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openmpi/opal/event/epoll.c
Jeff Squyres 314ab2c6e7 Update internal libevent to upstream (v1.4.2-rc + OMPI changes).
Greatly reduce the number of "foo" -> "opal_foo" symbol renames in the
libevent source, and instead greatly expand the event_rename.h file
that uses preprocessor macros to make all public symbols be
"opal_foo".

This commit was SVN r17923.
2008-03-23 12:33:04 +00:00

381 строка
8.7 KiB
C

/*
* Copyright 2000-2003 Niels Provos <provos@citi.umich.edu>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "opal_config.h"
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <sys/_time.h>
#endif
#include <sys/queue.h>
#include <sys/epoll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include "event.h"
#include "event-internal.h"
#include "evsignal.h"
#include "log.h"
#include "opal/threads/mutex.h"
extern volatile sig_atomic_t opal_evsignal_caught;
extern opal_mutex_t opal_event_lock;
/* due to limitations in the epoll interface, we need to keep track of
* all file descriptors outself.
*/
struct evepoll {
struct event *evread;
struct event *evwrite;
};
struct epollop {
struct evepoll *fds;
int nfds;
struct epoll_event *events;
int nevents;
int epfd;
};
static void *epoll_init (struct event_base *);
static int epoll_add (void *, struct event *);
static int epoll_del (void *, struct event *);
static int epoll_dispatch (struct event_base *, void *, struct timeval *);
static void epoll_dealloc (struct event_base *, void *);
struct eventop epollops = {
"epoll",
epoll_init,
epoll_add,
epoll_del,
epoll_dispatch,
epoll_dealloc,
1 /* need reinit */
};
#ifdef HAVE_SETFD
#define FD_CLOSEONEXEC(x) do { \
if (fcntl(x, F_SETFD, 1) == -1) \
event_warn("fcntl(%d, F_SETFD)", x); \
} while (0)
#else
#define FD_CLOSEONEXEC(x)
#endif
#define NEVENT 32000
static void *
epoll_init(struct event_base *base)
{
int epfd, nfiles = NEVENT;
struct rlimit rl;
struct epollop *epollop;
/* Disable epollueue when this environment variable is set */
if (getenv("EVENT_NOEPOLL"))
return (NULL);
if (getrlimit(RLIMIT_NOFILE, &rl) == 0 &&
rl.rlim_cur != RLIM_INFINITY) {
/*
* Solaris is somewhat retarded - it's important to drop
* backwards compatibility when making changes. So, don't
* dare to put rl.rlim_cur here.
*/
nfiles = rl.rlim_cur - 1;
}
/* Initalize the kernel queue */
if ((epfd = epoll_create(nfiles)) == -1) {
event_warn("epoll_create");
return (NULL);
}
FD_CLOSEONEXEC(epfd);
if (!(epollop = calloc(1, sizeof(struct epollop))))
return (NULL);
epollop->epfd = epfd;
/* Initalize fields */
epollop->events = malloc(nfiles * sizeof(struct epoll_event));
if (epollop->events == NULL) {
free(epollop);
return (NULL);
}
epollop->nevents = nfiles;
epollop->fds = calloc(nfiles, sizeof(struct evepoll));
if (epollop->fds == NULL) {
free(epollop->events);
free(epollop);
return (NULL);
}
epollop->nfds = nfiles;
#if OPAL_EVENT_USE_SIGNALS
evsignal_init(base);
#endif
return (epollop);
}
static int
epoll_recalc(struct event_base *base, void *arg, int max)
{
struct epollop *epollop = arg;
if (max > epollop->nfds) {
struct evepoll *fds;
int nfds;
nfds = epollop->nfds;
while (nfds < max)
nfds <<= 1;
fds = realloc(epollop->fds, nfds * sizeof(struct evepoll));
if (fds == NULL) {
event_warn("realloc");
return (-1);
}
epollop->fds = fds;
memset(fds + epollop->nfds, 0,
(nfds - epollop->nfds) * sizeof(struct evepoll));
epollop->nfds = nfds;
}
return (0);
}
static int
epoll_dispatch(struct event_base *base, void *arg, struct timeval *tv)
{
struct epollop *epollop = arg;
struct epoll_event *events = epollop->events;
