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Comparing libev/ev_select.c (file contents):
Revision 1.6 by root, Wed Oct 31 20:46:44 2007 UTC vs.
Revision 1.33 by root, Mon May 26 04:14:32 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 int new_max = (fd >> 5) + 1; 97 int new_max = word + 1;
53 98
54 vec_ri = (unsigned char *)realloc (vec_ri, new_max * 4); 99 vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
55 vec_ro = (unsigned char *)realloc (vec_ro, new_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, new_max * 4); 101 vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
57 vec_wo = (unsigned char *)realloc (vec_wo, new_max * 4); /* could free/malloc */ 102 vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
103 #ifdef _WIN32
104 vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
105 #endif
58 106
59 for (; vec_max < new_max; ++vec_max) 107 for (; vec_max < new_max; ++vec_max)
60 ((uint32_t *)vec_ri)[vec_max] = 108 ((fd_mask *)vec_ri) [vec_max] =
61 ((uint32_t *)vec_wi)[vec_max] = 0; 109 ((fd_mask *)vec_wi) [vec_max] = 0;
62 } 110 }
63 111
64 vec_ri [offs] |= mask; 112 ((fd_mask *)vec_ri) [word] |= mask;
65 if (!(nev & EV_READ)) 113 if (!(nev & EV_READ))
66 vec_ri [offs] &= ~mask; 114 ((fd_mask *)vec_ri) [word] &= ~mask;
67 115
68 vec_wi [offs] |= mask; 116 ((fd_mask *)vec_wi) [word] |= mask;
69 if (!(nev & EV_WRITE)) 117 if (!(nev & EV_WRITE))
70 vec_wi [offs] &= ~mask; 118 ((fd_mask *)vec_wi) [word] &= ~mask;
119#endif
120 }
71} 121}
72 122
73static void 123static void
74select_poll (ev_tstamp timeout) 124select_poll (EV_P_ ev_tstamp timeout)
75{ 125{
76 struct timeval tv; 126 struct timeval tv;
77 int res; 127 int res;
78 128 int fd_setsize;
79 memcpy (vec_ro, vec_ri, vec_max * 4);
80 memcpy (vec_wo, vec_wi, vec_max * 4);
81 129
82 tv.tv_sec = (long)timeout; 130 tv.tv_sec = (long)timeout;
83 tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6); 131 tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
84 132
133#if EV_SELECT_USE_FD_SET
134 fd_setsize = sizeof (fd_set);
135#else
136 fd_setsize = vec_max * NFDBYTES;
137#endif
138
139 memcpy (vec_ro, vec_ri, fd_setsize);
140 memcpy (vec_wo, vec_wi, fd_setsize);
141
142#ifdef _WIN32
143 /* pass in the write set as except set.
144 * the idea behind this is to work around a windows bug that causes
145 * errors to be reported as an exception and not by setting
146 * the writable bit. this is so uncontrollably lame.
147 */
148 memcpy (vec_eo, vec_wi, fd_setsize);
149 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_eo, &tv);
150#else
85 res = select (vec_max * 32, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); 151 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
152#endif
86 153
87 if (res > 0) 154 if (expect_false (res < 0))
88 { 155 {
89 int word, offs; 156 #if EV_SELECT_IS_WINSOCKET
157 errno = WSAGetLastError ();
158 #endif
159 #ifdef WSABASEERR
160 /* on windows, select returns incompatible error codes, fix this */
161 if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
162 if (errno == WSAENOTSOCK)
163 errno = EBADF;
164 else
165 errno -= WSABASEERR;
166 #endif
90 167
91 for (word = vec_max; word--; ) 168 #ifdef _WIN32
169 /* select on windows errornously returns EINVAL when no fd sets have been
170 * provided (this is documented). what microsoft doesn't tell you that this bug
171 * exists even when the fd sets are provided, so we have to check for this bug
172 * here and emulate by sleeping manually.
