Tony said I should use a rwlock for this, so now I do

diff --git a/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c b/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c
index 48068bd1ddc54799ef4b80e62a803bd374459d60..22c78887d121165f5bcb8838fd1b1800b8cf5c3e 100644 (file)
--- a/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c
+++ b/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c
@@ -148,7 +148,11 @@ static void send_event_to_attached_sessions(listener_t *listener, switch_event_t
                return;
        }
 
-       if ((s = (session_elem_t*)switch_core_hash_find(listener->sessions, uuid))) {
+       switch_thread_rwlock_rdlock(listener->session_rwlock);
+       s = (session_elem_t*)switch_core_hash_find(listener->sessions, uuid);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
+
+       if (s) {
                int send = 0;
                if (s->event_list[SWITCH_EVENT_ALL]) {
                        send = 1;
@@ -315,7 +319,9 @@ static listener_t *find_listener(char *nodename)
 
 static void add_session_elem_to_listener(listener_t *listener, session_elem_t *session_element)
 {
-       switch_core_hash_insert_locked(listener->sessions, session_element->uuid_str, (void*) session_element, listener->session_mutex);
+       switch_thread_rwlock_wrlock(listener->session_rwlock);
+       switch_core_hash_insert(listener->sessions, session_element->uuid_str, (void*) session_element);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
 }
 
 
@@ -340,9 +346,9 @@ static void destroy_session_elem(session_elem_t *session_element)
 
 static void remove_session_elem_from_listener_locked(listener_t *listener, session_elem_t *session_element)
 {
-       switch_mutex_lock(listener->session_mutex);
+       switch_thread_rwlock_wrlock(listener->session_rwlock);
        remove_session_elem_from_listener(listener, session_element);
-       switch_mutex_unlock(listener->session_mutex);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
 }
 
 
@@ -353,16 +359,16 @@ session_elem_t *find_session_elem_by_pid(listener_t *listener, erlang_pid *pid)
        void *val = NULL;
        session_elem_t *session = NULL;
 
-       switch_mutex_lock(listener->session_mutex);
+       switch_thread_rwlock_rdlock(listener->session_rwlock);
        for (iter = switch_hash_first(NULL, listener->sessions); iter; iter = switch_hash_next(iter)) {
                switch_hash_this(iter, &key, NULL, &val);
                session = (session_elem_t*)val;
                if (session->process.type == ERLANG_PID && !ei_compare_pids(pid, &session->process.pid)) {
-                       switch_mutex_unlock(listener->session_mutex);
+                       switch_thread_rwlock_unlock(listener->session_rwlock);
                        return session;
                }
        }
-       switch_mutex_unlock(listener->session_mutex);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
 
        return NULL;
 }
@@ -579,7 +585,7 @@ static switch_status_t check_attached_sessions(listener_t *listener)
           if they have pending events in their queues then send them
           if the session has finished then clean it up
         */
-       switch_mutex_lock(listener->session_mutex);
+       switch_thread_rwlock_rdlock(listener->session_rwlock);
        for (iter = switch_hash_first(NULL, listener->sessions); iter; iter = switch_hash_next(iter)) {
                switch_hash_this(iter, &key, NULL, &value);
                sp = (session_elem_t*)value;
@@ -659,6 +665,9 @@ static switch_status_t check_attached_sessions(listener_t *listener)
                        switch_event_destroy(&pevent);
                }
        }
+       switch_thread_rwlock_unlock(listener->session_rwlock);
+       /* release the read lock and get a write lock */
+       switch_thread_rwlock_wrlock(listener->session_rwlock);
        /* do the deferred remove */
        for (header = event->headers; header; header = header->next) {
                if ((sp = (session_elem_t*)switch_core_hash_find(listener->sessions, header->value))) {
@@ -667,7 +676,7 @@ static switch_status_t check_attached_sessions(listener_t *listener)
                }
        }
 
-       switch_mutex_unlock(listener->session_mutex);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
        if (prefs.done) {
                return SWITCH_STATUS_FALSE;     /* we're shutting down */
        } else {
@@ -996,14 +1005,13 @@ static void *SWITCH_THREAD_FUNC listener_run(switch_thread_t *thread, void *obj)
        remove_binding(listener, NULL);
 
