xref: /illumos-gate/usr/src/lib/libc/port/gen/waitpid.c (revision 0ccfe5834c3b867c1b6c273cae02ec8922bc0fd2)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * All of the wait*() functions are cancellation points.
32  */
33 #pragma weak _waitpid = waitpid
34 #pragma weak _wait = wait
35 
36 #include "lint.h"
37 #include <unistd.h>
38 #include <string.h>
39 #include <errno.h>
40 #include <wait.h>
41 #include <sys/types.h>
42 #include <sys/siginfo.h>
43 #include <sys/times.h>
44 #include <sys/resource.h>
45 
46 /*
47  * Convert the siginfo_t code and status fields to an old style wait status.
48  */
49 static int
50 wstat(int code, int status)
51 {
52 	int stat = (status & 0377);
53 
54 	switch (code) {
55 	case CLD_EXITED:
56 		stat <<= 8;
57 		break;
58 	case CLD_DUMPED:
59 		stat |= WCOREFLG;
60 		break;
61 	case CLD_KILLED:
62 		break;
63 	case CLD_TRAPPED:
64 	case CLD_STOPPED:
65 		stat <<= 8;
66 		stat |= WSTOPFLG;
67 		break;
68 	case CLD_CONTINUED:
69 		stat = WCONTFLG;
70 		break;
71 	}
72 	return (stat);
73 }
74 
75 pid_t
76 waitpid(pid_t pid, int *stat_loc, int options)
77 {
78 	idtype_t idtype;
79 	id_t id;
80 	siginfo_t info;
81 	int error;
82 
83 	if (pid > 0) {
84 		idtype = P_PID;
85 		id = pid;
86 	} else if (pid < -1) {
87 		idtype = P_PGID;
88 		id = -pid;
89 	} else if (pid == -1) {
90 		idtype = P_ALL;
91 		id = 0;
92 	} else {
93 		idtype = P_PGID;
94 		id = getpgid(0);
95 	}
96 
97 	options |= (WEXITED|WTRAPPED);
98 
99 	if ((error = waitid(idtype, id, &info, options)) < 0)
100 		return (error);
101 
102 	if (stat_loc)
103 		*stat_loc = wstat(info.si_code, info.si_status);
104 
105 	return (info.si_pid);
106 }
107 
108 pid_t
109 wait(int *stat_loc)
110 {
111 	return (waitpid(-1, stat_loc, 0));
112 }
113 
114 pid_t
115 wait4(pid_t pid, int *stat_loc, int options, struct rusage *rp)
116 {
117 	struct tms	before_tms;
118 	struct tms	after_tms;
119 	siginfo_t	info;
120 	int		error;
121 	int		noptions;
122 	idtype_t	idtype;
123 
124 	if (rp)
125 		(void) memset(rp, 0, sizeof (struct rusage));
126 	(void) memset(&info, 0, sizeof (siginfo_t));
127 
128 	if (times(&before_tms) == (clock_t)-1)
129 		return (-1);		/* errno is set by times() */
130 
131 	/*
132 	 * SunOS's wait4() previously supported only WNOHANG &
133 	 * WUNTRACED.  XPG4v2 mandates that wait3() (which calls
134 	 * wait4()) also support WCONTINUED.
135 	 */
136 	if (options & ~(WNOHANG|WUNTRACED|WCONTINUED)) {
137 		errno = EINVAL;
138 		return (-1);
139 	}
140 	noptions = options | WEXITED | WTRAPPED;
141 
142 	/*
143 	 * Emulate undocumented 4.x semantics for 1186845
144 	 */
145 	if (pid < 0) {
146 		pid = -pid;
147 		idtype = P_PGID;
148 	} else if (pid == 0) {
149 		idtype = P_ALL;
150 	} else {
151 		idtype = P_PID;
152 	}
153 
154 	error = waitid(idtype, pid, &info, noptions);
155 	if (error == 0) {
156 		clock_t diffu;	/* difference in usertime (ticks) */
157 		clock_t diffs;	/* difference in systemtime (ticks) */
158 		clock_t hz;
159 
160 		if ((options & WNOHANG) && info.si_pid == 0)
161 			return (0);	/* no child found */
162 
163 		if (rp) {
164 			if (times(&after_tms) == (clock_t)-1)
165 				return (-1);	/* errno set by times() */
166 			/*
167 			 * The system/user time is an approximation only !!!
168 			 */
169 			diffu = after_tms.tms_cutime - before_tms.tms_cutime;
170 			diffs = after_tms.tms_cstime - before_tms.tms_cstime;
171 			hz = CLK_TCK;
172 			rp->ru_utime.tv_sec = diffu / hz;
173 			rp->ru_utime.tv_usec = (diffu % hz) * (1000000 / hz);
174 			rp->ru_stime.tv_sec = diffs / hz;
175 			rp->ru_stime.tv_usec = (diffs % hz) * (1000000 / hz);
176 		}
177 		if (stat_loc)
178 			*stat_loc = wstat(info.si_code, info.si_status);
179 		return (info.si_pid);
180 	} else {
181 		return (-1);		/* error number is set by waitid() */
182 	}
183 }
184 
185 pid_t
186 wait3(int *stat_loc, int options, struct rusage *rp)
187 {
188 	return (wait4(0, stat_loc, options, rp));
189 }
190