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
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, 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 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#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;
    int 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  = 1e-2; /* needed to compensate for select returning early, very conservative */
  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:	1.24
Committed:	Sun Dec 9 02:12:44 2007 UTC (16 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.23:	+4 -4 lines
Log Message:	µ-opts
#	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			* Redistribution and use in source and binary forms, with or without
8			* modification, are permitted provided that the following conditions are
9			* met:
10			*
11			* * Redistributions of source code must retain the above copyright
12			* notice, this list of conditions and the following disclaimer.
13			*
14			* * Redistributions in binary form must reproduce the above
15			* copyright notice, this list of conditions and the following
16			* disclaimer in the documentation and/or other materials provided
17			* with the distribution.
18			*
19			* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20			* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21			* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22			* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23			* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29			* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30			*/
31
32	root	1.20	#ifndef _WIN32
33	root	1.2	/* for unix systems */
34	root	1.20	# include <sys/select.h>
35			# include <inttypes.h>
36			#endif
37
38			#ifndef EV_SELECT_USE_FD_SET
39			# ifdef NFDBITS
40			# define EV_SELECT_USE_FD_SET 0
41			# else
42	root	1.18	# define EV_SELECT_USE_FD_SET 1
43			# endif
44	root	1.9	#endif
45	root	1.2
46	root	1.20	#if EV_SELECT_IS_WINSOCKET
47	root	1.18	# undef EV_SELECT_USE_FD_SET
48			# define EV_SELECT_USE_FD_SET 1
49	root	1.20	# undef EINTR
50			# define EINTR WSAEINTR
51			# undef EBADF
52			# define EBADF WSAENOTSOCK
53			# undef ENOMEM
54			# define ENOMEM (errno + 1)
55			#endif
56
57			#if !EV_SELECT_USE_FD_SET
58			# define NFDBYTES (NFDBITS / 8)
59	root	1.18	#endif
60
61	root	1.2	#include <string.h>
62
63			static void
64	root	1.10	select_modify (EV_P_ int fd, int oev, int nev)
65	root	1.2	{
66	root	1.13	if (oev == nev)
67			return;
68
69	root	1.20	{
70	root	1.17	#if EV_SELECT_USE_FD_SET
71	root	1.18
72	root	1.20	#if EV_SELECT_IS_WINSOCKET
73			SOCKET handle = anfds [fd].handle;
74			#else
75			int handle = fd;
76			#endif
77
78			if (nev & EV_READ)
79			FD_SET (handle, (fd_set *)vec_ri);
80			else
81			FD_CLR (handle, (fd_set *)vec_ri);
82
83			if (nev & EV_WRITE)
84			FD_SET (handle, (fd_set *)vec_wi);
85			else
86			FD_CLR (handle, (fd_set *)vec_wi);
87
88	root	1.17	#else
89
90	root	1.20	int word = fd / NFDBITS;
91			int mask = 1UL << (fd % NFDBITS);
92
93	root	1.24	if (expect_false (vec_max < word + 1))
94	root	1.17	{
95	root	1.20	int new_max = word + 1;
96	root	1.17
97	root	1.20	vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES);
98			vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */
99			vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES);
100			vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */
101	root	1.17
102			for (; vec_max < new_max; ++vec_max)
103	root	1.20	((fd_mask *)vec_ri)[vec_max] =
104			((fd_mask *)vec_wi)[vec_max] = 0;
105	root	1.17	}
106
107	root	1.20	((fd_mask *)vec_ri) [word] \|= mask;
