afb-evt: Use 16 bits for ids

16 bits are enough

Bug-AGL: SPEC-2968

Change-Id: I0e8708c1d6a3934a342721a6ce5edb4676df6d1b
Signed-off-by: Jose Bollo <jose.bollo@iot.bzh>

6 files changed, 42 insertions, 35 deletions

diff --git a/src/afb-api-dbus.c b/src/afb-api-dbus.c
index 76894caa..0ac4f499 100644
--- a/src/afb-api-dbus.c
+++ b/src/afb-api-dbus.c
@@ -636,9 +636,9 @@ error:
 
 /******************* event structures for server part **********************************/
 
-static void afb_api_dbus_server_event_add(void *closure, const char *event, int eventid);
-static void afb_api_dbus_server_event_remove(void *closure, const char *event, int eventid);
-static void afb_api_dbus_server_event_push(void *closure, const char *event, int eventid, struct json_object *object);
+static void afb_api_dbus_server_event_add(void *closure, const char *event, uint16_t eventid);
+static void afb_api_dbus_server_event_remove(void *closure, const char *event, uint16_t eventid);
+static void afb_api_dbus_server_event_push(void *closure, const char *event, uint16_t eventid, struct json_object *object);
 static void afb_api_dbus_server_event_broadcast(void *closure, const char *event, struct json_object *object, const uuid_binary_t uuid, uint8_t hop);
 
 /* the interface for events broadcasting */
@@ -904,17 +904,17 @@ end:
 	sd_bus_message_unref(msg);
 }
 
-static void afb_api_dbus_server_event_add(void *closure, const char *event, int eventid)
+static void afb_api_dbus_server_event_add(void *closure, const char *event, uint16_t eventid)
 {
 	afb_api_dbus_server_event_send(closure, '+', event, eventid, "", 0);
 }
 
-static void afb_api_dbus_server_event_remove(void *closure, const char *event, int eventid)
+static void afb_api_dbus_server_event_remove(void *closure, const char *event, uint16_t eventid)
 {
 	afb_api_dbus_server_event_send(closure, '-', event, eventid, "", 0);
 }
 
-static void afb_api_dbus_server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
+static void afb_api_dbus_server_event_push(void *closure, const char *event, uint16_t eventid, struct json_object *object)
 {
 	const char *data = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN|JSON_C_TO_STRING_NOSLASHESCAPE);
 	afb_api_dbus_server_event_send(closure, '!', event, eventid, data, 0);
diff --git a/src/afb-evt.c b/src/afb-evt.c
index f54f34e1..c0e43200 100644
--- a/src/afb-evt.c
+++ b/src/afb-evt.c
@@ -56,7 +56,7 @@ struct afb_evt_listener {
 	pthread_rwlock_t rwlock;
 
 	/* count of reference to the listener */
-	int refcount;
+	uint16_t refcount;
 };
 
 /*
@@ -82,10 +82,10 @@ struct afb_evtid {
 #endif
 
 	/* refcount */
-	int refcount;
+	uint16_t refcount;
 
 	/* id of the event */
-	int id;
+	uint16_t id;
 
 	/* has client? */
 	int has_client;
@@ -176,8 +176,8 @@ static struct afb_evt_listener *listeners = NULL;
 /* handling id of events */
 static pthread_rwlock_t events_rwlock = PTHREAD_RWLOCK_INITIALIZER;
 static struct afb_evtid *evtids = NULL;
-static int event_id_counter = 0;
-static int event_id_wrapped = 0;
+static uint16_t event_genid = 0;
+static uint16_t event_count = 0;
 
 /* head of uniqueness of events */
 #if !defined(EVENT_BROADCAST_HOP_MAX)
@@ -545,6 +545,7 @@ struct afb_evtid *afb_evt_evtid_create(const char *fullname)
 {
 	size_t len;
 	struct afb_evtid *evtid, *oevt;
+	uint16_t id;
 
 	/* allocates the event */
 	len = strlen(fullname);
@@ -554,15 +555,20 @@ struct afb_evtid *afb_evt_evtid_create(const char *fullname)
 
