libev/ev_select.c

/*
 * libev select fd activity backend
 *
 * Copyright (c) 2007,2008 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
#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;
    fd_mask mask = 1UL << (fd % NFDBITS);

    if (expect_false (vec_max <= word))
      {
        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 */
        #ifdef _WIN32
        vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
        #endif

        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;
  int fd_setsize;

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

#if EV_SELECT_USE_FD_SET
  fd_setsize = sizeof (fd_set);
#else
  fd_setsize = vec_max * NFDBYTES;
#endif

  memcpy (vec_ro, vec_ri, fd_setsize);
  memcpy (vec_wo, vec_wi, fd_setsize);

#ifdef _WIN32
  /* pass in the write set as except set.
   * the idea behind this is to work around a windows bug that causes
   * errors to be reported as an exception and not by setting
   * the writable bit. this is so uncontrollably lame.
   */
  memcpy (vec_eo, vec_wi, fd_setsize);
  res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_eo, &tv);
#else
  res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
#endif

  if (expect_false (res < 0))
    {
      #if EV_SELECT_IS_WINSOCKET
      errno = WSAGetLastError ();
      #endif
      #ifdef WSABASEERR
      /* on windows, select returns incompatible error codes, fix this */
      if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
        if (errno == WSAENOTSOCK)
          errno = EBADF;
        else
          errno -= WSABASEERR;
      #endif

      #ifdef _WIN32
      /* select on windows errornously returns EINVAL when no fd sets have been
       * provided (this is documented). what microsoft doesn't tell you that this bug
       * exists even when the fd sets are provided, so we have to check for this bug
       * here and emulate by sleeping manually.
       * we also get EINVAL when the timeout is invalid, but we ignore this case here
       * and assume that EINVAL always means: you have to wait manually.
       */
      if (errno == EINVAL)
        {
          ev_sleep (timeout);
          return;
        }
      #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;
          #ifdef _WIN32
          if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE;
          #endif

          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];
        #ifdef _WIN32
        word_w |= ((fd_mask *)vec_eo) [word];
        #endif

        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));
  #ifdef _WIN32
  vec_eo  = ev_malloc (sizeof (fd_set));
  #endif
#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);
}