108	root	1.17	if (!(nev & EV_READ))
109	root	1.20	((fd_mask *)vec_ri) [word] &= ~mask;
110	root	1.17
111	root	1.20	((fd_mask *)vec_wi) [word] \|= mask;
112	root	1.17	if (!(nev & EV_WRITE))
113	root	1.20	((fd_mask *)vec_wi) [word] &= ~mask;
114			#endif
115	root	1.17	}
116	root	1.2	}
117
118	root	1.6	static void
119	root	1.10	select_poll (EV_P_ ev_tstamp timeout)
120	root	1.2	{
121			struct timeval tv;
122			int res;
123
124	root	1.17	#if EV_SELECT_USE_FD_SET
125	root	1.20	memcpy (vec_ro, vec_ri, sizeof (fd_set));
126			memcpy (vec_wo, vec_wi, sizeof (fd_set));
127	root	1.17	#else
128	root	1.20	memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
129			memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
130	root	1.17	#endif
131	root	1.2
132			tv.tv_sec = (long)timeout;
133			tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
134
135	root	1.20	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
136	root	1.2
137	root	1.24	if (expect_false (res < 0))
138	root	1.2	{
139	root	1.20	#if EV_SELECT_IS_WINSOCKET
140			errno = WSAGetLastError ();
141			#endif
142	root	1.17
143	root	1.14	if (errno == EBADF)
144			fd_ebadf (EV_A);
145			else if (errno == ENOMEM && !syserr_cb)
146			fd_enomem (EV_A);
147			else if (errno != EINTR)
148	root	1.15	syserr ("(libev) select");
149	root	1.2
150	root	1.14	return;
151	root	1.2	}
152	root	1.14
153	root	1.17	#if EV_SELECT_USE_FD_SET
154	root	1.20
155			{
156			int fd;
157
158			for (fd = 0; fd < anfdmax; ++fd)
159			if (anfds [fd].events)
160	root	1.18	{
161	root	1.20	int events = 0;
162			#if EV_SELECT_IS_WINSOCKET
163			SOCKET handle = anfds [fd].handle;
164			#else
165			int handle = fd;
166			#endif
167
168			if (FD_ISSET (handle, (fd_set *)vec_ro)) events \|= EV_READ;
169			if (FD_ISSET (handle, (fd_set *)vec_wo)) events \|= EV_WRITE;
170
171	root	1.24	if (expect_true (events))
172	root	1.20	fd_event (EV_A_ fd, events);
173			}
174			}
175	root	1.18
176	root	1.20	#else
177
178			{
179			int word, bit;
180			for (word = vec_max; word--; )
181			{
182			fd_mask word_r = ((fd_mask *)vec_ro) [word];
183			fd_mask word_w = ((fd_mask *)vec_wo) [word];
184
185			if (word_r \|\| word_w)
186			for (bit = NFDBITS; bit--; )
187	root	1.18	{
188	root	1.20	fd_mask mask = 1UL << bit;
189	root	1.18	int events = 0;
190
191	root	1.20	events \|= word_r & mask ? EV_READ : 0;
192			events \|= word_w & mask ? EV_WRITE : 0;
193	root	1.18
194	root	1.24	if (expect_true (events))
195	root	1.20	fd_event (EV_A_ word * NFDBITS + bit, events);
196	root	1.18	}
197	root	1.20	}
198			}
199	root	1.17
200			#endif
201	root	1.2	}
202
203	root	1.23	int inline_size
204	root	1.10	select_init (EV_P_ int flags)
205	root	1.2	{
206	root	1.22	backend_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
207			backend_modify = select_modify;
208			backend_poll = select_poll;
209	root	1.10
210	root	1.17	#if EV_SELECT_USE_FD_SET
211			vec_max = FD_SETSIZE / 32;
212	root	1.20	vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri);
213			vec_ro = ev_malloc (sizeof (fd_set));
214			vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi);
215			vec_wo = ev_malloc (sizeof (fd_set));
216	root	1.17	#else
217	root	1.12	vec_max = 0;
218			vec_ri = 0;
219			vec_ri = 0;
220			vec_wo = 0;
221			vec_wo = 0;
222	root	1.17	#endif
223	root	1.12
224	root	1.21	return EVBACKEND_SELECT;
225	root	1.2	}
226
227	root	1.23	void inline_size
228	root	1.12	select_destroy (EV_P)
229			{
230	root	1.14	ev_free (vec_ri);
231			ev_free (vec_ro);
232			ev_free (vec_wi);
233			ev_free (vec_wo);
234	root	1.12	}
235
236