        /* clean up all the attached sessions */
-       switch_mutex_lock(listener->session_mutex); // TODO is iterating thread safe?
-       /* TODO destroy memory pools since they're not children of the listener's pool */
+       switch_thread_rwlock_wrlock(listener->session_rwlock);
        for (iter = switch_hash_first(NULL, listener->sessions); iter; iter = switch_hash_next(iter)) {
                switch_hash_this(iter, &key, NULL, &value);
                s = (session_elem_t*)value;
                destroy_session_elem(s);
        }
-       switch_mutex_unlock(listener->session_mutex);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
 
        if (listener->pool) {
                switch_memory_pool_t *pool = listener->pool;
@@ -1134,7 +1142,7 @@ static listener_t *new_listener(struct ei_cnode_s *ec, int clientfd)
        listener->level = SWITCH_LOG_DEBUG;
        switch_mutex_init(&listener->flag_mutex, SWITCH_MUTEX_NESTED, listener->pool);
        switch_mutex_init(&listener->sock_mutex, SWITCH_MUTEX_NESTED, listener->pool);
-       switch_mutex_init(&listener->session_mutex, SWITCH_MUTEX_NESTED, listener->pool);
+       switch_thread_rwlock_create(&listener->session_rwlock, listener->pool);
        switch_core_hash_init(&listener->event_hash, listener->pool);
        switch_core_hash_init(&listener->sessions, listener->pool);
 
@@ -1349,12 +1357,11 @@ int count_listener_sessions(listener_t *listener)
        int count = 0;
        switch_hash_index_t *iter;
 
-       switch_mutex_lock(listener->session_mutex);
+       switch_thread_rwlock_rdlock(listener->session_rwlock);
        for (iter = switch_hash_first(NULL, listener->sessions); iter; iter = switch_hash_next(iter)) {
                count++;
        }
-
-       switch_mutex_unlock(listener->session_mutex);
+       switch_thread_rwlock_unlock(listener->session_rwlock);
 
        return count;
 }
@@ -1559,7 +1566,7 @@ SWITCH_STANDARD_API(erlang_cmd)
                                void *value;
 
                                found = 1;
-                               switch_mutex_lock(l->session_mutex);
+                               switch_thread_rwlock_rdlock(l->session_rwlock);
                                for (iter = switch_hash_first(NULL, l->sessions); iter; iter = switch_hash_next(iter)) {
                                        empty = 0;
                                        switch_hash_this(iter, &key, NULL, &value);
@@ -1571,7 +1578,7 @@ SWITCH_STANDARD_API(erlang_cmd)
                                if (empty) {
                                        stream->write_function(stream, "No active sessions for %s\n", argv[1]);
                                }
-                               switch_mutex_unlock(l->session_mutex);
+                               switch_thread_rwlock_unlock(l->session_rwlock);
                                break;
                        }
                }
@@ -1581,7 +1588,8 @@ SWITCH_STANDARD_API(erlang_cmd)
                        stream->write_function(stream, "Could not find a listener for %s\n", argv[1]);
 
        } else {
-               stream->write_function(stream, "USAGE: erlang sessions <nodename>\n");
+               stream->write_function(stream,  "USAGE: erlang sessions <nodename>\n"
+                                                                               "       erlang listeners\n");
                goto done;
        }
 

diff --git a/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.h b/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.h
index 65f8a89e49bd6b6d26314888987c525e6ca43e0a..a900f02dcec80750750a2ae6c69136a86a6257c9 100644 (file)
--- a/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.h
+++ b/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.h
@@ -107,7 +107,7 @@ struct listener {
        switch_hash_t *event_hash;
        switch_hash_t *spawn_pid_hash;
        switch_thread_rwlock_t *rwlock;
-       switch_mutex_t *session_mutex;
+       switch_thread_rwlock_t *session_rwlock;
        //session_elem_t *session_list;
        switch_hash_t *sessions;
        int lost_events;