libev/ev_port.c

/*
 * libev solaris event port backend
 *
 * Copyright (c) 2007,2008,2009,2010,2011,2019 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.
 */

/* useful reading:
 *
 * https://archive.is/jN6Ck (random results)
 * https://archive.is/bBikp (just totally broken)
 * https://archive.is/eJhmu (manpage ETIME)
 * https://archive.is/RbgYw (implementation ETIME)
 * http://www.mail-archive.com/networking-discuss@opensolaris.org/msg11898.html ETIME vs. nget
 * http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/event_port.c (libc)
 * http://cvs.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/fs/portfs/port.c#1325 (kernel)
 */

#include <sys/types.h>
#include <sys/time.h>
#include <poll.h>
#include <port.h>
#include <string.h>
#include <errno.h>

inline_speed
void
port_associate_and_check (EV_P_ int fd, int ev)
{
  if (0 >
      port_associate (
         backend_fd, PORT_SOURCE_FD, fd,
         (ev & EV_READ ? POLLIN : 0)
         | (ev & EV_WRITE ? POLLOUT : 0),
         0
      )
  )
    {
      if (errno == EBADFD)
        {
          assert (("libev: port_associate found invalid fd", errno != EBADFD));
          fd_kill (EV_A_ fd);
        }
      else
        ev_syserr ("(libev) port_associate");
    }
}

static void
port_modify (EV_P_ int fd, int oev, int nev)
{
  /* we need to reassociate no matter what, as closes are
   * once more silently being discarded.
   */
  if (!nev)
    {
      if (oev)
        port_dissociate (backend_fd, PORT_SOURCE_FD, fd);
    }
  else
    port_associate_and_check (EV_A_ fd, nev);
}

static void
port_poll (EV_P_ ev_tstamp timeout)
{
  int res, i;
  struct timespec ts;
  uint_t nget = 1;

  /* we initialise this to something we will skip in the loop, as */
  /* port_getn can return with nget unchanged, but no indication */
  /* whether it was the original value or has been updated :/ */
  port_events [0].portev_source = 0;

  EV_RELEASE_CB;
  EV_TS_SET (ts, timeout);
  res = port_getn (backend_fd, port_events, port_eventmax, &nget, &ts);
  EV_ACQUIRE_CB;

  /* port_getn may or may not set nget on error */
  /* so we rely on port_events [0].portev_source not being updated */
  if (res == -1 && errno != ETIME && errno != EINTR)
    ev_syserr ("(libev) port_getn (see https://archive.is/jN6Ck, try LIBEV_FLAGS=3 env variable)");

  for (i = 0; i < nget; ++i)
    {
      if (port_events [i].portev_source == PORT_SOURCE_FD)
        {
          int fd = port_events [i].portev_object;

          fd_event (
            EV_A_
            fd,
            (port_events [i].portev_events & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
            | (port_events [i].portev_events & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
          );

          fd_change (EV_A_ fd, EV__IOFDSET);
        }
    }

  if (ecb_expect_false (nget == port_eventmax))
    {
      ev_free (port_events);
      port_eventmax = array_nextsize (sizeof (port_event_t), port_eventmax, port_eventmax + 1);
      port_events = (port_event_t *)ev_malloc (sizeof (port_event_t) * port_eventmax);
    }
}

inline_size
int
port_init (EV_P_ int flags)
{
  /* Initialize the kernel queue */
  if ((backend_fd = port_create ()) < 0)
    return 0;

  assert (("libev: PORT_SOURCE_FD must not be zero", PORT_SOURCE_FD));

  fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */

  /* if my reading of the opensolaris kernel sources are correct, then
   * opensolaris does something very stupid: it checks if the time has already
   * elapsed and doesn't round up if that is the case, otherwise it DOES round
   * up. Since we can't know what the case is, we need to guess by using a
   * "large enough" timeout. Normally, 1e-9 would be correct.
   */
  backend_mintime = EV_TS_CONST (1e-3); /* needed to compensate for port_getn returning early */
  backend_modify  = port_modify;
  backend_poll    = port_poll;

  port_eventmax = 64; /* initial number of events receivable per poll */
  port_events = (port_event_t *)ev_malloc (sizeof (port_event_t) * port_eventmax);

  return EVBACKEND_PORT;
}

inline_size
void
port_destroy (EV_P)
{
  ev_free (port_events);
}

inline_size
void
port_fork (EV_P)
{
  close (backend_fd);

  while ((backend_fd = port_create ()) < 0)
    ev_syserr ("(libev) port");

  fcntl (backend_fd, F_SETFD, FD_CLOEXEC);

