Fix: auto-resize hash table destroy deadlock

[urcu.git] / src / urcu-call-rcu-impl.h

diff --git a/src/urcu-call-rcu-impl.h b/src/urcu-call-rcu-impl.h
index 0c252c12133ed4f3fa1cf7edede849455178569d..c264da5f7775c623d0e9ae952ceed38a8be90add 100644 (file)
--- a/src/urcu-call-rcu-impl.h
+++ b/src/urcu-call-rcu-impl.h
@@ -102,7 +102,6 @@ static pthread_mutex_t call_rcu_mutex = PTHREAD_MUTEX_INITIALIZER;
 static struct call_rcu_data *default_call_rcu_data;
 
 static struct urcu_atfork *registered_rculfhash_atfork;
-static unsigned long registered_rculfhash_atfork_refcount;
 
 /*
  * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are
@@ -1018,20 +1017,20 @@ void call_rcu_after_fork_child(void)
 
 void urcu_register_rculfhash_atfork(struct urcu_atfork *atfork)
 {
+       if (CMM_LOAD_SHARED(registered_rculfhash_atfork))
+               return;
        call_rcu_lock(&call_rcu_mutex);
-       if (registered_rculfhash_atfork_refcount++)
-               goto end;
-       registered_rculfhash_atfork = atfork;
-end:
+       if (!registered_rculfhash_atfork)
+               registered_rculfhash_atfork = atfork;
        call_rcu_unlock(&call_rcu_mutex);
 }
 
+/*
+ * This unregistration function is deprecated, meant only for internal
+ * use by rculfhash.
+ */
+__attribute__((noreturn))
 void urcu_unregister_rculfhash_atfork(struct urcu_atfork *atfork __attribute__((unused)))
 {
-       call_rcu_lock(&call_rcu_mutex);
-       if (--registered_rculfhash_atfork_refcount)
-               goto end;
-       registered_rculfhash_atfork = NULL;
-end:
-       call_rcu_unlock(&call_rcu_mutex);
+       urcu_die(EPERM);
 }