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 (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 (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 (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 (events)
                fd_event (EV_A_ word * NFDBITS + bit, events);
            }
      }
  }

#endif
}

static int
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;
}

static void
select_destroy (EV_P)
{
  ev_free (vec_ri);
  ev_free (vec_ro);
  ev_free (vec_wi);
  ev_free (vec_wo);
}


Revision:	1.22
Committed:	Fri Nov 23 05:13:49 2007 UTC (18 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_4, rel-1_3
Changes since 1.21:	+3 -3 lines
Log Message:	more thorough renaming, might even work now
#	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
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	#ifndef _WIN32
33	/* for unix systems */
34	# 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	# define EV_SELECT_USE_FD_SET 1
43	# endif
44	#endif
45
46	#if EV_SELECT_IS_WINSOCKET
47	# undef EV_SELECT_USE_FD_SET
48	# define EV_SELECT_USE_FD_SET 1
49	# 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	#endif
60
61	#include <string.h>
62
63	static void
64	select_modify (EV_P_ int fd, int oev, int nev)
65	{
66	if (oev == nev)
67	return;
68
69	{
70	#if EV_SELECT_USE_FD_SET
71
72	#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	#else
89
90	int word = fd / NFDBITS;
91	int mask = 1UL << (fd % NFDBITS);
92
93	if (vec_max < word + 1)
94	{
95	int new_max = word + 1;
96
97	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
102	for (; vec_max < new_max; ++vec_max)
103	((fd_mask *)vec_ri)[vec_max] =
104	((fd_mask *)vec_wi)[vec_max] = 0;
105	}
106
107	((fd_mask *)vec_ri) [word] \|= mask;
108	if (!(nev & EV_READ))
109	((fd_mask *)vec_ri) [word] &= ~mask;
110
111	((fd_mask *)vec_wi) [word] \|= mask;
112	if (!(nev & EV_WRITE))
113	((fd_mask *)vec_wi) [word] &= ~mask;
114	#endif
115	}
116	}
117
118	static void
119	select_poll (EV_P_ ev_tstamp timeout)
120	{
121	struct timeval tv;
122	int res;
123
124	#if EV_SELECT_USE_FD_SET
125	memcpy (vec_ro, vec_ri, sizeof (fd_set));
126	memcpy (vec_wo, vec_wi, sizeof (fd_set));
127	#else
128	memcpy (vec_ro, vec_ri, vec_max * NFDBYTES);
129	memcpy (vec_wo, vec_wi, vec_max * NFDBYTES);
130	#endif
131
132	tv.tv_sec = (long)timeout;
133	tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
134
135	res = select (vec_max * NFDBITS, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
136
137	if (res < 0)
138	{
139	#if EV_SELECT_IS_WINSOCKET
140	errno = WSAGetLastError ();
141	#endif
142
143	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	syserr ("(libev) select");
149
150	return;
151	}
152
153	#if EV_SELECT_USE_FD_SET
154
155	{
156	int fd;
157
158	for (fd = 0; fd < anfdmax; ++fd)
159	if (anfds [fd].events)
160	{
161	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	if (events)
172	fd_event (EV_A_ fd, events);
173	}
174	}
175
176	#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	{
188	fd_mask mask = 1UL << bit;
189	int events = 0;
190
191	events \|= word_r & mask ? EV_READ : 0;
192	events \|= word_w & mask ? EV_WRITE : 0;
193
194	if (events)
195	fd_event (EV_A_ word * NFDBITS + bit, events);
196	}
197	}
198	}
199
200	#endif
201	}
202
203	static int
204	select_init (EV_P_ int flags)
205	{
206	backend_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
207	backend_modify = select_modify;
208	backend_poll = select_poll;
209
210	#if EV_SELECT_USE_FD_SET
211	vec_max = FD_SETSIZE / 32;
212	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	#else
217	vec_max = 0;
218	vec_ri = 0;
219	vec_ri = 0;
220	vec_wo = 0;
221	vec_wo = 0;
222	#endif
223
224	return EVBACKEND_SELECT;
225	}
226
227	static void
228	select_destroy (EV_P)
229	{
230	ev_free (vec_ri);
231	ev_free (vec_ro);
232	ev_free (vec_wi);
233	ev_free (vec_wo);
234	}
235
236