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/cvs/libev/ev_select.c
Revision: 1.27
Committed: Tue Dec 25 07:05:45 2007 UTC (16 years, 7 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-2_01, rel-3_1, rel-3_0
Changes since 1.26: +30 -22 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * libev select fd activity backend
3 *
4 * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
5 * All rights reserved.
6 *
7 * 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 *
28 * 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 */
39
40 #ifndef _WIN32
41 /* for unix systems */
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 # undef EINTR
58 # define EINTR WSAEINTR
59 # undef EBADF
60 # define EBADF WSAENOTSOCK
61 # undef ENOMEM
62 # define ENOMEM (errno + 1)
63 #endif
64
65 #if !EV_SELECT_USE_FD_SET
66 # define NFDBYTES (NFDBITS / 8)
67 #endif
68
69 #include <string.h>
70
71 static void
72 select_modify (EV_P_ int fd, int oev, int nev)
73 {
74 if (oev == nev)
75 return;
76
77 {
78 #if EV_SELECT_USE_FD_SET
79
80 #if EV_SELECT_IS_WINSOCKET
81 SOCKET handle = anfds [fd].handle;
82 #else
83 int handle = fd;
84 #endif
85
86 if (nev & EV_READ)
87 FD_SET (handle, (fd_set *)vec_ri);
88 else
89 FD_CLR (handle, (fd_set *)vec_ri);
90
91 if (nev & EV_WRITE)
92 FD_SET (handle, (fd_set *)vec_wi);
93 else
94 FD_CLR (handle, (fd_set *)vec_wi);
95
96 #else
97
98 int word = fd / NFDBITS;
99 int mask = 1UL << (fd % NFDBITS);
100
101 if (expect_false (vec_max < word + 1))
102 {
103 int new_max = word + 1;
104
105 vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
106 vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
107 vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
108 vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
109
110 for (; vec_max < new_max; ++vec_max)
111 ((fd_mask *)vec_ri)[vec_max] =
112 ((fd_mask *)vec_wi)[vec_max] = 0;
113 }
114
115 ((fd_mask *)vec_ri) [word] |= mask;
116 if (!(nev & EV_READ))
117 ((fd_mask *)vec_ri) [word] &= ~mask;
118
119 ((fd_mask *)vec_wi) [word] |= mask;
120 if (!(nev & EV_WRITE))
121 ((fd_mask *)vec_wi) [word] &= ~mask;
122 #endif
123 }
124 }
125
126 static void
127 select_poll (EV_P_ ev_tstamp timeout)
128 {
129 struct timeval tv;
130 int res;
131
132 #if EV_SELECT_USE_FD_SET
133 memcpy (vec_ro, vec_ri, sizeof (fd_set));
134 memcpy (vec_wo, vec_wi, sizeof (fd_set));
135 #else
136 memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
137 memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
138 #endif
139
140 tv.tv_sec = (long)timeout;
141 tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
142
143 res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
144
145 if (expect_false (res < 0))
146 {
147 #if EV_SELECT_IS_WINSOCKET
148 errno = WSAGetLastError ();
149 #endif
150
151 if (errno == EBADF)
152 fd_ebadf (EV_A);
153 else if (errno == ENOMEM && !syserr_cb)
154 fd_enomem (EV_A);
155 else if (errno != EINTR)
156 syserr ("(libev) select");
157
158 return;
159 }
160
161 #if EV_SELECT_USE_FD_SET
162
163 {
164 int fd;
165
166 for (fd = 0; fd < anfdmax; ++fd)
167 if (anfds [fd].events)
168 {
169 int events = 0;
170 #if EV_SELECT_IS_WINSOCKET
171 SOCKET handle = anfds [fd].handle;
172 #else
173 int handle = fd;
174 #endif
175
176 if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
177 if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;
178
179 if (expect_true (events))
180 fd_event (EV_A_ fd, events);
181 }
182 }
183
184 #else
185
186 {
187 int word, bit;
188 for (word = vec_max; word--; )
189 {
190 fd_mask word_r = ((fd_mask *)vec_ro) [word];
191 fd_mask word_w = ((fd_mask *)vec_wo) [word];
192
193 if (word_r || word_w)
194 for (bit = NFDBITS; bit--; )
195 {
196 fd_mask mask = 1UL << bit;
197 int events = 0;
198
199 events |= word_r & mask ? EV_READ : 0;
200 events |= word_w & mask ? EV_WRITE : 0;
201
202 if (expect_true (events))
203 fd_event (EV_A_ word * NFDBITS + bit, events);
204 }
205 }
206 }
207
208 #endif
209 }
210
211 int inline_size
212 select_init (EV_P_ int flags)
213 {
214 backend_fudge = 0.; /* posix says this is zero */
215 backend_modify = select_modify;
216 backend_poll = select_poll;
217
218 #if EV_SELECT_USE_FD_SET
219 vec_max = FD_SETSIZE / 32;
220 vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
221 vec_ro = ev_malloc (sizeof (fd_set));
222 vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
223 vec_wo = ev_malloc (sizeof (fd_set));
224 #else
225 vec_max = 0;
226 vec_ri = 0;
227 vec_ri = 0;
228 vec_wo = 0;
229 vec_wo = 0;
230 #endif
231
232 return EVBACKEND_SELECT;
233 }
234
235 void inline_size
236 select_destroy (EV_P)
237 {
238 ev_free (vec_ri);
239 ev_free (vec_ro);
240 ev_free (vec_wi);
241 ev_free (vec_wo);
242 }
243
244