libev/ev_select.c

/*
 * libev select fd activity backend
 *
 * Copyright (c) 2007,2008,2009,2010,2011 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 <inttypes.h>
# ifndef __hpux
/* for REAL unix systems */
#  include <sys/select.h>
# endif
#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 NFDBITS
# define NFDBITS 0
#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

    assert (("libev: fd >= FD_SETSIZE passed to fd_set-based select backend", fd < FD_SETSIZE));

    /* FD_SET is broken on windows (it adds the fd to a set twice or more,
     * which eventually leads to overflows). Need to call it only on changes.
     */
    #if EV_SELECT_IS_WINSOCKET
    if ((oev ^ nev) & EV_READ)
    #endif
      if (nev & EV_READ)
        FD_SET (handle, (fd_set *)vec_ri);
      else
        FD_CLR (handle, (fd_set *)vec_ri);

    #if EV_SELECT_IS_WINSOCKET
    if ((oev ^ nev) & EV_WRITE)
    #endif
      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;

  EV_RELEASE_CB;
  EV_TV_SET (tv, timeout);

#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);
#elif EV_SELECT_USE_FD_SET
  fd_setsize = anfdmax < FD_SETSIZE ? anfdmax : FD_SETSIZE;
  res = select (fd_setsize, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
#else
  res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
#endif
  EV_ACQUIRE_CB;

  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 erroneously 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)
        {
          if (timeout)
            {
              unsigned long ms = timeout * 1e3;
              Sleep (ms ? ms : 1);
            }

          return;
        }
      #endif

      if (errno == EBADF)
        fd_ebadf (EV_A);
      else if (errno == ENOMEM && !syserr_cb)
        fd_enomem (EV_A);
      else if (errno != EINTR)
        ev_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  = 1e-6;
  backend_modify = select_modify;
  backend_poll   = select_poll;

#if EV_SELECT_USE_FD_SET
  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_ro  = 0;
  vec_wi  = 0;
  vec_wo  = 0;
  #ifdef _WIN32
  vec_eo  = 0;
  #endif
#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);
  #ifdef _WIN32
  ev_free (vec_eo);
  #endif
}

