ircd-hybrid-7.2/src/s_bsd_sigio.c

/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *  s_bsd_sigio.c: Linux Realtime SIGIO compatible network routines.
 *
 *  Originally by Aaron Sethman <androsyn@ratbox.org>
 *    based upon: s_bsd_poll.c by Adrian Chadd <adrian@creative.net.au>
 *  Copyright (C) 2001-2002 Hybrid Development Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id$
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1           /* Needed for F_SETSIG */
#endif

#include "stdinc.h"
#if USE_IOPOLL_MECHANISM == __IOPOLL_MECHANISM_RTSIGIO
#include <sys/poll.h>
#include "fdlist.h"
#include "hook.h"
#include "ircd.h"
#include "s_bsd.h"
#include "s_log.h"

#define SIGIO_SIGNAL SIGRTMIN

static pid_t my_pid;
static sigset_t our_sigset;
static struct pollfd *pollfds;
static int pollmax = -1;  /* highest FD number */
static dlink_node *fdlim_hook, *setupfd_hook;

/*
 * static void mask_our_signal(int s)
 *
 * Input: None
 * Output: None
 * Side Effects:  Block our signal
 */
static void
mask_our_signal()
{
  sigemptyset(&our_sigset);
  sigaddset(&our_sigset, SIGIO_SIGNAL);
  sigaddset(&our_sigset, SIGIO);
  sigprocmask(SIG_BLOCK, &our_sigset, NULL);
}

/*
 * void setup_sigio_fd(int fd)
 * 
 * Input: File descriptor
 * Output: None
 * Side Effect: Sets the FD up for SIGIO
 */
static void *
setup_sigio_fd(va_list args)
{
  int fd = va_arg(args, int);

  fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_ASYNC);
  fcntl(fd, F_SETSIG, SIGIO_SIGNAL);
  fcntl(fd, F_SETOWN, my_pid);

  return pass_callback(setupfd_hook, fd);
}

/*
 * changing_fdlimit
 *
 * Resize pollfds array if necessary.
 */
static void *
changing_fdlimit(va_list args)
{
  int old_fdlimit = hard_fdlimit;

  pass_callback(fdlim_hook, va_arg(args, int));

  if (hard_fdlimit != old_fdlimit)
    pollfds = MyRealloc(pollfds, sizeof(struct pollfd) * hard_fdlimit);

  return NULL;
}

/*
 * void init_netio(void)
 *
 * Input: None
 * Output: None
 * Side Effects: This is a needed exported function which will 
 *               be called to initialise the network loop code.
 */
void
init_netio(void)
{
  int fd;

  pollfds = MyMalloc(sizeof(struct pollfd) * hard_fdlimit);

  for (fd = 0; fd < hard_fdlimit; fd++)
    pollfds[fd].fd = -1;

  setupfd_hook = install_hook(setup_socket_cb, setup_sigio_fd);
  fdlim_hook = install_hook(fdlimit_cb, changing_fdlimit);

  my_pid = getpid();
  mask_our_signal(SIGIO_SIGNAL);
}

/*
 * find a spare slot in the fd list. We can optimise this out later!
 *   -- adrian
 */
static inline int
poll_findslot(void)
{
  int i;

  for (i = 0; i < hard_fdlimit; i++)
  {
    if (pollfds[i].fd == -1)
    {
      /* MATCH!!#$*&$ */
      return i;
    }
  }

  assert(1 == 0);
  /* NOTREACHED */
  return -1;
}

/*
 * comm_setselect
 *
 * This is a needed exported function which will be called to register
 * and deregister interest in a pending IO state for a given FD.
 */
void
comm_setselect(fde_t *F, unsigned int type, PF *handler,
               void *client_data, time_t timeout)
{
  int new_events;

  if ((type & COMM_SELECT_READ))
  {
    F->read_handler = handler;
    F->read_data = client_data;
  }

  if ((type & COMM_SELECT_WRITE))
  {
    F->write_handler = handler;
    F->write_data = client_data;
  }

  new_events = (F->read_handler ? POLLRDNORM : 0) |
    (F->write_handler ? POLLWRNORM : 0);

  if (timeout != 0)
    F->timeout = CurrentTime + (timeout / 1000);

  if (new_events != F->evcache)
  {
    if (new_events == 0)
    {
      pollfds[F->comm_index].fd = -1;
      pollfds[F->comm_index].revents = 0;

      if (pollmax == F->comm_index)
        while (pollmax >= 0 && pollfds[pollmax].fd == -1)
          pollmax--;
    }
    else
    {
      if (F->evcache == 0)
      {
        F->comm_index = poll_findslot();
        if (F->comm_index > pollmax)
          pollmax = F->comm_index;

        pollfds[F->comm_index].fd = F->fd;
      }
      pollfds[F->comm_index].events = new_events;
      pollfds[F->comm_index].revents = 0;
    }

