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ngircd-tor/src/ngircd/io.c

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/*
* 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.
* Please read the file COPYING, README and AUTHORS for more information.
*
* I/O abstraction interface.
* Copyright (c) 2005 Florian Westphal (westphal@foo.fh-furtwangen.de)
*
*/
#include "portab.h"
static char UNUSED id[] = "$Id: io.c,v 1.11 2005/09/04 13:38:59 fw Exp $";
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include "array.h"
#include "io.h"
#include "log.h"
typedef struct {
void (*callback)(int, short);
int fd;
short what;
} io_event;
#define INIT_IOEVENT { NULL, -1, 0, NULL }
#define IO_ERROR 4
#ifdef HAVE_EPOLL_CREATE
#define IO_USE_EPOLL 1
#else
# ifdef HAVE_KQUEUE
#define IO_USE_KQUEUE 1
# else
#define IO_USE_SELECT 1
#endif
#endif
static bool library_initialized;
#ifdef IO_USE_EPOLL
#include <sys/epoll.h>
static int io_masterfd;
static bool io_event_new_epoll(int fd, short what);
static bool io_event_change_epoll(int fd, short what);
static int io_dispatch_epoll(struct timeval *tv);
#endif
#ifdef IO_USE_KQUEUE
#include <sys/types.h>
#include <sys/event.h>
static array io_evcache;
static int io_masterfd;
static int io_dispatch_kqueue(struct timeval *tv);
static bool io_event_add_kqueue(int, short);
#endif
#ifdef IO_USE_SELECT
#include "defines.h" /* for conn.h */
#include "conn.h" /* for CONN_IDX (needed by resolve.h) */
#include "resolve.h" /* for RES_STAT (needed by conf.h) */
#include "conf.h" /* for Conf_MaxConnections */
static fd_set readers;
static fd_set writers;
static int select_maxfd; /* the select() interface sucks badly */
static int io_dispatch_select(struct timeval *tv);
#endif
static array io_events;
static void io_docallback PARAMS((int fd, short what));
static io_event *
io_event_get(int fd)
{
io_event *i;
assert(fd >= 0);
i = (io_event *) array_get(&io_events, sizeof(io_event), fd);
assert(i);
return i;
}
bool
io_library_init(unsigned int eventsize)
{
bool ret;
#ifdef IO_USE_EPOLL
int ecreate_hint = (int)eventsize;
if (ecreate_hint <= 0)
ecreate_hint = 128;
#endif
if (library_initialized)
return true;
#ifdef IO_USE_SELECT
#ifdef FD_SETSIZE
if (eventsize >= FD_SETSIZE)
eventsize = FD_SETSIZE - 1;
#endif
#endif
if (eventsize && !array_alloc(&io_events, sizeof(io_event), eventsize))
eventsize = 0;
#ifdef IO_USE_EPOLL
io_masterfd = epoll_create(ecreate_hint);
Log(LOG_INFO,
"IO subsystem: epoll (hint size %d, initial maxfd %u, masterfd %d).",
ecreate_hint, eventsize, io_masterfd);
ret = io_masterfd >= 0;
if (ret) library_initialized = true;
return ret;
#endif
#ifdef IO_USE_SELECT
Log(LOG_INFO, "IO subsystem: select (initial maxfd %u).",
eventsize);
FD_ZERO(&readers);
FD_ZERO(&writers);
#ifdef FD_SETSIZE
if (Conf_MaxConnections >= FD_SETSIZE) {
Log(LOG_WARNING,
"MaxConnections (%d) exceeds limit (%u), changed MaxConnections to %u.",
Conf_MaxConnections, FD_SETSIZE, FD_SETSIZE - 1);
Conf_MaxConnections = FD_SETSIZE - 1;
}
#else
Log(LOG_WARNING,
"FD_SETSIZE undefined, don't know how many descriptors select() can handle on your platform ...");
#endif /* FD_SETSIZE */
library_initialized = true;
return true;
#endif /* SELECT */
#ifdef IO_USE_KQUEUE
io_masterfd = kqueue();
Log(LOG_INFO,
"IO subsystem: kqueue (initial maxfd %u, masterfd %d)",
eventsize, io_masterfd);
ret = io_masterfd >= 0;
if (ret) library_initialized = true;
return ret;
#endif
}
void
io_library_shutdown(void)
{
#ifdef IO_USE_SELECT
FD_ZERO(&readers);
FD_ZERO(&writers);
#else
close(io_masterfd); /* kqueue, epoll */
io_masterfd = -1;
#endif
#ifdef IO_USE_KQUEUE
array_free(&io_evcache);
#endif
library_initialized = false;
}
bool
