpl<NotificationListener> {
+	public:
+		virtual ~NotificationListener();
+
+		virtual void EventOccured(NotificationService& service,
+			const KMessage* event);
+		virtual void AllListenersNotified();
+};
+
+class UserMessagingMessageSender {
+	public:
+		UserMessagingMessageSender();
+
+		void SendMessage(const KMessage* message, port_id port, int32 token);
+		void FlushMessage();
+
+	private:
+		enum {
+			MAX_MESSAGING_TARGET_COUNT	= 16,
+		};
+
+		const KMessage*		fMessage;
+		messaging_target	fTargets[MAX_MESSAGING_TARGET_COUNT];
+		int32				fTargetCount;
+};
+
+class UserMessagingListener : public NotificationListener {
+	public:
+		UserMessagingListener(UserMessagingMessageSender& sender, port_id port,
+			int32 token);
+		virtual ~UserMessagingListener();
+
+		virtual void EventOccured(NotificationService& service,
+			const KMessage* event);
+		virtual void AllListenersNotified();
+
+		port_id Port()	{ return fPort; }
+		int32 Token()	{ return fToken; }
+
+	private:
+		UserMessagingMessageSender&	fSender;
+		port_id						fPort;
+		int32						fToken;
+};
+
+class NotificationListenerUpdater {
+	public:
+		enum update_action {
+			UPDATED,
+			SKIP,
+			DELETE,
+			REMOVE
+		};
+
+		NotificationListenerUpdater(const KMessage* eventSpecifier);
+		virtual ~NotificationListenerUpdater();
+
+		virtual status_t UpdateListener(NotificationListener& listener,
+			enum update_action& action);
+
+		virtual status_t CreateListener(NotificationListener** _listener);
+
+		virtual void SetEventSpecifier(const KMessage* eventSpecifier);
+		const KMessage* EventSpecifier() const	{ return fEventSpecifier; }
+
+	protected:
+		const KMessage* fEventSpecifier;
+};
+
+class UserMessagingListenerUpdater : public NotificationListenerUpdater {
+	public:
+		UserMessagingListenerUpdater(const KMessage* eventSpecifier, port_id port,
+			int32 token);
+
+		virtual status_t UpdateListener(NotificationListener& listener,
+			enum update_action& action);
+
+	protected:
+		virtual status_t UpdateListener(UserMessagingListener& listener,
+			enum update_action& action) = 0;
+
+		port_id	fPort;
+		int32	fToken;
+};
+
+class NotificationService : public Referenceable {
+	public:
+		virtual ~NotificationService() = 0;
+
+		virtual status_t AddListener(const KMessage* eventSpecifier,
+			NotificationListener& listener) = 0;
+		virtual status_t RemoveListener(const KMessage* eventSpecifier,
+			NotificationListener& listener) = 0;
+		virtual status_t UpdateListener(NotificationListenerUpdater& updater) = 0;
+
+		virtual const char* Name() = 0;
+		HashTableLink<NotificationService>& Link() { return fLink; }
+
+	private:
+		HashTableLink<NotificationService> fLink;
+};
+
+class NotificationManager {
+	public:
+		static NotificationManager& Manager();
+		static status_t CreateManager();
+
+		status_t RegisterService(NotificationService& service);
+		void UnregisterService(NotificationService& service);
+
+		NotificationService* GetService(const char* name);
+		void PutService(NotificationService* service);
+
+		status_t AddListener(const char* service, uint32 eventMask,
+			NotificationListener& listener);
+		status_t AddListener(const char* service,
+			const KMessage* eventSpecifier, NotificationListener& listener);
+
+		status_t RemoveListener(const char* service, uint32 eventMask,
+			NotificationListener& listener);
+		status_t RemoveListener(const char* service,
+			const KMessage* eventSpecifier, NotificationListener& listener);
+
+		status_t UpdateListener(const char* service,
+			NotificationListenerUpdater& updater);
+
+	private:
+		NotificationManager();
+		~NotificationManager();
+
+		status_t _Init();
+		NotificationService* _ServiceFor(const char* name);
+
+		struct HashDefinition {
+			typedef const char* KeyType;
+			typedef	NotificationService ValueType;
+
+			size_t HashKey(const char* key) const
+				{ return hash_hash_string(key); }
+			size_t Hash(NotificationService *service) const
+				{ return hash_hash_string(service->Name()); }
+			bool Compare(const char* key, NotificationService* service) const
+				{ return !strcmp(key, service->Name()); }
+			HashTableLink<NotificationService>* GetLink(
+					NotificationService* service) const
+				{ return &service->Link(); }
+		};
+
+		static NotificationManager sManager;
+
+		mutex fLock;
+		typedef OpenHashTable<HashDefinition> ServiceHash;
+		ServiceHash	fServiceHash;
+};
+
+extern "C" {
+
+#endif	// __cplusplus
+
+void notifications_init(void);
+
+#ifdef __cplusplus
+}
+#endif	// __cplusplus
+
+#endif	// _KERNEL_NOTIFICATIONS_H