Revision:	1.54
Committed:	Fri Jun 3 00:04:52 2011 UTC (12 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.53:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.4	/*
2	root	1.7	* libev select fd activity backend
3			*
4	root	1.54	* Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de>
5	root	1.4	* All rights reserved.
6			*
7	root	1.27	* Redistribution and use in source and binary forms, with or without modifica-
8			* tion, are permitted provided that the following conditions are met:
9	root	1.52	*
10	root	1.27	* 1. Redistributions of source code must retain the above copyright notice,
11			* this list of conditions and the following disclaimer.
12	root	1.52	*
13	root	1.27	* 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	root	1.52	*
17	root	1.27	* 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	root	1.4	*
28	root	1.27	* 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	root	1.4	*/
39
40	root	1.20	#ifndef _WIN32
41	root	1.2	/* for unix systems */
42	root	1.50	# include <inttypes.h>
43			# ifndef __hpux
44			/* for REAL unix systems */
45	root	1.51	# include <sys/select.h>
46	root	1.50	# endif
47	root	1.20	#endif
48
49			#ifndef EV_SELECT_USE_FD_SET
50			# ifdef NFDBITS
51			# define EV_SELECT_USE_FD_SET 0
52			# else
53	root	1.18	# define EV_SELECT_USE_FD_SET 1
54			# endif
55	root	1.9	#endif
56	root	1.2
57	root	1.20	#if EV_SELECT_IS_WINSOCKET
58	root	1.18	# undef EV_SELECT_USE_FD_SET
59			# define EV_SELECT_USE_FD_SET 1
60	root	1.36	# undef NFDBITS
61			# define NFDBITS 0
62	root	1.20	#endif
63
64			#if !EV_SELECT_USE_FD_SET
65			# define NFDBYTES (NFDBITS / 8)
66	root	1.18	#endif
67
68	root	1.2	#include <string.h>
69
70			static void
71	root	1.10	select_modify (EV_P_ int fd, int oev, int nev)
72	root	1.2	{
73	root	1.13	if (oev == nev)
74			return;
75
76	root	1.20	{
77	root	1.17	#if EV_SELECT_USE_FD_SET
78	root	1.42
79	root	1.20	#if EV_SELECT_IS_WINSOCKET
80			SOCKET handle = anfds [fd].handle;
81			#else
82			int handle = fd;
83			#endif
84
85	root	1.41	assert (("libev: fd >= FD_SETSIZE passed to fd_set-based select backend", fd < FD_SETSIZE));
86
87	root	1.37	/* FD_SET is broken on windows (it adds the fd to a set twice or more,
88			* which eventually leads to overflows). Need to call it only on changes.
89			*/
90			#if EV_SELECT_IS_WINSOCKET
91			if ((oev ^ nev) & EV_READ)
92			#endif
93			if (nev & EV_READ)
94			FD_SET (handle, (fd_set *)vec_ri);
95			else
96			FD_CLR (handle, (fd_set *)vec_ri);
97
98			#if EV_SELECT_IS_WINSOCKET
99			if ((oev ^ nev) & EV_WRITE)
100			#endif
101			if (nev & EV_WRITE)
102			FD_SET (handle, (fd_set *)vec_wi);
103			else
104			FD_CLR (handle, (fd_set *)vec_wi);
105	root	1.20
106	root	1.17	#else
107
108	root	1.28	int word = fd / NFDBITS;
109			fd_mask mask = 1UL << (fd % NFDBITS);
110	root	1.20
111	root	1.29	if (expect_false (vec_max <= word))
112	root	1.17	{
113	root	1.20	int new_max = word + 1;
114	root	1.17
115	root	1.20	vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
116			vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
117			vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
118			vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
119	root	1.33	#ifdef _WIN32
120			vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
121			#endif
122	root	1.17
123			for (; vec_max < new_max; ++vec_max)
124	root	1.28	((fd_mask *)vec_ri) [vec_max] =
125			((fd_mask *)vec_wi) [vec_max] = 0;
126	root	1.17	}
127
128	root	1.20	((fd_mask *)vec_ri) [word] \|= mask;
129	root	1.17	if (!(nev & EV_READ))
130	root	1.20	((fd_mask *)vec_ri) [word] &= ~mask;
131	root	1.17
132	root	1.20	((fd_mask *)vec_wi) [word] \|= mask;
133	root	1.17	if (!(nev & EV_WRITE))
134	root	1.20	((fd_mask *)vec_wi) [word] &= ~mask;
135			#endif
136	root	1.17	}
137	root	1.2	}
138
139	root	1.6	static void
140	root	1.10	select_poll (EV_P_ ev_tstamp timeout)
141	root	1.2	{
142			struct timeval tv;
143			int res;
144	root	1.33	int fd_setsize;
145
146	root	1.45	EV_RELEASE_CB;
147	root	1.48	EV_TV_SET (tv, timeout);
148	root	1.2
149	root	1.17	#if EV_SELECT_USE_FD_SET
150	root	1.33	fd_setsize = sizeof (fd_set);
151	root	1.17	#else
152	root	1.33	fd_setsize = vec_max * NFDBYTES;
153	root	1.17	#endif
154	root	1.2
155	root	1.33	memcpy (vec_ro, vec_ri, fd_setsize);
156			memcpy (vec_wo, vec_wi, fd_setsize);
157	root	1.2
158	root	1.32	#ifdef _WIN32
159			/* pass in the write set as except set.
160			* the idea behind this is to work around a windows bug that causes
161			* errors to be reported as an exception and not by setting
