source: EcnlProtoTool/trunk/prototool/src/libbb/safe_poll.c@ 279

/* 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 source tree.
 */

#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;
        }
}