Fix an issue that made it so you could only have a single caller executing

a custom feature at a time.  This was especially problematic when custom
features ran for any appreciable amount of time.

The fix turned out to be quite simple.  The dynamic features are now stored
in a read/write list instead of a list using a mutex.

(closes issue #13478)
Reported by: neutrino88
Fix suggested by file


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@163092 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_features.c

@@ -1008,7 +1008,7 @@ static struct ast_call_feature builtin_features[] =
 };
 
 
-static AST_LIST_HEAD_STATIC(feature_list,ast_call_feature);
+static AST_RWLIST_HEAD_STATIC(feature_list, ast_call_feature);
 
 /*! \brief register new feature into feature_list*/
 void ast_register_feature(struct ast_call_feature *feature)
@@ -1018,12 +1018,13 @@ void ast_register_feature(struct ast_call_feature *feature)
     		return;
 	}
   
-	AST_LIST_LOCK(&feature_list);
-	AST_LIST_INSERT_HEAD(&feature_list,feature,feature_entry);
-	AST_LIST_UNLOCK(&feature_list);
+	AST_RWLIST_WRLOCK(&feature_list);
+	AST_RWLIST_INSERT_HEAD(&feature_list, feature, feature_entry);
+	AST_RWLIST_UNLOCK(&feature_list);
 
-	if (option_verbose >= 2) 
+	if (option_verbose >= 2) {
 		ast_verbose(VERBOSE_PREFIX_2 "Registered Feature '%s'\n",feature->sname);
+	}
 }
 
 /*! \brief unregister feature from feature_list */
@@ -1032,9 +1033,10 @@ void ast_unregister_feature(struct ast_call_feature *feature)
 	if (!feature)
 		return;
 
-	AST_LIST_LOCK(&feature_list);
-	AST_LIST_REMOVE(&feature_list,feature,feature_entry);
-	AST_LIST_UNLOCK(&feature_list);
+	AST_RWLIST_WRLOCK(&feature_list);
+	AST_RWLIST_REMOVE(&feature_list, feature, feature_entry);
+	AST_RWLIST_UNLOCK(&feature_list);
+	
 	free(feature);
 }
 
@@ -1043,10 +1045,11 @@ static void ast_unregister_features(void)
 {
 	struct ast_call_feature *feature;
 
-	AST_LIST_LOCK(&feature_list);
-	while ((feature = AST_LIST_REMOVE_HEAD(&feature_list,feature_entry)))
+	AST_RWLIST_WRLOCK(&feature_list);
+	while ((feature = AST_LIST_REMOVE_HEAD(&feature_list, feature_entry))) {
 		free(feature);
-	AST_LIST_UNLOCK(&feature_list);
+	}
+	AST_RWLIST_UNLOCK(&feature_list);
 }
 
 /*! \brief find a feature by name */
@@ -1054,9 +1057,10 @@ static struct ast_call_feature *find_dynamic_feature(const char *name)
 {
 	struct ast_call_feature *tmp;
 
-	AST_LIST_TRAVERSE(&feature_list, tmp, feature_entry) {
-		if (!strcasecmp(tmp->sname, name))
+	AST_RWLIST_TRAVERSE(&feature_list, tmp, feature_entry) {
+		if (!strcasecmp(tmp->sname, name)) {
 			break;
+		}
 	}
 
 	return tmp;
@@ -1201,9 +1205,9 @@ static int ast_feature_interpret(struct ast_channel *chan, struct ast_channel *p
 	tmp = ast_strdupa(dynamic_features);
 
 	while ((tok = strsep(&tmp, "#"))) {
-		AST_LIST_LOCK(&feature_list);	
+		AST_RWLIST_RDLOCK(&feature_list);	
 		if (!(feature = find_dynamic_feature(tok))) {
-			AST_LIST_UNLOCK(&feature_list);
+			AST_RWLIST_UNLOCK(&feature_list);
 			continue;
 		}
 			
@@ -1213,14 +1217,14 @@ static int ast_feature_interpret(struct ast_channel *chan, struct ast_channel *p
 				ast_verbose(VERBOSE_PREFIX_3 " Feature Found: %s exten: %s\n",feature->sname, tok);
 			res = feature->operation(chan, peer, config, code, sense, feature);
 			if (res != FEATURE_RETURN_KEEPTRYING) {
-				AST_LIST_UNLOCK(&feature_list);
+				AST_RWLIST_UNLOCK(&feature_list);
 				break;
 			}
 			res = FEATURE_RETURN_PASSDIGITS;
 		} else if (!strncmp(feature->exten, code, strlen(code)))
 			res = FEATURE_RETURN_STOREDIGITS;
 
-		AST_LIST_UNLOCK(&feature_list);
+		AST_RWLIST_UNLOCK(&feature_list);
 	}
 	
 	return res;
@@ -1255,14 +1259,14 @@ static void set_config_flags(struct ast_channel *chan, struct ast_channel *peer,
 
 			/* while we have a feature */
 			while ((tok = strsep(&tmp, "#"))) {
-				AST_LIST_LOCK(&feature_list);
+				AST_RWLIST_RDLOCK(&feature_list);
 				if ((feature = find_dynamic_feature(tok)) && ast_test_flag(feature, AST_FEATURE_FLAG_NEEDSDTMF)) {
 					if (ast_test_flag(feature, AST_FEATURE_FLAG_BYCALLER))
 						ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_0);
 					if (ast_test_flag(feature, AST_FEATURE_FLAG_BYCALLEE))
 						ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_1);
 				}
-				AST_LIST_UNLOCK(&feature_list);
+				AST_RWLIST_UNLOCK(&feature_list);
 			}
 		}
 	}
@@ -2286,13 +2290,14 @@ static int handle_showfeatures(int fd, int argc, char *argv[])
 	ast_cli(fd, "\n");
 	ast_cli(fd, format, "Dynamic Feature", "Default", "Current");
 	ast_cli(fd, format, "---------------", "-------", "-------");
-	if (AST_LIST_EMPTY(&feature_list))
+	if (AST_RWLIST_EMPTY(&feature_list)) {
 		ast_cli(fd, "(none)\n");
-	else {
-		AST_LIST_LOCK(&feature_list);
-		AST_LIST_TRAVERSE(&feature_list, feature, feature_entry)
-			ast_cli(fd, format, feature->sname, "no def", feature->exten);	
-		AST_LIST_UNLOCK(&feature_list);
+	} else {
+		AST_RWLIST_RDLOCK(&feature_list);
+		AST_RWLIST_TRAVERSE(&feature_list, feature, feature_entry) {
+			ast_cli(fd, format, feature->sname, "no def", feature->exten);
+		}
+		AST_RWLIST_UNLOCK(&feature_list);
 	}
 	ast_cli(fd, "\nCall parking\n");
 	ast_cli(fd, "------------\n");
@@ -2646,13 +2651,13 @@ static int load_config(void)
 			continue;
 		}
 
-		AST_LIST_LOCK(&feature_list);
+		AST_RWLIST_RDLOCK(&feature_list);
 		if ((feature = find_dynamic_feature(var->name))) {
-			AST_LIST_UNLOCK(&feature_list);
+			AST_RWLIST_UNLOCK(&feature_list);
 			ast_log(LOG_WARNING, "Dynamic Feature '%s' specified more than once!\n", var->name);
 			continue;
 		}
-		AST_LIST_UNLOCK(&feature_list);
+		AST_RWLIST_UNLOCK(&feature_list);
 				
 		if (!(feature = ast_calloc(1, sizeof(*feature))))
 			continue;