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openmpi/opal/event/select.c

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7.9 KiB
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/* $OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */
/*
* Copyright 2000-2002 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 "ompi_config.h"
#include "opal/util/output.h"
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <sys/_time.h>
#endif
#include <sys/queue.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#include <err.h>
#include "mca/oob/base/base.h"
#ifdef USE_LOG
#include "log.h"
#else
#define LOG_DBG(x)
#define log_error(x) perror(x)
#endif
#include "event.h"
#if OPAL_EVENT_USE_SIGNALS
#include "evsignal.h"
#endif
#include "opal/threads/mutex.h"
extern struct opal_event_list opal_eventqueue;
extern opal_mutex_t opal_event_lock;
#ifndef howmany
#define howmany(x, y) (((x)+((y)-1))/(y))
#endif
#if OPAL_EVENT_USE_SIGNALS
extern volatile sig_atomic_t opal_evsignal_caught;
#endif
static struct selectop {
int event_fds; /* Highest fd in fd set */
int event_fdsz;
fd_set *event_readset;
fd_set *event_writeset;
#if OPAL_EVENT_USE_SIGNALS
sigset_t evsigmask;
#endif
} sop;
static void *select_init (void);
static int select_add (void *, struct opal_event *);
static int select_del (void *, struct opal_event *);
static int select_recalc (void *, int);
static int select_dispatch (void *, struct timeval *);
const struct opal_eventop opal_selectops = {
"select",
select_init,
select_add,
select_del,
#ifdef WIN32
NULL,
#else
select_recalc,
#endif
select_dispatch
};
static void *
select_init(void)
{
/* Disable select when this environment variable is set */
if (getenv("EVENT_NOSELECT"))
return (NULL);
memset(&sop, 0, sizeof(sop));
#ifdef WIN32
sop.event_fds = FD_SETSIZE;
sop.event_fdsz = FD_SETSIZE;
sop.event_readset = malloc (sizeof(fd_set));
sop.event_writeset = malloc (sizeof(fd_set));
#endif
#if OPAL_EVENT_USE_SIGNALS
opal_evsignal_init(&sop.evsigmask);
#endif
return (&sop);
}
/*
* Called with the highest fd that we know about. If it is 0, completely
* recalculate everything.
*/
#ifndef WIN32
static int
select_recalc(void *arg, int max)
{
struct selectop *sop = arg;
fd_set *readset, *writeset;
struct opal_event *ev;
int fdsz;
if (sop->event_fds < max)
sop->event_fds = max;
if (!sop->event_fds) {
TAILQ_FOREACH(ev, &opal_eventqueue, ev_next)
if (ev->ev_fd > sop->event_fds)
sop->event_fds = ev->ev_fd;
}
fdsz = howmany(sop->event_fds + 1, NFDBITS) * sizeof(fd_mask);
if (fdsz > sop->event_fdsz) {
if ((readset = realloc(sop->event_readset, fdsz)) == NULL) {
log_error("malloc");
return (-1);
}
if ((writeset = realloc(sop->event_writeset, fdsz)) == NULL) {
log_error("malloc");
free(readset);
return (-1);
}
memset((char *)readset + sop->event_fdsz, 0,
fdsz - sop->event_fdsz);
memset((char *)writeset + sop->event_fdsz, 0,
fdsz - sop->event_fdsz);
sop->event_readset = readset;
sop->event_writeset = writeset;
sop->event_fdsz = fdsz;
}
#if OPAL_EVENT_USE_SIGNALS
