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/cvs/libev/ev_select.c
Revision: 1.37
Committed: Mon Jun 9 14:11:30 2008 UTC (16 years, 5 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-3_44, rel-3_45, rel-3_42, rel-3_43, rel-3_431
Changes since 1.36: +18 -9 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 1.31 * Copyright (c) 2007,2008 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     *
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.
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 1.20 # 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 root 1.18 # define EV_SELECT_USE_FD_SET 1
51     # endif
52 root 1.9 #endif
53 root 1.2
54 root 1.20 #if EV_SELECT_IS_WINSOCKET
55 root 1.18 # undef EV_SELECT_USE_FD_SET
56     # define EV_SELECT_USE_FD_SET 1
57 root 1.36 # undef NFDBITS
58     # define NFDBITS 0
59 root 1.20 #endif
60    
61     #if !EV_SELECT_USE_FD_SET
62     # define NFDBYTES (NFDBITS / 8)
63 root 1.18 #endif
64    
65 root 1.2 #include <string.h>
66    
67     static void
68 root 1.10 select_modify (EV_P_ int fd, int oev, int nev)
69 root 1.2 {
70 root 1.13 if (oev == nev)
71     return;
72    
73 root 1.20 {
74 root 1.17 #if EV_SELECT_USE_FD_SET
75 root 1.18
76 root 1.20 #if EV_SELECT_IS_WINSOCKET
77     SOCKET handle = anfds [fd].handle;
78     #else
79     int handle = fd;
80     #endif
81    
82 root 1.37 /* FD_SET is broken on windows (it adds the fd to a set twice or more,
83     * which eventually leads to overflows). Need to call it only on changes.
84     */
85     #if EV_SELECT_IS_WINSOCKET
86     if ((oev ^ nev) & EV_READ)
87     #endif
88     if (nev & EV_READ)
89     FD_SET (handle, (fd_set *)vec_ri);
90     else
91     FD_CLR (handle, (fd_set *)vec_ri);
92    
93     #if EV_SELECT_IS_WINSOCKET
94     if ((oev ^ nev) & EV_WRITE)
95     #endif
96     if (nev & EV_WRITE)
97     FD_SET (handle, (fd_set *)vec_wi);
98     else
99     FD_CLR (handle, (fd_set *)vec_wi);
100 root 1.20
101 root 1.17 #else
102    
103 root 1.28 int word = fd / NFDBITS;
104     fd_mask mask = 1UL << (fd % NFDBITS);
105 root 1.20
106 root 1.29 if (expect_false (vec_max <= word))
107 root 1.17 {
108 root 1.20 int new_max = word + 1;
109 root 1.17
110 root 1.20 vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
111     vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
112     vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
113     vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
114 root 1.33 #ifdef _WIN32
115     vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
116     #endif
117 root 1.17
118     for (; vec_max < new_max; ++vec_max)
119 root 1.28 ((fd_mask *)vec_ri) [vec_max] =
120     ((fd_mask *)vec_wi) [vec_max] = 0;
121 root 1.17 }
122    
123 root 1.20 ((fd_mask *)vec_ri) [word] |= mask;
124 root 1.17 if (!(nev & EV_READ))
125 root 1.20 ((fd_mask *)vec_ri) [word] &= ~mask;
126 root 1.17
127 root 1.20 ((fd_mask *)vec_wi) [word] |= mask;
128 root 1.17 if (!(nev & EV_WRITE))
129 root 1.20 ((fd_mask *)vec_wi) [word] &= ~mask;
130     #endif
131 root 1.17 }
132 root 1.2 }
133    
134 root 1.6 static void
135 root 1.10 select_poll (EV_P_ ev_tstamp timeout)
136 root 1.2 {
137     struct timeval tv;
138     int res;
139 root 1.33 int fd_setsize;
140    
141     tv.tv_sec = (long)timeout;
142     tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
143 root 1.2
144 root 1.17 #if EV_SELECT_USE_FD_SET
145 root 1.33 fd_setsize = sizeof (fd_set);
146 root 1.17 #else
147 root 1.33 fd_setsize = vec_max * NFDBYTES;
148 root 1.17 #endif
149 root 1.2
150 root 1.33 memcpy (vec_ro, vec_ri, fd_setsize);
151     memcpy (vec_wo, vec_wi, fd_setsize);
152 root 1.2
153 root 1.32 #ifdef _WIN32
154     /* pass in the write set as except set.
155     * the idea behind this is to work around a windows bug that causes
156     * errors to be reported as an exception and not by setting
157     * the writable bit. this is so uncontrollably lame.
