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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
|
/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <sys/types.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <stdlib.h>
#include <string.h>
/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
(if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
after waiting the interval specified therein. Returns the number of ready
descriptors, or -1 for errors. */
int
DEFUN(__select, (nfds, readfds, writefds, exceptfds, timeout),
int nfds AND fd_set *readfds AND fd_set *writefds AND
fd_set *exceptfds AND struct timeval *timeout)
{
int i;
mach_port_t port;
int got;
int *types;
struct hurd_userlink *ulink;
mach_port_t *ports;
struct hurd_fd **cells;
error_t err;
fd_set rfds, wfds, xfds;
int firstfd, lastfd;
mach_msg_timeout_t to = (timeout != NULL ?
(timeout->tv_sec * 1000 +
timeout->tv_usec / 1000) :
0);
/* Use local copies so we can't crash from user bogosity. */
if (readfds == NULL)
FD_ZERO (&rfds);
else
rfds = *readfds;
if (writefds == NULL)
FD_ZERO (&wfds);
else
wfds = *writefds;
if (exceptfds == NULL)
FD_ZERO (&xfds);
else
xfds = *exceptfds;
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_dtable_lock);
if (nfds > _hurd_dtablesize)
nfds = _hurd_dtablesize;
/* Collect the ports for interesting FDs. */
cells = __alloca (nfds * sizeof (*cells));
ports = __alloca (nfds * sizeof (*ports));
types = __alloca (nfds * sizeof (*types));
ulink = __alloca (nfds * sizeof (*ulink));
firstfd = lastfd = -1;
for (i = 0; i < nfds; ++i)
{
int type = 0;
if (readfds != NULL && FD_ISSET (i, &rfds))
type |= SELECT_READ;
if (writefds != NULL && FD_ISSET (i, &wfds))
type |= SELECT_WRITE;
if (exceptfds != NULL && FD_ISSET (i, &xfds))
type |= SELECT_URG;
types[i] = type;
if (type)
{
cells[i] = _hurd_dtable[i];
ports[i] = _hurd_port_get (&cells[i]->port, &ulink[i]);
if (ports[i] == MACH_PORT_NULL)
{
/* If one descriptor is bogus, we fail completely. */
while (i-- > 0)
_hurd_port_free (&cells[i]->port, &ulink[i], ports[i]);
errno = EBADF;
break;
}
lastfd = i;
if (firstfd == -1)
firstfd = i;
}
}
__mutex_unlock (&_hurd_dtable_lock);
HURD_CRITICAL_END;
if (i < nfds)
return -1;
/* Get a port to receive the io_select_reply messages on. */
port = __mach_reply_port ();
/* Send them all io_select request messages. */
got = 0;
err = 0;
for (i = firstfd; i <= lastfd; ++i)
if (types[i])
{
if (!err)
{
int tag = i;
err = __io_select (ports[i], port,
/* Poll for each but the last. */
(i == lastfd && got == 0) ? to : 0,
&types[i], &tag);
if (!err)
{
if (tag != i)
err = EGRATUITOUS;
else if (types[i] & (SELECT_READ|SELECT_URG|SELECT_WRITE))
++got;
}
}
_hurd_port_free (&cells[i]->port, &ulink[i], ports[i]);
}
/* Now wait for reply messages. */
if (!err && got == 0 && port != MACH_PORT_NULL)
{
/* Now wait for io_select_reply messages on PORT,
timing out as appropriate. */
union
{
mach_msg_header_t head;
struct
{
mach_msg_header_t head;
mach_msg_type_t err_type;
error_t err;
} error;
struct
{
mach_msg_header_t head;
mach_msg_type_t err_type;
error_t err;
mach_msg_type_t result_type;
int result;
mach_msg_type_t tag_type;
int tag;
} success;
} msg;
mach_msg_option_t options = (timeout == NULL ? 0 : MACH_RCV_TIMEOUT);
error_t msgerr;
while ((msgerr = __mach_msg (&msg.head,
MACH_RCV_MSG | options,
sizeof msg, 0, port, to,
MACH_PORT_NULL)) == MACH_MSG_SUCCESS)
{
/* We got a message. Decode it. */
#define IO_SELECT_REPLY_MSGID (21012 + 100) /* XXX */
const mach_msg_type_t inttype =
{ MACH_MSG_TYPE_INTEGER_32, 32, 1, 1, 0, 0 };
if (msg.head.msgh_id == IO_SELECT_REPLY_MSGID &&
msg.head.msgh_size >= sizeof msg.error &&
!(msg.head.msgh_bits & MACH_MSGH_BITS_COMPLEX) &&
*(int *) &msg.error.err_type == *(int *) &inttype)
{
/* This is a properly formatted message so far.
See if it is a success or a failure. */
if (msg.error.err)
{
err = msg.error.err;
if (msg.head.msgh_size != sizeof msg.error)
__mach_msg_destroy (&msg);
}
else if (msg.head.msgh_size != sizeof msg.success ||
*(int *) &msg.success.tag_type != *(int *) &inttype ||
*(int *) &msg.success.result_type != *(int *) &inttype)
__mach_msg_destroy (&msg);
else if ((msg.success.result &
(SELECT_READ|SELECT_WRITE|SELECT_URG)) == 0 ||
msg.success.tag < firstfd || msg.success.tag > lastfd)
err = EGRATUITOUS;
else
{
/* This is a winning io_select_reply message!
Record the readiness it indicates and send a reply. */
if (types[msg.success.tag] == 0)
/* This descriptor is ready and it was not before,
so we increment our count of ready descriptors. */
++got;
types[msg.success.tag] |= msg.success.result;
}
}
if (msg.head.msgh_remote_port != MACH_PORT_NULL)
__mach_port_deallocate (__mach_task_self (),
msg.head.msgh_remote_port);
if (got || err == EINTR)
{
/* Poll for another message. */
to = 0;
options |= MACH_RCV_TIMEOUT;
}
}
if (err == MACH_RCV_TIMED_OUT)
/* This is the normal value for ERR. We might have timed out and
read no messages. Otherwise, after receiving the first message,
we poll for more messages. We receive with a timeout of 0 to
effect a poll, so ERR is MACH_RCV_TIMED_OUT when the poll finds no
message waiting. */
err = 0;
if (got && err == EINTR)
/* Some calls were interrupted, but at least one descriptor
is known to be ready now, so we will return success. */
err = 0;
}
if (port != MACH_PORT_NULL)
/* We must destroy the port if we made some select requests
that might send notification on that port after we no longer care.
If the port were reused, that notification could confuse the next
select call to use the port. The notification might be valid,
but the descriptor may have changed to a different server. */
__mach_port_destroy (__mach_task_self (), port);
if (timeout && got == 0 && err == MACH_RCV_TIMED_OUT)
/* No io_select call returned success immediately, and the last call
blocked for our full timeout period and then timed out. So the
multiplex times out too. */
return 0;
if (err)
return __hurd_fail (err);
/* Set the user bitarrays. */
for (i = 0; i < nfds; ++i)
{
if (readfds != NULL)
if (types[i] & SELECT_READ)
FD_SET (i, readfds);
else
FD_CLR (i, readfds);
if (writefds != NULL)
if (types[i] & SELECT_WRITE)
FD_SET (i, writefds);
else
FD_CLR (i, writefds);
if (exceptfds != NULL)
if (types[i] & SELECT_URG)
FD_SET (i, exceptfds);
else
FD_CLR (i, exceptfds);
}
return got;
}
weak_alias (__select, select)
|
