libev/ev_select.c

/*
 * libev select fd activity backend
 *
 * Copyright (c) 2007,2008,2009 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 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)
        {
          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)
        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  = 0.; /* posix says this is zero */
  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:	1.48
Committed:	Fri Oct 15 22:44:42 2010 UTC (13 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.47:	+1 -2 lines
Log Message:	clean up tv/ts handling
#	User	Rev	Content
1	root	1.4	/*
2	root	1.7	* libev select fd activity backend
3			*
4	root	1.40	* Copyright (c) 2007,2008,2009 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			*
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	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	1.20	# 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	root	1.18	# define EV_SELECT_USE_FD_SET 1
51			# endif
52	root	1.9	#endif
53	root	1.2
54	root	1.20	#if EV_SELECT_IS_WINSOCKET
55	root	1.18	# undef EV_SELECT_USE_FD_SET
56			# define EV_SELECT_USE_FD_SET 1
57	root	1.36	# undef NFDBITS
58			# define NFDBITS 0
59	root	1.20	#endif
60
61			#if !EV_SELECT_USE_FD_SET
62			# define NFDBYTES (NFDBITS / 8)
63	root	1.18	#endif
64
65	root	1.2	#include <string.h>
66
67			static void
68	root	1.10	select_modify (EV_P_ int fd, int oev, int nev)
69	root	1.2	{
70	root	1.13	if (oev == nev)
71			return;
72
73	root	1.20	{
74	root	1.17	#if EV_SELECT_USE_FD_SET
75	root	1.42
76	root	1.20	#if EV_SELECT_IS_WINSOCKET
77			SOCKET handle = anfds [fd].handle;
78			#else
79			int handle = fd;
80			#endif
81
82	root	1.41	assert (("libev: fd >= FD_SETSIZE passed to fd_set-based select backend", fd < FD_SETSIZE));
83
84	root	1.37	/* FD_SET is broken on windows (it adds the fd to a set twice or more,
85			* which eventually leads to overflows). Need to call it only on changes.
86			*/
87			#if EV_SELECT_IS_WINSOCKET
88			if ((oev ^ nev) & EV_READ)
89			#endif
90			if (nev & EV_READ)
91			FD_SET (handle, (fd_set *)vec_ri);
92			else
93			FD_CLR (handle, (fd_set *)vec_ri);
94
95			#if EV_SELECT_IS_WINSOCKET
96			if ((oev ^ nev) & EV_WRITE)
97			#endif
98			if (nev & EV_WRITE)
99			FD_SET (handle, (fd_set *)vec_wi);
100			else
101			FD_CLR (handle, (fd_set *)vec_wi);
102	root	1.20
103	root	1.17	#else
104
105	root	1.28	int word = fd / NFDBITS;
106			fd_mask mask = 1UL << (fd % NFDBITS);
107	root	1.20
108	root	1.29	if (expect_false (vec_max <= word))
109	root	1.17	{
110	root	1.20	int new_max = word + 1;
111	root	1.17
112	root	1.20	vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
113			vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
114			vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
115			vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
116	root	1.33	#ifdef _WIN32
117			vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */
118			#endif
119	root	1.17
120			for (; vec_max < new_max; ++vec_max)
121	root	1.28	((fd_mask *)vec_ri) [vec_max] =
122			((fd_mask *)vec_wi) [vec_max] = 0;
123	root	1.17	}
124
125	root	1.20	((fd_mask *)vec_ri) [word] \|= mask;
126	root	1.17	if (!(nev & EV_READ))
127	root	1.20	((fd_mask *)vec_ri) [word] &= ~mask;
128	root	1.17
129	root	1.20	((fd_mask *)vec_wi) [word] \|= mask;
130	root	1.17	if (!(nev & EV_WRITE))
131	root	1.20	((fd_mask *)vec_wi) [word] &= ~mask;
132			#endif
133	root	1.17	}
134	root	1.2	}
135
136	root	1.6	static void
137	root	1.10	select_poll (EV_P_ ev_tstamp timeout)
138	root	1.2	{
139			struct timeval tv;
140			int res;
141	root	1.33	int fd_setsize;
142
143	root	1.45	EV_RELEASE_CB;
144	root	1.48	EV_TV_SET (tv, timeout);
145	root	1.2
146	root	1.17	#if EV_SELECT_USE_FD_SET
147	root	1.33	fd_setsize = sizeof (fd_set);
148	root	1.17	#else
149	root	1.33	fd_setsize = vec_max * NFDBYTES;
150	root	1.17	#endif
151	root	1.2
152	root	1.33	memcpy (vec_ro, vec_ri, fd_setsize);
153			memcpy (vec_wo, vec_wi, fd_setsize);
154	root	1.2
155	root	1.32	#ifdef _WIN32
156			/* pass in the write set as except set.
157			* the idea behind this is to work around a windows bug that causes
158			* errors to be reported as an exception and not by setting
159			* the writable bit. this is so uncontrollably lame.