struct evepoll *evep;
int i, res, timeout = -1;
if (tv != NULL)
timeout = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
/* we should release the lock if we're going to enter the
kernel in a multi-threaded application. However, if we're
single threaded, there's really no advantage to releasing
the lock and it just takes up time we could spend doing
something else. */
OPAL_THREAD_UNLOCK(&opal_event_lock);
res = epoll_wait(epollop->epfd, events, epollop->nevents, timeout);
OPAL_THREAD_LOCK(&opal_event_lock);
if (res == -1) {
if (errno != EINTR) {
event_warn("epoll_wait");
return (-1);
}
#if OPAL_EVENT_USE_SIGNALS
evsignal_process(base);
#endif
return (0);
} else if (base->sig.evsignal_caught) {
#if OPAL_EVENT_USE_SIGNALS
evsignal_process(base);
#endif
}
event_debug(("%s: epoll_wait reports %d", __func__, res));
for (i = 0; i < res; i++) {
int what = events[i].events;
struct event *evread = NULL, *evwrite = NULL;
evep = (struct evepoll *)events[i].data.ptr;
if (what & (EPOLLHUP|EPOLLERR)) {
evread = evep->evread;
evwrite = evep->evwrite;
} else {
if (what & EPOLLIN) {
evread = evep->evread;
}
if (what & EPOLLOUT) {
evwrite = evep->evwrite;
}
}
if (!(evread||evwrite))
continue;
if (evread != NULL)
event_active(evread, EV_READ, 1);
if (evwrite != NULL)
event_active(evwrite, EV_WRITE, 1);
}
return (0);
}
static int
epoll_add(void *arg, struct event *ev)
{
struct epollop *epollop = arg;
struct epoll_event epev = {0, {0}};
struct evepoll *evep;
int fd, op, events;
#if OPAL_EVENT_USE_SIGNALS
if (ev->ev_events & EV_SIGNAL)
return (evsignal_add(ev));
#endif
fd = ev->ev_fd;
if (fd >= epollop->nfds) {
/* Extent the file descriptor array as necessary */
if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
return (-1);
}
evep = &epollop->fds[fd];
op = EPOLL_CTL_ADD;
events = 0;
if (evep->evread != NULL) {
events |= EPOLLIN;
op = EPOLL_CTL_MOD;
}
if (evep->evwrite != NULL) {
events |= EPOLLOUT;
op = EPOLL_CTL_MOD;
}
if (ev->ev_events & EV_READ)
events |= EPOLLIN;
if (ev->ev_events & EV_WRITE)
events |= EPOLLOUT;
epev.data.ptr = evep;
epev.events = events;
if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
return (-1);
/* Update events responsible */
if (ev->ev_events & EV_READ)
evep->evread = ev;
if (ev->ev_events & EV_WRITE)
evep->evwrite = ev;
return (0);
}
static int
epoll_del(void *arg, struct event *ev)
{
struct epollop *epollop = arg;
struct epoll_event epev = {0, {0}};
struct evepoll *evep;
int fd, events, op;
int needwritedelete = 1, needreaddelete = 1;
#if OPAL_EVENT_USE_SIGNALS
if (ev->ev_events & EV_SIGNAL)
return (evsignal_del(ev));
#endif
fd = ev->ev_fd;
if (fd >= epollop->nfds)
return (0);
evep = &epollop->fds[fd];
op = EPOLL_CTL_DEL;
events = 0;
if (ev->ev_events & EV_READ)
events |= EPOLLIN;
if (ev->ev_events & EV_WRITE)
events |= EPOLLOUT;
if ((events & (EPOLLIN|EPOLLOUT)) != (EPOLLIN|EPOLLOUT)) {
if ((events & EPOLLIN) && evep->evwrite != NULL) {
needwritedelete = 0;
events = EPOLLOUT;
op = EPOLL_CTL_MOD;
} else if ((events & EPOLLOUT) && evep->evread != NULL) {
needreaddelete = 0;
events = EPOLLIN;
op = EPOLL_CTL_MOD;
}
}
epev.events = events;
epev.data.ptr = evep;
if (needreaddelete)
evep->evread = NULL;
if (needwritedelete)
evep->evwrite = NULL;
if (epoll_ctl(epollop->epfd, op, fd, &epev) == -1)
return (-1);
return (0);
}
static void
epoll_dealloc(struct event_base *base, void *arg)
{
struct epollop *epollop = arg;
evsignal_dealloc(base);
if (epollop->fds)
free(epollop->fds);
if (epollop->events)
free(epollop->events);
if (epollop->epfd >= 0)
close(epollop->epfd);
memset(epollop, 0, sizeof(struct epollop));
free(epollop);
}