xref: /illumos-gate/usr/src/lib/libnsl/rpc/rpc_sel2poll.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 /*
24  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /* Copyright (c) 1988 AT&T */
29 /* All Rights Reserved */
30 
31 #include "mt.h"
32 #include <sys/select.h>
33 #include <sys/types.h>
34 #include <sys/time.h>
35 #include <sys/poll.h>
36 #include "rpc_mt.h"
37 
38 
39 /*
40  *	Given an fd_set pointer and the number of bits to check in it,
41  *	initialize the supplied pollfd array for RPC's use (RPC only
42  *	polls for input events).  We return the number of pollfd slots
43  *	we initialized.
44  */
45 int
46 __rpc_select_to_poll(
47 	int	fdmax,		/* number of bits we must test */
48 	fd_set	*fdset,		/* source fd_set array */
49 	struct pollfd	*p0)	/* target pollfd array */
50 {
51 	int j;		/* loop counter */
52 	int n;
53 	struct pollfd	*p = p0;
54 
55 	/*
56 	 * For each fd, if the appropriate bit is set convert it into
57 	 * the appropriate pollfd struct.
58 	 */
59 	j = ((fdmax >= FD_SETSIZE) ? FD_SETSIZE : fdmax);
60 	for (n = 0; n < j; n++) {
61 		if (FD_ISSET(n, fdset)) {
62 			p->fd = n;
63 			p->events = MASKVAL;
64 			p->revents = 0;
65 			p++;
66 		}
67 	}
68 	return (p - p0);
69 }
70 
71 /*
72  *	Arguments are similar to rpc_select_to_poll() except that
73  *	the second argument is pointer to an array of pollfd_t
74  *	which is the source array which will be compressed and
75  *	copied to the target array in p0.  The size of the
76  *	source argument is given by pollfdmax. The array can be
77  *	sparse. The space for the target is allocated before
78  *	calling this function. It should have atleast pollfdmax
79  *	elements.  This function scans the source pollfd array
80  *	and copies only the valid ones to the target p0.
81  */
82 int
83 __rpc_compress_pollfd(int pollfdmax, pollfd_t *srcp, pollfd_t *p0)
84 {
85 	int n;
86 	pollfd_t *p = p0;
87 
88 	for (n = 0; n < pollfdmax; n++) {
89 		if (POLLFD_ISSET(n, srcp)) {
90 			p->fd = srcp[n].fd;
91 			p->events = srcp[n].events;
92 			p->revents = 0;
93 			p++;
94 		}
95 	}
96 	return (p - p0);
97 }
98 
99 /*
100  *	Convert from timevals (used by select) to milliseconds (used by poll).
101  */
102 int
103 __rpc_timeval_to_msec(struct timeval *t)
104 {
105 	int	t1, tmp;
106 
107 	/*
108 	 * We're really returning t->tv_sec * 1000 + (t->tv_usec / 1000)
109 	 * but try to do so efficiently.  Note:  1000 = 1024 - 16 - 8.
110 	 */
111 	tmp = (int)t->tv_sec << 3;
112 	t1 = -tmp;
113 	t1 += t1 << 1;
114 	t1 += tmp << 7;
115 	if (t->tv_usec)
116 		t1 += t->tv_usec / 1000;
117 
118 	return (t1);
119 }
120