Merge pull request #1622 from jakemoroni/master

rping: Fix spurious failure return codes

Author: rleon

librdmacm/examples/rping.c

@@ -36,6 +36,9 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
+#include <unistd.h>
+#include <sys/poll.h>
+#include <sys/eventfd.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
@@ -151,6 +154,7 @@ struct rping_cb {
 	int validate;			/* validate ping data */
 
 	/* CM stuff */
+	int eventfd;
 	pthread_t cmthread;
 	struct rdma_event_channel *cm_channel;
 	struct rdma_cm_id *cm_id;	/* connection on client side,*/
@@ -666,18 +670,36 @@ static void *cm_thread(void *arg)
 {
 	struct rping_cb *cb = arg;
 	struct rdma_cm_event *event;
+	struct pollfd pfds[2];
 	int ret;
 
+	pfds[0].fd = cb->eventfd;
+	pfds[0].events = POLLIN;
+	pfds[1].fd = cb->cm_channel->fd;
+	pfds[1].events = POLLIN;
+
 	while (1) {
-		ret = rdma_get_cm_event(cb->cm_channel, &event);
-		if (ret) {
-			perror("rdma_get_cm_event");
+		ret = poll(pfds, 2, -1);
+		if (ret == -1 && errno != EINTR) {
+			perror("poll failed");
 			exit(ret);
+		} else if (ret < 1)
+			continue;
+
+		if (pfds[0].revents & POLLIN)
+			return NULL;
+
+		if (pfds[1].revents & POLLIN) {
+			ret = rdma_get_cm_event(cb->cm_channel, &event);
+			if (ret) {
+				perror("rdma_get_cm_event");
+				exit(ret);
+			}
+			ret = rping_cma_event_handler(event->id, event);
+			rdma_ack_cm_event(event);
+			if (ret)
+				exit(ret);
 		}
-		ret = rping_cma_event_handler(event->id, event);
-		rdma_ack_cm_event(event);
-		if (ret)
-			exit(ret);
 	}
 }
 
@@ -1279,6 +1301,7 @@ int main(int argc, char *argv[])
 	int op;
 	int ret = 0;
 	int persistent_server = 0;
+	const uint64_t efdw = 1;
 
 	cb = malloc(sizeof(*cb));
 	if (!cb)
@@ -1366,6 +1389,13 @@ int main(int argc, char *argv[])
 		goto out;
 	}
 
+	cb->eventfd = eventfd(0, EFD_NONBLOCK);
+	if (cb->eventfd == -1) {
+		perror("Could not create event FD");
+		ret = errno;
+		goto out;
+	}
+
 	cb->cm_channel = create_event_channel();
 	if (!cb->cm_channel) {
 		ret = errno;
@@ -1397,6 +1427,10 @@ int main(int argc, char *argv[])
 	DEBUG_LOG("destroy cm_id %p\n", cb->cm_id);
 	rdma_destroy_id(cb->cm_id);
 out2:
+	if (write(cb->eventfd, &efdw, sizeof(efdw)) != sizeof(efdw))
+		fprintf(stderr, "Failed to signal CM thread\n");
+
+	pthread_join(cb->cmthread, NULL);
 	rdma_destroy_event_channel(cb->cm_channel);
 out:
 	free(cb);