1 /* Emulate waitpid on systems that just have wait.
2 Copyright (C) 1994 Free Software Foundation, Inc.
3
4 This file is part of GNU DIFF.
5
6 GNU DIFF is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU DIFF is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details. */
15
16 #ifndef __VMS_VER
17 #define __VMS_VER 0
18 #endif
19 #ifndef __DECC_VER
20 #define __DECC_VER 0
21 #endif
22
23 #if __VMS_VER < 70200000 || __DECC_VER < 50700000
24
25 #include "vms.h"
26
27 #define WAITPID_CHILDREN 8
28 static pid_t waited_pid[WAITPID_CHILDREN];
29 static int waited_status[WAITPID_CHILDREN];
30
31 pid_t
waitpid(pid,stat_loc,options)32 waitpid (pid, stat_loc, options)
33 pid_t pid;
34 int *stat_loc;
35 int options;
36 {
37 int i;
38 pid_t p;
39
40 if (!options && (0 < pid || pid == -1))
41 {
42 /* If we have already waited for this child, return it immediately. */
43 for (i = 0; i < WAITPID_CHILDREN; i++)
44 {
45 p = waited_pid[i];
46 if (p && (p == pid || pid == -1))
47 {
48 waited_pid[i] = 0;
49 goto success;
50 }
51 }
52
53 /* The child has not returned yet; wait for it, accumulating status. */
54 for (i = 0; i < WAITPID_CHILDREN; i++)
55 if (! waited_pid[i])
56 {
57 p = wait (&waited_status[i]);
58 if (p < 0)
59 return p;
60 if (p == pid || pid == -1)
61 goto success;
62 waited_pid[i] = p;
63 }
64 }
65
66 /* We cannot emulate this wait call, e.g. because of too many children. */
67 abort ();
68
69 success:
70 if (stat_loc)
71 *stat_loc = waited_status[i];
72 return p;
73 }
74
75 #else /* __VMS_VER >= 70200000 && __DECC_VER >= 50700000 */
76 #pragma message disable EMPTYFILE
77 #endif /* __VMS_VER >= 70200000 && __DECC_VER >= 50700000 */
78