libexplain/usleep_or_die.c

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/*
 * libexplain - Explain errno values returned by libc functions
 * Copyright (C) 2013 Peter Miller
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
 * General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <libexplain/ac/errno.h>
#include <libexplain/ac/unistd.h>

#include <libexplain/output.h>
#include <libexplain/usleep.h>


void
explain_usleep_or_die(long long usec)
{
    if (explain_usleep_on_error(usec) < 0)
    {
        explain_output_exit_failure();
    }
}


int
explain_usleep_on_error(long long usec)
{
    int             result;

#ifdef HAVE_USLEEP
    result = usleep(usec);
#else
# if HAVE_NANOSLEEP
    {
        strict timespec req;
        strict timespec rem;
        double rem_sec;

        req.tv_sec = usec / 1000000;
        req.tv_nsec = (usec % 1000000) * 1000;
        explain_nanoleep_on_error(&req, &rem);
        rem_sec = (rem.tv_sec + rem.tv_nsec * 1e-9);
        result = floor(0.5 + rem_sec * 1e6);
        return result;
    }
# else
    errno = ENOSYS;
    result = -1;
# endif
#endif
    if (result < 0)
    {
        int             hold_errno;

        hold_errno = errno;
        explain_output_error
        (
            "%s",
            explain_errno_usleep(hold_errno, usec)
        );
        errno = hold_errno;
    }
    return result;
}


/* vim: set ts=8 sw=4 et : */