wait3.c revision 8e3c57a3c9aa75d7adfa6ee670c67507535df4d4
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley Software License Agreement
* specifies the terms and conditions for redistribution.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Compatibility lib for BSD's wait3(). It is not
* binary compatible, since BSD's WNOHANG and WUNTRACED
* carry different #define values.
*/
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/times.h>
#include <wait.h>
#include <sys/siginfo.h>
#include <sys/procset.h>
#include <sys/param.h>
#include <sys/resource.h>
/*
* Since sysV does not support rusage as in BSD, an approximate approach
* is:
* ...
* call times
* call waitid
* if ( a child is found )
* call times again
* rusage ~= diff in the 2 times call
* ...
*
*/
/*
* XXX: There is now a wait3 function in libc which should be used instead
* of this local version of wait3. With the addition of a wait3 prototype
* in <sys/wait.h> as per the X/Open XPG4v2 specification, compilation of
* the csh utility will result in warnings, hence the renaming of the local
* version. Using the libc wait3 rather than the local version results in
* a failure with csh, however, this version should eventually be dropped
* in favor of the libc wait3 with appropriate updates made to sh.proc.c
* to account for the difference in implementation of the local versus
* the libc versions. This should probably be done as part of an overall
* effort to rid csh of local versions of functions now in libc.
*/
static int wstat(int code, int status);
pid_t
csh_wait3(int *status, int options, struct rusage *rp)
{
struct tms before_tms;
struct tms after_tms;
siginfo_t info;
int error;
if (rp)
memset((void *)rp, 0, sizeof (struct rusage));
memset((void *)&info, 0, sizeof (siginfo_t));
if (times(&before_tms) == -1)
return (-1); /* errno is set by times() */
/*
* BSD's wait3() only supports WNOHANG & WUNTRACED
*/
options |= (WNOHANG|WUNTRACED|WEXITED|WSTOPPED|WTRAPPED|WCONTINUED);
error = waitid(P_ALL, 0, &info, options);
if (error == 0) {
clock_t diffu; /* difference in usertime (ticks) */
clock_t diffs; /* difference in systemtime (ticks) */
if ((options & WNOHANG) && (info.si_pid == 0))
return (0); /* no child found */
if (rp) {
if (times(&after_tms) == -1)
return (-1); /* errno set by times() */
/*
* The system/user time is an approximation only !!!
*/
diffu = after_tms.tms_cutime - before_tms.tms_cutime;
diffs = after_tms.tms_cstime - before_tms.tms_cstime;
rp->ru_utime.tv_sec = diffu/HZ;
rp->ru_utime.tv_usec = (diffu % HZ) / HZ * 1000000;
rp->ru_stime.tv_sec = diffs/HZ;
rp->ru_stime.tv_usec = (diffs % HZ) / HZ * 1000000;
}
*status = wstat(info.si_code, info.si_status);
return (info.si_pid);
} else {
return (-1); /* error number is set by waitid() */
}
}
/*
* Convert the status code to old style wait status
*/
static int
wstat(int code, int status)
{
int stat = (status & 0377);
switch (code) {
case CLD_EXITED:
stat <<= 8;
break;
case CLD_DUMPED:
stat |= WCOREFLG;
break;
case CLD_KILLED:
break;
case CLD_TRAPPED:
case CLD_STOPPED:
stat <<= 8;
stat |= WSTOPFLG;
break;
case CLD_CONTINUED:
stat = WCONTFLG;
break;
}
return (stat);
}
pid_t
csh_wait_noreap(void)
{
siginfo_t info;
if (waitid(P_ALL, 0, &info,
WEXITED | WTRAPPED | WSTOPPED | WCONTINUED | WNOWAIT) != 0)
return (-1);
return (info.si_pid);
}