loader: Create ast_module_running_ref.

This function returns NULL if the module in question is not running.  I
did not change ast_module_ref as most callers do not check the result
and they always call ast_module_unref.

Make use of this function when running registered items from:
* app_stack API's
* bridge technologies
* CLI commands
* File formats
* Manager Actions
* RTP engines
* Sorcery Wizards
* Timing Interfaces
* Translators
* AGI Commands
* Fax Technologies

ASTERISK-20346 #close

Change-Id: Ia16fd28e188b2fc0b9d18b8a5d9cacc31df73fcc

1 files changed, 9 insertions, 3 deletions

diff --git a/main/file.c b/main/file.c
index 41131f9ee..8dded8123 100644
--- a/main/file.c
+++ b/main/file.c
@@ -425,11 +425,17 @@ static void filestream_destructor(void *arg)
 static struct ast_filestream *get_filestream(struct ast_format_def *fmt, FILE *bfile)
 {
 	struct ast_filestream *s;
-
 	int l = sizeof(*s) + fmt->buf_size + fmt->desc_size;	/* total allocation size */
-	if ( (s = ao2_alloc(l, filestream_destructor)) == NULL)
+
+	if (!ast_module_running_ref(fmt->module)) {
+		return NULL;
+	}
+
+	s = ao2_alloc(l, filestream_destructor);
+	if (!s) {
+		ast_module_unref(fmt->module);
 		return NULL;
-	ast_module_ref(fmt->module);
+	}
 	s->fmt = fmt;
 	s->f = bfile;