libev/ev_select.c

/*
 * 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;
    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 */

        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
      #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;

          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);
}


Revision:	1.29
Committed:	Tue May 20 19:26:45 2008 UTC (15 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_4
Changes since 1.28:	+24 -1 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* libev select fd activity backend
3	*
4	* Copyright (c) 2007 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	# undef EINTR
58	# define EINTR WSAEINTR
59	# undef EBADF
60	# define EBADF WSAENOTSOCK
61	# undef ENOMEM
62	# define ENOMEM (errno + 1)
63	#endif
64
65	#if !EV_SELECT_USE_FD_SET
66	# define NFDBYTES (NFDBITS / 8)
67	#endif
68
69	#include <string.h>
70
71	static void
72	select_modify (EV_P_ int fd, int oev, int nev)
73	{
74	if (oev == nev)
75	return;
76
77	{
78	#if EV_SELECT_USE_FD_SET
79
80	#if EV_SELECT_IS_WINSOCKET
81	SOCKET handle = anfds [fd].handle;
82	#else
83	int handle = fd;
84	#endif
85
86	if (nev & EV_READ)
87	FD_SET (handle, (fd_set *)vec_ri);
88	else
89	FD_CLR (handle, (fd_set *)vec_ri);
90
91	if (nev & EV_WRITE)
92	FD_SET (handle, (fd_set *)vec_wi);
93	else
94	FD_CLR (handle, (fd_set *)vec_wi);
95
96	#else
97
98	int word = fd / NFDBITS;
99	fd_mask mask = 1UL << (fd % NFDBITS);
100
101	if (expect_false (vec_max <= word))
102	{
103	int new_max = word + 1;
104
105	vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
106	vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
107	vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
108	vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
109
110	for (; vec_max < new_max; ++vec_max)
111	((fd_mask *)vec_ri) [vec_max] =
112	((fd_mask *)vec_wi) [vec_max] = 0;
113	}
114
115	((fd_mask *)vec_ri) [word] \|= mask;
116	if (!(nev & EV_READ))
117	((fd_mask *)vec_ri) [word] &= ~mask;
118
119	((fd_mask *)vec_wi) [word] \|= mask;
120	if (!(nev & EV_WRITE))
121	((fd_mask *)vec_wi) [word] &= ~mask;
122	#endif
123	}
124	}
125
126	static void
127	select_poll (EV_P_ ev_tstamp timeout)
128	{
129	struct timeval tv;
130	int res;
131
132	#if EV_SELECT_USE_FD_SET
133	memcpy (vec_ro, vec_ri, sizeof (fd_set));
134	memcpy (vec_wo, vec_wi, sizeof (fd_set));
135	#else
136	memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
137	memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
138	#endif
139
140	tv.tv_sec = (long)timeout;
141	tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
142
143	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
144
145	if (expect_false (res < 0))
146	{
147	#if EV_SELECT_IS_WINSOCKET
148	errno = WSAGetLastError ();
149	#endif
150	#ifdef WSABASEERR
151	/* on windows, select returns incompatible error codes, fix this */
152	if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
153	if (errno == WSAENOTSOCK)
154	errno = EBADF;
155	else
156	errno -= WSABASEERR;
157	#endif
158
159	#ifdef _WIN32
160	/* select on windows errornously returns EINVAL when no fd sets have been
161	* provided (this is documented). what microsoft doesn't tell you that this bug
162	* exists even when the fd sets are provided, so we have to check for this bug
163	* here and emulate by sleeping manually.
164	* we also get EINVAL when the timeout is invalid, but we ignore this case here
165	* and assume that EINVAL always means: you have to wait manually.
166	*/
167	if (errno == EINVAL)
168	{
169	ev_sleep (timeout);
170	return;
171	}
172	#endif
173
174	if (errno == EBADF)
175	fd_ebadf (EV_A);
176	else if (errno == ENOMEM && !syserr_cb)
177	fd_enomem (EV_A);
178	else if (errno != EINTR)
179	syserr ("(libev) select");
180
181	return;
182	}
183
184	#if EV_SELECT_USE_FD_SET
185
186	{
187	int fd;
188
189	for (fd = 0; fd < anfdmax; ++fd)
190	if (anfds [fd].events)
191	{
192	int events = 0;
193	#if EV_SELECT_IS_WINSOCKET
194	SOCKET handle = anfds [fd].handle;
195	#else
196	int handle = fd;
197	#endif
198
199	if (FD_ISSET (handle, (fd_set *)vec_ro)) events \|= EV_READ;
200	if (FD_ISSET (handle, (fd_set *)vec_wo)) events \|= EV_WRITE;
201
202	if (expect_true (events))
203	fd_event (EV_A_ fd, events);
204	}
205	}
206
207	#else
208
209	{
210	int word, bit;
211	for (word = vec_max; word--; )
212	{
213	fd_mask word_r = ((fd_mask *)vec_ro) [word];
214	fd_mask word_w = ((fd_mask *)vec_wo) [word];
215
216	if (word_r \|\| word_w)
217	for (bit = NFDBITS; bit--; )
218	{
219	fd_mask mask = 1UL << bit;
220	int events = 0;
221
222	events \|= word_r & mask ? EV_READ : 0;
223	events \|= word_w & mask ? EV_WRITE : 0;
224
225	if (expect_true (events))
226	fd_event (EV_A_ word * NFDBITS + bit, events);
227	}
228	}
229	}
230
231	#endif
232	}
233
234	int inline_size
235	select_init (EV_P_ int flags)
236	{
237	backend_fudge = 0.; /* posix says this is zero */
238	backend_modify = select_modify;
239	backend_poll = select_poll;
240
241	#if EV_SELECT_USE_FD_SET
242	vec_max = FD_SETSIZE / 32;
243	vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
244	vec_ro = ev_malloc (sizeof (fd_set));
245	vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
246	vec_wo = ev_malloc (sizeof (fd_set));
247	#else
248	vec_max = 0;
249	vec_ri = 0;
250	vec_ri = 0;
251	vec_wo = 0;
252	vec_wo = 0;
253	#endif
254
255	return EVBACKEND_SELECT;
256	}
257
258	void inline_size
259	select_destroy (EV_P)
260	{
261	ev_free (vec_ri);
262	ev_free (vec_ro);
263	ev_free (vec_wi);
264	ev_free (vec_wo);
265	}
266
267