1 /* $NetBSD: win32select.c,v 1.1.1.4 2021/04/07 02:43:14 christos Exp $ */
2 /*
3 * Copyright 2007-2012 Niels Provos and Nick Mathewson
4 * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>
5 * Copyright 2003 Michael A. Davis <mike@datanerds.net>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT 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 OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29 #include "event2/event-config.h"
30 #include <sys/cdefs.h>
31 __RCSID("$NetBSD: win32select.c,v 1.1.1.4 2021/04/07 02:43:14 christos Exp $");
32 #include "evconfig-private.h"
33
34 #ifdef _WIN32
35
36 #include <winsock2.h>
37 #include <windows.h>
38 #include <sys/types.h>
39 #include <sys/queue.h>
40 #include <limits.h>
41 #include <signal.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <errno.h>
46
47 #include "event2/util.h"
48 #include "util-internal.h"
49 #include "log-internal.h"
50 #include "event2/event.h"
51 #include "event-internal.h"
52 #include "evmap-internal.h"
53 #include "event2/thread.h"
54 #include "evthread-internal.h"
55 #include "time-internal.h"
56
57 #define XFREE(ptr) do { if (ptr) mm_free(ptr); } while (0)
58
59 extern struct event_list timequeue;
60 extern struct event_list addqueue;
61
62 struct win_fd_set {
63 unsigned int fd_count;
64 SOCKET fd_array[1];
65 };
66
67 /* MSDN says this is required to handle SIGFPE */
68 volatile double SIGFPE_REQ = 0.0f;
69
70 struct idx_info {
71 int read_pos_plus1;
72 int write_pos_plus1;
73 };
74
75 struct win32op {
76 unsigned num_fds_in_fd_sets;
77 int resize_out_sets;
78 struct win_fd_set *readset_in;
79 struct win_fd_set *writeset_in;
80 struct win_fd_set *readset_out;
81 struct win_fd_set *writeset_out;
82 struct win_fd_set *exset_out;
83 unsigned signals_are_broken : 1;
84 };
85
86 static void *win32_init(struct event_base *);
87 static int win32_add(struct event_base *, evutil_socket_t, short old, short events, void *idx_);
88 static int win32_del(struct event_base *, evutil_socket_t, short old, short events, void *idx_);
89 static int win32_dispatch(struct event_base *base, struct timeval *);
90 static void win32_dealloc(struct event_base *);
91
92 struct eventop win32ops = {
93 "win32",
94 win32_init,
95 win32_add,
96 win32_del,
97 win32_dispatch,
98 win32_dealloc,
99 0, /* doesn't need reinit */
100 0, /* No features supported. */
101 sizeof(struct idx_info),
102 };
103
104 #define FD_SET_ALLOC_SIZE(n) ((sizeof(struct win_fd_set) + ((n)-1)*sizeof(SOCKET)))
105
106 static int
grow_fd_sets(struct win32op * op,unsigned new_num_fds)107 grow_fd_sets(struct win32op *op, unsigned new_num_fds)
108 {
109 size_t size;
110
111 EVUTIL_ASSERT(new_num_fds >= op->readset_in->fd_count &&
112 new_num_fds >= op->writeset_in->fd_count);
113 EVUTIL_ASSERT(new_num_fds >= 1);
114
115 size = FD_SET_ALLOC_SIZE(new_num_fds);
116 if (!(op->readset_in = mm_realloc(op->readset_in, size)))
117 return (-1);
118 if (!(op->writeset_in = mm_realloc(op->writeset_in, size)))
119 return (-1);
120 op->resize_out_sets = 1;
121 op->num_fds_in_fd_sets = new_num_fds;
122 return (0);
123 }
124
125 static int
do_fd_set(struct win32op * op,struct idx_info * ent,evutil_socket_t s,int read)126 do_fd_set(struct win32op *op, struct idx_info *ent, evutil_socket_t s, int read)
127 {
128 struct win_fd_set *set = read ? op->readset_in : op->writeset_in;
129 if (read) {
130 if (ent->read_pos_plus1 > 0)
131 return (0);
132 } else {
133 if (ent->write_pos_plus1 > 0)
134 return (0);
135 }
136 if (set->fd_count == op->num_fds_in_fd_sets) {
137 if (grow_fd_sets(op, op->num_fds_in_fd_sets*2))
138 return (-1);
139 /* set pointer will have changed and needs reiniting! */