io_event_setcb(int fd, void (*cbfunc) (int, short))
{
io_event *i = io_event_get(fd);
if (!i)
return false;
i->callback = cbfunc;
return true;
}
bool
io_event_create(int fd, short what, void (*cbfunc) (int, short))
{
io_event *i;
assert(fd >= 0);
#ifdef IO_USE_SELECT
#ifdef FD_SETSIZE
if (fd >= FD_SETSIZE) {
Log(LOG_ERR,
"fd %d exceeds FD_SETSIZE (%u) (select can't handle more file descriptors)",
fd, FD_SETSIZE);
return false;
}
#endif /* FD_SETSIZE */
#endif /* IO_USE_SELECT */
i = (io_event *) array_alloc(&io_events, sizeof(io_event), fd);
if (!i) {
Log(LOG_WARNING,
"array_alloc failed: could not allocate space for %d io_event structures",
fd);
return false;
}
i->fd = fd;
i->callback = cbfunc;
#ifdef IO_USE_EPOLL
i->what = what;
return io_event_new_epoll(fd, what);
#endif
#ifdef IO_USE_KQUEUE
i->what = what;
return io_event_add_kqueue(fd, what);
#endif
#ifdef IO_USE_SELECT
i->what = 0;
return io_event_add(fd, what);
#endif
}
#ifdef IO_USE_EPOLL
static bool
io_event_new_epoll(int fd, short what)
{
struct epoll_event ev = { 0, {0} };
ev.data.fd = fd;
if (what & IO_WANTREAD)
ev.events = EPOLLIN | EPOLLPRI;
if (what & IO_WANTWRITE)
ev.events |= EPOLLOUT;
return epoll_ctl(io_masterfd, EPOLL_CTL_ADD, fd, &ev) == 0;
}
static bool
io_event_change_epoll(int fd, short what)
{
struct epoll_event ev = { 0, {0} };
ev.data.fd = fd;
if (what & IO_WANTREAD)
ev.events = EPOLLIN | EPOLLPRI;
if (what & IO_WANTWRITE)
ev.events |= EPOLLOUT;
return epoll_ctl(io_masterfd, EPOLL_CTL_MOD, fd, &ev) == 0;
}
#endif
#ifdef IO_USE_KQUEUE
static bool
io_event_kqueue_commit_cache(void)
{
struct kevent *events;
bool ret;
int len = (int) array_length(&io_evcache, sizeof (struct kevent));
if (!len) /* nothing to do */
return true;
assert(len>0);
if (len < 0) {
array_free(&io_evcache);
return false;
}
events = array_start(&io_evcache);
assert(events);
ret = kevent(io_masterfd, events, len, NULL, 0, NULL) == 0;
if (ret)
array_trunc(&io_evcache);
return ret;
}
static bool
io_event_add_kqueue(int fd, short what)
{
struct kevent kev;
short filter = 0;
size_t len = array_length(&io_evcache, sizeof kev);
if (what & IO_WANTREAD)
filter = EVFILT_READ;
if (what & IO_WANTWRITE)
filter |= EVFILT_WRITE;
if (len >= 100) {
(void)io_event_kqueue_commit_cache();
}
EV_SET(&kev, fd, filter, EV_ADD | EV_ENABLE, 0, 0, NULL);
return array_catb(&io_evcache, (char*) &kev, sizeof (kev));
}
#endif
bool
io_event_add(int fd, short what)
{
io_event *i = io_event_get(fd);
assert(i);
if (!i)
return false;
if (i->what == what)
return true;
#ifdef DEBUG
Log(LOG_DEBUG, "io_event_add(): fd %d (arg: %d), what %d.", i->fd, fd, what);
#endif
i->what |= what;
#ifdef IO_USE_EPOLL
return io_event_change_epoll(fd, i->what);
#endif
#ifdef IO_USE_KQUEUE
return io_event_add_kqueue(fd, what);
#endif
#ifdef IO_USE_SELECT
if (fd > select_maxfd)
select_maxfd = fd;
if (what & IO_WANTREAD)
FD_SET(fd, &readers);
if (what & IO_WANTWRITE)
FD_SET(fd, &writers);
return true;
#endif
}
bool
io_setnonblock(int fd)
{
int flags = fcntl(fd, F_GETFL);
if (flags == -1)
return false;
#ifndef O_NONBLOCK
#define O_NONBLOCK O_NDELAY
#endif
flags |= O_NONBLOCK;
return fcntl(fd, F_SETFL, flags) == 0;
}
bool
io_close(int fd)
{
io_event *i = io_event_get(fd);
if (i) {
memset(i, 0, sizeof(io_event));
i->fd = -1;
}
#ifdef IO_USE_SELECT
FD_CLR(fd, &writers);
FD_CLR(fd, &readers);
if (fd == select_maxfd)
select_maxfd--;
#endif
#ifdef IO_USE_KQUEUE
if (array_length(&io_evcache, sizeof (struct kevent))) /* pending data in cache? */
io_event_kqueue_commit_cache();
#endif
#ifdef IO_USE_EPOLL
epoll_ctl(io_masterfd, EPOLL_CTL_DEL, fd, NULL);
#endif
return close(fd) == 0; /* kqueue will remove fd from all sets automatically */
}
bool
io_event_del(int fd, short what)
{
