342 lines
8.0 KiB
C
342 lines
8.0 KiB
C
|
/* $OpenBSD: poll.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>
|
||
|
|
* Copyright 2007-2012 Niels Provos and Nick Mathewson
|
||
|
|
*
|
||
|
|
* 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 "event2/event-config.h"
|
||
|
|
#include "evconfig-private.h"
|
||
|
|
|
||
|
|
#ifdef EVENT__HAVE_POLL
|
||
|
|
|
||
|
|
#include <sys/types.h>
|
||
|
|
#ifdef EVENT__HAVE_SYS_TIME_H
|
||
|
|
#include <sys/time.h>
|
||
|
|
#endif
|
||
|
|
#include <sys/queue.h>
|
||
|
|
#include <poll.h>
|
||
|
|
#include <signal.h>
|
||
|
|
#include <limits.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <errno.h>
|
||
|
|
|
||
|
|
#include "event-internal.h"
|
||
|
|
#include "evsignal-internal.h"
|
||
|
|
#include "log-internal.h"
|
||
|
|
#include "evmap-internal.h"
|
||
|
|
#include "event2/thread.h"
|
||
|
|
#include "evthread-internal.h"
|
||
|
|
#include "time-internal.h"
|
||
|
|
|
||
|
|
struct pollidx {
|
||
|
|
int idxplus1;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct pollop {
|
||
|
|
int event_count; /* Highest number alloc */
|
||
|
|
int nfds; /* Highest number used */
|
||
|
|
int realloc_copy; /* True iff we must realloc
|
||
|
|
* event_set_copy */
|
||
|
|
struct pollfd *event_set;
|
||
|
|
struct pollfd *event_set_copy;
|
||
|
|
};
|
||
|
|
|
||
|
|
static void *poll_init(struct event_base *);
|
||
|
|
static int poll_add(struct event_base *, int, short old, short events, void *idx);
|
||
|
|
static int poll_del(struct event_base *, int, short old, short events, void *idx);
|
||
|
|
static int poll_dispatch(struct event_base *, struct timeval *);
|
||
|
|
static void poll_dealloc(struct event_base *);
|
||
|
|
|
||
|
|
const struct eventop pollops = {
|
||
|
|
"poll",
|
||
|
|
poll_init,
|
||
|
|
poll_add,
|
||
|
|
poll_del,
|
||
|
|
poll_dispatch,
|
||
|
|
poll_dealloc,
|
||
|
|
0, /* doesn't need_reinit */
|
||
|
|
EV_FEATURE_FDS,
|
||
|
|
sizeof(struct pollidx),
|
||
|
|
};
|
||
|
|
|
||
|
|
static void *
|
||
|
|
poll_init(struct event_base *base)
|
||
|
|
{
|
||
|
|
struct pollop *pollop;
|
||
|
|
|
||
|
|
if (!(pollop = mm_calloc(1, sizeof(struct pollop))))
|
||
|
|
return (NULL);
|
||
|
|
|
||
|
|
evsig_init_(base);
|
||
|
|
|
||
|
|
evutil_weakrand_seed_(&base->weakrand_seed, 0);
|
||
|
|
|
||
|
|
return (pollop);
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef CHECK_INVARIANTS
|
||
|
|
static void
|
||
|
|
poll_check_ok(struct pollop *pop)
|
||
|
|
{
|
||
|
|
int i, idx;
|
||
|
|
struct event *ev;
|
||
|
|
|
||
|
|
for (i = 0; i < pop->fd_count; ++i) {
|
||
|
|
idx = pop->idxplus1_by_fd[i]-1;
|
||
|
|
if (idx < 0)
|
||
|
|
continue;
|
||
|
|
EVUTIL_ASSERT(pop->event_set[idx].fd == i);
|
||
|
|
}
|
||
|
|
for (i = 0; i < pop->nfds; ++i) {
|
||
|
|
struct pollfd *pfd = &pop->event_set[i];
|
||
|
|
EVUTIL_ASSERT(pop->idxplus1_by_fd[pfd->fd] == i+1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
#define poll_check_ok(pop)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static int
|
||
|
|
poll_dispatch(struct event_base *base, struct timeval *tv)
|
||
|
|
{
|
||
|
|
int res, i, j, nfds;
|
||
|
|
long msec = -1;
|
||
|
|
struct pollop *pop = base->evbase;
|
||
|
|
struct pollfd *event_set;
|
||
|
|
|
||
|
|
poll_check_ok(pop);
|
||
|
|
|
||
|
|
nfds = pop->nfds;
|
||
|
|
|
||
|
|
#ifndef EVENT__DISABLE_THREAD_SUPPORT
|
||
|
|
if (base->th_base_lock) {
|
||
|
|
/* If we're using this backend in a multithreaded setting,
|
||
|
|
* then we need to work on a copy of event_set, so that we can
|
||
|
|
* let other threads modify the main event_set while we're
|
||
|
|
* polling. If we're not multithreaded, then we'll skip the
