X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fafb-evt.c;h=1c81fd53bee206ff6ef9c9218325185d72668a47;hb=170aef20bc3a59d5139c2eff8794d9ba4c83a2e5;hp=00261b6ca8c99ea64785f5d602151491fa8fa91e;hpb=7e0abe76db7b90369429bf387d7aad0fb5a42328;p=src%2Fapp-framework-binder.git

diff --git a/src/afb-evt.c b/src/afb-evt.c
index 00261b6c..1c81fd53 100644
--- a/src/afb-evt.c
+++ b/src/afb-evt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015, 2016 "IoT.bzh"
+ * Copyright (C) 2015, 2016, 2017 "IoT.bzh"
  * Author "Fulup Ar Foll"
  * Author José Bollo <jose.bollo@iot.bzh>
  *
@@ -22,138 +22,369 @@
 #include <string.h>
 #include <assert.h>
 #include <errno.h>
+#include <pthread.h>
 
 #include <json-c/json.h>
 #include <afb/afb-event-itf.h>
 
 #include "afb-evt.h"
-
+#include "afb-hook.h"
+#include "verbose.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;
+
+	/* mutex of the listener */
+	pthread_mutex_t mutex;
+
+	/* 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;
+
+	/* hooking */
+	int hookflags;
+
+	/* mutex of the event */
+	pthread_mutex_t mutex;
+
+	/* 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);
+static const char *evt_name(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,
+	.name = (void*)evt_name
 };
 
+/* head of the list of listeners */
+static pthread_mutex_t listeners_mutex = PTHREAD_MUTEX_INITIALIZER;
 static struct afb_evt_listener *listeners = NULL;
 
-static inline int evt_trash(struct json_object *obj)
-{
-	return 0;
-}
-
-static int evt_broadcast(struct afb_evt_event *evt, struct json_object *object)
-{
-	return afb_evt_broadcast(evt->name, object);
-}
+/* handling id of events */
+static pthread_mutex_t events_mutex = PTHREAD_MUTEX_INITIALIZER;
+static struct afb_evt_event *events = NULL;
+static int event_id_counter = 0;
+static int event_id_wrapped = 0;
 
-int afb_evt_broadcast(const char *event, struct json_object *object)
+/*
+ * Broadcasts the 'event' of 'id' with its 'obj'
+ * 'obj' is released (like json_object_put)
+ * calls hooks if hookflags isn't 0
+ * Returns the count of listener having receive the event.
+ */
+static int broadcast(const char *event, struct json_object *obj, int id, int hookflags)
 {
 	int result;
 	struct afb_evt_listener *listener;
 
+	if (hookflags & afb_hook_flag_evt_broadcast_before)
+		afb_hook_evt_broadcast_before(event, id, obj);
 	result = 0;
+	pthread_mutex_lock(&listeners_mutex);
 	listener = listeners;
 	while(listener) {
-		listener->send(listener->closure, event, json_object_get(object));
+		if (listener->itf->broadcast != NULL) {
+			listener->itf->broadcast(listener->closure, event, id, json_object_get(obj));
+			result++;
+		}
 		listener = listener->next;
 	}
-	json_object_put(object);
+	pthread_mutex_unlock(&listeners_mutex);
+	if (hookflags & afb_hook_flag_evt_broadcast_after)
+		afb_hook_evt_broadcast_after(event, id, obj, result);
+	json_object_put(obj);
 	return result;
 }
 
-static int evt_push(struct afb_evt_event *evt, struct json_object *obj)
+/*
+ * 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 broadcast(evt->name, object, evt->id, evt->hookflags);
+}
+
+/*
+ * 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)
+{
+	return broadcast(event, object, 0, -1);
+}
+
+/*
+ * Pushes the event 'evt' with 'obj' to its listeners
+ * 'obj' is released (like json_object_put)
+ * calls hooks if hookflags isn't 0
+ * Returns the count of listener taht received the event.
+ */
+static int push(struct afb_evt_event *evt, struct json_object *obj, int hookflags)
 {
 	int result;
 	struct afb_evt_watch *watch;
 	struct afb_evt_listener *listener;
 
 	result = 0;
+	pthread_mutex_lock(&evt->mutex);
+	if (hookflags & afb_hook_flag_evt_push_before)
+		afb_hook_evt_push_before(evt->name, evt->id, obj);
 	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));
+			result++;
+		}
 		watch = watch->next_by_event;
 	}
+	if (hookflags & afb_hook_flag_evt_push_after)
+		afb_hook_evt_push_after(evt->name, evt->id, obj, result);
+	pthread_mutex_unlock(&evt->mutex);
 	json_object_put(obj);
 	return result;
 }
 
