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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 1.16 2006/07/23 23:11:44 alex 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"
- /* Enables extra debug messages in event add/delete/callback code. */
- /* #define DEBUG_IO */
- typedef struct {
- void (*callback)(int, short);
- 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_change_epoll(int fd, short what, const int action);
- 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_change_kqueue(int, short, const int action);
- #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), (size_t) fd);
- assert(i != NULL);
- return i;
- }
- bool
- io_library_init(unsigned int eventsize)
- {
- #if defined(IO_USE_EPOLL) || defined(IO_USE_KQUEUE)
- bool ret;
- #endif
- #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 > 0) && !array_alloc(&io_events, sizeof(io_event), (size_t)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 >= (int)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))
- {
- bool ret;
- 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), (size_t) fd);
- if (!i) {
- Log(LOG_WARNING,
- "array_alloc failed: could not allocate space for %d io_event structures",
- fd);
- return false;
- }
- i->callback = cbfunc;
- i->what = 0;
- #ifdef IO_USE_EPOLL
- ret = io_event_change_epoll(fd, what, EPOLL_CTL_ADD);
- #endif
- #ifdef IO_USE_KQUEUE
- ret = io_event_change_kqueue(fd, what, EV_ADD|EV_ENABLE);
- #endif
- #ifdef IO_USE_SELECT
- ret = io_event_add(fd, what);
- #endif
- if (ret) i->what = what;
- return ret;
- }
- #ifdef IO_USE_EPOLL
- static bool
- io_event_change_epoll(int fd, short what, const int action)
- {
- 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, action, 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 != NULL);
- ret = kevent(io_masterfd, events, len, NULL, 0, NULL) == 0;
- if (ret)
- array_trunc(&io_evcache);
- return ret;
- }
- static bool
- io_event_change_kqueue(int fd, short what, const int action)
- {
- struct kevent kev;
- bool ret = true;
- if (what & IO_WANTREAD) {
- EV_SET(&kev, fd, EVFILT_READ, action, 0, 0, 0);
- ret = array_catb(&io_evcache, (char*) &kev, sizeof (kev));
- if (!ret)
- ret = kevent(io_masterfd, &kev,1, NULL, 0, NULL) == 0;
- }
- if (ret && (what & IO_WANTWRITE)) {
- EV_SET(&kev, fd, EVFILT_WRITE, action, 0, 0, 0);
- ret = array_catb(&io_evcache, (char*) &kev, sizeof (kev));
- if (!ret)
- ret = kevent(io_masterfd, &kev, 1, NULL, 0, NULL) == 0;
- }
- if (array_length(&io_evcache, sizeof kev) >= 100)
- io_event_kqueue_commit_cache();
- return ret;
- }
- #endif
- bool
- io_event_add(int fd, short what)
- {
- io_event *i = io_event_get(fd);
- if (!i) return false;
- if (i->what == what) return true;
- #ifdef DEBUG_IO
- 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, EPOLL_CTL_MOD);
- #endif
- #ifdef IO_USE_KQUEUE
- return io_event_change_kqueue(fd, what, EV_ADD | EV_ENABLE);
- #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;
- #ifdef IO_USE_SELECT
- FD_CLR(fd, &writers);
- FD_CLR(fd, &readers);
- if (fd == select_maxfd) {
- while (select_maxfd>0) {
- --select_maxfd; /* find largest fd */
- i = io_event_get(select_maxfd);
- if (i && i->callback) break;
- }
- }
- #endif
- i = io_event_get(fd);
- #ifdef IO_USE_KQUEUE
- if (array_length(&io_evcache, sizeof (struct kevent))) /* pending data in cache? */
- io_event_kqueue_commit_cache();
- /* both kqueue and epoll remove fd from all sets automatically on the last close
- * of the descriptor. since we don't know if this is the last close we'll have
- * to remove the set explicitly. */
- if (i) {
- io_event_change_kqueue(fd, i->what, EV_DELETE);
- io_event_kqueue_commit_cache();
- }
- #endif
- #ifdef IO_USE_EPOLL
- io_event_change_epoll(fd, 0, EPOLL_CTL_DEL);
- #endif
- if (i) {
- i->callback = NULL;
- i->what = 0;
- }
- return close(fd) == 0;
- }
- bool
- io_event_del(int fd, short what)
- {
- io_event *i = io_event_get(fd);
- #ifdef DEBUG_IO
- Log(LOG_DEBUG, "io_event_del(): trying to delete eventtype %d on fd %d", what, fd);
- #endif
- if (!i) return false;
- i->what &= ~what;
- #ifdef IO_USE_EPOLL
- return io_event_change_epoll(fd, i->what, EPOLL_CTL_MOD);
- #endif
- #ifdef IO_USE_KQUEUE
- return io_event_change_kqueue(fd, what, EV_DISABLE);
- #endif
- #ifdef IO_USE_SELECT
- if (what & IO_WANTWRITE)
- FD_CLR(fd, &writers);
- if (what & IO_WANTREAD)
- FD_CLR(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;
- 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 != NULL);
- #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++) {
- if (kev[i].flags & EV_EOF) {
- #ifdef DEBUG
- LogDebug("kev.flag has EV_EOF set, setting IO_ERROR",
- kev[i].filter, kev[i].ident);
- #endif
- io_docallback((int)kev[i].ident, IO_ERROR);
- continue;
- }
- switch (kev[i].filter) {
- case EVFILT_READ:
- io_docallback((int)kev[i].ident, IO_WANTREAD);
- break;
- case EVFILT_WRITE:
- io_docallback((int)kev[i].ident, IO_WANTWRITE);
- break;
- default:
- #ifdef DEBUG
- LogDebug("Unknown kev.filter number %d for fd %d",
- kev[i].filter, kev[i].ident); /* Fall through */
- #endif
- case EV_ERROR:
- io_docallback((int)kev[i].ident, IO_ERROR);
- break;
- }
- }
- 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_IO
- Log(LOG_DEBUG, "doing callback for fd %d, what %d", fd, what);
- #endif
- i = io_event_get(fd);
- if (i->callback) { /* callback might be NULL if a 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) that were registered */
- }
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