1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/* $OpenBSD: uthread_select.c,v 1.6 2003/01/19 21:22:31 marc Exp $ */
/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: uthread_select.c,v 1.13 1999/08/30 00:02:08 deischen Exp $
*/
#include <unistd.h>
#include <errno.h>
#include <poll.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/fcntl.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
int
select(int numfds, fd_set * readfds, fd_set * writefds,
fd_set * exceptfds, struct timeval * timeout)
{
struct pthread *curthread = _get_curthread();
struct timespec ts;
int i, ret = 0, f_wait = 1;
int pfd_index, got_one = 0, fd_count = 0;
struct pthread_poll_data data;
/* this is a cancellation point per IEEE Std 1003.1-2001 */
_thread_enter_cancellation_point();
if (numfds > _thread_dtablesize) {
numfds = _thread_dtablesize;
}
/* Check if a timeout was specified: */
if (timeout) {
if (timeout->tv_sec < 0 ||
timeout->tv_usec < 0 || timeout->tv_usec >= 1000000) {
errno = EINVAL;
ret = -1;
goto done;
}
/* Convert the timeval to a timespec: */
TIMEVAL_TO_TIMESPEC(timeout, &ts);
/* Set the wake up time: */
_thread_kern_set_timeout(&ts);
if (ts.tv_sec == 0 && ts.tv_nsec == 0)
f_wait = 0;
} else {
/* Wait for ever: */
_thread_kern_set_timeout(NULL);
}
/* Count the number of file descriptors to be polled: */
if (readfds || writefds || exceptfds) {
for (i = 0; i < numfds; i++) {
if ((readfds && FD_ISSET(i, readfds)) ||
(exceptfds && FD_ISSET(i, exceptfds)) ||
(writefds && FD_ISSET(i, writefds))) {
fd_count++;
}
}
}
/*
* Allocate memory for poll data if it hasn't already been
* allocated or if previously allocated memory is insufficient.
*/
if ((curthread->poll_data.fds == NULL) ||
(curthread->poll_data.nfds < fd_count)) {
data.fds = (struct pollfd *) realloc(curthread->poll_data.fds,
sizeof(struct pollfd) * MAX(128, fd_count));
if (data.fds == NULL) {
errno = ENOMEM;
ret = -1;
}
else {
/*
* Note that the threads poll data always
* indicates what is allocated, not what is
* currently being polled.
*/
curthread->poll_data.fds = data.fds;
curthread->poll_data.nfds = MAX(128, fd_count);
}
}
if (ret == 0) {
/* Setup the wait data. */
data.fds = curthread->poll_data.fds;
data.nfds = fd_count;
/*
* Setup the array of pollfds. Optimize this by
* running the loop in reverse and stopping when
* the number of selected file descriptors is reached.
*/
for (i = numfds - 1, pfd_index = fd_count - 1;
(i >= 0) && (pfd_index >= 0); i--) {
data.fds[pfd_index].events = 0;
if (readfds && FD_ISSET(i, readfds)) {
data.fds[pfd_index].events = POLLRDNORM;
}
if (exceptfds && FD_ISSET(i, exceptfds)) {
data.fds[pfd_index].events |= POLLRDBAND;
}
if (writefds && FD_ISSET(i, writefds)) {
data.fds[pfd_index].events |= POLLWRNORM;
}
if (data.fds[pfd_index].events != 0) {
/*
* Set the file descriptor to be polled and
* clear revents in case of a timeout which
* leaves fds unchanged:
*/
data.fds[pfd_index].fd = i;
data.fds[pfd_index].revents = 0;
pfd_index--;
}
}
if (((ret = _thread_sys_poll(data.fds, data.nfds, 0)) == 0) &&
(f_wait != 0)) {
curthread->data.poll_data = &data;
curthread->interrupted = 0;
_thread_kern_sched_state(PS_SELECT_WAIT, __FILE__, __LINE__);
if (curthread->interrupted) {
errno = EINTR;
data.nfds = 0;
ret = -1;
} else
ret = data.nfds;
}
}
if (ret >= 0) {
numfds = 0;
for (i = 0; i < fd_count; i++) {
/*
* Check the results of the poll and clear
* this file descriptor from the fdset if
* the requested event wasn't ready.
*/
got_one = 0;
if (readfds != NULL) {
if (FD_ISSET(data.fds[i].fd, readfds)) {
if (data.fds[i].revents & (POLLIN |
POLLRDNORM))
got_one = 1;
else
FD_CLR(data.fds[i].fd, readfds);
}
}
if (writefds != NULL) {
if (FD_ISSET(data.fds[i].fd, writefds)) {
if (data.fds[i].revents & (POLLOUT |
POLLWRNORM | POLLWRBAND))
got_one = 1;
else
FD_CLR(data.fds[i].fd,
writefds);
}
}
if (exceptfds != NULL) {
if (FD_ISSET(data.fds[i].fd, exceptfds)) {
if (data.fds[i].revents & (POLLRDBAND |
POLLPRI | POLLHUP | POLLERR |
POLLNVAL))
got_one = 1;
else
FD_CLR(data.fds[i].fd,
exceptfds);
}
}
if (got_one)
numfds++;
}
ret = numfds;
}
done:
_thread_leave_cancellation_point();
return (ret);
}
#endif
|
