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 tarball for details.
8 */
9
10#include "libbb.h"
11
12/* Wrapper which restarts poll on EINTR or ENOMEM.
13 * On other errors does perror("poll") and returns.
14 * Warning! May take longer than timeout_ms to return! */
15int FAST_FUNC safe_poll(struct pollfd *ufds, nfds_t nfds, int timeout)
16{
17	while (1) {
18		int n = poll(ufds, nfds, timeout);
19		if (n >= 0)
20			return n;
21		/* Make sure we inch towards completion */
22		if (timeout > 0)
23			timeout--;
24		/* E.g. strace causes poll to return this */
25		if (errno == EINTR)
26			continue;
27		/* Kernel is very low on memory. Retry. */
28		/* I doubt many callers would handle this correctly! */
29		if (errno == ENOMEM)
30			continue;
31		bb_perror_msg("poll");
32		return n;
33	}
34}
35