[asterisk-commits] mmichelson: trunk r187421 - /trunk/res/res_musiconhold.c
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Thu Apr 9 12:30:54 CDT 2009
Author: mmichelson
Date: Thu Apr 9 12:30:39 2009
New Revision: 187421
URL: http://svn.digium.com/svn-view/asterisk?view=rev&rev=187421
Log:
Fix a crash in res_musiconhold when using cached realtime moh.
The moh_register function links an mohclass and then immediately
unrefs the class since the container now has a reference. The problem
with using realtime music on hold is that the class is allocated,
registered, and started in one fell swoop. The refcounting logic
resulted in the count being off by one. The same problem did not
happen when using a static config because the allocation and registration
of an mohclass is a separate operation from starting moh. This also did
not affect non-cached realtime moh because the classes are not registered
at all.
I also have modified res_musiconhold to use the _t_ variants of the ao2_
functions so that more info can be gleaned when attempting to trace the
refcounts. I found this to be incredibly helpful for debugging this issue
and there's no good reason to remove it.
(closes issue #14661)
Reported by: sum
Modified:
trunk/res/res_musiconhold.c
Modified: trunk/res/res_musiconhold.c
URL: http://svn.digium.com/svn-view/asterisk/trunk/res/res_musiconhold.c?view=diff&rev=187421&r1=187420&r2=187421
==============================================================================
--- trunk/res/res_musiconhold.c (original)
+++ trunk/res/res_musiconhold.c Thu Apr 9 12:30:39 2009
@@ -186,8 +186,8 @@
static int reload(void);
-#define mohclass_ref(class) (ao2_ref((class), +1), class)
-#define mohclass_unref(class) (ao2_ref((class), -1), (struct mohclass *) NULL)
+#define mohclass_ref(class,string) (ao2_t_ref((class), +1, string), class)
+#define mohclass_unref(class,string) (ao2_t_ref((class), -1, string), (struct mohclass *) NULL)
static void moh_files_release(struct ast_channel *chan, void *data)
{
@@ -214,7 +214,7 @@
state->save_pos = state->pos;
- mohclass_unref(state->class);
+ mohclass_unref(state->class, "Unreffing channel's music class upon deactivation of generator");
}
static int ast_moh_files_next(struct ast_channel *chan)
@@ -330,7 +330,7 @@
}
}
- state->class = mohclass_ref(class);
+ state->class = mohclass_ref(class, "Reffing music class for channel");
state->origwfmt = chan->writeformat;
ast_verb(3, "Started music on hold, class '%s', on %s\n", class->name, chan->name);
@@ -349,7 +349,7 @@
/*! \note This function should be called with the mohclasses list locked */
static struct mohclass *get_mohbydigit(char digit)
{
- return ao2_callback(mohclasses, 0, moh_digit_match, &digit);
+ return ao2_t_callback(mohclasses, 0, moh_digit_match, &digit, "digit callback");
}
static void moh_handle_digit(struct ast_channel *chan, char digit)
@@ -359,7 +359,7 @@
if ((class = get_mohbydigit(digit))) {
classname = ast_strdupa(class->name);
- class = mohclass_unref(class);
+ class = mohclass_unref(class, "Unreffing ao2_find from finding by digit");
}
if (!class) {
@@ -721,7 +721,7 @@
ast_copy_string(tmp_class.name, name, sizeof(tmp_class.name));
- moh = ao2_find(mohclasses, &tmp_class, 0);
+ moh = ao2_t_find(mohclasses, &tmp_class, 0, "Finding by name");
if (!moh && warn) {
ast_log(LOG_DEBUG, "Music on Hold class '%s' not found in memory\n", name);
@@ -754,7 +754,7 @@
moh->f.subclass = cl->format;
moh->f.offset = AST_FRIENDLY_OFFSET;
- moh->parent = mohclass_ref(cl);
+ moh->parent = mohclass_ref(cl, "Reffing music class for mohdata parent");
ao2_lock(cl);
AST_LIST_INSERT_HEAD(&cl->members, moh, list);
@@ -778,7 +778,7 @@
oldwfmt = moh->origwfmt;
- moh->parent = class = mohclass_unref(class);
+ moh->parent = class = mohclass_unref(class, "unreffing moh->parent upon deactivation of generator");
ast_free(moh);
@@ -1064,18 +1064,18 @@
/*!