+/*
+ * Pushes the event 'evt' with 'obj' to its listeners
+ * 'obj' 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)
+{
+	return push(evt, obj, evt->hookflags);
+}
+
+/*
+ * Returns the name associated to the event 'evt'.
+ */
+static const char *evt_name(struct afb_evt_event *evt)
+{
+	const char *name = strchr(evt->name, '/');
+	name = name ? name + 1 : evt->name;
+	if (evt->hookflags & afb_hook_flag_evt_name)
+		afb_hook_evt_name(evt->name, evt->id);
+	return name;
+}
+
+/*
+ * 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)
 {
+	int found;
+	struct afb_evt_event **prv;
+	struct afb_evt_listener *listener;
+
 	if (evt != NULL) {
-		while(evt->watchs != NULL)
-			remove_watch(evt->watchs);
-		free(evt);
+		/* unlinks the event if valid! */
+		pthread_mutex_lock(&events_mutex);
+		found = 0;
+		prv = &events;
+		while (*prv && !(found = (*prv == evt)))
+			prv = &(*prv)->next;
+		if (found)
+			*prv = evt->next;
+		pthread_mutex_unlock(&events_mutex);
+
+		/* destroys the event */
+		if (found) {
+			/* removes all watchers */
+			while(evt->watchs != NULL) {
+				listener = evt->watchs->listener;
+				pthread_mutex_lock(&listener->mutex);
+				pthread_mutex_lock(&evt->mutex);
+				remove_watch(evt->watchs);
+				pthread_mutex_unlock(&evt->mutex);
+				pthread_mutex_unlock(&listener->mutex);
+			}
+
+			/* hook */
+			if (evt->hookflags & afb_hook_flag_evt_drop)
+				afb_hook_evt_drop(evt->name, evt->id);
+
+			/* free */
+			pthread_mutex_destroy(&evt->mutex);
+			free(evt);
+		}
 	}
 }
 
+/*
+ * 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;
+	struct afb_evt_event *evt, *oevt;
 
+	/* 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;
+
+	/* allocates the id */
+	pthread_mutex_lock(&events_mutex);
+	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;
+		oevt = events;
+		while(oevt != NULL && oevt->id != event_id_counter)
+			oevt = oevt->next;
+	} while (oevt != NULL);
+
+	/* initialize the event */
+	memcpy(evt->name, name, len + 1);
+	evt->next = events;
+	evt->watchs = NULL;
+	evt->id = event_id_counter;
+	pthread_mutex_init(&evt->mutex, NULL);
+	events = evt;
+	evt->hookflags = afb_hook_flags_evt(evt->name);
+	if (evt->hookflags & afb_hook_flag_evt_create)
+		afb_hook_evt_create(evt->name, evt->id);
+	pthread_mutex_unlock(&events_mutex);
+
+	/* 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 */
+	pthread_mutex_lock(&listeners_mutex);
 	listener = listeners;
 	while (listener != NULL) {
-		if (listener->send == send && listener->closure == closure)
-			return afb_evt_listener_addref(listener);
+		if (listener->itf == itf && listener->closure == closure) {
+			listener = afb_evt_listener_addref(listener);
+			goto found;
+		}
 		listener = listener->next;
 	}
 
@@ -161,83 +392,124 @@ struct afb_evt_listener *afb_evt_listener_create(void (*send)(void *closure, con
 	listener = calloc(1, sizeof *listener);
 	if (listener != NULL) {
 		/* init */
-		listener->next = listeners;
-		listener->send = send;
+		listener->itf = itf;
 		listener->closure = closure;
 		listener->watchs = NULL;
 		listener->refcount = 1;
+		pthread_mutex_init(&listener->mutex, NULL);
+		listener->next = listeners;
 		listeners = listener;
 	}
+ found:
+	pthread_mutex_unlock(&listeners_mutex);
 	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++;
+	__atomic_add_fetch(&listener->refcount, 1, __ATOMIC_RELAXED);
 	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) {
-		struct afb_evt_listener **prv;
+	struct afb_evt_listener **prv;
+	struct afb_evt_event *evt;
 