    F->evcache = new_events;
  }
}

/*
 * comm_select
 *
 * Called to do the new-style IO, courtesy of squid (like most of this
 * new IO code). This routine handles the stuff we've hidden in
 * comm_setselect and fd_table[] and calls callbacks for IO ready
 * events.
 */
void
comm_select(void)
{
  static time_t last_rtsigqo_warning = 0;
  struct timespec timeout;
  struct siginfo si;
  int i, revents, num;
  fde_t *F;
  PF *hdl;

  timeout.tv_sec = 0;
  timeout.tv_nsec = 1000000 * SELECT_DELAY;
  i = sigtimedwait(&our_sigset, &si, &timeout);

  set_time();

  if (i != SIGIO)
  {
    if (i > 0)
    {
      F = lookup_fd(si.si_fd);
      if (F == NULL || !F->flags.open)
        return;

      if (si.si_band & (POLLRDNORM | POLLIN | POLLHUP | POLLERR))
        if ((hdl = F->read_handler) != NULL)
        {
          F->read_handler = NULL;
          hdl(F, F->read_data);
          if (!F->flags.open)
            return;
        }

      if (si.si_band & (POLLWRNORM | POLLOUT | POLLHUP | POLLERR))
        if ((hdl = F->write_handler) != NULL)
        {
          F->write_handler = NULL;
          hdl(F, F->write_data);
          if (!F->flags.open)
            return;
        }

      comm_setselect(F, 0, NULL, NULL, 0);
    }

    return;
  }

  /* RT signal queue overflowed.. */

  if (CurrentTime - last_rtsigqo_warning >= 30)
  {
    ilog(L_WARN, "Kernel RT Signal queue overflowed.  "
                 "Is /proc/sys/kernel/rtsig-max too small?");
    last_rtsigqo_warning = CurrentTime;
  }

  signal(SIGIO_SIGNAL, SIG_IGN);
  signal(SIGIO_SIGNAL, SIG_DFL);

  /* ..try polling instead */

  while ((num = poll(pollfds, pollmax + 1, 0)) < 0 && ignoreErrno(errno))
    ;

  /* update current time again, eww.. */
  set_time();

  for (i = 0; i <= pollmax && num > 0; i++)
  {
    if ((revents = pollfds[i].revents) == 0 || pollfds[i].fd == -1)
      continue;
    num--;

    F = lookup_fd(pollfds[i].fd);
    if (F == NULL || !F->flags.open)
      continue;

    if (revents & (POLLRDNORM | POLLIN | POLLHUP | POLLERR))
      if ((hdl = F->read_handler) != NULL)
      {
        F->read_handler = NULL;
        hdl(F, F->read_data);
        if (!F->flags.open)
          continue;
      }

    if (revents & (POLLWRNORM | POLLOUT | POLLHUP | POLLERR))
      if ((hdl = F->write_handler) != NULL)
      {
        F->write_handler = NULL;
        hdl(F, F->write_data);
        if (!F->flags.open)
          continue;
      }

