usr/src/ucblib/libucb/port/sys/wait4.c

   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
  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
 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 }