xref: /illumos-gate/usr/src/ucblib/libucb/port/sys/wait4.c (revision 7c478bd9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 1995-1997, by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 
31 /* 	Portions Copyright(c) 1988, Sun Microsystems Inc.	*/
32 /*	All Rights Reserved					*/
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI"	/* SVr4.0 1.1	*/
35 
36 /*LINTLIBRARY*/
37 
38 /*
39  * Compatibility lib for SunOS's wait4().
40  */
41 
42 #include <sys/types.h>
43 #include <sys/time.h>
44 #include <sys/times.h>
45 #include <sys/wait.h>
46 #include <sys/siginfo.h>
47 #include <sys/procset.h>
48 #include <sys/param.h>
49 #include <sys/resource.h>
50 #include <unistd.h>
51 #include <string.h>
52 #include <errno.h>
53 
54 /*
55  * Since sysV does not support rusage as in BSD, an approximate approach
56  * is:
57  *      ...
58  *      call times
59  *      call waitid
60  *      if ( a child is found )
61  *              call times again
62  *              rusage ~= diff in the 2 times call
63  *      ...
64  */
65 
66 /*
67  * forward declaration
68  */
69 static int wstat(int, int);
70 
71 pid_t
wait4(pid_t pid,int * status,int options,struct rusage * rp)72 wait4(pid_t pid, int *status, int options, struct rusage *rp)
73 {
74 	struct  tms	before_tms;
75 	struct  tms	after_tms;
76 	siginfo_t	info;
77 	int		error;
78 	int 		noptions;
79 	idtype_t	idtype;
80 
81 	if ((long)status == -1L || (long)rp == -1L) {
82 		errno = EFAULT;
83 		return (-1);
84 	}
85 
86 	if (rp)
87 		(void) memset(rp, 0, sizeof (struct rusage));
88 	(void) memset(&info, 0, sizeof (siginfo_t));
89 	if (times(&before_tms) < 0)
90 		return (-1);	/* errno is set by times() */
91 
92 	/*
93 	 * SunOS's wait4() only supports WNOHANG & WUNTRACED
94 	 */
95 	if (options & ~(WNOHANG|WUNTRACED))
96 		return (EINVAL);	/* used to be done by the kernel */
97 	noptions = options | WEXITED | WTRAPPED;
98 
99 	/*
100 	 * Emulate undocumented 4.x semantics for 1186845
101 	 */
102 	if (pid < 0) {
103 		pid = -pid;
104 		idtype = P_PGID;
105 	} else if (pid == 0)
106 		idtype = P_ALL;
107 	else
108 		idtype = P_PID;
109 
110 	error = waitid(idtype, pid, &info, noptions);
111 	if (error == 0) {
112 		clock_t	diffu;  /* difference in usertime (ticks) */
113 		clock_t	diffs;  /* difference in systemtime (ticks) */
114 
115 		if ((options & WNOHANG) && (info.si_pid == 0))
116 			return (0);	/* no child found */
117 
118 		if (rp) {
119 			if (times(&after_tms) < 0)
120 				return (-1);    /* errno set by times() */
121 			/*
122 			 * The system/user time is an approximation only !!!
123 			 */
124 			diffu = after_tms.tms_cutime - before_tms.tms_cutime;
125 			diffs = after_tms.tms_cstime - before_tms.tms_cstime;
126 			rp->ru_utime.tv_sec = diffu / HZ;
127 			rp->ru_utime.tv_usec = (diffu % HZ) * (1000000 / HZ);
128 			rp->ru_stime.tv_sec = diffs/ HZ;
129 			rp->ru_stime.tv_usec = (diffs % HZ) * (1000000 / HZ);
130 		}
131 		if (status)
132 			*status = wstat(info.si_code, info.si_status);
133 		return (info.si_pid);
134 	} else {
135 		return (-1);		/* error number is set by waitid() */
136 	}
137 }
138 
139 /*
140  * Convert the status code to old style wait status
141  */
142 static int
wstat(int code,int status)143 wstat(int code, int status)
144 {
145 	int stat = (status & 0377);
146 
147 	switch (code) {
148 	case CLD_EXITED:
149 		stat <<= 8;
150 		break;
151 	case CLD_DUMPED:
152 		stat |= WCOREFLG;
153 		break;
154 	case CLD_KILLED:
155 		break;
156 	case CLD_TRAPPED:
157 	case CLD_STOPPED:
158 		stat <<= 8;
159 		stat |= WSTOPFLG;
160 		break;
161 	case CLD_CONTINUED:
162 		stat = WCONTFLG;
163 		break;
164 	}
165 	return (stat);
166 }
167