75 lines
2.0 KiB
C
75 lines
2.0 KiB
C
/* $NetBSD: waitpid.c,v 1.1.1.1 2003/01/26 00:43:15 wiz Exp $ */
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/* Emulate waitpid on systems that just have wait.
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Copyright (C) 1994, 1995, 1998, 1999 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING.
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If not, write to the Free Software Foundation,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <errno.h>
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#ifndef errno
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extern int errno;
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#endif
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#define WAITPID_CHILDREN 8
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static pid_t waited_pid[WAITPID_CHILDREN];
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static int waited_status[WAITPID_CHILDREN];
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pid_t
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waitpid (pid_t pid, int *stat_loc, int options)
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{
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int i;
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pid_t p;
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if (!options && (pid == -1 || 0 < pid))
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{
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/* If we have already waited for this child, return it immediately. */
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for (i = 0; i < WAITPID_CHILDREN; i++)
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{
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p = waited_pid[i];
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if (p && (p == pid || pid == -1))
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{
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waited_pid[i] = 0;
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goto success;
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}
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}
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/* The child has not returned yet; wait for it, accumulating status. */
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for (i = 0; i < WAITPID_CHILDREN; i++)
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if (! waited_pid[i])
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{
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p = wait (&waited_status[i]);
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if (p < 0)
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return p;
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if (p == pid || pid == -1)
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goto success;
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waited_pid[i] = p;
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}
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}
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/* We cannot emulate this wait call, e.g. because of too many children. */
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errno = EINVAL;
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return -1;
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success:
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if (stat_loc)
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*stat_loc = waited_status[i];
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return p;
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}
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