summaryrefslogtreecommitdiff
path: root/ev_select.c
blob: b52a88ddb856a3d1685fa8d53947868fd9060149 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/*
 * libev select fd activity backend
 *
 * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 */

#ifndef _WIN32
/* for unix systems */
# include <sys/select.h>
# include <inttypes.h>
#endif

#ifndef EV_SELECT_USE_FD_SET
# ifdef NFDBITS
#  define EV_SELECT_USE_FD_SET 0
# else
#  define EV_SELECT_USE_FD_SET 1
# endif
#endif

#if EV_SELECT_IS_WINSOCKET
# undef EV_SELECT_USE_FD_SET
# define EV_SELECT_USE_FD_SET 1
# undef EINTR
# define EINTR WSAEINTR
# undef EBADF
# define EBADF WSAENOTSOCK
# undef ENOMEM
# define ENOMEM (errno + 1)
#endif

#if !EV_SELECT_USE_FD_SET
# define NFDBYTES (NFDBITS / 8)
#endif

#include <string.h>

static void
select_modify (EV_P_ int fd, int oev, int nev)
{
  if (oev == nev)
    return;

  {
#if EV_SELECT_USE_FD_SET

    #if EV_SELECT_IS_WINSOCKET
    SOCKET handle = anfds [fd].handle;
    #else
    int handle = fd;
    #endif

    if (nev & EV_READ)
      FD_SET (handle, (fd_set *)vec_ri);
    else
      FD_CLR (handle, (fd_set *)vec_ri);

    if (nev & EV_WRITE)
      FD_SET (handle, (fd_set *)vec_wi);
    else
      FD_CLR (handle, (fd_set *)vec_wi);

#else

    int word = fd / NFDBITS;
    int mask = 1UL << (fd % NFDBITS);

    if (expect_false (vec_max < word + 1))
      {
        int new_max = word + 1;

        vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
        vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
        vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
        vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */

        for (; vec_max < new_max; ++vec_max)
          ((fd_mask *)vec_ri)[vec_max] =
          ((fd_mask *)vec_wi)[vec_max] = 0;
      }

    ((fd_mask *)vec_ri) [word] |= mask;
    if (!(nev & EV_READ))
      ((fd_mask *)vec_ri) [word] &= ~mask;

    ((fd_mask *)vec_wi) [word] |= mask;
    if (!(nev & EV_WRITE))
      ((fd_mask *)vec_wi) [word] &= ~mask;
#endif
  }
}

static void
select_poll (EV_P_ ev_tstamp timeout)
{
  struct timeval tv;
  int res;

#if EV_SELECT_USE_FD_SET
  memcpy (vec_ro, vec_ri, sizeof (fd_set));
  memcpy (vec_wo, vec_wi, sizeof (fd_set));
#else
  memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
  memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
#endif

  tv.tv_sec  = (long)timeout;
  tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);

  res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);

  if (expect_false (res < 0))
    {
      #if EV_SELECT_IS_WINSOCKET
      errno = WSAGetLastError ();
      #endif

      if (errno == EBADF)
        fd_ebadf (EV_A);
      else if (errno == ENOMEM && !syserr_cb)
        fd_enomem (EV_A);
      else if (errno != EINTR)
        syserr ("(libev) select");

      return;
    }

#if EV_SELECT_USE_FD_SET

  {
    int fd;

    for (fd = 0; fd < anfdmax; ++fd)
      if (anfds [fd].events)
        {
          int events = 0;
          #if EV_SELECT_IS_WINSOCKET
          SOCKET handle = anfds [fd].handle;
          #else
          int handle = fd;
          #endif

          if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ;
          if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE;

          if (expect_true (events))
            fd_event (EV_A_ fd, events);
        }
  }

#else

  {
    int word, bit;
    for (word = vec_max; word--; )
      {
        fd_mask word_r = ((fd_mask *)vec_ro) [word];
        fd_mask word_w = ((fd_mask *)vec_wo) [word];

        if (word_r || word_w)
          for (bit = NFDBITS; bit--; )
            {
              fd_mask mask = 1UL << bit;
              int events = 0;

              events |= word_r & mask ? EV_READ  : 0;
              events |= word_w & mask ? EV_WRITE : 0;

              if (expect_true (events))
                fd_event (EV_A_ word * NFDBITS + bit, events);
            }
      }
  }

#endif
}

int inline_size
select_init (EV_P_ int flags)
{
  backend_fudge  = 0.; /* posix says this is zero */
  backend_modify = select_modify;
  backend_poll   = select_poll;

#if EV_SELECT_USE_FD_SET
  vec_max = FD_SETSIZE / 32;
  vec_ri  = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
  vec_ro  = ev_malloc (sizeof (fd_set));
  vec_wi  = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
  vec_wo  = ev_malloc (sizeof (fd_set));
#else
  vec_max = 0;
  vec_ri  = 0; 
  vec_ri  = 0;   
  vec_wo  = 0; 
  vec_wo  = 0; 
#endif

  return EVBACKEND_SELECT;
}

void inline_size
select_destroy (EV_P)
{
  ev_free (vec_ri);
  ev_free (vec_ro);
  ev_free (vec_wi);
  ev_free (vec_wo);
}