From: Paul Eggert Date: Sat, 14 Aug 1999 07:05:51 +0000 (+0000) Subject: Initial revision X-Git-Url: https://git.dogcows.com/gitweb?a=commitdiff_plain;h=ea2373a8a3165e0b4c471ad0e932cb35b85aec0f;p=chaz%2Ftar Initial revision --- diff --git a/lib/waitpid.c b/lib/waitpid.c new file mode 100644 index 0000000..f2b4235 --- /dev/null +++ b/lib/waitpid.c @@ -0,0 +1,72 @@ +/* Emulate waitpid on systems that just have wait. + Copyright 1994, 1995, 1998, 1999 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; see the file COPYING. + If not, write to the Free Software Foundation, + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#if HAVE_CONFIG_H +# include +#endif + +#include +#ifndef errno +extern int errno; +#endif + +#define WAITPID_CHILDREN 8 +static pid_t waited_pid[WAITPID_CHILDREN]; +static int waited_status[WAITPID_CHILDREN]; + +pid_t +waitpid (pid_t pid, int *stat_loc, int options) +{ + int i; + pid_t p; + + if (!options && (pid == -1 || 0 < pid)) + { + /* If we have already waited for this child, return it immediately. */ + for (i = 0; i < WAITPID_CHILDREN; i++) + { + p = waited_pid[i]; + if (p && (p == pid || pid == -1)) + { + waited_pid[i] = 0; + goto success; + } + } + + /* The child has not returned yet; wait for it, accumulating status. */ + for (i = 0; i < WAITPID_CHILDREN; i++) + if (! waited_pid[i]) + { + p = wait (&waited_status[i]); + if (p < 0) + return p; + if (p == pid || pid == -1) + goto success; + waited_pid[i] = p; + } + } + + /* We cannot emulate this wait call, e.g. because of too many children. */ + errno = EINVAL; + return -1; + +success: + if (stat_loc) + *stat_loc = waited_status[i]; + return p; +}