| 1 | /* Emulate waitpid on systems that just have wait. |
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| 2 | Copyright 1994, 1995, 1998, 1999 Free Software Foundation, Inc. |
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| 3 | |
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| 4 | This program is free software; you can redistribute it and/or modify |
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| 5 | it under the terms of the GNU General Public License as published by |
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| 6 | the Free Software Foundation; either version 2, or (at your option) |
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| 7 | any later version. |
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| 8 | |
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| 9 | This program is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 12 | GNU General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU General Public License |
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| 15 | along with this program; see the file COPYING. |
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| 16 | If not, write to the Free Software Foundation, |
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| 17 | 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
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| 18 | |
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| 19 | #if HAVE_CONFIG_H |
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| 20 | # include <config.h> |
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| 21 | #endif |
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| 22 | |
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| 23 | #include <errno.h> |
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| 24 | #ifndef errno |
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| 25 | extern int errno; |
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| 26 | #endif |
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| 27 | |
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| 28 | #define WAITPID_CHILDREN 8 |
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| 29 | static pid_t waited_pid[WAITPID_CHILDREN]; |
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| 30 | static int waited_status[WAITPID_CHILDREN]; |
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| 31 | |
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| 32 | pid_t |
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| 33 | waitpid (pid_t pid, int *stat_loc, int options) |
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| 34 | { |
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| 35 | int i; |
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| 36 | pid_t p; |
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| 37 | |
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| 38 | if (!options && (pid == -1 || 0 < pid)) |
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| 39 | { |
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| 40 | /* If we have already waited for this child, return it immediately. */ |
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| 41 | for (i = 0; i < WAITPID_CHILDREN; i++) |
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| 42 | { |
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| 43 | p = waited_pid[i]; |
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| 44 | if (p && (p == pid || pid == -1)) |
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| 45 | { |
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| 46 | waited_pid[i] = 0; |
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| 47 | goto success; |
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| 48 | } |
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| 49 | } |
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| 50 | |
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| 51 | /* The child has not returned yet; wait for it, accumulating status. */ |
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| 52 | for (i = 0; i < WAITPID_CHILDREN; i++) |
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| 53 | if (! waited_pid[i]) |
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| 54 | { |
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| 55 | p = wait (&waited_status[i]); |
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| 56 | if (p < 0) |
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| 57 | return p; |
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| 58 | if (p == pid || pid == -1) |
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| 59 | goto success; |
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| 60 | waited_pid[i] = p; |
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| 61 | } |
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| 62 | } |
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| 63 | |
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| 64 | /* We cannot emulate this wait call, e.g. because of too many children. */ |
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| 65 | errno = EINVAL; |
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| 66 | return -1; |
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| 67 | |
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| 68 | success: |
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| 69 | if (stat_loc) |
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| 70 | *stat_loc = waited_status[i]; |
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| 71 | return p; |
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| 72 | } |
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