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Comparing libev/ev_select.c (file contents):
Revision 1.7 by root, Thu Nov 1 13:11:12 2007 UTC vs.
Revision 1.51 by root, Mon Jan 31 00:49:26 2011 UTC

1/* 1/*
2 * libev select fd activity backend 2 * libev select fd activity backend
3 * 3 *
4 * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de> 4 * Copyright (c) 2007,2008,2009,2010 Marc Alexander Lehmann <libev@schmorp.de>
5 * All rights reserved. 5 * All rights reserved.
6 * 6 *
7 * Redistribution and use in source and binary forms, with or without 7 * Redistribution and use in source and binary forms, with or without modifica-
8 * modification, are permitted provided that the following conditions are 8 * tion, are permitted provided that the following conditions are met:
9 * 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.
10 * 27 *
11 * * Redistributions of source code must retain the above copyright 28 * Alternatively, the contents of this file may be used under the terms of
12 * notice, this list of conditions and the following disclaimer. 29 * the GNU General Public License ("GPL") version 2 or any later version,
13 * 30 * in which case the provisions of the GPL are applicable instead of
14 * * Redistributions in binary form must reproduce the above 31 * the above. If you wish to allow the use of your version of this file
15 * 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
16 * disclaimer in the documentation and/or other materials provided 33 * version of this file under the BSD license, indicate your decision
17 * with the distribution. 34 * by deleting the provisions above and replace them with the notice
18 * 35 * and other provisions required by the GPL. If you do not delete the
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 36 * provisions above, a recipient may use your version of this file under
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 37 * either the BSD or the GPL.
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */ 38 */
31 39
32/* for broken bsd's */ 40#ifndef _WIN32
33#include <sys/time.h>
34#include <sys/types.h>
35#include <unistd.h>
36
37/* for unix systems */ 41/* for unix systems */
42# include <inttypes.h>
43# ifndef __hpux
44/* for REAL unix systems */
38#include <sys/select.h> 45# include <sys/select.h>
46# endif
47#endif
48
49#ifndef EV_SELECT_USE_FD_SET
50# ifdef NFDBITS
51# define EV_SELECT_USE_FD_SET 0
52# else
53# define EV_SELECT_USE_FD_SET 1
54# endif
55#endif
56
57#if EV_SELECT_IS_WINSOCKET
58# undef EV_SELECT_USE_FD_SET
59# define EV_SELECT_USE_FD_SET 1
60# undef NFDBITS
61# define NFDBITS 0
62#endif
63
64#if !EV_SELECT_USE_FD_SET
65# define NFDBYTES (NFDBITS / 8)
66#endif
39 67
40#include <string.h> 68#include <string.h>
41#include <inttypes.h>
42
43static unsigned char *vec_ri, *vec_ro, *vec_wi, *vec_wo;
44static int vec_max;
45 69
46static void 70static void
47select_modify (int fd, int oev, int nev) 71select_modify (EV_P_ int fd, int oev, int nev)
48{ 72{
49 int offs = fd >> 3; 73 if (oev == nev)
50 int mask = 1 << (fd & 7); 74 return;
51 75
52 if (vec_max < (fd >> 5) + 1) 76 {
77#if EV_SELECT_USE_FD_SET
78
79 #if EV_SELECT_IS_WINSOCKET
80 SOCKET handle = anfds [fd].handle;
81 #else
82 int handle = fd;
83 #endif
84
85 assert (("libev: fd >= FD_SETSIZE passed to fd_set-based select backend", fd < FD_SETSIZE));
86
87 /* FD_SET is broken on windows (it adds the fd to a set twice or more,
88 * which eventually leads to overflows). Need to call it only on changes.