 	/* allocates the id */
 	pthread_rwlock_wrlock(&events_rwlock);
+	if (event_count == UINT16_MAX) {
+		pthread_rwlock_unlock(&events_rwlock);
+		free(evtid);
+		ERROR("Can't create more events");
+		return NULL;
+	}
+	event_count++;
 	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;
+		/* TODO add a guard (counting number of event created) */
+		id = ++event_genid;
+		if (!id)
+			id = event_genid = 1;
 		oevt = evtids;
-		while(oevt != NULL && oevt->id != event_id_counter)
+		while(oevt != NULL && oevt->id != id)
 			oevt = oevt->next;
 	} while (oevt != NULL);
 
@@ -571,7 +577,7 @@ struct afb_evtid *afb_evt_evtid_create(const char *fullname)
 	evtid->next = evtids;
 	evtid->refcount = 1;
 	evtid->watchs = NULL;
-	evtid->id = event_id_counter;
+	evtid->id = id;
 	evtid->has_client = 0;
 	pthread_rwlock_init(&evtid->rwlock, NULL);
 	evtids = evtid;
@@ -649,8 +655,10 @@ void afb_evt_evtid_unref(struct afb_evtid *evtid)
 		prv = &evtids;
 		while (*prv && !(found = (*prv == evtid)))
 			prv = &(*prv)->next;
-		if (found)
+		if (found) {
 			*prv = evtid->next;
+			event_count--;
+		}
 		pthread_rwlock_unlock(&events_rwlock);
 
 		/* destroys the event */
@@ -720,7 +728,7 @@ const char *afb_evt_evtid_hooked_name(struct afb_evtid *evtid)
 /*
  * Returns the id of the 'event'
  */
-int afb_evt_evtid_id(struct afb_evtid *evtid)
+uint16_t afb_evt_evtid_id(struct afb_evtid *evtid)
 {
 	return evtid->id;
 }
@@ -943,7 +951,7 @@ const char *afb_evt_event_x2_fullname(struct afb_event_x2 *eventid)
 /*
  * Returns the id of the 'eventid'
  */
-int afb_evt_event_x2_id(struct afb_event_x2 *eventid)
+uint16_t afb_evt_event_x2_id(struct afb_event_x2 *eventid)
 {
 	struct afb_evtid *evtid = afb_evt_event_x2_to_evtid(eventid);
 	return evtid ? evtid->id : 0;
diff --git a/src/afb-evt.h b/src/afb-evt.h
index 3e37df53..6e0297f6 100644
--- a/src/afb-evt.h
+++ b/src/afb-evt.h
@@ -28,10 +28,10 @@ struct afb_evt_listener;
 
 struct afb_evt_itf
 {
-	void (*push)(void *closure, const char *event, int evtid, struct json_object *object);
+	void (*push)(void *closure, const char *event, uint16_t evtid, struct json_object *object);
 	void (*broadcast)(void *closure, const char *event, struct json_object *object, const uuid_binary_t uuid, uint8_t hop);
-	void (*add)(void *closure, const char *event, int evtid);
-	void (*remove)(void *closure, const char *event, int evtid);
+	void (*add)(void *closure, const char *event, uint16_t evtid);
+	void (*remove)(void *closure, const char *event, uint16_t evtid);
 };
 
 extern struct afb_evt_listener *afb_evt_listener_create(const struct afb_evt_itf *itf, void *closure);
@@ -50,7 +50,7 @@ extern struct afb_evtid *afb_evt_evtid_addref(struct afb_evtid *evtid);
 extern void afb_evt_evtid_unref(struct afb_evtid *evtid);
 
 extern const char *afb_evt_evtid_fullname(struct afb_evtid *evtid);
-extern int afb_evt_evtid_id(struct afb_evtid *evtid);
+extern uint16_t afb_evt_evtid_id(struct afb_evtid *evtid);
 
 extern const char *afb_evt_evtid_name(struct afb_evtid *evtid);
 
@@ -62,11 +62,10 @@ extern int afb_evt_watch_add_evtid(struct afb_evt_listener *listener, struct afb
 extern int afb_evt_watch_sub_evtid(struct afb_evt_listener *listener, struct afb_evtid *evtid);
 