158     */
159 root 1.33 memcpy (vec_eo, vec_wi, fd_setsize);
160     res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_eo, &tv);
161 root 1.32 #else
162 root 1.20 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
163 root 1.32 #endif
164 root 1.2
165 root 1.24 if (expect_false (res < 0))
166 root 1.2 {
167 root 1.20 #if EV_SELECT_IS_WINSOCKET
168     errno = WSAGetLastError ();
169     #endif
170 root 1.29 #ifdef WSABASEERR
171     /* on windows, select returns incompatible error codes, fix this */
172     if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
173     if (errno == WSAENOTSOCK)
174     errno = EBADF;
175     else
176     errno -= WSABASEERR;
177     #endif
178    
179     #ifdef _WIN32
180     /* select on windows errornously returns EINVAL when no fd sets have been
181     * provided (this is documented). what microsoft doesn't tell you that this bug
182     * exists even when the fd sets are provided, so we have to check for this bug
183     * here and emulate by sleeping manually.
184     * we also get EINVAL when the timeout is invalid, but we ignore this case here
185     * and assume that EINVAL always means: you have to wait manually.
186     */
187     if (errno == EINVAL)
188     {
189     ev_sleep (timeout);
190     return;
191     }
192     #endif
193 root 1.17
194 root 1.14 if (errno == EBADF)
195     fd_ebadf (EV_A);
196     else if (errno == ENOMEM && !syserr_cb)
197     fd_enomem (EV_A);
198     else if (errno != EINTR)
199 root 1.15 syserr ("(libev) select");
200 root 1.2
201 root 1.14 return;
202 root 1.2 }
203 root 1.14
204 root 1.17 #if EV_SELECT_USE_FD_SET
205 root 1.20
206     {
207     int fd;
208    
209     for (fd = 0; fd < anfdmax; ++fd)
210     if (anfds [fd].events)
211 root 1.18 {
212 root 1.20 int events = 0;
213     #if EV_SELECT_IS_WINSOCKET
214     SOCKET handle = anfds [fd].handle;
215     #else
216     int handle = fd;
217     #endif
218    
219     if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
220     if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;
221 root 1.33 #ifdef _WIN32
222     if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE;
223     #endif
224 root 1.20
225 root 1.24 if (expect_true (events))
226 root 1.20 fd_event (EV_A_ fd, events);
227     }
228     }
229 root 1.18
230 root 1.20 #else
231    
232     {
233     int word, bit;
234     for (word = vec_max; word--; )
235     {
236     fd_mask word_r = ((fd_mask *)vec_ro) [word];
237     fd_mask word_w = ((fd_mask *)vec_wo) [word];
238 root 1.33 #ifdef _WIN32
239     word_w |= ((fd_mask *)vec_eo) [word];
240     #endif
241 root 1.20
242     if (word_r || word_w)
243     for (bit = NFDBITS; bit--; )
244 root 1.18 {
245 root 1.20 fd_mask mask = 1UL << bit;
246 root 1.18 int events = 0;
247    
248 root 1.20 events |= word_r & mask ? EV_READ : 0;
249     events |= word_w & mask ? EV_WRITE : 0;
250 root 1.18
251 root 1.24 if (expect_true (events))
252 root 1.20 fd_event (EV_A_ word * NFDBITS + bit, events);
253 root 1.18 }
254 root 1.20 }
255     }
256 root 1.17
257     #endif
258 root 1.2 }
259    
260 root 1.23 int inline_size
261 root 1.10 select_init (EV_P_ int flags)
262 root 1.2 {
263 root 1.26 backend_fudge = 0.; /* posix says this is zero */
264 root 1.22 backend_modify = select_modify;
265     backend_poll = select_poll;
266 root 1.10
267 root 1.17 #if EV_SELECT_USE_FD_SET
268     vec_max = FD_SETSIZE / 32;
269 root 1.20 vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
270     vec_ro = ev_malloc (sizeof (fd_set));
271     vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
272     vec_wo = ev_malloc (sizeof (fd_set));
273 root 1.33 #ifdef _WIN32
274     vec_eo = ev_malloc (sizeof (fd_set));
275     #endif
276 root 1.17 #else
277 root 1.12 vec_max = 0;
278     vec_ri = 0;
279     vec_ri = 0;
280     vec_wo = 0;
281     vec_wo = 0;
282 root 1.17 #endif
283 root 1.12
284 root 1.21 return EVBACKEND_SELECT;
285 root 1.2 }
286    
287 root 1.23 void inline_size
288 root 1.12 select_destroy (EV_P)
289     {
290 root 1.14 ev_free (vec_ri);
291     ev_free (vec_ro);
292     ev_free (vec_wi);
293     ev_free (vec_wo);
294 root 1.12 }
295    
296