timersub.h

Go to the documentation of this file.

/*
 * Copyright (C) 1991-1994,1996-2003,2005,2006,2009
 *               Free Software Foundation, Inc.
 *
 * The GNU C Library 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 2.1 of the License, or (at your option) any later version.
 *
 * The GNU C Library 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 the GNU C Library; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */
 
#include <sys/time.h>
 
#ifndef timersub
# define timersub(a, b, result)                      \
  do {                                               \
    (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;    \
    (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
    if ((result)->tv_usec < 0) {                     \
      --(result)->tv_sec;                            \
      (result)->tv_usec += 1000000;                  \
    }                                                \
  } while (0)
#endif