/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */

/*
 * All of the wait*() functions are cancellation points.
 */
#pragma weak _waitpid = waitpid
#pragma weak _wait = wait

#include "lint.h"
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <wait.h>
#include <sys/types.h>
#include <sys/siginfo.h>
#include <sys/times.h>
#include <sys/resource.h>

/*
 * Convert the siginfo_t code and status fields to an 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
waitpid(pid_t pid, int *stat_loc, int options)
{
        idtype_t idtype;
        id_t id;
        siginfo_t info;
        int error;

        if (pid > 0) {
                idtype = P_PID;
                id = pid;
        } else if (pid < -1) {
                idtype = P_PGID;
                id = -pid;
        } else if (pid == -1) {
                idtype = P_ALL;
                id = 0;
        } else {
                idtype = P_PGID;
                id = getpgid(0);
        }

        options |= (WEXITED|WTRAPPED);

        if ((error = waitid(idtype, id, &info, options)) < 0)
                return (error);

        if (stat_loc)
                *stat_loc = wstat(info.si_code, info.si_status);

        return (info.si_pid);
}

pid_t
wait(int *stat_loc)
{
        return (waitpid(-1, stat_loc, 0));
}

pid_t
wait4(pid_t pid, int *stat_loc, int options, struct rusage *rp)
{
        struct tms      before_tms;
        struct tms      after_tms;
        siginfo_t       info;
        int             error;
        int             noptions;
        idtype_t        idtype;

        if (rp)
                (void) memset(rp, 0, sizeof (struct rusage));
        (void) memset(&info, 0, sizeof (siginfo_t));

        if (times(&before_tms) == (clock_t)-1)
                return (-1);            /* errno is set by times() */

        /*
         * SunOS's wait4() previously supported only WNOHANG &
         * WUNTRACED.  XPG4v2 mandates that wait3() (which calls
         * wait4()) also support WCONTINUED.
         */
        if (options & ~(WNOHANG|WUNTRACED|WCONTINUED)) {
                errno = EINVAL;
                return (-1);
        }
        noptions = options | WEXITED | WTRAPPED;

        /*
         * Emulate undocumented 4.x semantics for 1186845
         */
        if (pid < 0) {
                pid = -pid;
                idtype = P_PGID;
        } else if (pid == 0) {
                idtype = P_ALL;
        } else {
                idtype = P_PID;
        }

        error = waitid(idtype, pid, &info, noptions);
        if (error == 0) {
                clock_t diffu;  /* difference in usertime (ticks) */
                clock_t diffs;  /* difference in systemtime (ticks) */
                clock_t hz;

                if ((options & WNOHANG) && info.si_pid == 0)
                        return (0);     /* no child found */

                if (rp) {
                        if (times(&after_tms) == (clock_t)-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;
                        hz = CLK_TCK;
                        rp->ru_utime.tv_sec = diffu / hz;
                        rp->ru_utime.tv_usec = (diffu % hz) * (1000000 / hz);
                        rp->ru_stime.tv_sec = diffs / hz;
                        rp->ru_stime.tv_usec = (diffs % hz) * (1000000 / hz);
                }
                if (stat_loc)
                        *stat_loc = wstat(info.si_code, info.si_status);
                return (info.si_pid);
        } else {
                return (-1);            /* error number is set by waitid() */
        }
}

pid_t
wait3(int *stat_loc, int options, struct rusage *rp)
{
        return (wait4(0, stat_loc, options, rp));
}