#ifdef IO_USE_KQUEUE
struct kevent kev;
short filter = 0;
#endif
io_event *i = io_event_get(fd);
#ifdef DEBUG
Log(LOG_DEBUG, "io_event_del(): trying to delete eventtype %d on fd %d", what, fd);
#endif
assert(i);
if (!i)
return false;
i->what &= ~what;
#ifdef IO_USE_EPOLL
return io_event_change_epoll(fd, i->what);
#endif
#ifdef IO_USE_KQUEUE
if (what & IO_WANTREAD)
filter = EVFILT_READ;
if (what & IO_WANTWRITE)
filter |= EVFILT_WRITE;
EV_SET(&kev, fd, filter, EV_DELETE, 0, 0, NULL);
return kevent(io_masterfd, &kev, 1, NULL, 0, NULL) == 0;
#endif
#ifdef IO_USE_SELECT
if (what & IO_WANTWRITE)
FD_CLR(i->fd, &writers);
if (what & IO_WANTREAD)
FD_CLR(i->fd, &readers);
return true;
#endif
}
#ifdef IO_USE_SELECT
static int
io_dispatch_select(struct timeval *tv)
{
fd_set readers_tmp = readers;
fd_set writers_tmp = writers;
short what;
int ret, i;
int fds_ready;
ret = select(select_maxfd + 1, &readers_tmp, &writers_tmp, NULL, tv);
if (ret <= 0)
return ret;
fds_ready = ret;
for (i = 0; i <= select_maxfd; i++) {
what = 0;
if (FD_ISSET(i, &readers_tmp)) {
what = IO_WANTREAD;
fds_ready--;
}
if (FD_ISSET(i, &writers_tmp)) {
what |= IO_WANTWRITE;
fds_ready--;
}
if (what)
io_docallback(i, what);
if (fds_ready <= 0)
break;
}
return ret;
}
#endif
#ifdef IO_USE_EPOLL
static int
io_dispatch_epoll(struct timeval *tv)
{
time_t sec = tv->tv_sec * 1000;
int i, total = 0, ret, timeout = tv->tv_usec + sec;
struct epoll_event epoll_ev[100];
short type;
if (timeout < 0)
timeout = 1000;
do {
ret = epoll_wait(io_masterfd, epoll_ev, 100, timeout);
total += ret;
if (ret <= 0)
return total;
for (i = 0; i < ret; i++) {
type = 0;
if (epoll_ev[i].events & (EPOLLERR | EPOLLHUP))
type = IO_ERROR;
if (epoll_ev[i].events & (EPOLLIN | EPOLLPRI))
type |= IO_WANTREAD;
if (epoll_ev[i].events & EPOLLOUT)
type |= IO_WANTWRITE;
io_docallback(epoll_ev[i].data.fd, type);
}
timeout = 0;
} while (ret == 100);
return total;
}
#endif
#ifdef IO_USE_KQUEUE
static int
io_dispatch_kqueue(struct timeval *tv)
{
int i, total = 0, ret;
struct kevent kev[100];
struct kevent *newevents;
struct timespec ts;
int newevents_len;
short type;
ts.tv_sec = tv->tv_sec;
ts.tv_nsec = tv->tv_usec * 1000;
do {
newevents_len = (int) array_length(&io_evcache, sizeof (struct kevent));
newevents = (newevents_len > 0) ? array_start(&io_evcache) : NULL;
assert(newevents_len >= 0);
if (newevents_len < 0)
newevents_len = 0;
#ifdef DEBUG
if (newevents_len)
assert(newevents);
#endif
ret = kevent(io_masterfd, newevents, newevents_len, kev,
100, &ts);
if ((newevents_len>0) && ret != -1)
array_trunc(&io_evcache);
total += ret;
if (ret <= 0)
return total;
for (i = 0; i < ret; i++) {
type = 0;
if (kev[i].flags & EV_EOF)
type = IO_ERROR;
if (kev[i].filter & EV_ERROR)
type = IO_ERROR;
if (kev[i].filter & EVFILT_READ)
type |= IO_WANTREAD;
if (kev[i].filter & EVFILT_WRITE)
type |= IO_WANTWRITE;
io_docallback(kev[i].ident, type);
}
ts.tv_sec = 0;
ts.tv_nsec = 0;
} while (ret == 100);
return total;
}
#endif
int
io_dispatch(struct timeval *tv)
{
#ifdef IO_USE_SELECT
return io_dispatch_select(tv);
#endif
#ifdef IO_USE_KQUEUE
return io_dispatch_kqueue(tv);
#endif
#ifdef IO_USE_EPOLL
return io_dispatch_epoll(tv);
#endif
}
/* call the callback function inside the struct matching fd */
static void
io_docallback(int fd, short what)
{
io_event *i;
#ifdef DEBUG
Log(LOG_DEBUG, "doing callback for fd %d, what %d", fd, what);
#endif
i = io_event_get(fd);
assert(i);
if (i->callback) /* callback might be 0 if previous callback function called io_close on this fd */
i->callback(fd, (what & IO_ERROR) ? i->what : what);
/* if error indicator is set, we return the event(s) the app asked for */
}
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