162			* the writable bit. this is so uncontrollably lame.
163			*/
164	root	1.33	memcpy (vec_eo, vec_wi, fd_setsize);
165			res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, (fd_set *)vec_eo, &tv);
166	root	1.40	#elif EV_SELECT_USE_FD_SET
167			fd_setsize = anfdmax < FD_SETSIZE ? anfdmax : FD_SETSIZE;
168			res = select (fd_setsize, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
169	root	1.32	#else
170	root	1.20	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
171	root	1.32	#endif
172	root	1.45	EV_ACQUIRE_CB;
173	root	1.2
174	root	1.24	if (expect_false (res < 0))
175	root	1.2	{
176	root	1.20	#if EV_SELECT_IS_WINSOCKET
177			errno = WSAGetLastError ();
178			#endif
179	root	1.29	#ifdef WSABASEERR
180			/* on windows, select returns incompatible error codes, fix this */
181			if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
182			if (errno == WSAENOTSOCK)
183			errno = EBADF;
184			else
185			errno -= WSABASEERR;
186			#endif
187
188			#ifdef _WIN32
189	sf-exg	1.47	/* select on windows erroneously returns EINVAL when no fd sets have been
190	root	1.29	* provided (this is documented). what microsoft doesn't tell you that this bug
191	root	1.39	* exists even when the fd sets _are_ provided, so we have to check for this bug
192	root	1.29	* here and emulate by sleeping manually.
193			* we also get EINVAL when the timeout is invalid, but we ignore this case here
194			* and assume that EINVAL always means: you have to wait manually.
195			*/
196			if (errno == EINVAL)
197			{
198	root	1.53	if (timeout)
199			{
200			unsigned long ms = timeout * 1e3;
201			Sleep (ms ? ms : 1);
202			}
203
204	root	1.29	return;
205			}
206			#endif
207	root	1.17
208	root	1.14	if (errno == EBADF)
209			fd_ebadf (EV_A);
210			else if (errno == ENOMEM && !syserr_cb)
211			fd_enomem (EV_A);
212			else if (errno != EINTR)
213	root	1.38	ev_syserr ("(libev) select");
214	root	1.2
215	root	1.14	return;
216	root	1.2	}
217	root	1.14
218	root	1.17	#if EV_SELECT_USE_FD_SET
219	root	1.20
220			{
221			int fd;
222
223			for (fd = 0; fd < anfdmax; ++fd)
224			if (anfds [fd].events)
225	root	1.18	{
226	root	1.20	int events = 0;
227			#if EV_SELECT_IS_WINSOCKET
228			SOCKET handle = anfds [fd].handle;
229			#else
230			int handle = fd;
231			#endif
232
233			if (FD_ISSET (handle, (fd_set *)vec_ro)) events \|= EV_READ;
234			if (FD_ISSET (handle, (fd_set *)vec_wo)) events \|= EV_WRITE;
235	root	1.33	#ifdef _WIN32
236			if (FD_ISSET (handle, (fd_set *)vec_eo)) events \|= EV_WRITE;
237			#endif
238	root	1.20
239	root	1.24	if (expect_true (events))
240	root	1.20	fd_event (EV_A_ fd, events);
241			}
242			}
243	root	1.18
244	root	1.20	#else
245
246			{
247			int word, bit;
248			for (word = vec_max; word--; )
249			{
250			fd_mask word_r = ((fd_mask *)vec_ro) [word];
251			fd_mask word_w = ((fd_mask *)vec_wo) [word];
252	root	1.33	#ifdef _WIN32
253			word_w \|= ((fd_mask *)vec_eo) [word];
254			#endif
255	root	1.20
256			if (word_r \|\| word_w)
257			for (bit = NFDBITS; bit--; )
258	root	1.18	{
259	root	1.20	fd_mask mask = 1UL << bit;
260	root	1.18	int events = 0;
261
262	root	1.20	events \|= word_r & mask ? EV_READ : 0;
263			events \|= word_w & mask ? EV_WRITE : 0;
264	root	1.18
265	root	1.24	if (expect_true (events))
266	root	1.20	fd_event (EV_A_ word * NFDBITS + bit, events);
267	root	1.18	}
268	root	1.20	}
269			}
270	root	1.17
271			#endif
272	root	1.2	}
273
274	root	1.23	int inline_size
275	root	1.10	select_init (EV_P_ int flags)
276	root	1.2	{
277	root	1.53	backend_fudge = 1e-6;
278	root	1.22	backend_modify = select_modify;
279			backend_poll = select_poll;
280	root	1.10
281	root	1.17	#if EV_SELECT_USE_FD_SET
282	root	1.20	vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
283			vec_ro = ev_malloc (sizeof (fd_set));
284			vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
285			vec_wo = ev_malloc (sizeof (fd_set));
286	root	1.33	#ifdef _WIN32
287			vec_eo = ev_malloc (sizeof (fd_set));
288			#endif
289	root	1.17	#else
290	root	1.12	vec_max = 0;
291	root	1.52	vec_ri = 0;
292			vec_ro = 0;
293			vec_wi = 0;
294			vec_wo = 0;
295	root	1.46	#ifdef _WIN32
296			vec_eo = 0;
297			#endif
298	root	1.17	#endif
299	root	1.12
300	root	1.21	return EVBACKEND_SELECT;
301	root	1.2	}
302
303	root	1.23	void inline_size
304	root	1.12	select_destroy (EV_P)
305			{
306	root	1.14	ev_free (vec_ri);
307			ev_free (vec_ro);
308			ev_free (vec_wi);
309			ev_free (vec_wo);
310	root	1.46	#ifdef _WIN32
311			ev_free (vec_eo);
312			#endif
313	root	1.12	}
314