89 */
90 #if EV_SELECT_IS_WINSOCKET
91 if ((oev ^ nev) & EV_READ)
92 #endif
93 if (nev & EV_READ)
94 FD_SET (handle, (fd_set *)vec_ri);
95 else
96 FD_CLR (handle, (fd_set *)vec_ri);
97
98 #if EV_SELECT_IS_WINSOCKET
99 if ((oev ^ nev) & EV_WRITE)
100 #endif
101 if (nev & EV_WRITE)
102 FD_SET (handle, (fd_set *)vec_wi);
103 else
104 FD_CLR (handle, (fd_set *)vec_wi);
105
106#else
107
108 int word = fd / NFDBITS;
109 fd_mask mask = 1UL << (fd % NFDBITS);
110
111 if (expect_false (vec_max <= word))
53 { 112 {
54 int new_max = (fd >> 5) + 1; 113 int new_max = word + 1;
55 114
56 vec_ri = (unsigned char *)realloc (vec_ri, new_max * 4); 115 vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
57 vec_ro = (unsigned char *)realloc (vec_ro, new_max * 4); /* could free/malloc */ 116 vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
58 vec_wi = (unsigned char *)realloc (vec_wi, new_max * 4); 117 vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
59 vec_wo = (unsigned char *)realloc (vec_wo, new_max * 4); /* could free/malloc */ 118 vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
119 #ifdef _WIN32
120 vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
121 #endif
60 122
61 for (; vec_max < new_max; ++vec_max) 123 for (; vec_max < new_max; ++vec_max)
62 ((uint32_t *)vec_ri)[vec_max] = 124 ((fd_mask *)vec_ri) [vec_max] =
63 ((uint32_t *)vec_wi)[vec_max] = 0; 125 ((fd_mask *)vec_wi) [vec_max] = 0;
64 } 126 }
65 127
66 vec_ri [offs] |= mask; 128 ((fd_mask *)vec_ri) [word] |= mask;
67 if (!(nev & EV_READ)) 129 if (!(nev & EV_READ))
68 vec_ri [offs] &= ~mask; 130 ((fd_mask *)vec_ri) [word] &= ~mask;
69 131
70 vec_wi [offs] |= mask; 132 ((fd_mask *)vec_wi) [word] |= mask;
71 if (!(nev & EV_WRITE)) 133 if (!(nev & EV_WRITE))
72 vec_wi [offs] &= ~mask; 134 ((fd_mask *)vec_wi) [word] &= ~mask;
135#endif
136 }
73} 137}
74 138
75static void 139static void
76select_poll (ev_tstamp timeout) 140select_poll (EV_P_ ev_tstamp timeout)
77{ 141{
78 struct timeval tv; 142 struct timeval tv;
79 int res; 143 int res;
144 int fd_setsize;
80 145
146 EV_RELEASE_CB;
147 EV_TV_SET (tv, timeout);
148
149#if EV_SELECT_USE_FD_SET
150 fd_setsize = sizeof (fd_set);
151#else
152 fd_setsize = vec_max * NFDBYTES;
153#endif
154
81 memcpy (vec_ro, vec_ri, vec_max * 4); 155 memcpy (vec_ro, vec_ri, fd_setsize);
82 memcpy (vec_wo, vec_wi, vec_max * 4); 156 memcpy (vec_wo, vec_wi, fd_setsize);
83 157
84 tv.tv_sec = (long)timeout; 158#ifdef _WIN32
85 tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6); 159 /* pass in the write set as except set.
86 160 * the idea behind this is to work around a windows bug that causes
161 * errors to be reported as an exception and not by setting
162 * the writable bit. this is so uncontrollably lame.
163 */
164 memcpy (vec_eo, vec_wi, fd_setsize);
165 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_eo, &tv);
166#elif EV_SELECT_USE_FD_SET
167 fd_setsize = anfdmax < FD_SETSIZE ? anfdmax : FD_SETSIZE;
168 res = select (fd_setsize, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
169#else
87 res = select (vec_max * 32, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); 170 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
171#endif
172 EV_ACQUIRE_CB;
88 173
89 if (res > 0) 174 if (expect_false (res < 0))
90 { 175 {
91 int word, offs; 176 #if EV_SELECT_IS_WINSOCKET
177 errno = WSAGetLastError ();
178 #endif
179 #ifdef WSABASEERR
180 /* on windows, select returns incompatible error codes, fix this */
181 if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
182 if (errno == WSAENOTSOCK)
183 errno = EBADF;
184 else
185 errno -= WSABASEERR;
186 #endif
92 187
93 for (word = vec_max; word--; ) 188 #ifdef _WIN32
189 /* select on windows erroneously returns EINVAL when no fd sets have been
190 * provided (this is documented). what microsoft doesn't tell you that this bug
191 * exists even when the fd sets _are_ provided, so we have to check for this bug
192 * here and emulate by sleeping manually.
