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.
 */

/* for unix systems */
#ifdef WIN32
typedef unsigned int uint32_t;
#else
# include <sys/select.h>
# include <inttypes.h>
#endif

#include <string.h>

static void
select_modify (EV_P_ int fd, int oev, int nev)
{
  int offs = fd >> 3;
  int mask = 1 << (fd & 7);

  if (oev == nev)
    return;

  if (vec_max < (fd >> 5) + 1)
    {
      int new_max = (fd >> 5) + 1;

      vec_ri = (unsigned char *)ev_realloc (vec_ri, new_max * 4);
      vec_ro = (unsigned char *)ev_realloc (vec_ro, new_max * 4); /* could free/malloc */
      vec_wi = (unsigned char *)ev_realloc (vec_wi, new_max * 4);
      vec_wo = (unsigned char *)ev_realloc (vec_wo, new_max * 4); /* could free/malloc */

      for (; vec_max < new_max; ++vec_max)
        ((uint32_t *)vec_ri)[vec_max] =
        ((uint32_t *)vec_wi)[vec_max] = 0;
    }

  vec_ri [offs] |= mask;
  if (!(nev & EV_READ))
    vec_ri [offs] &= ~mask;

  vec_wi [offs] |= mask;
  if (!(nev & EV_WRITE))
    vec_wi [offs] &= ~mask;
}

static void
select_poll (EV_P_ ev_tstamp timeout)
{
  int word, offs;
  struct timeval tv;
  int res;

  memcpy (vec_ro, vec_ri, vec_max * 4);
  memcpy (vec_wo, vec_wi, vec_max * 4);

  tv.tv_sec  = (long)timeout;
  tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);

  res = select (vec_max * 32, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);

  if (res < 0)
    {
      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;
    }

  for (word = vec_max; word--; )
    {
      if (((uint32_t *)vec_ro) [word] | ((uint32_t *)vec_wo) [word])
        for (offs = 4; offs--; )
          {
            int idx = word * 4 + offs;
            unsigned char byte_r = vec_ro [idx];
            unsigned char byte_w = vec_wo [idx];
            int bit;

            if (byte_r | byte_w)
              for (bit = 8; bit--; )
                {
                  int events = 0;
                  events |= byte_r & (1 << bit) ? EV_READ  : 0;
                  events |= byte_w & (1 << bit) ? EV_WRITE : 0;

                  if (events)
                    fd_event (EV_A_ idx * 8 + bit, events);
                }
          }
    }
}

static int
select_init (EV_P_ int flags)
{
  method_fudge  = 1e-2; /* needed to compensate for select returning early, very conservative */
  method_modify = select_modify;
  method_poll   = select_poll;

  vec_max = 0;
  vec_ri  = 0; 
  vec_ri  = 0;   
  vec_wo  = 0; 
  vec_wo  = 0; 

  return EVMETHOD_SELECT;
}

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


Revision:	1.16
Committed:	Tue Nov 6 13:17:55 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.15:	+4 -7 lines
Log Message:	now port to microsofts goddamn broken pseudo-c-we-do-it-different-to-spite-you so-called c compiler
#	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	1.2	/* for unix systems */
33	root	1.16	#ifdef WIN32
34			typedef unsigned int uint32_t;
35			#else
36	root	1.9	# include <sys/select.h>
37	root	1.16	# include <inttypes.h>
38	root	1.9	#endif
39	root	1.2
40			#include <string.h>
41
42			static void
43	root	1.10	select_modify (EV_P_ int fd, int oev, int nev)
44	root	1.2	{
45			int offs = fd >> 3;
46			int mask = 1 << (fd & 7);
47
48	root	1.13	if (oev == nev)
49			return;
50
51	root	1.2	if (vec_max < (fd >> 5) + 1)
52			{
53	root	1.5	int new_max = (fd >> 5) + 1;
54	root	1.2
55	root	1.14	vec_ri = (unsigned char )ev_realloc (vec_ri, new_max 4);
56			vec_ro = (unsigned char )ev_realloc (vec_ro, new_max 4); /* could free/malloc */
57			vec_wi = (unsigned char )ev_realloc (vec_wi, new_max 4);
58			vec_wo = (unsigned char )ev_realloc (vec_wo, new_max 4); /* could free/malloc */
59	root	1.5
60			for (; vec_max < new_max; ++vec_max)
61			((uint32_t *)vec_ri)[vec_max] =
62			((uint32_t *)vec_wi)[vec_max] = 0;
63	root	1.2	}
64
65			vec_ri [offs] \|= mask;
66			if (!(nev & EV_READ))
67			vec_ri [offs] &= ~mask;
68
69			vec_wi [offs] \|= mask;
70			if (!(nev & EV_WRITE))
71			vec_wi [offs] &= ~mask;
72			}
73
74	root	1.6	static void
75	root	1.10	select_poll (EV_P_ ev_tstamp timeout)
76	root	1.2	{
77	root	1.14	int word, offs;
78	root	1.2	struct timeval tv;
79			int res;
80
81			memcpy (vec_ro, vec_ri, vec_max * 4);
82			memcpy (vec_wo, vec_wi, vec_max * 4);
83
84			tv.tv_sec = (long)timeout;
85			tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
86
87			res = select (vec_max * 32, (fd_set )vec_ro, (fd_set )vec_wo, 0, &tv);
88
89	root	1.14	if (res < 0)
90	root	1.2	{
91	root	1.14	if (errno == EBADF)
92			fd_ebadf (EV_A);
93			else if (errno == ENOMEM && !syserr_cb)
94			fd_enomem (EV_A);
95			else if (errno != EINTR)
96	root	1.15	syserr ("(libev) select");
97	root	1.2
98	root	1.14	return;
99	root	1.2	}
100	root	1.14
101			for (word = vec_max; word--; )
102	root	1.5	{
103	root	1.14	if (((uint32_t )vec_ro) [word] \| ((uint32_t )vec_wo) [word])
104			for (offs = 4; offs--; )
105			{
106			int idx = word * 4 + offs;
107			unsigned char byte_r = vec_ro [idx];
108			unsigned char byte_w = vec_wo [idx];
109			int bit;
110
111			if (byte_r \| byte_w)
112			for (bit = 8; bit--; )
113			{
114			int events = 0;
115			events \|= byte_r & (1 << bit) ? EV_READ : 0;
116			events \|= byte_w & (1 << bit) ? EV_WRITE : 0;
117
118			if (events)
119			fd_event (EV_A_ idx * 8 + bit, events);
120			}
121			}
122	root	1.5	}
123	root	1.2	}
124
125	root	1.10	static int
126			select_init (EV_P_ int flags)
127	root	1.2	{
128			method_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
129			method_modify = select_modify;
130			method_poll = select_poll;
131	root	1.10
132	root	1.12	vec_max = 0;
133			vec_ri = 0;
134			vec_ri = 0;
135			vec_wo = 0;
136			vec_wo = 0;
137
138	root	1.10	return EVMETHOD_SELECT;
139	root	1.2	}
140
141	root	1.12	static void
142			select_destroy (EV_P)
143			{
144	root	1.14	ev_free (vec_ri);
145			ev_free (vec_ro);
146			ev_free (vec_wi);
147			ev_free (vec_wo);
148	root	1.12	}
149
150