trunk/src/s_bsd_epoll.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 2005-2021 ircd-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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

/*! \file s_bsd_epoll.c
 * \brief Linux epoll() compatible network routines.
 * \version $Id$
 */

#include "stdinc.h"
#if USE_IOPOLL_MECHANISM == __IOPOLL_MECHANISM_EPOLL
#include "fdlist.h"
#include "ircd.h"
#include "s_bsd.h"
#include "log.h"
#include "memory.h"
#include <sys/epoll.h>

enum
{
  INITIAL_NEVENT =   16,
  MAXIMUM_NEVENT = 4096
};

struct epollop
{
  struct epoll_event *events;
  int nevents;
  int fd;
};

static struct epollop *epollop;


/*
 * comm_select_init
 *
 * This is a needed exported function which will be called to initialise
 * the network loop code.
 */
void
comm_select_init(void)
{
  int fd = epoll_create1(EPOLL_CLOEXEC);
  if (fd < 0)
  {
    ilog(LOG_TYPE_IRCD, "comm_select_init: couldn't open epoll fd: %s",
         strerror(errno));
    exit(EXIT_FAILURE); /* Whee! */
  }

  fd_open(fd, false, "epoll file descriptor");

  epollop = xcalloc(sizeof(*epollop));
  epollop->fd = fd;
  epollop->nevents = INITIAL_NEVENT;
  epollop->events = xcalloc(epollop->nevents * sizeof(*epollop->events));
}

/*
 * 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, void (*handler)(fde_t *, void *),
               void *client_data, uintmax_t timeout)
{
  int new_events, op;
  struct epoll_event ep_event;

  assert(F);
  assert(F->flags.open == true);

  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 ? EPOLLIN : 0) |
    (F->write_handler ? EPOLLOUT : 0);

  if (timeout)
  {
    F->timeout = event_base->time.sec_monotonic + timeout;
    F->timeout_handler = handler;
    F->timeout_data = client_data;
  }

  if (new_events != F->evcache)
  {
    if (new_events == 0)
      op = EPOLL_CTL_DEL;
    else if (F->evcache == 0)
      op = EPOLL_CTL_ADD;
    else
      op = EPOLL_CTL_MOD;

    memset(&ep_event, 0, sizeof(ep_event));
    ep_event.events = F->evcache = new_events;
    ep_event.data.ptr = F;

    if (epoll_ctl(epollop->fd, op, F->fd, &ep_event))
    {
      ilog(LOG_TYPE_IRCD, "comm_setselect: epoll_ctl() failed: %s", strerror(errno));
      abort();
    }
  }
}

/*
 * comm_select()
 *
 * Called to do the new-style IO, courtesy of 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)
{
  int num;
  void (*hdl)(fde_t *, void *);

  num = epoll_wait(epollop->fd, epollop->events, epollop->nevents, SELECT_DELAY);
  assert(num <= epollop->nevents);

  event_time_set();

  if (num < 0)
  {
    const struct timespec req = { .tv_sec = 0, .tv_nsec = 50000000 };
    nanosleep(&req, NULL);  /* Avoid 99% CPU in comm_select */
    return;
  }

  for (int i = 0; i < num; ++i)
  {
    fde_t *F = epollop->events[i].data.ptr;

    if (F->flags.open == false)
      continue;

    if ((epollop->events[i].events & (EPOLLIN | EPOLLHUP | EPOLLERR)))
    {
      if ((hdl = F->read_handler))
      {
        F->read_handler = NULL;
        hdl(F, F->read_data);

        if (F->flags.open == false)
          continue;
      }
    }

    if ((epollop->events[i].events & (EPOLLOUT | EPOLLHUP | EPOLLERR)))
    {
      if ((hdl = F->write_handler))
      {
        F->write_handler = NULL;
        hdl(F, F->write_data);

        if (F->flags.open == false)
          continue;
      }
    }

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

  if (num == epollop->nevents && epollop->nevents < MAXIMUM_NEVENT)
  {
    /*
     * We used all of the event space this time. We should be
     * ready for more events next time.
     */
    int new_nevents = epollop->nevents * 2;
    struct epoll_event *new_events = xrealloc(epollop->events, new_nevents * sizeof(*epollop->events));