160			*/
161	root	1.33	memcpy (vec_eo, vec_wi, fd_setsize);
162			res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, (fd_set *)vec_eo, &tv);
163	root	1.40	#elif EV_SELECT_USE_FD_SET
164			fd_setsize = anfdmax < FD_SETSIZE ? anfdmax : FD_SETSIZE;
165			res = select (fd_setsize, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
166	root	1.32	#else
167	root	1.20	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
168	root	1.32	#endif
169	root	1.45	EV_ACQUIRE_CB;
170	root	1.2
171	root	1.24	if (expect_false (res < 0))
172	root	1.2	{
173	root	1.20	#if EV_SELECT_IS_WINSOCKET
174			errno = WSAGetLastError ();
175			#endif
176	root	1.29	#ifdef WSABASEERR
177			/* on windows, select returns incompatible error codes, fix this */
178			if (errno >= WSABASEERR && errno < WSABASEERR + 1000)
179			if (errno == WSAENOTSOCK)
180			errno = EBADF;
181			else
182			errno -= WSABASEERR;
183			#endif
184
185			#ifdef _WIN32
186	sf-exg	1.47	/* select on windows erroneously returns EINVAL when no fd sets have been
187	root	1.29	* provided (this is documented). what microsoft doesn't tell you that this bug
188	root	1.39	* exists even when the fd sets _are_ provided, so we have to check for this bug
189	root	1.29	* here and emulate by sleeping manually.
190			* we also get EINVAL when the timeout is invalid, but we ignore this case here
191			* and assume that EINVAL always means: you have to wait manually.
192			*/
193			if (errno == EINVAL)
194			{
195			ev_sleep (timeout);
196			return;
197			}
198			#endif
199	root	1.17
200	root	1.14	if (errno == EBADF)
201			fd_ebadf (EV_A);
202			else if (errno == ENOMEM && !syserr_cb)
203			fd_enomem (EV_A);
204			else if (errno != EINTR)
205	root	1.38	ev_syserr ("(libev) select");
206	root	1.2
207	root	1.14	return;
208	root	1.2	}
209	root	1.14
210	root	1.17	#if EV_SELECT_USE_FD_SET
211	root	1.20
212			{
213			int fd;
214
215			for (fd = 0; fd < anfdmax; ++fd)
216			if (anfds [fd].events)
217	root	1.18	{
218	root	1.20	int events = 0;
219			#if EV_SELECT_IS_WINSOCKET
220			SOCKET handle = anfds [fd].handle;
221			#else
222			int handle = fd;
223			#endif
224
225			if (FD_ISSET (handle, (fd_set *)vec_ro)) events \|= EV_READ;
226			if (FD_ISSET (handle, (fd_set *)vec_wo)) events \|= EV_WRITE;
227	root	1.33	#ifdef _WIN32
228			if (FD_ISSET (handle, (fd_set *)vec_eo)) events \|= EV_WRITE;
229			#endif
230	root	1.20
231	root	1.24	if (expect_true (events))
232	root	1.20	fd_event (EV_A_ fd, events);
233			}
234			}
235	root	1.18
236	root	1.20	#else
237
238			{
239			int word, bit;
240			for (word = vec_max; word--; )
241			{
242			fd_mask word_r = ((fd_mask *)vec_ro) [word];
243			fd_mask word_w = ((fd_mask *)vec_wo) [word];
244	root	1.33	#ifdef _WIN32
245			word_w \|= ((fd_mask *)vec_eo) [word];
246			#endif
247	root	1.20
248			if (word_r \|\| word_w)
249			for (bit = NFDBITS; bit--; )
250	root	1.18	{
251	root	1.20	fd_mask mask = 1UL << bit;
252	root	1.18	int events = 0;
253
254	root	1.20	events \|= word_r & mask ? EV_READ : 0;
255			events \|= word_w & mask ? EV_WRITE : 0;
256	root	1.18
257	root	1.24	if (expect_true (events))
258	root	1.20	fd_event (EV_A_ word * NFDBITS + bit, events);
259	root	1.18	}
260	root	1.20	}
261			}
262	root	1.17
263			#endif
264	root	1.2	}
265
266	root	1.23	int inline_size
267	root	1.10	select_init (EV_P_ int flags)
268	root	1.2	{
269	root	1.26	backend_fudge = 0.; /* posix says this is zero */
270	root	1.22	backend_modify = select_modify;
271			backend_poll = select_poll;
272	root	1.10
273	root	1.17	#if EV_SELECT_USE_FD_SET
274	root	1.20	vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
275			vec_ro = ev_malloc (sizeof (fd_set));
276			vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
277			vec_wo = ev_malloc (sizeof (fd_set));
278	root	1.33	#ifdef _WIN32
279			vec_eo = ev_malloc (sizeof (fd_set));
280			#endif
281	root	1.17	#else
282	root	1.12	vec_max = 0;
283			vec_ri = 0;
284	root	1.46	vec_ro = 0;
285			vec_wi = 0;
286	root	1.12	vec_wo = 0;
287	root	1.46	#ifdef _WIN32
288			vec_eo = 0;
289			#endif
290	root	1.17	#endif
291	root	1.12
292	root	1.21	return EVBACKEND_SELECT;
293	root	1.2	}
294
295	root	1.23	void inline_size
296	root	1.12	select_destroy (EV_P)
297			{
298	root	1.14	ev_free (vec_ri);
299			ev_free (vec_ro);
300			ev_free (vec_wi);
301			ev_free (vec_wo);
302	root	1.46	#ifdef _WIN32
303			ev_free (vec_eo);
304			#endif
305	root	1.12	}
306
307