LOOP: move pipe creation into qb_loop_signals_create()

Also make sure the pipe is non blocking.

Signed-off-by: Angus Salkeld <asalkeld@redhat.com>

lib/ipc_us.c

@@ -73,43 +73,6 @@ static void socket_nosigpipe(int32_t s)
 }
 #endif
 
-static int32_t set_cloexec_flag(int32_t fd)
-{
-	int32_t res;
-	char error_str[100];
-	int32_t oldflags = fcntl(fd, F_GETFD, 0);
-
-	if (oldflags < 0) {
-		oldflags = 0;
-	}
-	oldflags |= FD_CLOEXEC;
-	res = fcntl(fd, F_SETFD, oldflags);
-	if (res == -1) {
-		res = -errno;
-		strerror_r(errno, error_str, 100);
-		qb_util_log(LOG_CRIT,
-			    "Could not set close-on-exit operation on socket: %s\n",
-			    error_str);
-	}
-	return res;
-}
-
-static int32_t set_nonblock_flag(int32_t fd)
-{
-	int32_t res;
-	char error_str[100];
-
-	res = fcntl(fd, F_SETFL, O_NONBLOCK);
-	if (res == -1) {
-		res = -errno;
-		strerror_r(errno, error_str, 100);
-		qb_util_log(LOG_CRIT,
-			    "Could not set non-blocking operation on socket: %s\n",
-			    error_str);
-	}
-	return res;
-}
-
 #ifndef MSG_NOSIGNAL
 #define MSG_NOSIGNAL 0
 #endif
@@ -302,11 +265,7 @@ static int32_t qb_ipcc_us_sock_connect(const char *socket_name, int32_t * sock_p
 #ifdef SO_NOSIGPIPE
 	socket_nosigpipe(request_fd);
 #endif /* SO_NOSIGPIPE */
-	res = set_cloexec_flag(request_fd);
-	if (res < 0) {
-		goto error_connect;
-	}
-	res = set_nonblock_flag(request_fd);
+	res = qb_util_fd_nonblock_cloexec_set(request_fd);
 	if (res < 0) {
 		goto error_connect;
 	}
@@ -481,11 +440,7 @@ int32_t qb_ipcs_us_publish(struct qb_ipcs_service * s)
 		return res;
 	}
 
-	res = set_cloexec_flag(s->server_sock);
-	if (res < 0) {
-		goto error_close;
-	}
-	res = set_nonblock_flag(s->server_sock);
+	res = qb_util_fd_nonblock_cloexec_set(s->server_sock);
 	if (res < 0) {
 		goto error_close;
 	}
@@ -816,12 +771,7 @@ retry_accept:
 		return 0;	/* This is an error, but -1 would indicate disconnect from poll loop */
 	}
 
-	res = set_cloexec_flag(new_fd);
-	if (res < 0) {
-		close(new_fd);
-		return 0;	/* This is an error, but -1 would indicate disconnect from poll loop */
-	}
-	res = set_nonblock_flag(new_fd);
+	res = qb_util_fd_nonblock_cloexec_set(new_fd);
 	if (res < 0) {
 		close(new_fd);
 		return 0;	/* This is an error, but -1 would indicate disconnect from poll loop */

lib/loop_poll.c

@@ -95,6 +95,8 @@ struct qb_poll_source {
 	int32_t not_enough_fds;
 };
 
+static int32_t _qb_signal_add_to_jobs_(struct qb_loop* l,
+				       struct qb_poll_entry* pe);
 
 #ifdef HAVE_EPOLL
 static int32_t poll_to_epoll_event(int32_t event)
@@ -741,8 +743,17 @@ struct qb_loop_sig {
 static void _handle_real_signal_(int signal_num, siginfo_t * si, void *context)
 {
 	int32_t sig = signal_num;
+	int32_t res = 0;
+
 	if (pipe_fds[1] > 0) {
-		(void)write(pipe_fds[1], &sig, sizeof(int32_t));
+ try_again:
+		res = write(pipe_fds[1], &sig, sizeof(int32_t));
+		if (res == -1 && errno == EAGAIN) {
+			goto try_again;
+		} else if (res != sizeof(int32_t)) {
+			qb_util_log(LOG_ERR, "failed to write signal to pipe [%d]",
+				    res);
+		}
 	}
 }
 
@@ -764,14 +775,49 @@ static void signal_dispatch_and_take_back(struct qb_loop_item * item,
 struct qb_loop_source *
 qb_loop_signals_create(struct qb_loop *l)
 {
+	int32_t res = 0;
+	struct qb_poll_entry *pe;
 	struct qb_signal_source *s = calloc(1, sizeof(struct qb_signal_source));
+
 	s->s.l = l;
 	s->s.dispatch_and_take_back = signal_dispatch_and_take_back;
 	s->s.poll = NULL;
 	qb_list_init(&s->sig_head);
 	sigemptyset(&s->signal_superset);
 