    epollop->events = new_events;
    epollop->nevents = new_nevents;
  }
}
#endif
1	adx	30	/*
2	michael	2916	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	adx	30	*
4	michael	9857	* Copyright (c) 2005-2021 ircd-hybrid development team
5	adx	30	*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18	michael	4565	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	adx	30	* USA
20			*/
21
22	michael	2916	/*! \file s_bsd_epoll.c
23			* \brief Linux epoll() compatible network routines.
24			* \version $Id$
25			*/
26
27	adx	30	#include "stdinc.h"
28	stu	908	#if USE_IOPOLL_MECHANISM == __IOPOLL_MECHANISM_EPOLL
29	adx	30	#include "fdlist.h"
30			#include "ircd.h"
31			#include "s_bsd.h"
32	michael	1309	#include "log.h"
33	michael	8533	#include "memory.h"
34	adx	30	#include <sys/epoll.h>
35
36	michael	8533	enum
37			{
38			INITIAL_NEVENT = 16,
39			MAXIMUM_NEVENT = 4096
40			};
41	adx	30
42	michael	8533	struct epollop
43			{
44			struct epoll_event *events;
45			int nevents;
46			int fd;
47			};
48	adx	30
49	michael	8533	static struct epollop *epollop;
50
51
52	adx	30	/*
53	michael	8414	* comm_select_init
54	adx	30	*
55			* This is a needed exported function which will be called to initialise
56			* the network loop code.
57			*/
58			void
59	michael	8414	comm_select_init(void)
60	adx	30	{
61	michael	8533	int fd = epoll_create1(EPOLL_CLOEXEC);
62			if (fd < 0)
63	adx	30	{
64	michael	8414	ilog(LOG_TYPE_IRCD, "comm_select_init: couldn't open epoll fd: %s",
65	michael	6560	strerror(errno));
66	michael	6553	exit(EXIT_FAILURE); /* Whee! */
67	adx	30	}
68
69	michael	8658	fd_open(fd, false, "epoll file descriptor");
70	michael	8533
71			epollop = xcalloc(sizeof(*epollop));
72			epollop->fd = fd;
73			epollop->nevents = INITIAL_NEVENT;
74			epollop->events = xcalloc(epollop->nevents * sizeof(*epollop->events));
75	adx	30	}
76
77			/*
78			* comm_setselect
79			*
80			* This is a needed exported function which will be called to register
81			* and deregister interest in a pending IO state for a given FD.
82			*/
83			void
84	michael	4461	comm_setselect(fde_t F, unsigned int type, void (handler)(fde_t , void ),
85	michael	7330	void *client_data, uintmax_t timeout)
86	adx	30	{
87			int new_events, op;
88	michael	8529	struct epoll_event ep_event;
89	adx	30
90	michael	8717	assert(F);
91	michael	8658	assert(F->flags.open == true);
92	michael	8466
93	adx	30	if ((type & COMM_SELECT_READ))
94			{
95			F->read_handler = handler;
96			F->read_data = client_data;
97			}
98
99			if ((type & COMM_SELECT_WRITE))
100			{
101			F->write_handler = handler;
102			F->write_data = client_data;
103			}
104
105			new_events = (F->read_handler ? EPOLLIN : 0) \|
106			(F->write_handler ? EPOLLOUT : 0);
107
108	michael	8431	if (timeout)
109	michael	2725	{
110	michael	8941	F->timeout = event_base->time.sec_monotonic + timeout;
111	michael	2725	F->timeout_handler = handler;
112			F->timeout_data = client_data;
113			}
114	adx	30
115			if (new_events != F->evcache)
116			{
117			if (new_events == 0)
118			op = EPOLL_CTL_DEL;
119			else if (F->evcache == 0)
120			op = EPOLL_CTL_ADD;
121			else
122			op = EPOLL_CTL_MOD;
123
124	michael	8529	memset(&ep_event, 0, sizeof(ep_event));
125	adx	30	ep_event.events = F->evcache = new_events;
126	michael	8383	ep_event.data.ptr = F;
127	adx	30
128	michael	8533	if (epoll_ctl(epollop->fd, op, F->fd, &ep_event))
129	adx	30	{
130	michael	1247	ilog(LOG_TYPE_IRCD, "comm_setselect: epoll_ctl() failed: %s", strerror(errno));
131	adx	30	abort();
132			}
133			}
134			}
135
136			/*
137			* comm_select()
138			*
139			* Called to do the new-style IO, courtesy of of squid (like most of this
140			* new IO code). This routine handles the stuff we've hidden in
141			* comm_setselect and fd_table[] and calls callbacks for IO ready
142			* events.
143			*/
144			void
145			comm_select(void)
146			{
147	michael	8431	int num;
148	michael	4461	void (hdl)(fde_t , void *);
149	adx	30
150	michael	8533	num = epoll_wait(epollop->fd, epollop->events, epollop->nevents, SELECT_DELAY);
151			assert(num <= epollop->nevents);
152	adx	30
153	michael	8900	event_time_set();
154	adx	30
155			if (num < 0)
156			{
157	michael	6542	const struct timespec req = { .tv_sec = 0, .tv_nsec = 50000000 };
158			nanosleep(&req, NULL); /* Avoid 99% CPU in comm_select */
159	adx	30	return;
160			}
161
162	michael	8431	for (int i = 0; i < num; ++i)
163	adx	30	{
164	michael	8533	fde_t *F = epollop->events[i].data.ptr;
165	michael	8339
166	michael	8658	if (F->flags.open == false)
167	adx	30	continue;
168
169	michael	8533	if ((epollop->events[i].events & (EPOLLIN \| EPOLLHUP \| EPOLLERR)))
170	michael	2650	{
171	michael	5902	if ((hdl = F->read_handler))
172	adx	30	{
173			F->read_handler = NULL;
174			hdl(F, F->read_data);
175	michael	8339
176	michael	8658	if (F->flags.open == false)
177	michael	2650	continue;
178	adx	30	}
179	michael	2650	}
180	adx	30
181	michael	8533	if ((epollop->events[i].events & (EPOLLOUT \| EPOLLHUP \| EPOLLERR)))
182	michael	2650	{
183	michael	5902	if ((hdl = F->write_handler))
184	adx	30	{
185			F->write_handler = NULL;
186			hdl(F, F->write_data);
187	michael	8339
188	michael	8658	if (F->flags.open == false)
189	michael	2650	continue;
190	adx	30	}
191	michael	2650	}
192	adx	30
193			comm_setselect(F, 0, NULL, NULL, 0);
194			}
195	michael	8533
196			if (num == epollop->nevents && epollop->nevents < MAXIMUM_NEVENT)
197			{
198			/*
199			* We used all of the event space this time. We should be
200			* ready for more events next time.
201			*/
202			int new_nevents = epollop->nevents * 2;
203			struct epoll_event new_events = xrealloc(epollop->events, new_nevents sizeof(*epollop->events));
204
205			epollop->events = new_events;
206			epollop->nevents = new_nevents;
207			}
208	adx	30	}
209	stu	908	#endif
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