X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fafb-evt.c;h=4924b8cb2b642bee647cc99b786176405463bf85;hb=bca90021828565bddb8624e8f6370bf4959cbfbf;hp=ad5695f140ef6355b6082d973fdab24541ef7baf;hpb=769cec6b4fed063de7f8f54e5fb4283bdb14ecf9;p=src%2Fapp-framework-binder.git

diff --git a/src/afb-evt.c b/src/afb-evt.c
index ad5695f1..4924b8cb 100644
--- a/src/afb-evt.c
+++ b/src/afb-evt.c
@@ -28,46 +28,103 @@
 
 #include "afb-evt.h"
 
-
 struct afb_evt_watch;
 
+/*
+ * Structure for event listeners
+ */
 struct afb_evt_listener {
+
+	/* chaining listeners */
 	struct afb_evt_listener *next;
-	void (*send)(void *closure, const char *event, struct json_object *object);
+
+	/* interface for callbacks */
+	const struct afb_evt_itf *itf;
+
+	/* closure for the callback */
 	void *closure;
+
+	/* head of the list of events listened */
 	struct afb_evt_watch *watchs;
+
+	/* count of reference to the listener */
 	int refcount;
 };
 
+/*
+ * Structure for describing events
+ */
 struct afb_evt_event {
+
+	/* next event */
+	struct afb_evt_event *next;
+
+	/* head of the list of listeners watching the event */
 	struct afb_evt_watch *watchs;
+
+	/* id of the event */
+	int id;
+
+	/* name of the event */
 	char name[1];
 };
 
+/*
+ * Structure for associating events and listeners
+ */
 struct afb_evt_watch {
+
+	/* the event */
 	struct afb_evt_event *event;
+
+	/* link to the next listener for the same event */
 	struct afb_evt_watch *next_by_event;
+
+	/* the listener */
 	struct afb_evt_listener *listener;
+
+	/* link to the next event for the same listener */
 	struct afb_evt_watch *next_by_listener;
+
+	/* activity */
+	unsigned activity;
 };
 
+/* declare functions */
 static int evt_broadcast(struct afb_evt_event *evt, struct json_object *obj);
 static int evt_push(struct afb_evt_event *evt, struct json_object *obj);
-static void evt_drop(struct afb_evt_event *evt);
+static void evt_destroy(struct afb_evt_event *evt);
 
+/* the interface for events */
 static struct afb_event_itf afb_evt_event_itf = {
 	.broadcast = (void*)evt_broadcast,
 	.push = (void*)evt_push,
-	.drop = (void*)evt_drop
+	.drop = (void*)evt_destroy
 };
 
+/* head of the list of listeners */
 static struct afb_evt_listener *listeners = NULL;
 
+/* handling id of events */
+static struct afb_evt_event *events = NULL;
+static int event_id_counter = 0;
+static int event_id_wrapped = 0;
+
+/*
+ * Broadcasts the event 'evt' with its 'object'
+ * 'object' is released (like json_object_put)
+ * Returns the count of listener that received the event.
+ */
 static int evt_broadcast(struct afb_evt_event *evt, struct json_object *object)
 {
 	return afb_evt_broadcast(evt->name, object);
 }
 
+/*
+ * Broadcasts the 'event' with its 'object'
+ * 'object' is released (like json_object_put)
+ * Returns the count of listener having receive the event.
+ */
 int afb_evt_broadcast(const char *event, struct json_object *object)
 {
 	int result;
@@ -76,13 +133,21 @@ int afb_evt_broadcast(const char *event, struct json_object *object)
 	result = 0;
 	listener = listeners;
 	while(listener) {
-		listener->send(listener->closure, event, json_object_get(object));
+		if (listener->itf->broadcast != NULL) {
+			listener->itf->broadcast(listener->closure, event, 0, json_object_get(object));
+			result++;
+		}
 		listener = listener->next;
 	}
 	json_object_put(object);
 	return result;
 }
 
