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Comparing libev/ev_select.c (file contents):
Revision 1.4 by root, Wed Oct 31 14:44:15 2007 UTC vs.
Revision 1.32 by root, Mon May 26 03:54:40 2008 UTC

1/* 1/*
2 * libev select fd activity backend
3 *
2 * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de> 4 * Copyright (c) 2007,2008 Marc Alexander Lehmann <libev@schmorp.de>
3 * All rights reserved. 5 * All rights reserved.
4 * 6 *
5 * Redistribution and use in source and binary forms, with or without 7 * Redistribution and use in source and binary forms, with or without modifica-
6 * modification, are permitted provided that the following conditions are 8 * tion, are permitted provided that the following conditions are met:
7 * met: 9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26 * OF THE POSSIBILITY OF SUCH DAMAGE.
8 * 27 *
9 * * Redistributions of source code must retain the above copyright 28 * Alternatively, the contents of this file may be used under the terms of
10 * notice, this list of conditions and the following disclaimer. 29 * the GNU General Public License ("GPL") version 2 or any later version,
11 * 30 * in which case the provisions of the GPL are applicable instead of
12 * * Redistributions in binary form must reproduce the above 31 * the above. If you wish to allow the use of your version of this file
13 * copyright notice, this list of conditions and the following 32 * only under the terms of the GPL and not to allow others to use your
14 * disclaimer in the documentation and/or other materials provided 33 * version of this file under the BSD license, indicate your decision
15 * with the distribution. 34 * by deleting the provisions above and replace them with the notice
16 * 35 * and other provisions required by the GPL. If you do not delete the
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 36 * provisions above, a recipient may use your version of this file under
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 37 * either the BSD or the GPL.
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */ 38 */
29 39
30/* for broken bsd's */ 40#ifndef _WIN32
31#include <sys/time.h>
32#include <sys/types.h>
33#include <unistd.h>
34
35/* for unix systems */ 41/* for unix systems */
36#include <sys/select.h> 42# include <sys/select.h>
43# include <inttypes.h>
44#endif
45
46#ifndef EV_SELECT_USE_FD_SET
47# ifdef NFDBITS
48# define EV_SELECT_USE_FD_SET 0
49# else
50# define EV_SELECT_USE_FD_SET 1
51# endif
52#endif
53
54#if EV_SELECT_IS_WINSOCKET
55# undef EV_SELECT_USE_FD_SET
56# define EV_SELECT_USE_FD_SET 1
57#endif
58
59#if !EV_SELECT_USE_FD_SET
60# define NFDBYTES (NFDBITS / 8)
61#endif
37 62
38#include <string.h> 63#include <string.h>
39#include <inttypes.h>
40
41static unsigned char *vec_ri, *vec_ro, *vec_wi, *vec_wo;
42static int vec_max;
43 64
44static void 65static void
45select_modify (int fd, int oev, int nev) 66select_modify (EV_P_ int fd, int oev, int nev)
46{ 67{
47 int offs = fd >> 3; 68 if (oev == nev)
48 int mask = 1 << (fd & 7); 69 return;
49 70
50 if (vec_max < (fd >> 5) + 1) 71 {
72#if EV_SELECT_USE_FD_SET
73
74 #if EV_SELECT_IS_WINSOCKET
75 SOCKET handle = anfds [fd].handle;
76 #else
77 int handle = fd;
78 #endif
79
80 if (nev & EV_READ)
81 FD_SET (handle, (fd_set *)vec_ri);
82 else
83 FD_CLR (handle, (fd_set *)vec_ri);
84
85 if (nev & EV_WRITE)
86 FD_SET (handle, (fd_set *)vec_wi);
87 else
88 FD_CLR (handle, (fd_set *)vec_wi);
89
90#else
91
92 int word = fd / NFDBITS;
93 fd_mask mask = 1UL << (fd % NFDBITS);
94
95 if (expect_false (vec_max <= word))
51 { 96 {
52 vec_max = (fd >> 5) + 1; 97 int new_max = word + 1;
53 98
54 vec_ri = (unsigned char *)realloc (vec_ri, vec_max * 4); 99 vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
55 vec_ro = (unsigned char *)realloc (vec_ro, vec_max * 4); /* could free/malloc */ 100 vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
56 vec_wi = (unsigned char *)realloc (vec_wi, vec_max * 4); 101 vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
57 vec_wo = (unsigned char *)realloc (vec_wo, vec_max * 4); /* could free/malloc */ 102 vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
103
104 for (; vec_max < new_max; ++vec_max)
105 ((fd_mask *)vec_ri) [vec_max] =
106 ((fd_mask *)vec_wi) [vec_max] = 0;
58 } 107 }
59 108
60 vec_ri [offs] |= mask; 109 ((fd_mask *)vec_ri) [word] |= mask;
61 if (!(nev & EV_READ)) 110 if (!(nev & EV_READ))
62 vec_ri [offs] &= ~mask; 111 ((fd_mask *)vec_ri) [word] &= ~mask;
63 112
64 vec_wi [offs] |= mask; 113 ((fd_mask *)vec_wi) [word] |= mask;
65 if (!(nev & EV_WRITE)) 114 if (!(nev & EV_WRITE))
66 vec_wi [offs] &= ~mask; 115 ((fd_mask *)vec_wi) [word] &= ~mask;
116#endif
117 }
67} 118}
68 119
120static void
69static void select_poll (ev_tstamp timeout) 121select_poll (EV_P_ ev_tstamp timeout)
70{ 122{
71 struct timeval tv; 123 struct timeval tv;
72 int res; 124 int res;
73 125
126#if EV_SELECT_USE_FD_SET
127 memcpy (vec_ro, vec_ri, sizeof (fd_set));
128 memcpy (vec_wo, vec_wi, sizeof (fd_set));
129#else
74 memcpy (vec_ro, vec_ri, vec_max * 4); 130 memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
75 memcpy (vec_wo, vec_wi, vec_max * 4); 131 memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
132#endif
76 133
77 tv.tv_sec = (long)timeout; 134 tv.tv_sec = (long)timeout;
78 tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6); 135 tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
79 136
137#ifdef _WIN32
138 /* pass in the write set as except set.
