X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Furcu-defer-impl.h;h=cbb0ca8565bfe2b52806e343f7f61d09117d6f8c;hb=8c677380d0f9241b9cd548082cf843c5111736d8;hp=8b5ad972421d52f523f18146a3a1a068c2bcb661;hpb=a0ec6d9b6b67e37fc81c98e04008907bc500cde8;p=urcu.git

diff --git a/src/urcu-defer-impl.h b/src/urcu-defer-impl.h
index 8b5ad97..cbb0ca8 100644
--- a/src/urcu-defer-impl.h
+++ b/src/urcu-defer-impl.h
@@ -33,7 +33,6 @@
 #include <pthread.h>
 #include <stdio.h>
 #include <signal.h>
-#include <assert.h>
 #include <string.h>
 #include <errno.h>
 #include <poll.h>
@@ -43,6 +42,7 @@
 
 #include "urcu/futex.h"
 
+#include <urcu/assert.h>
 #include <urcu/compiler.h>
 #include <urcu/arch.h>
 #include <urcu/uatomic.h>
@@ -194,17 +194,25 @@ static void wait_defer(void)
 		uatomic_set(&defer_thread_futex, 0);
 	} else {
 		cmm_smp_rmb();	/* Read queue before read futex */
-		if (uatomic_read(&defer_thread_futex) != -1)
-			return;
-		while (futex_noasync(&defer_thread_futex, FUTEX_WAIT, -1,
-				NULL, NULL, 0)) {
+		while (uatomic_read(&defer_thread_futex) == -1) {
+			if (!futex_noasync(&defer_thread_futex, FUTEX_WAIT, -1, NULL, NULL, 0)) {
+				/*
+				 * Prior queued wakeups queued by unrelated code
+				 * using the same address can cause futex wait to
+				 * return 0 even through the futex value is still
+				 * -1 (spurious wakeups). Check the value again
+				 * in user-space to validate whether it really
+				 * differs from -1.
+				 */
+				continue;
+			}
 			switch (errno) {
-			case EWOULDBLOCK:
+			case EAGAIN:
 				/* Value already changed. */
 				return;
 			case EINTR:
 				/* Retry if interrupted by signal. */
-				break;	/* Get out of switch. */
+				break;	/* Get out of switch. Check again. */
 			default:
 				/* Unexpected error. */
 				urcu_die(errno);
@@ -325,9 +333,9 @@ static void _defer_rcu(void (*fct)(void *p), void *p)
 	 * Worse-case: must allow 2 supplementary entries for fct pointer.
 	 */
 	if (caa_unlikely(head - tail >= DEFER_QUEUE_SIZE - 2)) {
-		assert(head - tail <= DEFER_QUEUE_SIZE);
+		urcu_posix_assert(head - tail <= DEFER_QUEUE_SIZE);
 		rcu_defer_barrier_thread();
-		assert(head - CMM_LOAD_SHARED(URCU_TLS(defer_queue).tail) == 0);
+		urcu_posix_assert(head - CMM_LOAD_SHARED(URCU_TLS(defer_queue).tail) == 0);
 	}
 
 	/*
@@ -401,9 +409,19 @@ void defer_rcu(void (*fct)(void *p), void *p)
 static void start_defer_thread(void)
 {
 	int ret;
+	sigset_t newmask, oldmask;
+
+	ret = sigfillset(&newmask);
+	urcu_posix_assert(!ret);
+	ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
+	urcu_posix_assert(!ret);
 
 	ret = pthread_create(&tid_defer, NULL, thr_defer, NULL);
-	assert(!ret);
+	if (ret)
+		urcu_die(ret);
+
+	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+	urcu_posix_assert(!ret);
 }
 
 static void stop_defer_thread(void)
@@ -417,19 +435,19 @@ static void stop_defer_thread(void)
 	wake_up_defer();
 
 	ret = pthread_join(tid_defer, &tret);
-	assert(!ret);
+	urcu_posix_assert(!ret);
 
 	CMM_STORE_SHARED(defer_thread_stop, 0);
 	/* defer thread should always exit when futex value is 0 */
-	assert(uatomic_read(&defer_thread_futex) == 0);
+	urcu_posix_assert(uatomic_read(&defer_thread_futex) == 0);
 }
 
 int rcu_defer_register_thread(void)
 {
 	int was_empty;
 
-	assert(URCU_TLS(defer_queue).last_head == 0);
-	assert(URCU_TLS(defer_queue).q == NULL);
+	urcu_posix_assert(URCU_TLS(defer_queue).last_head == 0);
+	urcu_posix_assert(URCU_TLS(defer_queue).q == NULL);
 	URCU_TLS(defer_queue).q = malloc(sizeof(void *) * DEFER_QUEUE_SIZE);
 	if (!URCU_TLS(defer_queue).q)
 		return -ENOMEM;
@@ -466,7 +484,7 @@ void rcu_defer_unregister_thread(void)
 
 void rcu_defer_exit(void)
 {
-	assert(cds_list_empty(&registry_defer));
+	urcu_posix_assert(cds_list_empty(&registry_defer));
 }
 
 #endif /* _URCU_DEFER_IMPL_H */