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/cvs/libev/ev_select.c
Revision: 1.58
Committed: Sat Aug 17 05:30:16 2019 UTC (4 years, 10 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: EV-rel-4_28, EV-rel-4_29, rel-4_33, EV-rel-4_31, EV-rel-4_30, rel-4_31, HEAD
Changes since 1.57: +2 -2 lines
Log Message:
*** empty log message ***

File Contents

# User Rev Content
1 root 1.4 /*
2 root 1.7 * libev select fd activity backend
3     *
4 root 1.54 * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de>
5 root 1.4 * All rights reserved.
6     *
7 root 1.27 * Redistribution and use in source and binary forms, with or without modifica-
8     * tion, are permitted provided that the following conditions are met:
9 root 1.52 *
10 root 1.27 * 1. Redistributions of source code must retain the above copyright notice,
11     * this list of conditions and the following disclaimer.
12 root 1.52 *
13 root 1.27 * 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 root 1.52 *
17 root 1.27 * 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.
27 root 1.4 *
28 root 1.27 * Alternatively, the contents of this file may be used under the terms of
29     * the GNU General Public License ("GPL") version 2 or any later version,
30     * in which case the provisions of the GPL are applicable instead of
31     * the above. If you wish to allow the use of your version of this file
32     * only under the terms of the GPL and not to allow others to use your
33     * version of this file under the BSD license, indicate your decision
34     * by deleting the provisions above and replace them with the notice
35     * and other provisions required by the GPL. If you do not delete the
36     * provisions above, a recipient may use your version of this file under
37     * either the BSD or the GPL.
38 root 1.4 */
39    
40 root 1.20 #ifndef _WIN32
41 root 1.2 /* for unix systems */
42 root 1.50 # include <inttypes.h>
43     # ifndef __hpux
44     /* for REAL unix systems */
45 root 1.51 # include <sys/select.h>
46 root 1.50 # endif
47 root 1.20 #endif
48    
49     #ifndef EV_SELECT_USE_FD_SET
50     # ifdef NFDBITS
51     # define EV_SELECT_USE_FD_SET 0
52     # else
53 root 1.18 # define EV_SELECT_USE_FD_SET 1
54     # endif
55 root 1.9 #endif
56 root 1.2
57 root 1.20 #if EV_SELECT_IS_WINSOCKET
58 root 1.18 # undef EV_SELECT_USE_FD_SET
59     # define EV_SELECT_USE_FD_SET 1
60 root 1.36 # undef NFDBITS
61     # define NFDBITS 0
62 root 1.20 #endif
63    
64     #if !EV_SELECT_USE_FD_SET
65     # define NFDBYTES (NFDBITS / 8)
66 root 1.18 #endif
67    
68 root 1.2 #include <string.h>
69    
70     static void
71 root 1.10 select_modify (EV_P_ int fd, int oev, int nev)
72 root 1.2 {
73 root 1.13 if (oev == nev)
74     return;
75    
76 root 1.20 {
77 root 1.17 #if EV_SELECT_USE_FD_SET
78 root 1.42
79 root 1.20 #if EV_SELECT_IS_WINSOCKET
80     SOCKET handle = anfds [fd].handle;
81     #else
82     int handle = fd;
83     #endif
84    
85 root 1.41 assert (("libev: fd >= FD_SETSIZE passed to fd_set-based select backend", fd < FD_SETSIZE));
86    
87 root 1.37 /* 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 root 1.20
106 root 1.17 #else
107    
108 root 1.28 int word = fd / NFDBITS;
109     fd_mask mask = 1UL << (fd % NFDBITS);
110 root 1.20
111 root 1.57 if (ecb_expect_false (vec_max <= word))
112 root 1.17 {
113 root 1.20 int new_max = word + 1;
114 root 1.17
115 root 1.20 vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
116     vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
117     vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
118     vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
119 root 1.33 #ifdef _WIN32
120     vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
121     #endif
122 root 1.17
123     for (; vec_max < new_max; ++vec_max)
124 root 1.28 ((fd_mask *)vec_ri) [vec_max] =
125     ((fd_mask *)vec_wi) [vec_max] = 0;
126 root 1.17 }
127    
128 root 1.20 ((fd_mask *)vec_ri) [word] |= mask;
129 root 1.17 if (!(nev & EV_READ))
130 root 1.20 ((fd_mask *)vec_ri) [word] &= ~mask;
131 root 1.17
132 root 1.20 ((fd_mask *)vec_wi) [word] |= mask;
133 root 1.17 if (!(nev & EV_WRITE))
134 root 1.20 ((fd_mask *)vec_wi) [word] &= ~mask;
135     #endif
136 root 1.17 }
137 root 1.2 }
138    
139 root 1.6 static void
140 root 1.10 select_poll (EV_P_ ev_tstamp timeout)
141 root 1.2 {
142     struct timeval tv;
143     int res;
144 root 1.33 int fd_setsize;
145    
146 root 1.45 EV_RELEASE_CB;
147 root 1.48 EV_TV_SET (tv, timeout);
148 root 1.2
149 root 1.17 #if EV_SELECT_USE_FD_SET
150 root 1.33 fd_setsize = sizeof (fd_set);
151 root 1.17 #else
152 root 1.33 fd_setsize = vec_max * NFDBYTES;
153 root 1.17 #endif
154 root 1.2
155 root 1.33 memcpy (vec_ro, vec_ri, fd_setsize);
156     memcpy (vec_wo, vec_wi, fd_setsize);
157 root 1.2
158 root 1.32 #ifdef _WIN32
159     /* pass in the write set as except set.