139 * the idea behind this is to work around a windows bug that causes
140 * errors to be reported as an exception and not by setting
141 * the writable bit. this is so uncontrollably lame.
142 */
143 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_wo, &tv);
144#else
80 res = select (vec_max * 32, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); 145 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
146#endif
81 147
82 if (res > 0) 148 if (expect_false (res < 0))
83 { 149 {
84 int word, offs; 150 #if EV_SELECT_IS_WINSOCKET
151 errno = WSAGetLastError ();
152 #endif
153 #ifdef WSABASEERR
154 /* on windows, select returns incompatible error codes, fix this */
155 if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
156 if (errno == WSAENOTSOCK)
157 errno = EBADF;
158 else
159 errno -= WSABASEERR;
160 #endif
85 161
86 for (word = vec_max; word--; ) 162 #ifdef _WIN32
163 /* select on windows errornously returns EINVAL when no fd sets have been
164 * provided (this is documented). what microsoft doesn't tell you that this bug
165 * exists even when the fd sets are provided, so we have to check for this bug
166 * here and emulate by sleeping manually.
167 * we also get EINVAL when the timeout is invalid, but we ignore this case here
168 * and assume that EINVAL always means: you have to wait manually.
169 */
170 if (errno == EINVAL)
87 { 171 {
88 if (((uint32_t *)vec_ro) [word] | ((uint32_t *)vec_wo) [word]) 172 ev_sleep (timeout);
89 for (offs = 4; offs--; ) 173 return;
90 {
91 int idx = word * 4 + offs;
92 unsigned char byte_r = vec_ro [idx];
93 unsigned char byte_w = vec_wo [idx];
94 int bit;
95
96 if (byte_r | byte_w)
97 for (bit = 8; bit--; )
98 {
99 int events = 0;
100 events |= byte_r & (1 << bit) ? EV_READ : 0;
101 events |= byte_w & (1 << bit) ? EV_WRITE : 0;
102
103 if (events)
104 fd_event (idx * 8 + bit, events);
105 }
106 }
107 } 174 }
175 #endif
176
177 if (errno == EBADF)
178 fd_ebadf (EV_A);
179 else if (errno == ENOMEM && !syserr_cb)
180 fd_enomem (EV_A);
181 else if (errno != EINTR)
182 syserr ("(libev) select");
183
184 return;
108 } 185 }
109}
110 186
187#if EV_SELECT_USE_FD_SET
188
189 {
190 int fd;
191
192 for (fd = 0; fd < anfdmax; ++fd)
193 if (anfds [fd].events)
194 {
195 int events = 0;
196 #if EV_SELECT_IS_WINSOCKET
197 SOCKET handle = anfds [fd].handle;
198 #else
199 int handle = fd;
200 #endif
201
202 if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
203 if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;
204
205 if (expect_true (events))
206 fd_event (EV_A_ fd, events);
207 }
208 }
209
210#else
211
212 {
213 int word, bit;
214 for (word = vec_max; word--; )
215 {
216 fd_mask word_r = ((fd_mask *)vec_ro) [word];
217 fd_mask word_w = ((fd_mask *)vec_wo) [word];
218
219 if (word_r || word_w)
220 for (bit = NFDBITS; bit--; )
221 {
222 fd_mask mask = 1UL << bit;
223 int events = 0;
224
225 events |= word_r & mask ? EV_READ : 0;
226 events |= word_w & mask ? EV_WRITE : 0;
227
228 if (expect_true (events))
229 fd_event (EV_A_ word * NFDBITS + bit, events);
230 }
231 }
232 }
233
234#endif
235}
236
237int inline_size
111void select_init (int flags) 238select_init (EV_P_ int flags)
112{ 239{
113 ev_method = EVMETHOD_SELECT; 240 backend_fudge = 0.; /* posix says this is zero */
114 method_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
115 method_modify = select_modify; 241 backend_modify = select_modify;
116 method_poll = select_poll; 242 backend_poll = select_poll;
117}
118 243
244#if EV_SELECT_USE_FD_SET
245 vec_max = FD_SETSIZE / 32;
246 vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
247 vec_ro = ev_malloc (sizeof (fd_set));
248 vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
249 vec_wo = ev_malloc (sizeof (fd_set));
250#else
251 vec_max = 0;
252 vec_ri = 0;
253 vec_ri = 0;
254 vec_wo = 0;
255 vec_wo = 0;
256#endif
119 257
258 return EVBACKEND_SELECT;
259}
260
261void inline_size
262select_destroy (EV_P)
263{
264 ev_free (vec_ri);
265 ev_free (vec_ro);
266 ev_free (vec_wi);
267 ev_free (vec_wo);
268}
269
270

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