+	if (pipe_fds[0] < 0) {
+		res = pipe(pipe_fds);
+		if (res == -1) {
+			res = -errno;
+			qb_util_log(LOG_ERR,
+				    "Can't light pipe: %s",
+				    strerror(-res));
+			goto error_exit;
+		}
+		(void)qb_util_fd_nonblock_cloexec_set(pipe_fds[0]);
+		(void)qb_util_fd_nonblock_cloexec_set(pipe_fds[1]);
+
+		res = _poll_add_(l, QB_LOOP_HIGH,
+				 pipe_fds[0], POLLIN,
+				 NULL, &pe);
+		if (res == 0) {
+			pe->poll_dispatch_fn = NULL;
+			pe->type = QB_SIGNAL;
+			pe->add_to_jobs = _qb_signal_add_to_jobs_;
+		} else {
+			qb_util_log(LOG_ERR,
+				    "Can't smoke pipe: %s",
+				    strerror(-res));
+			goto error_exit;
+		}
+	}
+
 	return (struct qb_loop_source *)s;
+
+ error_exit:
+	free(s);
+	errno = -res;
+	return NULL;
 }
 
 void qb_loop_signals_destroy(struct qb_loop *l)
@@ -860,9 +906,7 @@ int32_t qb_loop_signal_add(qb_loop_t *l,
 			   qb_loop_signal_handle *handle)
 {
 	struct qb_loop_sig *sig;
-	struct qb_poll_entry *pe;
 	struct qb_signal_source *s;
-	int32_t res = 0;
 
 	if (l == NULL || dispatch_fn == NULL) {
 		return -EINVAL;
@@ -882,22 +926,6 @@ int32_t qb_loop_signal_add(qb_loop_t *l,
 	qb_list_init(&sig->item.list);
 	qb_list_add_tail(&sig->item.list, &s->sig_head);
 
-	if (pipe_fds[0] < 0) {
-		pipe(pipe_fds);
-		res = _poll_add_(l, QB_LOOP_HIGH,
-				 pipe_fds[0], POLLIN,
-				 NULL, &pe);
-		if (res == 0) {
-			pe->poll_dispatch_fn = NULL;
-			pe->type = QB_SIGNAL;
-			pe->add_to_jobs = _qb_signal_add_to_jobs_;
-		} else {
-			qb_util_log(LOG_ERR,
-				    "failed to setup pipe: %s",
-				    strerror(-res));
-		}
-	}
-
 	if (sigismember(&s->signal_superset, the_sig) != 1) {
 		_adjust_sigactions_(s);
 	}

lib/util.c

@@ -353,3 +353,36 @@ int32_t qb_util_circular_mmap(int32_t fd, void **buf, size_t bytes)
 	*buf = addr_orig;
 	return (0);
 }
+
+int32_t qb_util_fd_nonblock_cloexec_set(int32_t fd)
+{
+	int32_t res;
+	char error_str[100];
+	int32_t oldflags = fcntl(fd, F_GETFD, 0);
+
+	if (oldflags < 0) {
+		oldflags = 0;
+	}
+	oldflags |= FD_CLOEXEC;
+	res = fcntl(fd, F_SETFD, oldflags);
+	if (res == -1) {
+		res = -errno;
+		strerror_r(errno, error_str, 100);
+		qb_util_log(LOG_CRIT,
+			    "Could not set close-on-exit operation on fd: %s\n",
+			    error_str);
+		return res;
+	}
+
+	res = fcntl(fd, F_SETFL, O_NONBLOCK);
+	if (res == -1) {
+		res = -errno;
+		strerror_r(errno, error_str, 100);
+		qb_util_log(LOG_CRIT,
+			    "Could not set non-blocking operation on fd: %s\n",
+			    error_str);
+	}
+	return res;
+}
+
+

lib/util_int.h

@@ -40,7 +40,7 @@ void _qb_util_log(const char *file_name,
  * @param file (in) the name of the file to be used.
  * @param bytes the size to truncate the file to.
  * @param file_flags same as passed into open()
- * @return 0 (success) or -1 (error)
+ * @return 0 (success) or -errno
  */
 int32_t qb_util_mmap_file_open(char *path, const char *file, size_t bytes,
 			       uint32_t file_flags);
@@ -51,8 +51,16 @@ int32_t qb_util_mmap_file_open(char *path, const char *file, size_t bytes,
  * @param fd an open file to use to back the shared memory.
  * @param buf (out) the pointer to the start of the memory.
  * @param bytes the size of the shared memory.
- * @return 0 (success) or -1 (error)
+ * @return 0 (success) or -errno
  */
 int32_t qb_util_circular_mmap(int32_t fd, void **buf, size_t bytes);
 
+
+/**
+ * Set O_NONBLOCK and FD_CLOEXEC on a file descriptor.
+ * @param fd the file descriptor.
+ * @return 0 (success) or -errno
+ */
+int32_t qb_util_fd_nonblock_cloexec_set(int32_t fd);
+
 #endif /* QB_UTIL_INT_H_DEFINED */