Revision:	1.35
Committed:	Mon May 26 04:59:08 2008 UTC (15 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.34:	+0 -1 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* libev select fd activity backend
3	*
4	* Copyright (c) 2007,2008 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	#endif
58
59	#if !EV_SELECT_USE_FD_SET
60	# define NFDBYTES (NFDBITS / 8)
61	#endif
62
63	#include <string.h>
64
65	static void
66	select_modify (EV_P_ int fd, int oev, int nev)
67	{
68	if (oev == nev)
69	return;
70
71	{
72	#if EV_SELECT_USE_FD_SET
73
74	#if EV_SELECT_IS_WINSOCKET
75	SOCKET handle = anfds [fd].handle;
76	#else
77	int handle = fd;
78	#endif
79
80	if (nev & EV_READ)
81	FD_SET (handle, (fd_set *)vec_ri);
82	else
83	FD_CLR (handle, (fd_set *)vec_ri);
84
85	if (nev & EV_WRITE)
86	FD_SET (handle, (fd_set *)vec_wi);
87	else
88	FD_CLR (handle, (fd_set *)vec_wi);
89
90	#else
91
92	int word = fd / NFDBITS;
93	fd_mask mask = 1UL << (fd % NFDBITS);
94
95	if (expect_false (vec_max <= word))
96	{
97	int new_max = word + 1;
98
99	vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
100	vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
101	vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
102	vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
103	#ifdef _WIN32
104	vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
105	#endif
106
107	for (; vec_max < new_max; ++vec_max)
108	((fd_mask *)vec_ri) [vec_max] =
109	((fd_mask *)vec_wi) [vec_max] = 0;
110	}
111
112	((fd_mask *)vec_ri) [word] \|= mask;
113	if (!(nev & EV_READ))
114	((fd_mask *)vec_ri) [word] &= ~mask;
115
116	((fd_mask *)vec_wi) [word] \|= mask;
117	if (!(nev & EV_WRITE))
118	((fd_mask *)vec_wi) [word] &= ~mask;
119	#endif
120	}
121	}
122
123	static void
124	select_poll (EV_P_ ev_tstamp timeout)
125	{
126	struct timeval tv;
127	int res;
128	int fd_setsize;
129
130	tv.tv_sec = (long)timeout;
131	tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
132
133	#if EV_SELECT_USE_FD_SET
134	fd_setsize = sizeof (fd_set);
135	#else
136	fd_setsize = vec_max * NFDBYTES;
137	#endif
138
139	memcpy (vec_ro, vec_ri, fd_setsize);
140	memcpy (vec_wo, vec_wi, fd_setsize);
141
142	#ifdef _WIN32
143	/* pass in the write set as except set.
144	* the idea behind this is to work around a windows bug that causes
145	* errors to be reported as an exception and not by setting
146	* the writable bit. this is so uncontrollably lame.
147	*/
148	memcpy (vec_eo, vec_wi, fd_setsize);
149	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, (fd_set *)vec_eo, &tv);
150	#else
151	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
152	#endif
153
154	if (expect_false (res < 0))
155	{
156	#if EV_SELECT_IS_WINSOCKET
157	errno = WSAGetLastError ();
158	#endif
159	#ifdef WSABASEERR
160	/* on windows, select returns incompatible error codes, fix this */
161	if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
162	if (errno == WSAENOTSOCK)
163	errno = EBADF;
164	else
165	errno -= WSABASEERR;
166	#endif
167
168	#ifdef _WIN32
169	/* select on windows errornously returns EINVAL when no fd sets have been
170	* provided (this is documented). what microsoft doesn't tell you that this bug
171	* exists even when the fd sets are provided, so we have to check for this bug
172	* here and emulate by sleeping manually.
173	* we also get EINVAL when the timeout is invalid, but we ignore this case here
174	* and assume that EINVAL always means: you have to wait manually.
175	*/
176	if (errno == EINVAL)
177	{
178	ev_sleep (timeout);
179	return;
180	}
181	#endif
182
183	if (errno == EBADF)
184	fd_ebadf (EV_A);
185	else if (errno == ENOMEM && !syserr_cb)
186	fd_enomem (EV_A);
187	else if (errno != EINTR)
188	syserr ("(libev) select");
189
190	return;
191	}
192
193	#if EV_SELECT_USE_FD_SET
194
195	{
196	int fd;
197
198	for (fd = 0; fd < anfdmax; ++fd)
199	if (anfds [fd].events)
200	{
201	int events = 0;
202	#if EV_SELECT_IS_WINSOCKET
203	SOCKET handle = anfds [fd].handle;
204	#else
205	int handle = fd;
206	#endif
207
208	if (FD_ISSET (handle, (fd_set *)vec_ro)) events \|= EV_READ;
209	if (FD_ISSET (handle, (fd_set *)vec_wo)) events \|= EV_WRITE;
210	#ifdef _WIN32
211	if (FD_ISSET (handle, (fd_set *)vec_eo)) events \|= EV_WRITE;
212	#endif
213
214	if (expect_true (events))
215	fd_event (EV_A_ fd, events);
216	}
217	}
218
219	#else
220
221	{
222	int word, bit;
223	for (word = vec_max; word--; )
224	{
225	fd_mask word_r = ((fd_mask *)vec_ro) [word];
226	fd_mask word_w = ((fd_mask *)vec_wo) [word];
227	#ifdef _WIN32
228	word_w \|= ((fd_mask *)vec_eo) [word];
229	#endif
230
231	if (word_r \|\| word_w)
232	for (bit = NFDBITS; bit--; )
233	{
234	fd_mask mask = 1UL << bit;
235	int events = 0;
236
237	events \|= word_r & mask ? EV_READ : 0;
238	events \|= word_w & mask ? EV_WRITE : 0;
239
240	if (expect_true (events))
241	fd_event (EV_A_ word * NFDBITS + bit, events);
242	}
243	}
244	}
245
246	#endif
247	}
248
249	int inline_size
250	select_init (EV_P_ int flags)
251	{
252	backend_fudge = 0.; /* posix says this is zero */
253	backend_modify = select_modify;
254	backend_poll = select_poll;
255
256	#if EV_SELECT_USE_FD_SET
257	vec_max = FD_SETSIZE / 32;
258	vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
259	vec_ro = ev_malloc (sizeof (fd_set));
260	vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
261	vec_wo = ev_malloc (sizeof (fd_set));
262	#ifdef _WIN32
263	vec_eo = ev_malloc (sizeof (fd_set));
264	#endif
265	#else
266	vec_max = 0;
267	vec_ri = 0;
268	vec_ri = 0;
269	vec_wo = 0;
270	vec_wo = 0;
271	#endif
272
273	return EVBACKEND_SELECT;
274	}
275
276	void inline_size
277	select_destroy (EV_P)
278	{
279	ev_free (vec_ri);
280	ev_free (vec_ro);
281	ev_free (vec_wi);
282	ev_free (vec_wo);
283	}
284
285