140 set = read ? op->readset_in : op->writeset_in;
141 }
142 set->fd_array[set->fd_count] = s;
143 if (read)
144 ent->read_pos_plus1 = set->fd_count+1;
145 else
146 ent->write_pos_plus1 = set->fd_count+1;
147 return (set->fd_count++);
148 }
149
150 static int
do_fd_clear(struct event_base * base,struct win32op * op,struct idx_info * ent,int read)151 do_fd_clear(struct event_base *base,
152 struct win32op *op, struct idx_info *ent, int read)
153 {
154 int i;
155 struct win_fd_set *set = read ? op->readset_in : op->writeset_in;
156 if (read) {
157 i = ent->read_pos_plus1 - 1;
158 ent->read_pos_plus1 = 0;
159 } else {
160 i = ent->write_pos_plus1 - 1;
161 ent->write_pos_plus1 = 0;
162 }
163 if (i < 0)
164 return (0);
165 if (--set->fd_count != (unsigned)i) {
166 struct idx_info *ent2;
167 SOCKET s2;
168 s2 = set->fd_array[i] = set->fd_array[set->fd_count];
169
170 ent2 = evmap_io_get_fdinfo_(&base->io, s2);
171
172 if (!ent2) /* This indicates a bug. */
173 return (0);
174 if (read)
175 ent2->read_pos_plus1 = i+1;
176 else
177 ent2->write_pos_plus1 = i+1;
178 }
179 return (0);
180 }
181
182 #define NEVENT 32
183 void *
win32_init(struct event_base * base)184 win32_init(struct event_base *base)
185 {
186 struct win32op *winop;
187 size_t size;
188 if (!(winop = mm_calloc(1, sizeof(struct win32op))))
189 return NULL;
190 winop->num_fds_in_fd_sets = NEVENT;
191 size = FD_SET_ALLOC_SIZE(NEVENT);
192 if (!(winop->readset_in = mm_malloc(size)))
193 goto err;
194 if (!(winop->writeset_in = mm_malloc(size)))
195 goto err;
196 if (!(winop->readset_out = mm_malloc(size)))
197 goto err;
198 if (!(winop->writeset_out = mm_malloc(size)))
199 goto err;
200 if (!(winop->exset_out = mm_malloc(size)))
201 goto err;
202 winop->readset_in->fd_count = winop->writeset_in->fd_count = 0;
203 winop->readset_out->fd_count = winop->writeset_out->fd_count
204 = winop->exset_out->fd_count = 0;
205
206 if (evsig_init_(base) < 0)
207 winop->signals_are_broken = 1;
208
209 evutil_weakrand_seed_(&base->weakrand_seed, 0);
210
211 return (winop);
212 err:
213 XFREE(winop->readset_in);
214 XFREE(winop->writeset_in);
215 XFREE(winop->readset_out);
216 XFREE(winop->writeset_out);
217 XFREE(winop->exset_out);
218 XFREE(winop);
219 return (NULL);
220 }
221
222 int
win32_add(struct event_base * base,evutil_socket_t fd,short old,short events,void * idx_)223 win32_add(struct event_base *base, evutil_socket_t fd,
224 short old, short events, void *idx_)
225 {
226 struct win32op *win32op = base->evbase;
227 struct idx_info *idx = idx_;
228
229 if ((events & EV_SIGNAL) && win32op->signals_are_broken)
230 return (-1);
231
232 if (!(events & (EV_READ|EV_WRITE)))
233 return (0);
234
235 event_debug(("%s: adding event for %d", __func__, (int)fd));
236 if (events & EV_READ) {
237 if (do_fd_set(win32op, idx, fd, 1)<0)
238 return (-1);
239 }
240 if (events & EV_WRITE) {
241 if (do_fd_set(win32op, idx, fd, 0)<0)
242 return (-1);
243 }
244 return (0);
245 }
246
247 int
win32_del(struct event_base * base,evutil_socket_t fd,short old,short events,void * idx_)248 win32_del(struct event_base *base, evutil_socket_t fd, short old, short events,
249 void *idx_)
250 {
251 struct win32op *win32op = base->evbase;
252 struct idx_info *idx = idx_;
253
254 event_debug(("%s: Removing event for "EV_SOCK_FMT,
255 __func__, EV_SOCK_ARG(fd)));
256 if (events & EV_READ)
257 do_fd_clear(base, win32op, idx, 1);
258 if (events & EV_WRITE)
259 do_fd_clear(base, win32op, idx, 0);
260
261 return 0;
262 }
263
264 static void
fd_set_copy(struct win_fd_set * out,const struct win_fd_set * in)265 fd_set_copy(struct win_fd_set *out, const struct win_fd_set *in)
266 {
267 out->fd_count = in->fd_count;
