Home | History | Annotate | Download | only in ktli
      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License, Version 1.0 only
      6  * (the "License").  You may not use this file except in compliance
      7  * with the License.
      8  *
      9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
     10  * or http://www.opensolaris.org/os/licensing.
     11  * See the License for the specific language governing permissions
     12  * and limitations under the License.
     13  *
     14  * When distributing Covered Code, include this CDDL HEADER in each
     15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     16  * If applicable, add the following below this CDDL HEADER, with the
     17  * fields enclosed by brackets "[]" replaced with your own identifying
     18  * information: Portions Copyright [yyyy] [name of copyright owner]
     19  *
     20  * CDDL HEADER END
     21  */
     22 /*
     23  * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
     28 /*	  All Rights Reserved  	*/
     29 
     30 /*
     31  * University Copyright- Copyright (c) 1982, 1986, 1988
     32  * The Regents of the University of California
     33  * All Rights Reserved
     34  *
     35  * University Acknowledgment- Portions of this document are derived from
     36  * software developed by the University of California, Berkeley, and its
     37  * contributors.
     38  */
     39 
     40 #pragma ident	"@(#)t_kspoll.c	1.28	05/06/08 SMI"
     41 
     42 /*
     43  * This function waits for timo clock ticks for something to arrive on
     44  * the specified stream. If more than one client is hanging off of a
     45  * single endpoint, and at least one has specified a non-zero timeout,
     46  * then all will be woken.
     47  *
     48  * Returns:
     49  * 	0 on success or positive error code. On
     50  * 	success, "events" is set to
     51  *	 0	on timeout or no events(timout = 0),
     52  *	 1	if desired event has occurred
     53  *
     54  * Most of the code is from strwaitq().
     55  */
     56 
     57 #include <sys/param.h>
     58 #include <sys/types.h>
     59 #include <sys/proc.h>
     60 #include <sys/file.h>
     61 #include <sys/user.h>
     62 #include <sys/vnode.h>
     63 #include <sys/errno.h>
     64 #include <sys/stream.h>
     65 #include <sys/ioctl.h>
     66 #include <sys/stropts.h>
     67 #include <sys/strsubr.h>
     68 #include <sys/tihdr.h>
     69 #include <sys/timod.h>
     70 #include <sys/tiuser.h>
     71 #include <sys/t_kuser.h>
     72 #include <sys/signal.h>
     73 #include <sys/siginfo.h>
     74 #include <sys/time.h>
     75 #include <sys/debug.h>
     76 
     77 /*
     78  * Poll for an input event.
     79  *
     80  * timo is measured in ticks
     81  */
     82 int
     83 t_kspoll(TIUSER *tiptr, int timo, int waitflg, int *events)
     84 {
     85 	file_t		*fp;
     86 	vnode_t		*vp;
     87 	klwp_t		*lwp = ttolwp(curthread);
     88 	clock_t		timout;	/* milliseconds */
     89 	int		error;
     90 	u_char 		pri;
     91 	int 		pflag;
     92 	rval_t		rval;
     93 
     94 	fp = tiptr->fp;
     95 	vp = fp->f_vnode;
     96 
     97 	if (events == NULL || ((waitflg & READWAIT) == 0))
     98 		return (EINVAL);
     99 
    100 	/* Convert from ticks to milliseconds */
    101 	if (timo < 0)
    102 		timout = -1;
    103 	else
    104 		timout = TICK_TO_MSEC(timo);
    105 
    106 	/*
    107 	 * Indicate that the lwp is not to be stopped while doing
    108 	 * this network traffic.  This is to avoid deadlock while
    109 	 * debugging a process via /proc.
    110 	 */
    111 	if (lwp != NULL)
    112 		lwp->lwp_nostop++;
    113 
    114 	if (waitflg & NOINTR)
    115 		pflag = MSG_ANY | MSG_HOLDSIG;
    116 	else
    117 		pflag = MSG_ANY;
    118 	pri = 0;
    119 	error = kstrgetmsg(vp, NULL, NULL, &pri, &pflag, timout, &rval);
    120 
    121 	if (lwp != NULL)
    122 		lwp->lwp_nostop--;
    123 
    124 	/* Set the return *events. */
    125 	if (error != 0) {
    126 		if (error == ETIME) {
    127 			*events = 0;
    128 			error = 0;
    129 		}
    130 		return (error);
    131 	}
    132 	*events = 1;
    133 	return (0);
    134 }
    135