diff options
author | Corey Farrell <git@cfware.com> | 2016-08-18 14:28:57 -0400 |
---|---|---|
committer | Corey Farrell <git@cfware.com> | 2016-09-02 10:28:01 -0400 |
commit | 3af3860151cb6e11e04ffd8ca12944210a4c1c1a (patch) | |
tree | 108475e675fd9045b87705ca75f328ac157b9cfb /main | |
parent | e260e507f2ae26b0388e418b41d61b928b23ab5d (diff) |
named_locks: Use ao2_weakproxy to deal with cleanup from container.
This allows standard ao2 functions to be used to release references to
an ast_named_lock. This change can cause less frequent locking of the
global named_locks container. The container is no longer locked when a
named_lock reference is being release except when this causes the
named_lock to be destroyed.
Change-Id: I644e39c6d83a153d71b3fae77ec05599d725e7e6
Diffstat (limited to 'main')
-rw-r--r-- | main/named_locks.c | 81 |
1 files changed, 62 insertions, 19 deletions
diff --git a/main/named_locks.c b/main/named_locks.c index 596048388..92b8262c1 100644 --- a/main/named_locks.c +++ b/main/named_locks.c @@ -35,13 +35,17 @@ ASTERISK_REGISTER_FILE() struct ao2_container *named_locks; #define NAMED_LOCKS_BUCKETS 101 -struct ast_named_lock { +struct named_lock_proxy { + AO2_WEAKPROXY(); char key[0]; }; +struct ast_named_lock { +}; + static int named_locks_hash(const void *obj, const int flags) { - const struct ast_named_lock *lock = obj; + const struct named_lock_proxy *lock = obj; switch (flags & OBJ_SEARCH_MASK) { case OBJ_SEARCH_KEY: @@ -57,8 +61,8 @@ static int named_locks_hash(const void *obj, const int flags) static int named_locks_cmp(void *obj_left, void *obj_right, int flags) { - const struct ast_named_lock *object_left = obj_left; - const struct ast_named_lock *object_right = obj_right; + const struct named_lock_proxy *object_left = obj_left; + const struct named_lock_proxy *object_right = obj_right; const char *right_key = obj_right; int cmp; @@ -98,31 +102,74 @@ int ast_named_locks_init(void) return 0; } +static void named_lock_proxy_cb(void *weakproxy, void *data) +{ + ao2_unlink(named_locks, weakproxy); +} + struct ast_named_lock *__ast_named_lock_get(const char *filename, int lineno, const char *func, enum ast_named_lock_type lock_type, const char *keyspace, const char *key) { + struct named_lock_proxy *proxy = NULL; struct ast_named_lock *lock = NULL; - int concat_key_buff_len = strlen(keyspace) + strlen(key) + 2; - char *concat_key = ast_alloca(concat_key_buff_len); + int keylen = strlen(keyspace) + strlen(key) + 2; + char *concat_key = ast_alloca(keylen); sprintf(concat_key, "%s-%s", keyspace, key); /* Safe */ ao2_lock(named_locks); - lock = ao2_find(named_locks, concat_key, OBJ_SEARCH_KEY | OBJ_NOLOCK); - if (lock) { + proxy = ao2_find(named_locks, concat_key, OBJ_SEARCH_KEY | OBJ_NOLOCK); + if (proxy) { ao2_unlock(named_locks); - ast_assert((ao2_options_get(lock) & AO2_ALLOC_OPT_LOCK_MASK) == lock_type); - return lock; + lock = __ao2_weakproxy_get_object(proxy, 0, __PRETTY_FUNCTION__, filename, lineno, func); + + if (lock) { + /* We have an existing lock and it's not being destroyed. */ + ao2_ref(proxy, -1); + ast_assert((ao2_options_get(lock) & AO2_ALLOC_OPT_LOCK_MASK) == lock_type); + + return lock; + } + + /* the old proxy is being destroyed, clean list before creating/adding new one */ + ao2_lock(named_locks); + ao2_unlink_flags(named_locks, proxy, OBJ_NOLOCK); + ao2_ref(proxy, -1); } - lock = ao2_alloc_options(sizeof(*lock) + concat_key_buff_len, NULL, lock_type); - if (lock) { - strcpy(lock->key, concat_key); /* Safe */ - ao2_link_flags(named_locks, lock, OBJ_NOLOCK); + proxy = ao2_t_weakproxy_alloc(sizeof(*proxy) + keylen, NULL, concat_key); + if (!proxy) { + goto failure_cleanup; + } + + lock = __ao2_alloc(sizeof(*lock) + keylen, NULL, lock_type, concat_key, filename, lineno, func); + if (!lock) { + goto failure_cleanup; } + + /* We have exclusive access to proxy and lock, no need for locking here. */ + if (ao2_weakproxy_set_object(proxy, lock, OBJ_NOLOCK)) { + goto failure_cleanup; + } + + if (ao2_weakproxy_subscribe(proxy, named_lock_proxy_cb, NULL, OBJ_NOLOCK)) { + goto failure_cleanup; + } + + strcpy(proxy->key, concat_key); /* Safe */ + ao2_link_flags(named_locks, proxy, OBJ_NOLOCK); ao2_unlock(named_locks); + ao2_t_ref(proxy, -1, "Release allocation reference"); return lock; + +failure_cleanup: + ao2_unlock(named_locks); + + ao2_cleanup(proxy); + ao2_cleanup(lock); + + return NULL; } int __ast_named_lock_put(const char *filename, int lineno, const char *func, @@ -132,11 +179,7 @@ int __ast_named_lock_put(const char *filename, int lineno, const char *func, return -1; } - ao2_lock(named_locks); - if (ao2_ref(lock, -1) == 2) { - ao2_unlink_flags(named_locks, lock, OBJ_NOLOCK); - } - ao2_unlock(named_locks); + __ao2_ref(lock, -1, __PRETTY_FUNCTION__, filename, lineno, func); return 0; } |