+/*
+ * Broadcasts the event 'evt' with its 'object'
+ * 'object' is released (like json_object_put)
+ * Returns the count of listener taht received the event.
+ */
 static int evt_push(struct afb_evt_event *evt, struct json_object *obj)
 {
 	int result;
@@ -91,63 +156,148 @@ static int evt_push(struct afb_evt_event *evt, struct json_object *obj)
 
 	result = 0;
 	watch = evt->watchs;
-	while(listener) {
+	while(watch) {
 		listener = watch->listener;
-		listener->send(listener->closure, evt->name, json_object_get(obj));
+		assert(listener->itf->push != NULL);
+		if (watch->activity != 0)
+			listener->itf->push(listener->closure, evt->name, evt->id, json_object_get(obj));
 		watch = watch->next_by_event;
+		result++;
 	}
 	json_object_put(obj);
 	return result;
 }
 
+/*
+ * remove the 'watch'
+ */
 static void remove_watch(struct afb_evt_watch *watch)
 {
 	struct afb_evt_watch **prv;
+	struct afb_evt_event *evt;
+	struct afb_evt_listener *listener;
+
+	/* notify listener if needed */
+	evt = watch->event;
+	listener = watch->listener;
+	if (watch->activity != 0 && listener->itf->remove != NULL)
+		listener->itf->remove(listener->closure, evt->name, evt->id);
 
-	prv = &watch->event->watchs;
+	/* unlink the watch for its event */
+	prv = &evt->watchs;
 	while(*prv != watch)
 		prv = &(*prv)->next_by_event;
 	*prv = watch->next_by_event;
 
-	prv = &watch->listener->watchs;
+	/* unlink the watch for its listener */
+	prv = &listener->watchs;
 	while(*prv != watch)
 		prv = &(*prv)->next_by_listener;
 	*prv = watch->next_by_listener;
 
+	/* recycle memory */
 	free(watch);
 }
 
-static void evt_drop(struct afb_evt_event *evt)
+/*
+ * Destroys the event 'evt'
+ */
+static void evt_destroy(struct afb_evt_event *evt)
 {
+	struct afb_evt_event **prv;
 	if (evt != NULL) {
-		while(evt->watchs != NULL)
-			remove_watch(evt->watchs);
-		free(evt);
+		/* removes the event if valid! */
+		prv = &events;
+		while (*prv != NULL) {
+			if (*prv != evt)
+				prv = &(*prv)->next;
+			else {
+				/* valid, unlink */
+				*prv = evt->next;
+
+				/* removes all watchers */
+				while(evt->watchs != NULL)
+					remove_watch(evt->watchs);
+
+				/* free */
+				free(evt);
+				break;
+			}
+		}
 	}
 }
 
+/*
+ * Creates an event of 'name' and returns it.
+ * Returns an event with closure==NULL in case of error.
+ */
 struct afb_event afb_evt_create_event(const char *name)
 {
 	size_t len;
 	struct afb_evt_event *evt;
 
+	/* allocates the id */
+	do {
+		if (++event_id_counter < 0) {
+			event_id_wrapped = 1;
+			event_id_counter = 1024; /* heuristic: small numbers are not destroyed */
+		}
+		if (!event_id_wrapped)
+			break;
+		evt = events;
+		while(evt != NULL && evt->id != event_id_counter)
+			evt = evt->next;
+	} while (evt != NULL);
+
+	/* allocates the event */
 	len = strlen(name);
 	evt = malloc(len + sizeof * evt);
-	if (evt != NULL) {
-		evt->watchs = NULL;
-		memcpy(evt->name, name, len + 1);
-	}
+	if (evt == NULL)
+		goto error;
+
+	/* initialize the event */
+	evt->next = events;
+	evt->watchs = NULL;
+	evt->id = event_id_counter;
+	assert(evt->id > 0);
+	memcpy(evt->name, name, len + 1);
+	events = evt;
+
+	/* returns the event */
 	return (struct afb_event){ .itf = &afb_evt_event_itf, .closure = evt };
+error:
+	return (struct afb_event){ .itf = NULL, .closure = NULL };
+}
+
+/*
+ * Returns the name of the 'event'
+ */
+const char *afb_evt_event_name(struct afb_event event)
+{
+	return (event.itf != &afb_evt_event_itf) ? NULL : ((struct afb_evt_event *)event.closure)->name;
+}
+
+/*
+ * Returns the id of the 'event'
+ */
+int afb_evt_event_id(struct afb_event event)
+{
+	return (event.itf != &afb_evt_event_itf) ? 0 : ((struct afb_evt_event *)event.closure)->id;
 }
 