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 root 1.33 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 root 1.40 #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 root 1.32 #else
170 root 1.20 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
171 root 1.32 #endif
172 root 1.45 EV_ACQUIRE_CB;
173 root 1.2
174 root 1.57 if (ecb_expect_false (res < 0))
175 root 1.2 {
176 root 1.20 #if EV_SELECT_IS_WINSOCKET
177     errno = WSAGetLastError ();
178     #endif
179 root 1.29 #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
187    
188     #ifdef _WIN32
189 sf-exg 1.47 /* select on windows erroneously returns EINVAL when no fd sets have been
190 root 1.29 * provided (this is documented). what microsoft doesn't tell you that this bug
191 root 1.39 * exists even when the fd sets _are_ provided, so we have to check for this bug
192 root 1.29 * 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)
197     {
198 root 1.53 if (timeout)
199     {
200 root 1.58 unsigned long ms = EV_TS_TO_MSEC (timeout);
201 root 1.53 Sleep (ms ? ms : 1);
202     }
203    
204 root 1.29 return;
205     }
206     #endif
207 root 1.17
208 root 1.14 if (errno == EBADF)
209     fd_ebadf (EV_A);
210     else if (errno == ENOMEM && !syserr_cb)
211     fd_enomem (EV_A);
212     else if (errno != EINTR)
213 root 1.38 ev_syserr ("(libev) select");
214 root 1.2
215 root 1.14 return;
216 root 1.2 }
217 root 1.14
218 root 1.17 #if EV_SELECT_USE_FD_SET
219 root 1.20
220     {
221     int fd;
222    
223     for (fd = 0; fd < anfdmax; ++fd)
224     if (anfds [fd].events)
225 root 1.18 {
226 root 1.20 int events = 0;
227     #if EV_SELECT_IS_WINSOCKET
228     SOCKET handle = anfds [fd].handle;
229     #else
230     int handle = fd;
231     #endif
232    
233     if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
234     if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;
235 root 1.33 #ifdef _WIN32
236     if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE;
237     #endif
238 root 1.20
239 root 1.57 if (ecb_expect_true (events))
240 root 1.20 fd_event (EV_A_ fd, events);
241     }
242     }
243 root 1.18
244 root 1.20 #else
245    
246     {
247     int word, bit;
248     for (word = vec_max; word--; )
249     {
250     fd_mask word_r = ((fd_mask *)vec_ro) [word];
251     fd_mask word_w = ((fd_mask *)vec_wo) [word];
252 root 1.33 #ifdef _WIN32
253     word_w |= ((fd_mask *)vec_eo) [word];
254     #endif
255 root 1.20
256     if (word_r || word_w)
257     for (bit = NFDBITS; bit--; )
258 root 1.18 {
259 root 1.20 fd_mask mask = 1UL << bit;
260 root 1.18 int events = 0;
261    
262 root 1.20 events |= word_r & mask ? EV_READ : 0;
263     events |= word_w & mask ? EV_WRITE : 0;
264 root 1.18
265 root 1.57 if (ecb_expect_true (events))
266 root 1.20 fd_event (EV_A_ word * NFDBITS + bit, events);
267 root 1.18 }
268 root 1.20 }
269     }
270 root 1.17
271     #endif
272 root 1.2 }
273    
274 root 1.56 inline_size
275     int
276 root 1.10 select_init (EV_P_ int flags)
277 root 1.2 {
278 root 1.58 backend_mintime = EV_TS_CONST (1e-6);
279 root 1.55 backend_modify = select_modify;
280     backend_poll = select_poll;
281 root 1.10
282 root 1.17 #if EV_SELECT_USE_FD_SET
283 root 1.20 vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
284     vec_ro = ev_malloc (sizeof (fd_set));
285     vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
286     vec_wo = ev_malloc (sizeof (fd_set));
287 root 1.33 #ifdef _WIN32
288     vec_eo = ev_malloc (sizeof (fd_set));
289     #endif
290 root 1.17 #else
291 root 1.12 vec_max = 0;
292 root 1.52 vec_ri = 0;
293     vec_ro = 0;
294     vec_wi = 0;
295     vec_wo = 0;
296 root 1.46 #ifdef _WIN32
297     vec_eo = 0;
298     #endif
299 root 1.17 #endif
300 root 1.12
301 root 1.21 return EVBACKEND_SELECT;
302 root 1.2 }
303    
304 root 1.56 inline_size
305     void
306 root 1.12 select_destroy (EV_P)
307     {
308 root 1.14 ev_free (vec_ri);
309     ev_free (vec_ro);
310     ev_free (vec_wi);
311     ev_free (vec_wo);
312 root 1.46 #ifdef _WIN32
313     ev_free (vec_eo);
314     #endif
315 root 1.12 }
316