common/bltins/sleep.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1982-2009 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                  David Korn <dgk (at) research.att.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[],void *extra)
{
	register char *cp;
	register double d=0;
	register Shell_t *shp = ((Shbltin_t*)extra)->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(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;
		}
		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();
		if(tloc < (now=time(NIL(time_t*))))
			break;
		d = (double)(tloc-now);
		if(shp->sigflag[SIGALRM]&SH_SIGTRAP)
			sh_timetraps();
	}
	return(0);
}

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

unsigned int sleep(unsigned int sec)
{
	Shell_t	*shp = &sh;
	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->waitevent || (*shp->waitevent)(-1,-1L,0)==0)
			pause();
		if(shp->sigflag[SIGALRM]&SH_SIGTRAP)
			sh_timetraps();
		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();
	return(0);
}

/*
 * delay execution for time <t>
 */

void	sh_delay(double t)
{
	register int n = (int)t;
	Shell_t	*shp = &sh;
#ifdef _lib_poll
	struct pollfd fd;
	if(t<=0)
		return;
	else if(n > 30)
	{
		sleep(n);
		t -= n;
	}
	if(n=(int)(1000*t))
	{
		if(!shp->waitevent || (*shp->waitevent)(-1,(long)n,0)==0)
			poll(&fd,0,n);
	}
#else
#   if defined(_lib_select) && defined(_mem_tv_usec_timeval)
	struct timeval timeloc;
	if(t<=0)
		return;
	if(n=(int)(1000*t) && shp->waitevent && (*shp->waitevent)(-1,(long)n,0))
		return;
	n = (int)t;
	timeloc.tv_sec = n;
	timeloc.tv_usec = 1000000*(t-(double)n);
	select(0,(fd_set*)0,(fd_set*)0,(fd_set*)0,&timeloc);
#   else
#	ifdef _lib_select
		/* for 9th edition machines */
		if(t<=0)
			return;
		if(n > 30)
		{
			sleep(n);
			t -= n;
		}
		if(n=(int)(1000*t))
		{
			if(!shp->waitevent || (*shp->waitevent)(-1,(long)n,0)==0)
				select(0,(fd_set*)0,(fd_set*)0,n);
		}
#	else
		struct tms tt;
		if(t<=0)
			return;
		sleep(n);
		t -= n;
		if(t)
		{
			clock_t begin = times(&tt);
			if(begin==0)
				return;
			t *= shp->lim.clk_tck;
			n += (t+.5);
			while((times(&tt)-begin) < n);
		}
#	endif
#   endif
#endif /* _lib_poll */
}