* \note This function owns the reference it gets to moh
*/
-static int moh_register(struct mohclass *moh, int reload)
+static int moh_register(struct mohclass *moh, int reload, int unref)
{
struct mohclass *mohclass = NULL;
if ((mohclass = get_mohbyname(moh->name, 0)) && !moh_diff(mohclass, moh)) {
if (!mohclass->delete) {
ast_log(LOG_WARNING, "Music on Hold class '%s' already exists\n", moh->name);
- mohclass = mohclass_unref(mohclass);
- moh = mohclass_unref(moh);
+ mohclass = mohclass_unref(mohclass, "unreffing mohclass we just found by name");
+ moh = mohclass_unref(moh, "unreffing potential new moh class (it is a duplicate)");
return -1;
}
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "Unreffing mohclass we just found by name");
}
time(&moh->start);
@@ -1083,25 +1083,27 @@
if (!strcasecmp(moh->mode, "files")) {
if (init_files_class(moh)) {
- moh = mohclass_unref(moh);
+ moh = mohclass_unref(moh, "unreffing potential new moh class (init_files_class failed)");
return -1;
}
} else if (!strcasecmp(moh->mode, "mp3") || !strcasecmp(moh->mode, "mp3nb") ||
!strcasecmp(moh->mode, "quietmp3") || !strcasecmp(moh->mode, "quietmp3nb") ||
!strcasecmp(moh->mode, "httpmp3") || !strcasecmp(moh->mode, "custom")) {
if (init_app_class(moh)) {
- moh = mohclass_unref(moh);
+ moh = mohclass_unref(moh, "unreffing potential new moh class (init_app_class_failed)");
return -1;
}
} else {
ast_log(LOG_WARNING, "Don't know how to do a mode '%s' music on hold\n", moh->mode);
- moh = mohclass_unref(moh);
- return -1;
- }
-
- ao2_link(mohclasses, moh);
-
- moh = mohclass_unref(moh);
+ moh = mohclass_unref(moh, "unreffing potential new moh class (unknown mode)");
+ return -1;
+ }
+
+ ao2_t_link(mohclasses, moh, "Adding class to container");
+
+ if (unref) {
+ moh = mohclass_unref(moh, "Unreffing new moh class because we just added it to the container");
+ }
return 0;
}
@@ -1122,7 +1124,7 @@
{
struct mohclass *class;
- if ((class = ao2_alloc(sizeof(*class), moh_class_destructor))) {
+ if ((class = ao2_t_alloc(sizeof(*class), moh_class_destructor, "Allocating new moh class"))) {
class->format = AST_FORMAT_SLINEAR;
}
@@ -1202,18 +1204,18 @@
strcpy(mohclass->dir, "nodir");
} else {
ast_log(LOG_WARNING, "A directory must be specified for class '%s'!\n", mohclass->name);
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (no directory specified)");
return -1;
}
}
if (ast_strlen_zero(mohclass->mode)) {
ast_log(LOG_WARNING, "A mode must be specified for class '%s'!\n", mohclass->name);
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (no mode specified)");
return -1;
}
if (ast_strlen_zero(mohclass->args) && !strcasecmp(mohclass->mode, "custom")) {
ast_log(LOG_WARNING, "An application must be specified for class '%s'!\n", mohclass->name);
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (no app specified for custom mode");
return -1;
}
@@ -1224,11 +1226,18 @@
ast_log(LOG_NOTICE, "This channel already has a MOH class attached (%s)!\n", state->class->name);
if (state->class->realtime && !ast_test_flag(global_flags, MOH_CACHERTCLASSES) && !strcasecmp(mohclass->name, state->class->name)) {
/* we found RT class with the same name, seems like we should continue playing existing one */
- mohclass = mohclass_unref(mohclass);
+ /* XXX This code is impossible to reach */
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (channel already has a class)");
mohclass = state->class;
}
}
- moh_register(mohclass, 0);
+ /* We don't want moh_register to unref the mohclass because we do it at the end of this function as well.
+ * If we allowed moh_register to unref the mohclass,too, then the count would be off by one. The result would
+ * be that the destructor would be called when the generator on the channel is deactivated. The container then
+ * has a pointer to a freed mohclass, so any operations involving the mohclass container would result in reading
+ * invalid memory.
