win32select.c revision 1.1.1.4
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
59extern struct event_list timequeue;
60extern struct event_list addqueue;
61
62struct win_fd_set {
63	unsigned int fd_count;
64	SOCKET fd_array[1];
65};
66
67/* MSDN says this is required to handle SIGFPE */
68volatile double SIGFPE_REQ = 0.0f;
69
70struct idx_info {
71	int read_pos_plus1;
72	int write_pos_plus1;
73};
74
75struct 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
86static void *win32_init(struct event_base *);
87static int win32_add(struct event_base *, evutil_socket_t, short old, short events, void *idx_);
88static int win32_del(struct event_base *, evutil_socket_t, short old, short events, void *idx_);
89static int win32_dispatch(struct event_base *base, struct timeval *);
90static void win32_dealloc(struct event_base *);
91
92struct 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
106static int
107grow_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
125static int
126do_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
150static int
151do_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
183void *
184win32_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
222int
223win32_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
247int
248win32_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
264static void
265fd_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
282int
283win32_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
370void
371win32_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