From ed1e02a4d35a66697c8c73432c493b155d638c1b Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Mon, 31 Oct 2011 17:51:22 +0000
Subject: [PATCH] Misc format capability fixes.
* Fixed typo in format_cap.c:joint_copy_helper() using the wrong variable.
* Fix potential race between checking if an interface exists and adding it
to the container in format.c:ast_format_attr_reg_interface().
* Fixed double rwlock destroy in format.c:ast_format_attr_init() error
exit path.
* Simplified format.c:find_interface() and format.c:has_interface().
........
Merged revisions 342824 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@342825 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
main/format.c | 48 ++++++++++++++++++++++-------------------------
main/format_cap.c | 2 +-
2 files changed, 23 insertions(+), 27 deletions(-)
diff --git a/main/format.c b/main/format.c
index 1c60ab7703..a365ab0d58 100644
--- a/main/format.c
+++ b/main/format.c
@@ -106,7 +106,7 @@ int ast_format_get_video_mark(const struct ast_format *format)
return format->fattr.rtp_marker_bit;
}
-static int has_interface(const struct ast_format *format)
+static struct interface_ao2_wrapper *find_interface(const struct ast_format *format)
{
struct interface_ao2_wrapper *wrapper;
struct interface_ao2_wrapper tmp_wrapper = {
@@ -114,30 +114,22 @@ static int has_interface(const struct ast_format *format)
};
ast_rwlock_rdlock(&ilock);
- if (!(wrapper = ao2_find(interfaces, &tmp_wrapper, (OBJ_POINTER | OBJ_NOLOCK)))) {
- ast_rwlock_unlock(&ilock);
- return 0;
- }
+ wrapper = ao2_find(interfaces, &tmp_wrapper, (OBJ_POINTER | OBJ_NOLOCK));
ast_rwlock_unlock(&ilock);
- ao2_ref(wrapper, -1);
- return 1;
+
+ return wrapper;
}
-static struct interface_ao2_wrapper *find_interface(const struct ast_format *format)
+static int has_interface(const struct ast_format *format)
{
struct interface_ao2_wrapper *wrapper;
- struct interface_ao2_wrapper tmp_wrapper = {
- .id = format->id,
- };
- ast_rwlock_rdlock(&ilock);
- if (!(wrapper = ao2_find(interfaces, &tmp_wrapper, (OBJ_POINTER | OBJ_NOLOCK)))) {
- ast_rwlock_unlock(&ilock);
- return NULL;
+ wrapper = find_interface(format);
+ if (!wrapper) {
+ return 0;
}
- ast_rwlock_unlock(&ilock);
-
- return wrapper;
+ ao2_ref(wrapper, -1);
+ return 1;
}
/*! \internal
@@ -1050,7 +1042,7 @@ static int format_list_init(void)
return 0;
}
-int ast_format_list_init()
+int ast_format_list_init(void)
{
if (ast_rwlock_init(&format_list_array_lock)) {
return -1;
@@ -1073,7 +1065,7 @@ init_list_cleanup:
return -1;
}
-int ast_format_attr_init()
+int ast_format_attr_init(void)
{
ast_cli_register_multiple(my_clis, ARRAY_LEN(my_clis));
if (ast_rwlock_init(&ilock)) {
@@ -1081,7 +1073,6 @@ int ast_format_attr_init()
}
if (!(interfaces = ao2_container_alloc(283, interface_hash_cb, interface_cmp_cb))) {
- ast_rwlock_destroy(&ilock);
goto init_cleanup;
}
return 0;
@@ -1316,17 +1307,23 @@ int ast_format_attr_reg_interface(const struct ast_format_attr_interface *interf
.id = interface->id,
};
- /* check for duplicates first*/
+ /*
+ * Grab the write lock before checking for duplicates in
+ * anticipation of adding a new interface and to prevent a
+ * duplicate from sneaking in between the check and add.
+ */
ast_rwlock_wrlock(&ilock);
+
+ /* check for duplicates first*/
if ((wrapper = ao2_find(interfaces, &tmp_wrapper, (OBJ_POINTER | OBJ_NOLOCK)))) {
ast_rwlock_unlock(&ilock);
ast_log(LOG_WARNING, "Can not register attribute interface for format id %d, interface already exists.\n", interface->id);
ao2_ref(wrapper, -1);
return -1;
}
- ast_rwlock_unlock(&ilock);
if (!(wrapper = ao2_alloc(sizeof(*wrapper), interface_destroy_cb))) {
+ ast_rwlock_unlock(&ilock);
return -1;
}
@@ -1334,9 +1331,8 @@ int ast_format_attr_reg_interface(const struct ast_format_attr_interface *interf
wrapper->id = interface->id;
ast_rwlock_init(&wrapper->wraplock);
- /* use the write lock whenever the interface container is modified */
- ast_rwlock_wrlock(&ilock);
- ao2_link(interfaces, wrapper);
+ /* The write lock is already held. */
+ ao2_link_nolock(interfaces, wrapper);
ast_rwlock_unlock(&ilock);
ao2_ref(wrapper, -1);
diff --git a/main/format_cap.c b/main/format_cap.c
index b632a7b1cf..a3e5131602 100644
--- a/main/format_cap.c
+++ b/main/format_cap.c
@@ -470,7 +470,7 @@ static int joint_copy_helper(const struct ast_format_cap *cap1, const struct ast
if (!append) {
ast_format_cap_remove_all(result);
}
- it = ao2_iterator_init(cap1->formats, cap2->nolock ? AO2_ITERATOR_DONTLOCK : 0);
+ it = ao2_iterator_init(cap1->formats, cap1->nolock ? AO2_ITERATOR_DONTLOCK : 0);
while ((tmp = ao2_iterator_next(&it))) {
data.format = tmp;
ao2_callback(cap2->formats,
--
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