X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fworkqueue.c;h=1039d7297b9ce13446c4b81aee86fa217a005eab;hb=ea3a28a3f71dd02fb34ed4e3108f93275dbef89a;hp=39d0e077acc101b5e1588c9a1fae954050bd134c;hpb=c6871b650af872296c57dc65f93bd912d2b4435e;p=urcu.git

diff --git a/src/workqueue.c b/src/workqueue.c
index 39d0e07..1039d72 100644
--- a/src/workqueue.c
+++ b/src/workqueue.c
@@ -25,7 +25,6 @@
 #include <stdio.h>
 #include <pthread.h>
 #include <signal.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
@@ -36,12 +35,13 @@
 #include <sched.h>
 
 #include "compat-getcpu.h"
-#include "urcu/wfcqueue.h"
-#include "urcu-pointer.h"
-#include "urcu/list.h"
-#include "urcu/futex.h"
-#include "urcu/tls-compat.h"
-#include "urcu/ref.h"
+#include <urcu/assert.h>
+#include <urcu/wfcqueue.h>
+#include <urcu/pointer.h>
+#include <urcu/list.h>
+#include <urcu/futex.h>
+#include <urcu/tls-compat.h>
+#include <urcu/ref.h>
 #include "urcu-die.h"
 
 #include "workqueue.h"
@@ -92,7 +92,7 @@ struct urcu_workqueue_completion_work {
  * Losing affinity can be caused by CPU hotunplug/hotplug, or by
  * cpuset(7).
  */
-#if HAVE_SCHED_SETAFFINITY
+#ifdef HAVE_SCHED_SETAFFINITY
 static int set_thread_cpu_affinity(struct urcu_workqueue *workqueue)
 {
 	cpu_set_t mask;
@@ -107,11 +107,8 @@ static int set_thread_cpu_affinity(struct urcu_workqueue *workqueue)
 
 	CPU_ZERO(&mask);
 	CPU_SET(workqueue->cpu_affinity, &mask);
-#if SCHED_SETAFFINITY_ARGS == 2
-	ret = sched_setaffinity(0, &mask);
-#else
 	ret = sched_setaffinity(0, sizeof(mask), &mask);
-#endif
+
 	/*
 	 * EINVAL is fine: can be caused by hotunplugged CPUs, or by
 	 * cpuset(7). This is why we should always retry if we detect
@@ -124,7 +121,7 @@ static int set_thread_cpu_affinity(struct urcu_workqueue *workqueue)
 	return ret;
 }
 #else
-static int set_thread_cpu_affinity(struct urcu_workqueue *workqueue)
+static int set_thread_cpu_affinity(struct urcu_workqueue *workqueue __attribute__((unused)))
 {
 	return 0;
 }
@@ -134,16 +131,25 @@ static void futex_wait(int32_t *futex)
 {
 	/* Read condition before read futex */
 	cmm_smp_mb();
-	if (uatomic_read(futex) != -1)
-		return;
-	while (futex_async(futex, FUTEX_WAIT, -1, NULL, NULL, 0)) {
+	while (uatomic_read(futex) == -1) {
+		if (!futex_async(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);
@@ -213,8 +219,8 @@ static void *workqueue_thread(void *arg)
 		cds_wfcq_init(&cbs_tmp_head, &cbs_tmp_tail);
 		splice_ret = __cds_wfcq_splice_blocking(&cbs_tmp_head,
 			&cbs_tmp_tail, &workqueue->cbs_head, &workqueue->cbs_tail);
-		assert(splice_ret != CDS_WFCQ_RET_WOULDBLOCK);
-		assert(splice_ret != CDS_WFCQ_RET_DEST_NON_EMPTY);
+		urcu_posix_assert(splice_ret != CDS_WFCQ_RET_WOULDBLOCK);
+		urcu_posix_assert(splice_ret != CDS_WFCQ_RET_DEST_NON_EMPTY);
 		if (splice_ret != CDS_WFCQ_RET_SRC_EMPTY) {
 			if (workqueue->grace_period_fct)
 				workqueue->grace_period_fct(workqueue, workqueue->priv);
@@ -246,7 +252,10 @@ static void *workqueue_thread(void *arg)
 				cmm_smp_mb();
 			}
 		} else {
-			(void) poll(NULL, 0, 10);
+			if (cds_wfcq_empty(&workqueue->cbs_head,
+					&workqueue->cbs_tail)) {
+				(void) poll(NULL, 0, 10);
+			}
 		}
 		if (workqueue->worker_after_wake_up_fct)
 			workqueue->worker_after_wake_up_fct(workqueue, workqueue->priv);
@@ -275,6 +284,7 @@ struct urcu_workqueue *urcu_workqueue_create(unsigned long flags,
 {
 	struct urcu_workqueue *workqueue;
 	int ret;
+	sigset_t newmask, oldmask;
 
 	workqueue = malloc(sizeof(*workqueue));
 	if (workqueue == NULL)
@@ -295,10 +305,20 @@ struct urcu_workqueue *urcu_workqueue_create(unsigned long flags,
 	workqueue->cpu_affinity = cpu_affinity;
 	workqueue->loop_count = 0;
 	cmm_smp_mb();  /* Structure initialized before pointer is planted. */
+
+	ret = sigfillset(&newmask);
+	urcu_posix_assert(!ret);
+	ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
+	urcu_posix_assert(!ret);
+
 	ret = pthread_create(&workqueue->tid, NULL, workqueue_thread, workqueue);
 	if (ret) {
 		urcu_die(ret);
 	}
+
+	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+	urcu_posix_assert(!ret);
+
 	return workqueue;
 }
 
@@ -336,7 +356,7 @@ void urcu_workqueue_destroy(struct urcu_workqueue *workqueue)
 	if (urcu_workqueue_destroy_worker(workqueue)) {
 		urcu_die(errno);
 	}
-	assert(cds_wfcq_empty(&workqueue->cbs_head, &workqueue->cbs_tail));
+	urcu_posix_assert(cds_wfcq_empty(&workqueue->cbs_head, &workqueue->cbs_tail));
 	free(workqueue);
 }
 
@@ -455,13 +475,23 @@ void urcu_workqueue_resume_worker(struct urcu_workqueue *workqueue)
 void urcu_workqueue_create_worker(struct urcu_workqueue *workqueue)
 {
 	int ret;
+	sigset_t newmask, oldmask;
 
 	/* Clear workqueue state from parent. */
 	workqueue->flags &= ~URCU_WORKQUEUE_PAUSED;
 	workqueue->flags &= ~URCU_WORKQUEUE_PAUSE;
 	workqueue->tid = 0;
+
+	ret = sigfillset(&newmask);
+	urcu_posix_assert(!ret);
+	ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
+	urcu_posix_assert(!ret);
+
 	ret = pthread_create(&workqueue->tid, NULL, workqueue_thread, workqueue);
 	if (ret) {
 		urcu_die(ret);
 	}
+
+	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+	urcu_posix_assert(!ret);
 }