    comm_setselect(F, 0, NULL, NULL, 0);
  }

  mask_our_signal(SIGIO_SIGNAL);
}
#endif
1	/*
2	* ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3	* s_bsd_sigio.c: Linux Realtime SIGIO compatible network routines.
4	*
5	* Originally by Aaron Sethman <androsyn@ratbox.org>
6	* based upon: s_bsd_poll.c by Adrian Chadd <adrian@creative.net.au>
7	* Copyright (C) 2001-2002 Hybrid Development Team
8	*
9	* This program is free software; you can redistribute it and/or modify
10	* it under the terms of the GNU General Public License as published by
11	* the Free Software Foundation; either version 2 of the License, or
12	* (at your option) any later version.
13	*
14	* This program is distributed in the hope that it will be useful,
15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17	* GNU General Public License for more details.
18	*
19	* You should have received a copy of the GNU General Public License
20	* along with this program; if not, write to the Free Software
21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
22	* USA
23	*
24	* $Id$
25	*/
26
27	#ifndef _GNU_SOURCE
28	#define _GNU_SOURCE 1 /* Needed for F_SETSIG */
29	#endif
30
31	#include "stdinc.h"
32	#if USE_IOPOLL_MECHANISM == __IOPOLL_MECHANISM_RTSIGIO
33	#include <sys/poll.h>
34	#include "fdlist.h"
35	#include "hook.h"
36	#include "ircd.h"
37	#include "s_bsd.h"
38	#include "s_log.h"
39
40	#define SIGIO_SIGNAL SIGRTMIN
41
42	static pid_t my_pid;
43	static sigset_t our_sigset;
44	static struct pollfd *pollfds;
45	static int pollmax = -1; /* highest FD number */
46	static dlink_node fdlim_hook, setupfd_hook;
47
48	/*
49	* static void mask_our_signal(int s)
50	*
51	* Input: None
52	* Output: None
53	* Side Effects: Block our signal
54	*/
55	static void
56	mask_our_signal()
57	{
58	sigemptyset(&our_sigset);
59	sigaddset(&our_sigset, SIGIO_SIGNAL);
60	sigaddset(&our_sigset, SIGIO);
61	sigprocmask(SIG_BLOCK, &our_sigset, NULL);
62	}
63
64	/*
65	* void setup_sigio_fd(int fd)
66	*
67	* Input: File descriptor
68	* Output: None
69	* Side Effect: Sets the FD up for SIGIO
70	*/
71	static void *
72	setup_sigio_fd(va_list args)
73	{
74	int fd = va_arg(args, int);
75
76	fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) \| O_ASYNC);
77	fcntl(fd, F_SETSIG, SIGIO_SIGNAL);
78	fcntl(fd, F_SETOWN, my_pid);
79
80	return pass_callback(setupfd_hook, fd);
81	}
82
83	/*
84	* changing_fdlimit
85	*
86	* Resize pollfds array if necessary.
87	*/
88	static void *
89	changing_fdlimit(va_list args)
90	{
91	int old_fdlimit = hard_fdlimit;
92
93	pass_callback(fdlim_hook, va_arg(args, int));
94
95	if (hard_fdlimit != old_fdlimit)
96	pollfds = MyRealloc(pollfds, sizeof(struct pollfd) * hard_fdlimit);
97
98	return NULL;
99	}
100
101	/*
102	* void init_netio(void)
103	*
104	* Input: None
105	* Output: None
106	* Side Effects: This is a needed exported function which will
107	* be called to initialise the network loop code.
108	*/
109	void
110	init_netio(void)
111	{
112	int fd;
113
114	pollfds = MyMalloc(sizeof(struct pollfd) * hard_fdlimit);
115
116	for (fd = 0; fd < hard_fdlimit; fd++)
117	pollfds[fd].fd = -1;
118
119	setupfd_hook = install_hook(setup_socket_cb, setup_sigio_fd);
120	fdlim_hook = install_hook(fdlimit_cb, changing_fdlimit);
121
122	my_pid = getpid();
123	mask_our_signal(SIGIO_SIGNAL);
124	}
125
126	/*
127	* find a spare slot in the fd list. We can optimise this out later!
128	* -- adrian
129	*/
130	static inline int
131	poll_findslot(void)
132	{
133	int i;
134
135	for (i = 0; i < hard_fdlimit; i++)
136	{
137	if (pollfds[i].fd == -1)
138	{
139	/* MATCH!!#$&$ /
140	return i;
141	}
142	}
143
144	assert(1 == 0);
145	/* NOTREACHED */
146	return -1;
147	}
148
149	/*
150	* comm_setselect
151	*
152	* This is a needed exported function which will be called to register
