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      1 /*
      2  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
      3  * Use is subject to license terms.
      4  */
      5 
      6 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
      7 /*	  All Rights Reserved	*/
      8 
      9 /*
     10  * Copyright (c) 1980 Regents of the University of California.
     11  * All rights reserved. The Berkeley Software License Agreement
     12  * specifies the terms and conditions for redistribution.
     13  */
     14 
     15 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     16 
     17 /*
     18  * Compatibility lib for BSD's wait3(). It is not
     19  * binary compatible, since BSD's WNOHANG and WUNTRACED
     20  * carry different #define values.
     21  */
     22 #include <errno.h>
     23 #include <sys/types.h>
     24 #include <sys/time.h>
     25 #include <sys/times.h>
     26 #include <wait.h>
     27 #include <sys/siginfo.h>
     28 #include <sys/procset.h>
     29 #include <sys/param.h>
     30 #include <sys/resource.h>
     31 
     32 /*
     33  * Since sysV does not support rusage as in BSD, an approximate approach
     34  * is:
     35  *	...
     36  *	call times
     37  *	call waitid
     38  *	if ( a child is found )
     39  *		call times again
     40  *		rusage ~= diff in the 2 times call
     41  *	...
     42  *
     43  */
     44 
     45 /*
     46  * XXX:  There is now a wait3 function in libc which should be used instead
     47  * of this local version of wait3.  With the addition of a wait3 prototype
     48  * in <sys/wait.h> as per the X/Open XPG4v2 specification, compilation of
     49  * the csh utility will result in warnings, hence the renaming of the local
     50  * version.  Using the libc wait3 rather than the local version results in
     51  * a failure with csh, however, this version should eventually be dropped
     52  * in favor of the libc wait3 with appropriate updates made to sh.proc.c
     53  * to account for the difference in implementation of the local versus
     54  * the libc versions.  This should probably be done as part of an overall
     55  * effort to rid csh of local versions of functions now in libc.
     56  */
     57 
     58 static int wstat(int code, int status);
     59 
     60 pid_t
     61 csh_wait3(int *status, int options, struct rusage *rp)
     62 {
     63 	struct tms before_tms;
     64 	struct tms after_tms;
     65 	siginfo_t info;
     66 	int error;
     67 
     68 	if (rp)
     69 		memset((void *)rp, 0, sizeof (struct rusage));
     70 	memset((void *)&info, 0, sizeof (siginfo_t));
     71 	if (times(&before_tms) == -1)
     72 		return (-1);	/* errno is set by times() */
     73 
     74 	/*
     75 	 * BSD's wait3() only supports WNOHANG & WUNTRACED
     76 	 */
     77 	options |= (WNOHANG|WUNTRACED|WEXITED|WSTOPPED|WTRAPPED|WCONTINUED);
     78 	error = waitid(P_ALL, 0, &info, options);
     79 	if (error == 0) {
     80 		clock_t	diffu;	/* difference in usertime (ticks) */
     81 		clock_t	diffs;	/* difference in systemtime (ticks) */
     82 
     83 		if ((options & WNOHANG) && (info.si_pid == 0))
     84 			return (0);	/* no child found */
     85 
     86 		if (rp) {
     87 			if (times(&after_tms) == -1)
     88 				return (-1);	/* errno set by times() */
     89 			/*
     90 			 * The system/user time is an approximation only !!!
     91 			 */
     92 			diffu = after_tms.tms_cutime - before_tms.tms_cutime;
     93 			diffs = after_tms.tms_cstime - before_tms.tms_cstime;
     94 			rp->ru_utime.tv_sec = diffu/HZ;
     95 			rp->ru_utime.tv_usec = ((diffu % HZ) * 1000000) / HZ;
     96 			rp->ru_stime.tv_sec = diffs/HZ;
     97 			rp->ru_stime.tv_usec = ((diffs % HZ) * 1000000) / HZ;
     98 		}
     99 		*status = wstat(info.si_code, info.si_status);
    100 		return (info.si_pid);
    101 
    102 	} else {
    103 		return (-1);	/* error number is set by waitid() */
    104 	}
    105 }
    106 
    107 /*
    108  * Convert the status code to old style wait status
    109  */
    110 static int
    111 wstat(int code, int status)
    112 {
    113 	int stat = (status & 0377);
    114 
    115 	switch (code) {
    116 		case CLD_EXITED:
    117 			stat <<= 8;
    118 			break;
    119 		case CLD_DUMPED:
    120 			stat |= WCOREFLG;
    121 			break;
    122 		case CLD_KILLED:
    123 			break;
    124 		case CLD_TRAPPED:
    125 		case CLD_STOPPED:
    126 			stat <<= 8;
    127 			stat |= WSTOPFLG;
    128 			break;
    129 		case CLD_CONTINUED:
    130 			stat = WCONTFLG;
    131 			break;
    132 	}
    133 	return (stat);
    134 }
    135 
    136 pid_t
    137 csh_wait_noreap(void)
    138 {
    139 	siginfo_t info;
    140 
    141 	if (waitid(P_ALL, 0, &info,
    142 	    WEXITED | WTRAPPED | WSTOPPED | WCONTINUED | WNOWAIT) != 0)
    143 		return (-1);
    144 	return (info.si_pid);
    145 }
    146