X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu-qsbr.c;h=af82fb7e6d3d6bbe3d6ef199c5c9d23ce9253163;hp=685efb5297dca06632697d810f5f078bc0aa835d;hb=19d0e7ef8f7998fb256017ba2da414d78b3cb91b;hpb=731ccb963c80afd067e20acee2f9bd7cb4875ffb

diff --git a/urcu-qsbr.c b/urcu-qsbr.c
index 685efb5..af82fb7 100644
--- a/urcu-qsbr.c
+++ b/urcu-qsbr.c
@@ -121,9 +121,22 @@ static void wait_gp(void)
 {
 	/* Read reader_gp before read futex */
 	cmm_smp_rmb();
-	if (uatomic_read(&rcu_gp.futex) == -1)
-		futex_noasync(&rcu_gp.futex, FUTEX_WAIT, -1,
-		      NULL, NULL, 0);
+	if (uatomic_read(&rcu_gp.futex) != -1)
+		return;
+	while (futex_noasync(&rcu_gp.futex, FUTEX_WAIT, -1,
+			NULL, NULL, 0)) {
+		switch (errno) {
+		case EWOULDBLOCK:
+			/* Value already changed. */
+			return;
+		case EINTR:
+			/* Retry if interrupted by signal. */
+			break;	/* Get out of switch. */
+		default:
+			/* Unexpected error. */
+			urcu_die(errno);
+		}
+	}
 }
 
 /*
@@ -455,6 +468,8 @@ void rcu_register_thread(void)
 	assert(URCU_TLS(rcu_reader).ctr == 0);
 
 	mutex_lock(&rcu_registry_lock);
+	assert(!URCU_TLS(rcu_reader).registered);
+	URCU_TLS(rcu_reader).registered = 1;
 	cds_list_add(&URCU_TLS(rcu_reader).node, &registry);
 	mutex_unlock(&rcu_registry_lock);
 	_rcu_thread_online();
@@ -467,6 +482,8 @@ void rcu_unregister_thread(void)
 	 * with a waiting writer.
 	 */
 	_rcu_thread_offline();
+	assert(URCU_TLS(rcu_reader).registered);
+	URCU_TLS(rcu_reader).registered = 0;
 	mutex_lock(&rcu_registry_lock);
 	cds_list_del(&URCU_TLS(rcu_reader).node);
 	mutex_unlock(&rcu_registry_lock);