8.2.x/src/s_bsd_epoll.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 2005-2018 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->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 = CurrentTime + (timeout / 1000);
    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);

  set_time();

  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
Revision:	8657
Committed:	Mon Nov 12 19:02:38 2018 UTC (5 years, 5 months ago) by michael
Content type:	text/x-csrc
File size:	4945 byte(s)
Log Message:	- Make use of the bool data type in some more places
#	User	Rev	Content
1	adx	30	/*
2	michael	2916	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	adx	30	*
4	michael	8280	* Copyright (c) 2005-2018 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	4564	* 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	8534	#include "memory.h"
34	adx	30	#include <sys/epoll.h>
35
36	michael	8534	enum
37			{
38			INITIAL_NEVENT = 16,
39			MAXIMUM_NEVENT = 4096
40			};
41	adx	30
42	michael	8534	struct epollop
43			{
44			struct epoll_event *events;
45			int nevents;
46			int fd;
47			};
48	adx	30
49	michael	8534	static struct epollop *epollop;
50
51
52	adx	30	/*
53	michael	8413	* 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	8413	comm_select_init(void)
60	adx	30	{
61	michael	8534	int fd = epoll_create1(EPOLL_CLOEXEC);
62			if (fd < 0)
63	adx	30	{
64	michael	8413	ilog(LOG_TYPE_IRCD, "comm_select_init: couldn't open epoll fd: %s",
65	michael	6559	strerror(errno));
66	michael	6554	exit(EXIT_FAILURE); /* Whee! */
67	adx	30	}
68
69	michael	8657	fd_open(fd, false, "epoll file descriptor");
70	michael	8534
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	4462	comm_setselect(fde_t F, unsigned int type, void (handler)(fde_t , void ),
85	michael	7329	void *client_data, uintmax_t timeout)
86	adx	30	{
87			int new_events, op;
88	michael	8530	struct epoll_event ep_event;
89	adx	30
90	michael	8657	assert(F->flags.open == true);
91	michael	8465
92	adx	30	if ((type & COMM_SELECT_READ))
93			{
94			F->read_handler = handler;
95			F->read_data = client_data;
96			}
97
98			if ((type & COMM_SELECT_WRITE))
99			{
100			F->write_handler = handler;
101			F->write_data = client_data;
102			}
103
104			new_events = (F->read_handler ? EPOLLIN : 0) \|
105			(F->write_handler ? EPOLLOUT : 0);
106
107	michael	8430	if (timeout)
108	michael	2725	{
109	adx	30	F->timeout = CurrentTime + (timeout / 1000);
110	michael	2725	F->timeout_handler = handler;
111			F->timeout_data = client_data;
112			}
113	adx	30
114			if (new_events != F->evcache)
115			{
116			if (new_events == 0)
117			op = EPOLL_CTL_DEL;
118			else if (F->evcache == 0)
119			op = EPOLL_CTL_ADD;
120			else
121			op = EPOLL_CTL_MOD;
122
123	michael	8530	memset(&ep_event, 0, sizeof(ep_event));
124	adx	30	ep_event.events = F->evcache = new_events;
125	michael	8382	ep_event.data.ptr = F;
126	adx	30
127	michael	8534	if (epoll_ctl(epollop->fd, op, F->fd, &ep_event))
128	adx	30	{
129	michael	1247	ilog(LOG_TYPE_IRCD, "comm_setselect: epoll_ctl() failed: %s", strerror(errno));
130	adx	30	abort();
131			}
132			}
133			}
134
135			/*
136			* comm_select()
137			*
138			* Called to do the new-style IO, courtesy of of squid (like most of this
139			* new IO code). This routine handles the stuff we've hidden in
140			* comm_setselect and fd_table[] and calls callbacks for IO ready
141			* events.
142			*/
143			void
144			comm_select(void)
145			{
146	michael	8430	int num;
147	michael	4462	void (hdl)(fde_t , void *);
148	adx	30
149	michael	8534	num = epoll_wait(epollop->fd, epollop->events, epollop->nevents, SELECT_DELAY);
150			assert(num <= epollop->nevents);
151	adx	30
152			set_time();
153
154			if (num < 0)
155			{
156	michael	6541	const struct timespec req = { .tv_sec = 0, .tv_nsec = 50000000 };
157			nanosleep(&req, NULL); /* Avoid 99% CPU in comm_select */
158	adx	30	return;
159			}
160
161	michael	8430	for (int i = 0; i < num; ++i)
162	adx	30	{
163	michael	8534	fde_t *F = epollop->events[i].data.ptr;
164	michael	8338
165	michael	8657	if (F->flags.open == false)
166	adx	30	continue;
167
168	michael	8534	if ((epollop->events[i].events & (EPOLLIN \| EPOLLHUP \| EPOLLERR)))
169	michael	2650	{
170	michael	5901	if ((hdl = F->read_handler))
171	adx	30	{
172			F->read_handler = NULL;
173			hdl(F, F->read_data);
174	michael	8338
175	michael	8657	if (F->flags.open == false)
176	michael	2650	continue;
177	adx	30	}
178	michael	2650	}
179	adx	30
180	michael	8534	if ((epollop->events[i].events & (EPOLLOUT \| EPOLLHUP \| EPOLLERR)))
181	michael	2650	{
182	michael	5901	if ((hdl = F->write_handler))
183	adx	30	{
184			F->write_handler = NULL;
185			hdl(F, F->write_data);
186	michael	8338
187	michael	8657	if (F->flags.open == false)
188	michael	2650	continue;
189	adx	30	}
190	michael	2650	}
191	adx	30
192			comm_setselect(F, 0, NULL, NULL, 0);
193			}
194	michael	8534
195			if (num == epollop->nevents && epollop->nevents < MAXIMUM_NEVENT)
196			{
197			/*
198			* We used all of the event space this time. We should be
199			* ready for more events next time.
200			*/
201			int new_nevents = epollop->nevents * 2;
202			struct epoll_event new_events = xrealloc(epollop->events, new_nevents sizeof(*epollop->events));
203
204			epollop->events = new_events;
205			epollop->nevents = new_nevents;
206			}
207	adx	30	}
208	stu	908	#endif