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 + 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);
}


Revision:	1.28
Committed:	Sun Mar 16 16:38:23 2008 UTC (16 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_31, rel-3_33, rel-3_3, rel-3_2
Changes since 1.27:	+4 -4 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	1.4	* Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
5			* 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	1.20	# 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	root	1.18	#endif
68
69	root	1.2	#include <string.h>
70
71			static void
72	root	1.10	select_modify (EV_P_ int fd, int oev, int nev)
73	root	1.2	{
74	root	1.13	if (oev == nev)
75			return;
76
77	root	1.20	{
78	root	1.17	#if EV_SELECT_USE_FD_SET
79	root	1.18
80	root	1.20	#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	root	1.17	#else
97
98	root	1.28	int word = fd / NFDBITS;
99			fd_mask mask = 1UL << (fd % NFDBITS);
100	root	1.20
101	root	1.24	if (expect_false (vec_max < word + 1))
102	root	1.17	{
103	root	1.20	int new_max = word + 1;
104	root	1.17
105	root	1.20	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	root	1.17
110			for (; vec_max < new_max; ++vec_max)
111	root	1.28	((fd_mask *)vec_ri) [vec_max] =
112			((fd_mask *)vec_wi) [vec_max] = 0;
113	root	1.17	}
114
115	root	1.20	((fd_mask *)vec_ri) [word] \|= mask;
116	root	1.17	if (!(nev & EV_READ))
117	root	1.20	((fd_mask *)vec_ri) [word] &= ~mask;
118	root	1.17
119	root	1.20	((fd_mask *)vec_wi) [word] \|= mask;
120	root	1.17	if (!(nev & EV_WRITE))
121	root	1.20	((fd_mask *)vec_wi) [word] &= ~mask;
122			#endif
123	root	1.17	}
124	root	1.2	}
125
126	root	1.6	static void
127	root	1.10	select_poll (EV_P_ ev_tstamp timeout)
128	root	1.2	{
129			struct timeval tv;
130			int res;
131
132	root	1.17	#if EV_SELECT_USE_FD_SET
133	root	1.20	memcpy (vec_ro, vec_ri, sizeof (fd_set));
134			memcpy (vec_wo, vec_wi, sizeof (fd_set));
135	root	1.17	#else
136	root	1.20	memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
137			memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
138	root	1.17	#endif
139	root	1.2
140			tv.tv_sec = (long)timeout;
141			tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
142
143	root	1.20	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
144	root	1.2
145	root	1.24	if (expect_false (res < 0))
146	root	1.2	{
147	root	1.20	#if EV_SELECT_IS_WINSOCKET
148			errno = WSAGetLastError ();
149			#endif
150	root	1.17
151	root	1.14	if (errno == EBADF)
152			fd_ebadf (EV_A);
153			else if (errno == ENOMEM && !syserr_cb)
154			fd_enomem (EV_A);
155			else if (errno != EINTR)
156	root	1.15	syserr ("(libev) select");
157	root	1.2
158	root	1.14	return;
159	root	1.2	}
160	root	1.14
161	root	1.17	#if EV_SELECT_USE_FD_SET
162	root	1.20
163			{
164			int fd;
165
166			for (fd = 0; fd < anfdmax; ++fd)
167			if (anfds [fd].events)
168	root	1.18	{
169	root	1.20	int events = 0;
170			#if EV_SELECT_IS_WINSOCKET
171			SOCKET handle = anfds [fd].handle;
172			#else
173			int handle = fd;
174			#endif
175
176			if (FD_ISSET (handle, (fd_set *)vec_ro)) events \|= EV_READ;
177			if (FD_ISSET (handle, (fd_set *)vec_wo)) events \|= EV_WRITE;
178
179	root	1.24	if (expect_true (events))
180	root	1.20	fd_event (EV_A_ fd, events);
181			}
182			}
183	root	1.18
184	root	1.20	#else
185
186			{
187			int word, bit;
188			for (word = vec_max; word--; )
189			{
190			fd_mask word_r = ((fd_mask *)vec_ro) [word];
191			fd_mask word_w = ((fd_mask *)vec_wo) [word];
192
193			if (word_r \|\| word_w)
194			for (bit = NFDBITS; bit--; )
195	root	1.18	{
196	root	1.20	fd_mask mask = 1UL << bit;
197	root	1.18	int events = 0;
198
199	root	1.20	events \|= word_r & mask ? EV_READ : 0;
200			events \|= word_w & mask ? EV_WRITE : 0;
201	root	1.18
202	root	1.24	if (expect_true (events))
203	root	1.20	fd_event (EV_A_ word * NFDBITS + bit, events);
204	root	1.18	}
205	root	1.20	}
206			}
207	root	1.17
208			#endif
209	root	1.2	}
210
211	root	1.23	int inline_size
212	root	1.10	select_init (EV_P_ int flags)
213	root	1.2	{
214	root	1.26	backend_fudge = 0.; /* posix says this is zero */
215	root	1.22	backend_modify = select_modify;
216			backend_poll = select_poll;
217	root	1.10
218	root	1.17	#if EV_SELECT_USE_FD_SET
219			vec_max = FD_SETSIZE / 32;
220	root	1.20	vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
221			vec_ro = ev_malloc (sizeof (fd_set));
222			vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
223			vec_wo = ev_malloc (sizeof (fd_set));
224	root	1.17	#else
225	root	1.12	vec_max = 0;
226			vec_ri = 0;
227			vec_ri = 0;
228			vec_wo = 0;
229			vec_wo = 0;
230	root	1.17	#endif
231	root	1.12
232	root	1.21	return EVBACKEND_SELECT;
233	root	1.2	}
234
235	root	1.23	void inline_size
236	root	1.12	select_destroy (EV_P)
237			{
238	root	1.14	ev_free (vec_ri);
239			ev_free (vec_ro);
240			ev_free (vec_wi);
241			ev_free (vec_wo);
242	root	1.12	}
243
244