src/system/kernel/Notifications.cpp

@@ -0,0 +1,344 @@
+/*
+ * Copyright 2007, 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>
+
+
+NotificationManager NotificationManager::sManager;
+
+
+// #pragma mark - UserMessagingListener
+
+
+NotificationListener::~NotificationListener()
+{
+}
+
+
+void
+NotificationListener::EventOccured(NotificationService& service,
+	const KMessage* event)
+{
+}
+
+
+void
+NotificationListener::AllListenersNotified()
+{
+}
+
+
+// #pragma mark - UserMessagingMessageSender
+
+
+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::EventOccured(NotificationService& service,
+	const KMessage* event)
+{
+	fSender.SendMessage(event, fPort, fToken);
+}
+
+
+void
+UserMessagingListener::AllListenersNotified()
+{
+	fSender.FlushMessage();
+}
+
+
+// #pragma mark - NotificationListenerUpdater
+
+
+NotificationListenerUpdater::NotificationListenerUpdater(
+		const KMessage* eventSpecifier)
+	: fEventSpecifier(eventSpecifier)
+{
+}
+
+
+NotificationListenerUpdater::~NotificationListenerUpdater()
+{
+}
+
+
+status_t
+NotificationListenerUpdater::UpdateListener(NotificationListener& listener,
+	enum update_action& action)
+{
+	action = SKIP;
+	return B_OK;
+}
+
+
+status_t
+NotificationListenerUpdater::CreateListener(NotificationListener** _listener)
+{
+	return B_ERROR;
+}
+
+
+void
+NotificationListenerUpdater::SetEventSpecifier(const KMessage* eventSpecifier)
+{
+	fEventSpecifier = eventSpecifier;
+}
+
+
+// #pragma mark - NotificationListenerUpdater
+
+
+UserMessagingListenerUpdater::UserMessagingListenerUpdater(
+		const KMessage* eventSpecifier, port_id port, int32 token)
+	:
+	NotificationListenerUpdater(eventSpecifier),
+	fPort(port),
+	fToken(token)
+{
+}
+
+
+status_t
+UserMessagingListenerUpdater::UpdateListener(NotificationListener& _listener,
+	enum update_action& action)
+{
+	UserMessagingListener* listener
+		= dynamic_cast<UserMessagingListener*>(&_listener);
+	if (listener != NULL && listener->Port() == fPort
+		&& listener->Token() == fToken) {
+		return UpdateListener(*listener, action);
+	}
+
+	action = SKIP;
+	return B_OK;
+}
+
+
+//	#pragma mark - NotificationManager
+
+#if 0
+NotificationService::~NotificationService()
+{
+}
+#endif
+
+
+//	#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()
+{
+	status_t status = mutex_init(&fLock, "notification manager");
+	if (status < B_OK)
+		return status;
+
+	return fServiceHash.InitCheck();
+}
+
+
+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.AddReference();
+
+	return status;
+}
+
+
+void
+NotificationManager::UnregisterService(NotificationService& service)
+{
+	MutexLocker _(fLock);
+	fServiceHash.Remove(&service);
+	service.RemoveReference();
+}
+
+
+status_t
+NotificationManager::AddListener(const char* serviceName,
+	uint32 eventMask, NotificationListener& listener)
+{
+	char buffer[96];
+	KMessage specifier;
+	specifier.SetTo(buffer, sizeof(buffer), 0);
+	specifier.AddInt32("event mask", 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;
+
+	Reference<NotificationService> reference(service);
+	locker.Unlock();
+
+	return service->AddListener(eventSpecifier, listener);
+}
+
+
+status_t
+NotificationManager::RemoveListener(const char* serviceName, uint32 eventMask,
+	NotificationListener& listener)
+{
+	char buffer[96];
+	KMessage specifier;
+	specifier.SetTo(buffer, sizeof(buffer), 0);
+	specifier.AddInt32("event mask", eventMask);
+
+	return RemoveListener(serviceName, &specifier, 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;
+
+	Reference<NotificationService> reference(service);
+	locker.Unlock();
+
+	return service->RemoveListener(eventSpecifier, listener);
+}
+
+
+status_t
+NotificationManager::UpdateListener(const char* serviceName,
+	NotificationListenerUpdater& updater)
+{
+	MutexLocker locker(fLock);
+	NotificationService* service = _ServiceFor(serviceName);
+	if (service == NULL)
+		return B_NAME_NOT_FOUND;
+
+	Reference<NotificationService> reference(service);
+	locker.Unlock();
+
+	return service->UpdateListener(updater);
+}
+
+
+//	#pragma mark -
+
+
+extern "C" void
+notifications_init(void)
+{
+	status_t status = NotificationManager::CreateDefault();
+	if (status < B_OK) {
+		panic("Creating the notification manager failed: %s\n",
+			strerror(status));
+	}
+}
+

src/system/kernel/lib/Jamfile

@@ -132,3 +132,13 @@ KernelMergeObject kernel_posix_arch_$(TARGET_ARCH).o :
 
 	: $(TARGET_KERNEL_PIC_CCFLAGS)
 ;
+
+UsePrivateHeaders shared ;
+
+SEARCH_SOURCE = [ FDirName $(HAIKU_TOP) src kits support ] ;
+
+KernelMergeObject kernel_misc.o :
+	Referenceable.cpp
+
+	: $(TARGET_KERNEL_PIC_CCFLAGS)
+;

src/system/kernel/main.c

@@ -26,6 +26,7 @@
 #include <kscheduler.h>
 #include <ksyscalls.h>
 #include <messaging.h>
+#include <Notifications.h>
 #include <port.h>
 #include <real_time_clock.h>
 #include <sem.h>
@@ -156,6 +157,8 @@ _start(kernel_args *bootKernelArgs, int currentCPU)
 		elf_init(&sKernelArgs);
 		TRACE("init scheduler\n");
 		scheduler_init();
+		TRACE("init notification services\n");
+		notifications_init();
 		TRACE("init VFS\n");
 		vfs_init(&sKernelArgs);