Index: app_meetme.c
===================================================================
--- app_meetme.c        (revision 59193)
+++ app_meetme.c        (working copy)
@@ -513,6 +513,11 @@
        .thread = AST_PTHREADT_NULL,
 };

+/*! map of being used conference numbers. */
+static int conf_map[1024] = { 0, };
+/*! conf_map mutex lock */
+AST_MUTEX_DEFINE_STATIC(conf_map_lock);
+
 /*! The number of audio buffers to be allocated on pseudo channels
  *  when in a conference */
 static int audio_buffers;
@@ -720,7 +725,7 @@
 {
        struct ast_conference *cnf;
        struct zt_confinfo ztc = { 0, };
-
+       int confno_int = 0;
        AST_LIST_LOCK(&confs);

        AST_LIST_TRAVERSE(&confs, cnf, list) {
@@ -780,7 +785,10 @@
 cnfout:
        if (cnf)
                ast_atomic_fetchadd_int(&cnf->refcount, refcount);
-
+       ast_mutex_lock(&conf_map_lock);
+       sscanf(confno, "%d", &confno_int);
+       conf_map[confno_int]++;
+       ast_mutex_unlock(&conf_map_lock);
        AST_LIST_UNLOCK(&confs);

        return cnf;
@@ -1312,12 +1320,18 @@
 static int dispose_conf(struct ast_conference *conf)
 {
        int res = 0;
+       int confno_int = 0;

        AST_LIST_LOCK(&confs);
        if (ast_atomic_dec_and_test(&conf->refcount)) {
                conf_free(conf);
                res = 1;
        }
+       /* free conf_map usage */
+       ast_mutex_lock(&conf_map_lock);
+       sscanf(conf->confno, "%d", &confno_int);
+       conf_map[confno_int] = 0;
+       ast_mutex_unlock(&conf_map_lock);
        AST_LIST_UNLOCK(&confs);

        return res;
@@ -2521,21 +2535,11 @@
                if (retrycnt > 3)
                        allowretry = 0;
                if (empty) {
-                       int i, map[1024] = { 0, };
+                       int i;
                        struct ast_config *cfg;
                        struct ast_variable *var;
                        int confno_int;
-
-                       AST_LIST_LOCK(&confs);
-                       AST_LIST_TRAVERSE(&confs, cnf, list) {
-                               if (sscanf(cnf->confno, "%d", &confno_int) == 1) {
-                                       /* Disqualify in use conference */
-                                       if (confno_int >= 0 && confno_int < 1024)
-                                               map[confno_int]++;
-                               }
-                       }
-                       AST_LIST_UNLOCK(&confs);
-
+
                        /* We only need to load the config file for static and empty_no_pin (otherwise we don't care) */
                        if ((empty_no_pin) || (!dynamic)) {
                                cfg = ast_config_load(CONFIG_FILE_NAME);
@@ -2547,13 +2551,6 @@
                                                        if (stringp) {
                                                                char *confno_tmp = strsep(&stringp, "|,");
                                                                int found = 0;
-                                                               if (sscanf(confno_tmp, "%d", &confno_int) == 1) {
-                                                                       if ((confno_int >= 0) && (confno_int < 1024)) {
-                                                                               if (stringp && empty_no_pin) {
-                                                                                       map[confno_int]++;
-                                                                               }
-                                                                       }
-                                                               }
                                                                if (!dynamic) {
                                                                        /* For static:  run through the list and see if this conference is empty */
                                                                        AST_LIST_LOCK(&confs);
@@ -2588,12 +2585,15 @@

                        /* Select first conference number not in use */
                        if (ast_strlen_zero(confno) && dynamic) {
-                               for (i = 0; i < sizeof(map) / sizeof(map[0]); i++) {
-                                       if (!map[i]) {
+                               ast_mutex_lock(&conf_map_lock);
+                               for (i = 0; i < sizeof(conf_map) / sizeof(conf_map[0]); i++) {
+                                       if (!conf_map[i]) {
                                                snprintf(confno, sizeof(confno), "%d", i);
+                                               conf_map[i]++;
                                                break;
                                        }
                                }
+                               ast_mutex_unlock(&conf_map_lock);
                        }

                        /* Not found? */