Fixes from FreeBSD's libc_r

rev 1.21
Make the libc_r version of select() set the readable or writable
file descriptor bit if poll() returns POLLERR, POLLHUP, or POLLNVAL.
Othewise, it's possible for select() to return successfully but
with no bits set.

rev 1.19
Return correct number of total bits set in all fd_set's.
Change case of POLLNVAL as an error.
Remove POLLHUP and POLLERR from one case, their place is most likely
amongst read events.

ok marc@

1 files changed, 26 insertions, 14 deletions

diff --git a/lib/libpthread/uthread/uthread_select.c b/lib/libpthread/uthread/uthread_select.c
index 112e07eb233..acc5d3017ae 100644
--- a/lib/libpthread/uthread/uthread_select.c
+++ b/lib/libpthread/uthread/uthread_select.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_select.c,v 1.10 2004/01/01 08:19:33 brad Exp $	*/
+/*	$OpenBSD: uthread_select.c,v 1.11 2004/01/03 07:35:10 brad Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -57,7 +57,7 @@ select(int numfds, fd_set * readfds, fd_set * writefds,
 	struct pthread	*curthread = _get_curthread();
 	struct timespec ts;
 	int             bit, i, j, ret = 0, f_wait = 1;
-	int		events, got_one = 0, fd_count = 0;
+	int		events, got_events = 0, fd_count = 0;
 	struct pthread_poll_data data;
 	fd_mask		mask, rmask, wmask, emask;
 
@@ -183,21 +183,34 @@ select(int numfds, fd_set * readfds, fd_set * writefds,
 			 * this file descriptor from the fdset if
 			 * the requested event wasn't ready.
 			 */
-			got_one = 0;
+
+			/*
+			 * First check for invalid descriptor.
+			 * If found, set errno and return -1.
+			 */
+			if (data.fds[i].revents & POLLNVAL) {
+				errno = EBADF;
+				ret = -1;
+				goto done;
+			}
+
+			got_events = 0;
 			if (readfds != NULL) {
 				if (FD_ISSET(data.fds[i].fd, readfds)) {
-					if (data.fds[i].revents & (POLLIN |
-					    POLLRDNORM))
-						got_one = 1;
+					if ((data.fds[i].revents & (POLLIN
+					    | POLLRDNORM | POLLERR
+					    | POLLHUP)) != 0)
+						got_events++;
 					else
 						FD_CLR(data.fds[i].fd, readfds);
 				}
 			}
 			if (writefds != NULL) {
 				if (FD_ISSET(data.fds[i].fd, writefds)) {
-					if (data.fds[i].revents & (POLLOUT |
-					    POLLWRNORM | POLLWRBAND))
-						got_one = 1;
+					if ((data.fds[i].revents & (POLLOUT
+					    | POLLWRNORM | POLLWRBAND | POLLERR
+					    | POLLHUP)) != 0)
+						got_events++;
 					else
 						FD_CLR(data.fds[i].fd,
 						    writefds);
@@ -206,16 +219,15 @@ select(int numfds, fd_set * readfds, fd_set * writefds,
 			if (exceptfds != NULL) {
 				if (FD_ISSET(data.fds[i].fd, exceptfds)) {
 					if (data.fds[i].revents & (POLLRDBAND |
-					    POLLPRI | POLLHUP | POLLERR |
-					    POLLNVAL))
-						got_one = 1;
+					    POLLPRI))
+						got_events++;
 					else
 						FD_CLR(data.fds[i].fd,
 						    exceptfds);
 				}
 			}
-			if (got_one)
-				numfds++;
+			if (got_events != 0)
+				numfds+=got_events;
 		}
 		ret = numfds;
 	}