173 * we also get EINVAL when the timeout is invalid, but we ignore this case here
174 * and assume that EINVAL always means: you have to wait manually.
175 */
176 if (errno == EINVAL)
92 { 177 {
93 if (((uint32_t *)vec_ro) [word] | ((uint32_t *)vec_wo) [word]) 178 ev_sleep (timeout);
94 for (offs = 4; offs--; ) 179 return;
95 {
96 int idx = word * 4 + offs;
97 unsigned char byte_r = vec_ro [idx];
98 unsigned char byte_w = vec_wo [idx];
99 int bit;
100
101 if (byte_r | byte_w)
102 for (bit = 8; bit--; )
103 {
104 int events = 0;
105 events |= byte_r & (1 << bit) ? EV_READ : 0;
106 events |= byte_w & (1 << bit) ? EV_WRITE : 0;
107
108 if (events)
109 fd_event (idx * 8 + bit, events);
110 }
111 }
112 } 180 }
181 #endif
182
183 if (errno == EBADF)
184 fd_ebadf (EV_A);
185 else if (errno == ENOMEM && !syserr_cb)
186 fd_enomem (EV_A);
187 else if (errno != EINTR)
188 syserr ("(libev) select");
189
190 return;
113 } 191 }
114 else if (res < 0) 192
193#if EV_SELECT_USE_FD_SET
194
195 {
196 int fd;
197
198 for (fd = 0; fd < anfdmax; ++fd)
199 if (anfds [fd].events)
200 {
201 int events = 0;
202 #if EV_SELECT_IS_WINSOCKET
203 SOCKET handle = anfds [fd].handle;
204 #else
205 int handle = fd;
206 #endif
207
208 if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
209 if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;
210 #ifdef _WIN32
211 if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE;
212 #endif
213
214 if (expect_true (events))
215 fd_event (EV_A_ fd, events);
216 }
217 }
218
219#else
220
221 {
222 int word, bit;
223 for (word = vec_max; word--; )
115 { 224 {
116 if (errno == EBADF) 225 fd_mask word_r = ((fd_mask *)vec_ro) [word];
117 fd_recheck (); 226 fd_mask word_w = ((fd_mask *)vec_wo) [word];
227 #ifdef _WIN32
228 word_w |= ((fd_mask *)vec_eo) [word];
229 #endif
230
231 if (word_r || word_w)
232 for (bit = NFDBITS; bit--; )
233 {
234 fd_mask mask = 1UL << bit;
235 int events = 0;
236
237 events |= word_r & mask ? EV_READ : 0;
238 events |= word_w & mask ? EV_WRITE : 0;
239
240 if (expect_true (events))
241 fd_event (EV_A_ word * NFDBITS + bit, events);
242 }
118 } 243 }
119} 244 }
120 245
121static void 246#endif
247}
248
249int inline_size
122select_init (int flags) 250select_init (EV_P_ int flags)
123{ 251{
124 ev_method = EVMETHOD_SELECT; 252 backend_fudge = 0.; /* posix says this is zero */
125 method_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
126 method_modify = select_modify; 253 backend_modify = select_modify;
127 method_poll = select_poll; 254 backend_poll = select_poll;
128}
129 255
256#if EV_SELECT_USE_FD_SET
257 vec_max = FD_SETSIZE / 32;
258 vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
259 vec_ro = ev_malloc (sizeof (fd_set));
260 vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
261 vec_wo = ev_malloc (sizeof (fd_set));
262 #ifdef _WIN32
263 vec_eo = ev_malloc (sizeof (fd_set));
264 #endif
265#else
266 vec_max = 0;
267 vec_ri = 0;
268 vec_ri = 0;
269 vec_wo = 0;
270 vec_wo = 0;
271#endif
272
273 return EVBACKEND_SELECT;
274}
275
276void inline_size
277select_destroy (EV_P)
278{
279 ev_free (vec_ri);
280 ev_free (vec_ro);
281 ev_free (vec_wi);
282 ev_free (vec_wo);
283}
284
285

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