hush/libbb/safe_poll.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 2007 by Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
/* Wrapper which restarts poll on EINTR or ENOMEM.
* On other errors does perror("poll") and returns.
* Warning! May take longer than timeout_ms to return! */
int FAST_FUNC safe_poll(struct pollfd *ufds, nfds_t nfds, int timeout)
{
while (1) {
int n = poll(ufds, nfds, timeout);
if (n >= 0)
return n;
/* Make sure we inch towards completion */
if (timeout > 0)
timeout--;
/* E.g. strace causes poll to return this */
if (errno == EINTR)
continue;
/* Kernel is very low on memory. Retry. */
/* I doubt many callers would handle this correctly! */
if (errno == ENOMEM)
continue;
bb_perror_msg("poll");
return n;
}
}