Fix deadlock in qsbr code

Readers must go offline because they unregister.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

diff --git a/urcu-qsbr.c b/urcu-qsbr.c
index 6ba03642f852763057781dcf14bf2ff4a01dc5b9..87c83d7fc154443dcee6329cb75abe2a97c33f8e 100644 (file)
--- a/urcu-qsbr.c
+++ b/urcu-qsbr.c
@@ -258,6 +258,11 @@ void rcu_register_thread(void)
 
 void rcu_unregister_thread(void)
 {
+       /*
+        * We have to make the thread offline otherwise we end up dealocking
+        * with a waiting writer.
+        */
+       _rcu_thread_offline();
        internal_urcu_lock();
        rcu_remove_reader(pthread_self());
        internal_urcu_unlock();