libevent/win32select.c

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