  /* re-register interest in fds */
  fd_rearm_all (EV_A);
}

Revision:	1.34
Committed:	Sat May 22 20:14:57 2021 UTC (3 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.33:	+5 -5 lines
Log Message:	replace soem urls
#	Content
1	/*
2	* libev solaris event port backend
3	*
4	* Copyright (c) 2007,2008,2009,2010,2011,2019 Marc Alexander Lehmann <libev@schmorp.de>
5	* All rights reserved.
6	*
7	* 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	*
28	* 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	*/
39
40	/* useful reading:
41	*
42	* https://archive.is/jN6Ck (random results)
43	* https://archive.is/bBikp (just totally broken)
44	* https://archive.is/eJhmu (manpage ETIME)
45	* https://archive.is/RbgYw (implementation ETIME)
46	* http://www.mail-archive.com/networking-discuss@opensolaris.org/msg11898.html ETIME vs. nget
47	* http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/event_port.c (libc)
48	* http://cvs.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/fs/portfs/port.c#1325 (kernel)
49	*/
50
51	#include <sys/types.h>
52	#include <sys/time.h>
53	#include <poll.h>
54	#include <port.h>
55	#include <string.h>
56	#include <errno.h>
57
58	inline_speed
59	void
60	port_associate_and_check (EV_P_ int fd, int ev)
61	{
62	if (0 >
63	port_associate (
64	backend_fd, PORT_SOURCE_FD, fd,
65	(ev & EV_READ ? POLLIN : 0)
66	\| (ev & EV_WRITE ? POLLOUT : 0),
67	0
68	)
69	)
70	{
71	if (errno == EBADFD)
72	{
73	assert (("libev: port_associate found invalid fd", errno != EBADFD));
74	fd_kill (EV_A_ fd);
75	}
76	else
77	ev_syserr ("(libev) port_associate");
78	}
79	}
80
81	static void
82	port_modify (EV_P_ int fd, int oev, int nev)
83	{
84	/* we need to reassociate no matter what, as closes are
85	* once more silently being discarded.
86	*/
87	if (!nev)
88	{
89	if (oev)
90	port_dissociate (backend_fd, PORT_SOURCE_FD, fd);
91	}
92	else
93	port_associate_and_check (EV_A_ fd, nev);
94	}
95
96	static void
97	port_poll (EV_P_ ev_tstamp timeout)
98	{
99	int res, i;
100	struct timespec ts;
101	uint_t nget = 1;
102
103	/* we initialise this to something we will skip in the loop, as */
104	/* port_getn can return with nget unchanged, but no indication */
105	/* whether it was the original value or has been updated :/ */
106	port_events [0].portev_source = 0;
107
108	EV_RELEASE_CB;
109	EV_TS_SET (ts, timeout);
110	res = port_getn (backend_fd, port_events, port_eventmax, &nget, &ts);
111	EV_ACQUIRE_CB;
112
113	/* port_getn may or may not set nget on error */
114	/* so we rely on port_events [0].portev_source not being updated */
115	if (res == -1 && errno != ETIME && errno != EINTR)
116	ev_syserr ("(libev) port_getn (see https://archive.is/jN6Ck, try LIBEV_FLAGS=3 env variable)");
117
118	for (i = 0; i < nget; ++i)
119	{
120	if (port_events [i].portev_source == PORT_SOURCE_FD)
121	{
122	int fd = port_events [i].portev_object;
123
124	fd_event (
125	EV_A_
126	fd,
127	(port_events [i].portev_events & (POLLOUT \| POLLERR \| POLLHUP) ? EV_WRITE : 0)
128	\| (port_events [i].portev_events & (POLLIN \| POLLERR \| POLLHUP) ? EV_READ : 0)
129	);
130
131	fd_change (EV_A_ fd, EV__IOFDSET);
132	}
133	}
134
135	if (ecb_expect_false (nget == port_eventmax))
136	{
137	ev_free (port_events);
138	port_eventmax = array_nextsize (sizeof (port_event_t), port_eventmax, port_eventmax + 1);
139	port_events = (port_event_t )ev_malloc (sizeof (port_event_t) port_eventmax);
140	}
141	}
142
143	inline_size
144	int
145	port_init (EV_P_ int flags)
146	{
147	/* Initialize the kernel queue */
148	if ((backend_fd = port_create ()) < 0)
149	return 0;
150
151	assert (("libev: PORT_SOURCE_FD must not be zero", PORT_SOURCE_FD));
152
153	fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
154
155	/* if my reading of the opensolaris kernel sources are correct, then
156	* opensolaris does something very stupid: it checks if the time has already
157	* elapsed and doesn't round up if that is the case, otherwise it DOES round
158	* up. Since we can't know what the case is, we need to guess by using a
159	* "large enough" timeout. Normally, 1e-9 would be correct.
160	*/
161	backend_mintime = EV_TS_CONST (1e-3); /* needed to compensate for port_getn returning early */
162	backend_modify = port_modify;
163	backend_poll = port_poll;
164
165	port_eventmax = 64; /* initial number of events receivable per poll */
166	port_events = (port_event_t )ev_malloc (sizeof (port_event_t) port_eventmax);
167
168	return EVBACKEND_PORT;
169	}
170
171	inline_size
172	void
173	port_destroy (EV_P)
174	{
175	ev_free (port_events);
176	}
177
178	inline_size
179	void
180	port_fork (EV_P)
181	{
182	close (backend_fd);
183
184	while ((backend_fd = port_create ()) < 0)
185	ev_syserr ("(libev) port");
186
187	fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
188
189	/* re-register interest in fds */
190	fd_rearm_all (EV_A);
191	}
192