1 /* vi: set sw=4 ts=4: */
2 /*
3 * Utility routines.
4 *
5 * Copyright (C) 2007 by Denys Vlasenko <vda.linux@googlemail.com>
6 *
7 * Licensed under GPLv2, see file LICENSE in this source tree.
8 */
9 #include "libbb.h"
10
11 /* Wrapper which restarts poll on EINTR or ENOMEM.
12 * On other errors does perror("poll") and returns.
13 * Warning! May take longer than timeout_ms to return! */
safe_poll(struct pollfd * ufds,nfds_t nfds,int timeout)14 int FAST_FUNC safe_poll(struct pollfd *ufds, nfds_t nfds, int timeout)
15 {
16 while (1) {
17 int n = poll(ufds, nfds, timeout);
18 if (n >= 0)
19 return n;
20 /* Make sure we inch towards completion */
21 if (timeout > 0)
22 timeout--;
23 /* E.g. strace causes poll to return this */
24 if (errno == EINTR)
25 continue;
26 /* Kernel is very low on memory. Retry. */
27 /* I doubt many callers would handle this correctly! */
28 if (errno == ENOMEM)
29 continue;
30 bb_simple_perror_msg("poll");
31 return n;
32 }
33 }
34