268 memcpy(out->fd_array, in->fd_array, in->fd_count * (sizeof(SOCKET)));
269 }
270
271 /*
272 static void dump_fd_set(struct win_fd_set *s)
273 {
274 unsigned int i;
275 printf("[ ");
276 for(i=0;i<s->fd_count;++i)
277 printf("%d ",(int)s->fd_array[i]);
278 printf("]\n");
279 }
280 */
281
282 int
win32_dispatch(struct event_base * base,struct timeval * tv)283 win32_dispatch(struct event_base *base, struct timeval *tv)
284 {
285 struct win32op *win32op = base->evbase;
286 int res = 0;
287 unsigned j, i;
288 int fd_count;
289 SOCKET s;
290
291 if (win32op->resize_out_sets) {
292 size_t size = FD_SET_ALLOC_SIZE(win32op->num_fds_in_fd_sets);
293 if (!(win32op->readset_out = mm_realloc(win32op->readset_out, size)))
294 return (-1);
295 if (!(win32op->exset_out = mm_realloc(win32op->exset_out, size)))
296 return (-1);
297 if (!(win32op->writeset_out = mm_realloc(win32op->writeset_out, size)))
298 return (-1);
299 win32op->resize_out_sets = 0;
300 }
301
302 fd_set_copy(win32op->readset_out, win32op->readset_in);
303 fd_set_copy(win32op->exset_out, win32op->writeset_in);
304 fd_set_copy(win32op->writeset_out, win32op->writeset_in);
305
306 fd_count =
307 (win32op->readset_out->fd_count > win32op->writeset_out->fd_count) ?
308 win32op->readset_out->fd_count : win32op->writeset_out->fd_count;
309
310 if (!fd_count) {
311 long msec = tv ? evutil_tv_to_msec_(tv) : LONG_MAX;
312 /* Sleep's DWORD argument is unsigned long */
313 if (msec < 0)
314 msec = LONG_MAX;
315 /* Windows doesn't like you to call select() with no sockets */
316 Sleep(msec);
317 return (0);
318 }
319
320 EVBASE_RELEASE_LOCK(base, th_base_lock);
321
322 res = select(fd_count,
323 (struct fd_set*)win32op->readset_out,
324 (struct fd_set*)win32op->writeset_out,
325 (struct fd_set*)win32op->exset_out, tv);
326
327 EVBASE_ACQUIRE_LOCK(base, th_base_lock);
328
329 event_debug(("%s: select returned %d", __func__, res));
330
331 if (res <= 0) {
332 event_debug(("%s: %s", __func__,
333 evutil_socket_error_to_string(EVUTIL_SOCKET_ERROR())));
334 return res;
335 }
336
337 if (win32op->readset_out->fd_count) {
338 i = evutil_weakrand_range_(&base->weakrand_seed,
339 win32op->readset_out->fd_count);
340 for (j=0; j<win32op->readset_out->fd_count; ++j) {
341 if (++i >= win32op->readset_out->fd_count)
342 i = 0;
343 s = win32op->readset_out->fd_array[i];
344 evmap_io_active_(base, s, EV_READ);
345 }
346 }
347 if (win32op->exset_out->fd_count) {
348 i = evutil_weakrand_range_(&base->weakrand_seed,
349 win32op->exset_out->fd_count);
350 for (j=0; j<win32op->exset_out->fd_count; ++j) {
351 if (++i >= win32op->exset_out->fd_count)
352 i = 0;
353 s = win32op->exset_out->fd_array[i];
354 evmap_io_active_(base, s, EV_WRITE);
355 }
356 }
357 if (win32op->writeset_out->fd_count) {
358 i = evutil_weakrand_range_(&base->weakrand_seed,
359 win32op->writeset_out->fd_count);
360 for (j=0; j<win32op->writeset_out->fd_count; ++j) {
361 if (++i >= win32op->writeset_out->fd_count)
362 i = 0;
363 s = win32op->writeset_out->fd_array[i];
364 evmap_io_active_(base, s, EV_WRITE);
365 }
366 }
367 return (0);
368 }
369
370 void
win32_dealloc(struct event_base * base)371 win32_dealloc(struct event_base *base)
372 {
373 struct win32op *win32op = base->evbase;
374
375 evsig_dealloc_(base);
376 if (win32op->readset_in)
377 mm_free(win32op->readset_in);
378 if (win32op->writeset_in)
379 mm_free(win32op->writeset_in);
380 if (win32op->readset_out)
381 mm_free(win32op->readset_out);
382 if (win32op->writeset_out)
383 mm_free(win32op->writeset_out);
384 if (win32op->exset_out)
385 mm_free(win32op->exset_out);
386 /* XXXXX free the tree. */
387
388 memset(win32op, 0, sizeof(*win32op));
389 mm_free(win32op);
390 }
391
392 #endif
393