/***********************************************************************
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2013 AT&T Intellectual Property          *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 1.0                  *
 *                    by AT&T Intellectual Property                     *
 *                                                                      *
 *                A copy of the License is available at                 *
 *          http://www.eclipse.org/org/documents/epl-v10.html           *
 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
 *                                                                      *
 *              Information and Software Systems Research               *
 *                            AT&T Research                             *
 *                           Florham Park NJ                            *
 *                                                                      *
 *                    David Korn <dgkorn@gmail.com>                     *
 *                                                                      *
 ***********************************************************************/
#pragma prototyped
/*
 * sleep delay
 *
 *   David Korn
 *   AT&T Labs
 *
 */

#define sleep	______sleep
#include	"defs.h"
#undef	sleep
#include	<error.h>
#include	<errno.h>
#include	<tmx.h>
#include	"builtins.h"
#include	"FEATURE/time"
#include	"FEATURE/poll"
#ifdef _NEXT_SOURCE
#   define sleep	_ast_sleep
#endif /* _NEXT_SOURCE */
#ifdef _lib_poll_notimer
#   undef _lib_poll
#endif /* _lib_poll_notimer */

int	b_sleep(register int argc,char *argv[],Shbltin_t *context)
{
	register char *cp;
	register double d=0;
	register Shell_t *shp = context->shp;
	int sflag=0;
	time_t tloc = 0;
	char *last;
	if(!(shp->sigflag[SIGALRM]&(SH_SIGFAULT|SH_SIGOFF)))
		sh_sigtrap(SIGALRM);
	while((argc = optget(argv,sh_optsleep))) switch(argc)
	{
		case 's':
			sflag=1;
			break;
		case ':':
			errormsg(SH_DICT,2, "%s", opt_info.arg);
			break;
		case '?':
			errormsg(SH_DICT,ERROR_usage(2), "%s", opt_info.arg);
			break;
	}
	argv += opt_info.index;
	if(cp = *argv)
	{
		d = strtod(cp, &last);
		if(*last)
		{
			Time_t now,ns;
			char* pp;
			now = TMX_NOW;
			if(*cp == 'P' || *cp == 'p')
				ns = tmxdate(cp, &last, now);
			else if(*last=='.' && shp->decomma && d==(unsigned long)d)
			{
				*(pp=last) = ',';
				if(!strchr(cp,'.'))
					d = strtod(cp,&last);
				*pp = '.';
				if(*last==0)
					goto skip;
			}
			else if(*last!='.' && *last!=',')
			{
				if(pp = sfprints("exact %s", cp))
					ns = tmxdate(pp, &last, now);
				if(*last && (pp = sfprints("p%s", cp)))
					ns = tmxdate(pp, &last, now);
			}
			if(*last)
				errormsg(SH_DICT,ERROR_exit(1),e_number,*argv);
			d = ns - now;
			d /= TMX_RESOLUTION;
		}
skip:
		if(argv[1])
			errormsg(SH_DICT,ERROR_exit(1),e_oneoperand);
	}
	else if(!sflag)
		errormsg(SH_DICT,ERROR_exit(1),e_oneoperand);
	if(d > .10)
	{
		time(&tloc);
		tloc += (time_t)(d+.5);
	}
	if(sflag && d==0)
		pause();
	else while(1)
	{
		time_t now;
		errno = 0;
		shp->lastsig=0;
		sh_delay(d);
		if(sflag || tloc==0 || errno!=EINTR || shp->lastsig)
			break;
		sh_sigcheck(shp);
		if(tloc < (now=time(NIL(time_t*))))
			break;
		d = (double)(tloc-now);
		if(shp->sigflag[SIGALRM]&SH_SIGTRAP)
			sh_timetraps(shp);
	}
	return(0);
}

static void completed(void * handle)
{
	char *expired = (char*)handle;
	*expired = 1;
}

unsigned int sleep(unsigned int sec)
{
	Shell_t	*shp = sh_getinterp();
	pid_t newpid, curpid=getpid();
	void *tp;
	char expired = 0;
	shp->lastsig = 0;
	tp = (void*)sh_timeradd(1000*sec, 0, completed, (void*)&expired);
	do
	{
		if(!shp->gd->waitevent || (*shp->gd->waitevent)(-1,-1L,0)==0)
			pause();
		if(shp->sigflag[SIGALRM]&SH_SIGTRAP)
			sh_timetraps(shp);
		if((newpid=getpid()) != curpid)
		{
			curpid = newpid;
			shp->lastsig = 0;
			shp->trapnote &= ~SH_SIGSET;
			if(expired)
				expired = 0;
			else
				timerdel(tp);
			tp = (void*)sh_timeradd(1000*sec, 0, completed, (void*)&expired);
		}
	}
	while(!expired && shp->lastsig==0);
	if(!expired)
		timerdel(tp);
	sh_sigcheck(shp);
	return(0);
}

//
// Delay execution for time <t>.
//
void sh_delay(double t) {
    Shell_t *shp = sh_getinterp();
    int n = (int)t;
    Tv_t ts, tx;

    ts.tv_sec = n;
    ts.tv_nsec = 1000000000 * (t - (double)n);
    while (tvsleep(&ts, &tx) < 0 && errno == EINTR) {
        if (shp->trapnote & (SH_SIGSET | SH_SIGTRAP)) return;
        ts = tx;
    }
 }