153	* and deregister interest in a pending IO state for a given FD.
154	*/
155	void
156	comm_setselect(fde_t F, unsigned int type, PF handler,
157	void *client_data, time_t timeout)
158	{
159	int new_events;
160
161	if ((type & COMM_SELECT_READ))
162	{
163	F->read_handler = handler;
164	F->read_data = client_data;
165	}
166
167	if ((type & COMM_SELECT_WRITE))
168	{
169	F->write_handler = handler;
170	F->write_data = client_data;
171	}
172
173	new_events = (F->read_handler ? POLLRDNORM : 0) \|
174	(F->write_handler ? POLLWRNORM : 0);
175
176	if (timeout != 0)
177	F->timeout = CurrentTime + (timeout / 1000);
178
179	if (new_events != F->evcache)
180	{
181	if (new_events == 0)
182	{
183	pollfds[F->comm_index].fd = -1;
184	pollfds[F->comm_index].revents = 0;
185
186	if (pollmax == F->comm_index)
187	while (pollmax >= 0 && pollfds[pollmax].fd == -1)
188	pollmax--;
189	}
190	else
191	{
192	if (F->evcache == 0)
193	{
194	F->comm_index = poll_findslot();
195	if (F->comm_index > pollmax)
196	pollmax = F->comm_index;
197
198	pollfds[F->comm_index].fd = F->fd;
199	}
200	pollfds[F->comm_index].events = new_events;
201	pollfds[F->comm_index].revents = 0;
202	}
203
204	F->evcache = new_events;
205	}
206	}
207
208	/*
209	* comm_select
210	*
211	* Called to do the new-style IO, courtesy of squid (like most of this
212	* new IO code). This routine handles the stuff we've hidden in
213	* comm_setselect and fd_table[] and calls callbacks for IO ready
214	* events.
215	*/
216	void
217	comm_select(void)
218	{
219	static time_t last_rtsigqo_warning = 0;
220	struct timespec timeout;
221	struct siginfo si;
222	int i, revents, num;
223	fde_t *F;
224	PF *hdl;
225
226	timeout.tv_sec = 0;
227	timeout.tv_nsec = 1000000 * SELECT_DELAY;
228	i = sigtimedwait(&our_sigset, &si, &timeout);
229
230	set_time();
231
232	if (i != SIGIO)
233	{
234	if (i > 0)
235	{
236	F = lookup_fd(si.si_fd);
237	if (F == NULL \|\| !F->flags.open)
238	return;
239
240	if (si.si_band & (POLLRDNORM \| POLLIN \| POLLHUP \| POLLERR))
241	if ((hdl = F->read_handler) != NULL)
242	{
243	F->read_handler = NULL;
244	hdl(F, F->read_data);
245	if (!F->flags.open)
246	return;
247	}
248
249	if (si.si_band & (POLLWRNORM \| POLLOUT \| POLLHUP \| POLLERR))
250	if ((hdl = F->write_handler) != NULL)
251	{
252	F->write_handler = NULL;
253	hdl(F, F->write_data);
254	if (!F->flags.open)
255	return;
256	}
257
258	comm_setselect(F, 0, NULL, NULL, 0);
259	}
260
261	return;
262	}
263
264	/* RT signal queue overflowed.. */
265
266	if (CurrentTime - last_rtsigqo_warning >= 30)
267	{
268	ilog(L_WARN, "Kernel RT Signal queue overflowed. "
269	"Is /proc/sys/kernel/rtsig-max too small?");
270	last_rtsigqo_warning = CurrentTime;
271	}
272
273	signal(SIGIO_SIGNAL, SIG_IGN);
274	signal(SIGIO_SIGNAL, SIG_DFL);
275
276	/* ..try polling instead */
277
278	while ((num = poll(pollfds, pollmax + 1, 0)) < 0 && ignoreErrno(errno))
279	;
280
281	/* update current time again, eww.. */
282	set_time();
283
284	for (i = 0; i <= pollmax && num > 0; i++)
285	{
286	if ((revents = pollfds[i].revents) == 0 \|\| pollfds[i].fd == -1)
287	continue;
288	num--;
289
290	F = lookup_fd(pollfds[i].fd);
291	if (F == NULL \|\| !F->flags.open)
292	continue;
293
294	if (revents & (POLLRDNORM \| POLLIN \| POLLHUP \| POLLERR))
295	if ((hdl = F->read_handler) != NULL)
296	{
297	F->read_handler = NULL;
298	hdl(F, F->read_data);
299	if (!F->flags.open)
300	continue;
301	}
302
303	if (revents & (POLLWRNORM \| POLLOUT \| POLLHUP \| POLLERR))
304	if ((hdl = F->write_handler) != NULL)
305	{
306	F->write_handler = NULL;
307	hdl(F, F->write_data);
308	if (!F->flags.open)
309	continue;
310	}
311
312	comm_setselect(F, 0, NULL, NULL, 0);
313	}
314
315	mask_our_signal(SIGIO_SIGNAL);
316	}
317	#endif
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