return (opal_evsignal_recalc(&sop->evsigmask));
#else
return (0);
#endif
}
#endif
static int
select_dispatch(void *arg, struct timeval *tv)
{
int maxfd, res;
struct opal_event *ev, *next;
struct selectop *sop = arg;
#ifndef WIN32
memset(sop->event_readset, 0, sop->event_fdsz);
memset(sop->event_writeset, 0, sop->event_fdsz);
#endif
TAILQ_FOREACH(ev, &opal_eventqueue, ev_next) {
if (ev->ev_events & OPAL_EV_WRITE)
FD_SET(ev->ev_fd, sop->event_writeset);
if (ev->ev_events & OPAL_EV_READ)
FD_SET(ev->ev_fd, sop->event_readset);
}
#if OPAL_EVENT_USE_SIGNALS
if (opal_evsignal_deliver(&sop->evsigmask) == -1)
return (-1);
#endif
/* release lock while waiting in kernel */
opal_mutex_unlock(&opal_event_lock);
res = select(sop->event_fds + 1, sop->event_readset,
sop->event_writeset, NULL, tv);
opal_mutex_lock(&opal_event_lock);
#if OPAL_EVENT_USE_SIGNALS
if (opal_evsignal_recalc(&sop->evsigmask) == -1)
return (-1);
#endif
if (res == -1) {
if (errno == EBADF) {
/* poll each of the file descriptors individually to determine
* which is bad
*/
for (ev = TAILQ_FIRST(&opal_eventqueue); ev != NULL; ev = next) {
next = TAILQ_NEXT(ev, ev_next);
tv->tv_sec = 0;
tv->tv_usec = 0;
memset(sop->event_readset, 0, sop->event_fdsz);
memset(sop->event_writeset, 0, sop->event_fdsz);
if (ev->ev_events & OPAL_EV_WRITE)
FD_SET(ev->ev_fd, sop->event_writeset);
if (ev->ev_events & OPAL_EV_READ)
FD_SET(ev->ev_fd, sop->event_readset);
res = select(sop->event_fds + 1, sop->event_readset,
sop->event_writeset, NULL, tv);
if(res < 0) {
opal_output(0, "bad file descriptor: %d\n", ev->ev_fd);
opal_event_del_i(ev);
}
}
}
if (errno != EINTR) {
opal_output(0, "select failed with errno=%d\n", errno);
return (-1);
}
#if OPAL_EVENT_USE_SIGNALS
opal_evsignal_process();
#endif
return (0);
}
#if OPAL_EVENT_USE_SIGNALS
else if (opal_evsignal_caught)
opal_evsignal_process();
#endif
maxfd = 0;
for (ev = TAILQ_FIRST(&opal_eventqueue); ev != NULL; ev = next) {
next = TAILQ_NEXT(ev, ev_next);
res = 0;
if (FD_ISSET(ev->ev_fd, sop->event_readset))
res |= OPAL_EV_READ;
if (FD_ISSET(ev->ev_fd, sop->event_writeset))
res |= OPAL_EV_WRITE;
res &= ev->ev_events;
if (res) {
if (!(ev->ev_events & OPAL_EV_PERSIST))
opal_event_del_i(ev);
opal_event_active_i(ev, res, 1);
}
if ((ev->ev_flags & ~OPAL_EVLIST_ACTIVE) == 0 && ev->ev_fd > maxfd)
maxfd = ev->ev_fd;
}
sop->event_fds = maxfd;
return (0);
}
static int
select_add(void *arg, struct opal_event *ev)
{
struct selectop *sop = arg;
#if OPAL_EVENT_USE_SIGNALS
if (ev->ev_events & OPAL_EV_SIGNAL)
return (opal_evsignal_add(&sop->evsigmask, ev));
#endif
/*
* Keep track of the highest fd, so that we can calculate the size
* of the fd_sets for select(2)
*/
if (sop->event_fds < ev->ev_fd)
sop->event_fds = ev->ev_fd;
return (0);
}
/*
* Nothing to be done here.
*/
static int
select_del(void *arg, struct opal_event *ev)
{
#if OPAL_EVENT_USE_SIGNALS
struct selectop *sop = arg;
if (!(ev->ev_events & OPAL_EV_SIGNAL))
return (0);
return (opal_evsignal_del(&sop->evsigmask, ev));
#else
return (0);
#endif
}