193 * we also get EINVAL when the timeout is invalid, but we ignore this case here
194 * and assume that EINVAL always means: you have to wait manually.
195 */
196 if (errno == EINVAL)
94 { 197 {
95 if (((uint32_t *)vec_ro) [word] | ((uint32_t *)vec_wo) [word]) 198 ev_sleep (timeout);
96 for (offs = 4; offs--; ) 199 return;
97 {
98 int idx = word * 4 + offs;
99 unsigned char byte_r = vec_ro [idx];
100 unsigned char byte_w = vec_wo [idx];
101 int bit;
102
103 if (byte_r | byte_w)
104 for (bit = 8; bit--; )
105 {
106 int events = 0;
107 events |= byte_r & (1 << bit) ? EV_READ : 0;
108 events |= byte_w & (1 << bit) ? EV_WRITE : 0;
109
110 if (events)
111 fd_event (idx * 8 + bit, events);
112 }
113 }
114 } 200 }
201 #endif
202
203 if (errno == EBADF)
204 fd_ebadf (EV_A);
205 else if (errno == ENOMEM && !syserr_cb)
206 fd_enomem (EV_A);
207 else if (errno != EINTR)
208 ev_syserr ("(libev) select");
209
210 return;
115 } 211 }
116 else if (res < 0) 212
213#if EV_SELECT_USE_FD_SET
214
215 {
216 int fd;
217
218 for (fd = 0; fd < anfdmax; ++fd)
219 if (anfds [fd].events)
220 {
221 int events = 0;
222 #if EV_SELECT_IS_WINSOCKET
223 SOCKET handle = anfds [fd].handle;
224 #else
225 int handle = fd;
226 #endif
227
228 if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
229 if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;
230 #ifdef _WIN32
231 if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE;
232 #endif
233
234 if (expect_true (events))
235 fd_event (EV_A_ fd, events);
236 }
237 }
238
239#else
240
241 {
242 int word, bit;
243 for (word = vec_max; word--; )
117 { 244 {
118 if (errno == EBADF) 245 fd_mask word_r = ((fd_mask *)vec_ro) [word];
119 fd_recheck (); 246 fd_mask word_w = ((fd_mask *)vec_wo) [word];
247 #ifdef _WIN32
248 word_w |= ((fd_mask *)vec_eo) [word];
249 #endif
250
251 if (word_r || word_w)
252 for (bit = NFDBITS; bit--; )
253 {
254 fd_mask mask = 1UL << bit;
255 int events = 0;
256
257 events |= word_r & mask ? EV_READ : 0;
258 events |= word_w & mask ? EV_WRITE : 0;
259
260 if (expect_true (events))
261 fd_event (EV_A_ word * NFDBITS + bit, events);
262 }
120 } 263 }
264 }
265
266#endif
121} 267}
122 268
123static void 269int inline_size
124select_init (int flags) 270select_init (EV_P_ int flags)
125{ 271{
126 ev_method = EVMETHOD_SELECT; 272 backend_fudge = 0.; /* posix says this is zero */
127 method_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
128 method_modify = select_modify; 273 backend_modify = select_modify;
129 method_poll = select_poll; 274 backend_poll = select_poll;
275
276#if EV_SELECT_USE_FD_SET
277 vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
278 vec_ro = ev_malloc (sizeof (fd_set));
279 vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
280 vec_wo = ev_malloc (sizeof (fd_set));
281 #ifdef _WIN32
282 vec_eo = ev_malloc (sizeof (fd_set));
283 #endif
284#else
285 vec_max = 0;
286 vec_ri = 0;
287 vec_ro = 0;
288 vec_wi = 0;
289 vec_wo = 0;
290 #ifdef _WIN32
291 vec_eo = 0;
292 #endif
293#endif
294
295 return EVBACKEND_SELECT;
130} 296}
131 297
298void inline_size
299select_destroy (EV_P)
300{
301 ev_free (vec_ri);
302 ev_free (vec_ro);
303 ev_free (vec_wi);
304 ev_free (vec_wo);
305 #ifdef _WIN32
306 ev_free (vec_eo);
307 #endif
308}
309
310

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