-struct afb_evt_listener *afb_evt_listener_create(void (*send)(void *closure, const char *event, struct json_object *object), void *closure)
+/*
+ * Returns an instance of the listener defined by the 'send' callback
+ * and the 'closure'.
+ * Returns NULL in case of memory depletion.
+ */
+struct afb_evt_listener *afb_evt_listener_create(const struct afb_evt_itf *itf, void *closure)
 {
 	struct afb_evt_listener *listener;
 
 	/* search if an instance already exists */
 	listener = listeners;
 	while (listener != NULL) {
-		if (listener->send == send && listener->closure == closure)
+		if (listener->itf == itf && listener->closure == closure)
 			return afb_evt_listener_addref(listener);
 		listener = listener->next;
 	}
@@ -157,7 +307,7 @@ struct afb_evt_listener *afb_evt_listener_create(void (*send)(void *closure, con
 	if (listener != NULL) {
 		/* init */
 		listener->next = listeners;
-		listener->send = send;
+		listener->itf = itf;
 		listener->closure = closure;
 		listener->watchs = NULL;
 		listener->refcount = 1;
@@ -166,12 +316,19 @@ struct afb_evt_listener *afb_evt_listener_create(void (*send)(void *closure, con
 	return listener;
 }
 
+/*
+ * Increases the reference count of 'listener' and returns it
+ */
 struct afb_evt_listener *afb_evt_listener_addref(struct afb_evt_listener *listener)
 {
 	listener->refcount++;
 	return listener;
 }
 
+/*
+ * Decreases the reference count of the 'listener' and destroys it
+ * when no more used.
+ */
 void afb_evt_listener_unref(struct afb_evt_listener *listener)
 {
 	if (0 == --listener->refcount) {
@@ -192,22 +349,27 @@ void afb_evt_listener_unref(struct afb_evt_listener *listener)
 	}
 }
 
+/*
+ * Makes the 'listener' watching 'event'
+ * Returns 0 in case of success or else -1.
+ */
 int afb_evt_add_watch(struct afb_evt_listener *listener, struct afb_event event)
 {
 	struct afb_evt_watch *watch;
 	struct afb_evt_event *evt;
 
 	/* check parameter */
-	if (event.itf != &afb_evt_event_itf) {
+	if (event.itf != &afb_evt_event_itf || listener->itf->push == NULL) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	/* search the existing watch */
+	/* search the existing watch for the listener */
+	evt = event.closure;
 	watch = listener->watchs;
 	while(watch != NULL) {
-		if (watch->event == event.closure)
-			return 0;
+		if (watch->event == evt)
+			goto found;
 		watch = watch->next_by_listener;
 	}
 
@@ -219,20 +381,30 @@ int afb_evt_add_watch(struct afb_evt_listener *listener, struct afb_event event)
 	}
 
 	/* initialise and link */
-	evt = event.closure;
 	watch->event = evt;
 	watch->next_by_event = evt->watchs;
 	watch->listener = listener;
 	watch->next_by_listener = listener->watchs;
+	watch->activity = 0;
 	evt->watchs = watch;
 	listener->watchs = watch;
-	
+
+found:
+	if (watch->activity == 0 && listener->itf->add != NULL)
+		listener->itf->add(listener->closure, evt->name, evt->id);
+	watch->activity++;
+
 	return 0;
 }
 
+/*
+ * Avoids the 'listener' to watch 'event'
+ * Returns 0 in case of success or else -1.
+ */
 int afb_evt_remove_watch(struct afb_evt_listener *listener, struct afb_event event)
 {
 	struct afb_evt_watch *watch;
+	struct afb_evt_event *evt;
 
 	/* check parameter */
 	if (event.itf != &afb_evt_event_itf) {
@@ -241,16 +413,21 @@ int afb_evt_remove_watch(struct afb_evt_listener *listener, struct afb_event eve
 	}
 
 	/* search the existing watch */
+	evt = event.closure;
 	watch = listener->watchs;
 	while(watch != NULL) {
-		if (watch->event == event.closure) {
+		if (watch->event == evt) {
 			/* found: remove it */
-			remove_watch(watch);
-			break;
+			if (watch->activity != 0) {
+				watch->activity--;
+				if (watch->activity == 0 && listener->itf->remove != NULL)
+					listener->itf->remove(listener->closure, evt->name, evt->id);
+			}
+			return 0;
 		}
 		watch = watch->next_by_listener;
 	}
-	return 0;
+	errno = ENOENT;
+	return -1;
 }
 
-