-		/* remove the watchers */
-		while (listener->watchs != NULL)
-			remove_watch(listener->watchs);
+	if (!__atomic_sub_fetch(&listener->refcount, 1, __ATOMIC_RELAXED)) {
 
 		/* unlink the listener */
+		pthread_mutex_lock(&listeners_mutex);
 		prv = &listeners;
 		while (*prv != listener)
 			prv = &(*prv)->next;
 		*prv = listener->next;
+		pthread_mutex_unlock(&listeners_mutex);
+
+		/* remove the watchers */
+		pthread_mutex_lock(&listener->mutex);
+		while (listener->watchs != NULL) {
+			evt = listener->watchs->event;
+			pthread_mutex_lock(&evt->mutex);
+			remove_watch(listener->watchs);
+			pthread_mutex_unlock(&evt->mutex);
+		}
+		pthread_mutex_unlock(&listener->mutex);
 
 		/* free the listener */
+		pthread_mutex_destroy(&listener->mutex);
 		free(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;
+	pthread_mutex_lock(&listener->mutex);
 	watch = listener->watchs;
 	while(watch != NULL) {
-		if (watch->event == event.closure)
-			return 0;
+		if (watch->event == evt)
+			goto found;
 		watch = watch->next_by_listener;
 	}
 
 	/* not found, allocate a new */
 	watch = malloc(sizeof *watch);
 	if (watch == NULL) {
+		pthread_mutex_unlock(&listener->mutex);
 		errno = ENOMEM;
 		return -1;
 	}
 
 	/* initialise and link */
-	evt = event.closure;
 	watch->event = evt;
-	watch->next_by_event = evt->watchs;
+	watch->activity = 0;
 	watch->listener = listener;
 	watch->next_by_listener = listener->watchs;
-	evt->watchs = watch;
 	listener->watchs = watch;
-	
+	pthread_mutex_lock(&evt->mutex);
+	watch->next_by_event = evt->watchs;
+	evt->watchs = watch;
+	pthread_mutex_unlock(&evt->mutex);
+
+found:
+	if (watch->activity == 0 && listener->itf->add != NULL)
+		listener->itf->add(listener->closure, evt->name, evt->id);
+	watch->activity++;
+	pthread_mutex_unlock(&listener->mutex);
+
 	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) {
@@ -246,16 +518,52 @@ int afb_evt_remove_watch(struct afb_evt_listener *listener, struct afb_event eve
 	}
 
 	/* search the existing watch */
+	evt = event.closure;
+	pthread_mutex_lock(&listener->mutex);
 	watch = listener->watchs;
 	while(watch != NULL) {
-		if (watch->event == event.closure) {
-			/* found: remove it */
-			remove_watch(watch);
-			break;
+		if (watch->event == evt) {
+			if (watch->activity != 0) {
+				watch->activity--;
+				if (watch->activity == 0 && listener->itf->remove != NULL)
+					listener->itf->remove(listener->closure, evt->name, evt->id);
+			}
+			pthread_mutex_unlock(&listener->mutex);
+			return 0;
 		}
 		watch = watch->next_by_listener;
 	}
+	pthread_mutex_unlock(&listener->mutex);
+	errno = ENOENT;
+	return -1;
+}
+
+/*
+ * update the hooks for events
+ */
+void afb_evt_update_hooks()
+{
+	struct afb_evt_event *evt;
+
+	pthread_mutex_lock(&events_mutex);
+	for (evt = events ; evt ; evt = evt->next)
+		evt->hookflags = afb_hook_flags_evt(evt->name);
+	pthread_mutex_unlock(&events_mutex);
+}
+
+int afb_evt_push(struct afb_event event, struct json_object *object)
+{
+	if (event.itf == &afb_evt_event_itf)
+		return evt_push((struct afb_evt_event *)event.closure, object);
+	json_object_put(object);
 	return 0;
 }
 
+int afb_evt_unhooked_push(struct afb_event event, struct json_object *object)
+{
+	if (event.itf == &afb_evt_event_itf)
+		return push((struct afb_evt_event *)event.closure, object, 0);
+	json_object_put(object);
+	return 0;
+}