 
-
 extern struct afb_event_x2 *afb_evt_event_x2_create(const char *fullname);
 extern struct afb_event_x2 *afb_evt_event_x2_create2(const char *prefix, const char *name);
 extern const char *afb_evt_event_x2_fullname(struct afb_event_x2 *event);
-extern int afb_evt_event_x2_id(struct afb_event_x2 *eventid);
+extern uint16_t afb_evt_event_x2_id(struct afb_event_x2 *eventid);
 extern struct afb_event_x2 *afb_evt_event_x2_addref(struct afb_event_x2 *eventid);
 extern void afb_evt_event_x2_unref(struct afb_event_x2 *eventid);
 
diff --git a/src/afb-export.c b/src/afb-export.c
index 3cf1fc94..a9643f54 100644
--- a/src/afb-export.c
+++ b/src/afb-export.c
@@ -1206,7 +1206,7 @@ static const struct afb_api_x3_itf hooked_api_x3_itf = {
 /*
  * Propagates the event to the service
  */
-static void listener_of_events(void *closure, const char *event, int eventid, struct json_object *object)
+static void listener_of_events(void *closure, const char *event, uint16_t eventid, struct json_object *object)
 {
 	const struct globset_handler *handler;
 	void (*callback)(void *, const char*, struct json_object*, struct afb_api_x3*);
@@ -1250,7 +1250,7 @@ static void listener_of_events(void *closure, const char *event, int eventid, st
 	json_object_put(object);
 }
 
-static void listener_of_pushed_events(void *closure, const char *event, int eventid, struct json_object *object)
+static void listener_of_pushed_events(void *closure, const char *event, uint16_t eventid, struct json_object *object)
 {
 	listener_of_events(closure, event, eventid, object);
 }
diff --git a/src/afb-stub-ws.c b/src/afb-stub-ws.c
index 40addd0b..2a48745b 100644
--- a/src/afb-stub-ws.c
+++ b/src/afb-stub-ws.c
@@ -316,7 +316,7 @@ static struct json_object *client_api_describe_cb(void * closure)
 
 /******************* server part: manage events **********************************/
 
-static void server_event_add_cb(void *closure, const char *event, int eventid)
+static void server_event_add_cb(void *closure, const char *event, uint16_t eventid)
 {
 	struct afb_stub_ws *stubws = closure;
 
@@ -324,7 +324,7 @@ static void server_event_add_cb(void *closure, const char *event, int eventid)
 		afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 }
 
-static void server_event_remove_cb(void *closure, const char *event, int eventid)
+static void server_event_remove_cb(void *closure, const char *event, uint16_t eventid)
 {
 	struct afb_stub_ws *stubws = closure;
 
@@ -332,7 +332,7 @@ static void server_event_remove_cb(void *closure, const char *event, int eventid
 		afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 }
 
-static void server_event_push_cb(void *closure, const char *event, int eventid, struct json_object *object)
+static void server_event_push_cb(void *closure, const char *event, uint16_t eventid, struct json_object *object)
 {
 	struct afb_stub_ws *stubws = closure;
 
diff --git a/src/afb-ws-json1.c b/src/afb-ws-json1.c
index a8461707..4f7991b6 100644
--- a/src/afb-ws-json1.c
+++ b/src/afb-ws-json1.c
@@ -47,7 +47,7 @@ struct afb_wsreq;
 /* predeclaration of websocket callbacks */
 static void aws_on_hangup_cb(void *closure, struct afb_wsj1 *wsj1);
 static void aws_on_call_cb(void *closure, const char *api, const char *verb, struct afb_wsj1_msg *msg);
-static void aws_on_push_cb(void *closure, const char *event, int eventid, struct json_object *object);
+static void aws_on_push_cb(void *closure, const char *event, uint16_t eventid, struct json_object *object);
 static void aws_on_broadcast_cb(void *closure, const char *event, struct json_object *object, const uuid_binary_t uuid, uint8_t hop);
 
 /* predeclaration of wsreq callbacks */
@@ -235,7 +235,7 @@ static void aws_on_event(struct afb_ws_json1 *aws, const char *event, struct jso
 	afb_wsj1_send_event_j(aws->wsj1, event, afb_msg_json_event(event, object));
 }
 
-static void aws_on_push_cb(void *closure, const char *event, int eventid, struct json_object *object)
+static void aws_on_push_cb(void *closure, const char *event, uint16_t eventid, struct json_object *object)
 {
 	aws_on_event(closure, event, object);
 }