+ */
+ moh_register(mohclass, 0, 0);
} else {
/* We don't register RT moh class, so let's init it manualy */
@@ -1237,7 +1246,7 @@
if (!strcasecmp(mohclass->mode, "files")) {
if (!moh_scan_files(mohclass)) {
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (moh_scan_files failed)");
return -1;
}
if (strchr(mohclass->args, 'r'))
@@ -1273,7 +1282,7 @@
ast_log(LOG_NOTICE, "This channel already has a MOH class attached (%s)!\n", state->class->name);
if (state->class->realtime && !ast_test_flag(global_flags, MOH_CACHERTCLASSES) && !strcasecmp(mohclass->name, state->class->name)) {
/* we found RT class with the same name, seems like we should continue playing existing one */
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (channel already has one)");
mohclass = state->class;
}
} else {
@@ -1283,13 +1292,13 @@
close(mohclass->pseudofd);
mohclass->pseudofd = -1;
}
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "Unreffing potential mohclass (failed to create background thread)");
return -1;
}
}
} else {
ast_log(LOG_WARNING, "Don't know how to do a mode '%s' music on hold\n", mohclass->mode);
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing potential mohclass (unknown mode)");
return -1;
}
}
@@ -1320,7 +1329,7 @@
res = ast_activate_generator(chan, &mohgen, mohclass);
}
- mohclass = mohclass_unref(mohclass);
+ mohclass = mohclass_unref(mohclass, "unreffing local reference to mohclass in local_ast_moh_start");
return res;
}
@@ -1432,7 +1441,7 @@
}
if (reload) {
- ao2_callback(mohclasses, OBJ_NODATA, moh_class_mark, NULL);
+ ao2_t_callback(mohclasses, OBJ_NODATA, moh_class_mark, NULL, "Mark deleted classes");
}
ast_clear_flag(global_flags, AST_FLAGS_ALL);
@@ -1489,31 +1498,31 @@
strcpy(class->dir, "nodir");
} else {
ast_log(LOG_WARNING, "A directory must be specified for class '%s'!\n", class->name);
- class = mohclass_unref(class);
+ class = mohclass_unref(class, "unreffing potential mohclass (no directory)");
continue;
}
}
if (ast_strlen_zero(class->mode)) {
ast_log(LOG_WARNING, "A mode must be specified for class '%s'!\n", class->name);
- class = mohclass_unref(class);
+ class = mohclass_unref(class, "unreffing potential mohclass (no mode)");
continue;
}
if (ast_strlen_zero(class->args) && !strcasecmp(class->mode, "custom")) {
ast_log(LOG_WARNING, "An application must be specified for class '%s'!\n", class->name);
- class = mohclass_unref(class);
+ class = mohclass_unref(class, "unreffing potential mohclass (no app for custom mode)");
continue;
}
/* Don't leak a class when it's already registered */
- if (!moh_register(class, reload)) {
+ if (!moh_register(class, reload, 1)) {
numclasses++;
}
}
ast_config_destroy(cfg);
- ao2_callback(mohclasses, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE,
- moh_classes_delete_marked, NULL);
+ ao2_t_callback(mohclasses, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE,
+ moh_classes_delete_marked, NULL, "Purge marked classes");
return numclasses;
}
@@ -1521,7 +1530,7 @@
static void ast_moh_destroy(void)
{
ast_verb(2, "Destroying musiconhold processes\n");
- ao2_callback(mohclasses, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
+ ao2_t_callback(mohclasses, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL, "Destroy callback");
}
static char *handle_cli_moh_reload(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
@@ -1568,7 +1577,7 @@
i = ao2_iterator_init(mohclasses, 0);
- for (; (class = ao2_iterator_next(&i)); mohclass_unref(class)) {
+ for (; (class = ao2_t_iterator_next(&i, "Show files iterator")); mohclass_unref(class, "Unref iterator in moh show files")) {
int x;
if (!class->total_files) {
@@ -1605,7 +1614,7 @@
i = ao2_iterator_init(mohclasses, 0);
- for (; (class = ao2_iterator_next(&i)); mohclass_unref(class)) {
+ for (; (class = ao2_t_iterator_next(&i, "Show classes iterator")); mohclass_unref(class, "Unref iterator in moh show classes")) {
ast_cli(a->fd, "Class: %s\n", class->name);
ast_cli(a->fd, "\tMode: %s\n", S_OR(class->mode, "<none>"));
ast_cli(a->fd, "\tDirectory: %s\n", S_OR(class->dir, "<none>"));
@@ -1644,7 +1653,7 @@
{
int res;
- if (!(mohclasses = ao2_container_alloc(53, moh_class_hash, moh_class_cmp))) {
+ if (!(mohclasses = ao2_t_container_alloc(53, moh_class_hash, moh_class_cmp, "Moh class container"))) {
return AST_MODULE_LOAD_DECLINE;
}
@@ -1695,8 +1704,8 @@
/* XXX This check shouldn't be required if module ref counting was being used
* properly ... */
- if ((class = ao2_callback(mohclasses, 0, moh_class_inuse, NULL))) {
- class = mohclass_unref(class);
+ if ((class = ao2_t_callback(mohclasses, 0, moh_class_inuse, NULL, "Module unload callback"))) {
+ class = mohclass_unref(class, "unref of class from module unload callback");
res = -1;
}
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