|
||
|
|
* copy step here to save memory and time. */
|
||
|
|
if (pop->realloc_copy) {
|
||
|
|
struct pollfd *tmp = mm_realloc(pop->event_set_copy,
|
||
|
|
pop->event_count * sizeof(struct pollfd));
|
||
|
|
if (tmp == NULL) {
|
||
|
|
event_warn("realloc");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
pop->event_set_copy = tmp;
|
||
|
|
pop->realloc_copy = 0;
|
||
|
|
}
|
||
|
|
memcpy(pop->event_set_copy, pop->event_set,
|
||
|
|
sizeof(struct pollfd)*nfds);
|
||
|
|
event_set = pop->event_set_copy;
|
||
|
|
} else {
|
||
|
|
event_set = pop->event_set;
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
event_set = pop->event_set;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
if (tv != NULL) {
|
||
|
|
msec = evutil_tv_to_msec_(tv);
|
||
|
|
if (msec < 0 || msec > INT_MAX)
|
||
|
|
msec = INT_MAX;
|
||
|
|
}
|
||
|
|
|
||
|
|
EVBASE_RELEASE_LOCK(base, th_base_lock);
|
||
|
|
|
||
|
|
res = poll(event_set, nfds, msec);
|
||
|
|
|
||
|
|
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
|
||
|
|
|
||
|
|
if (res == -1) {
|
||
|
|
if (errno != EINTR) {
|
||
|
|
event_warn("poll");
|
||
|
|
return (-1);
|
||
|
|
}
|
||
|
|
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
event_debug(("%s: poll reports %d", __func__, res));
|
||
|
|
|
||
|
|
if (res == 0 || nfds == 0)
|
||
|
|
return (0);
|
||
|
|
|
||
|
|
i = evutil_weakrand_range_(&base->weakrand_seed, nfds);
|
||
|
|
for (j = 0; j < nfds; j++) {
|
||
|
|
int what;
|
||
|
|
if (++i == nfds)
|
||
|
|
i = 0;
|
||
|
|
what = event_set[i].revents;
|
||
|
|
if (!what)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
res = 0;
|
||
|
|
|
||
|
|
/* If the file gets closed notify */
|
||
|
|
if (what & (POLLHUP|POLLERR|POLLNVAL))
|
||
|
|
what |= POLLIN|POLLOUT;
|
||
|
|
if (what & POLLIN)
|
||
|
|
res |= EV_READ;
|
||
|
|
if (what & POLLOUT)
|
||
|
|
res |= EV_WRITE;
|
||
|
|
if (res == 0)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
evmap_io_active_(base, event_set[i].fd, res);
|
||
|
|
}
|
||
|
|
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int
|
||
|
|
poll_add(struct event_base *base, int fd, short old, short events, void *idx_)
|
||
|
|
{
|
||
|
|
struct pollop *pop = base->evbase;
|
||
|
|
struct pollfd *pfd = NULL;
|
||
|
|
struct pollidx *idx = idx_;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
EVUTIL_ASSERT((events & EV_SIGNAL) == 0);
|
||
|
|
if (!(events & (EV_READ|EV_WRITE)))
|
||
|
|
return (0);
|
||
|
|
|
||
|
|
poll_check_ok(pop);
|
||
|
|
if (pop->nfds + 1 >= pop->event_count) {
|
||
|
|
struct pollfd *tmp_event_set;
|
||
|
|
int tmp_event_count;
|
||
|
|
|
||
|
|
if (pop->event_count < 32)
|
||
|
|
tmp_event_count = 32;
|
||
|
|
else
|
||
|
|
tmp_event_count = pop->event_count * 2;
|
||
|
|
|
||
|
|
/* We need more file descriptors */
|
||
|
|
tmp_event_set = mm_realloc(pop->event_set,
|
||
|
|
tmp_event_count * sizeof(struct pollfd));
|
||
|
|
if (tmp_event_set == NULL) {
|
||
|
|
event_warn("realloc");
|
||
|
|
return (-1);
|
||
|
|
}
|
||
|
|
pop->event_set = tmp_event_set;
|
||
|
|
|
||
|
|
pop->event_count = tmp_event_count;
|
||
|
|
pop->realloc_copy = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
i = idx->idxplus1 - 1;
|
||
|
|
|
||
|
|
if (i >= 0) {
|
||
|
|
pfd = &pop->event_set[i];
|
||
|
|
} else {
|
||
|
|
i = pop->nfds++;
|
||
|
|
pfd = &pop->event_set[i];
|
||
|
|
pfd->events = 0;
|
||
|
|
pfd->fd = fd;
|
||
|
|
idx->idxplus1 = i + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
pfd->revents = 0;
|
||
|
|
if (events & EV_WRITE)
|
||
|
|
pfd->events |= POLLOUT;
|
||
|
|
if (events & EV_READ)
|
||
|
|
pfd->events |= POLLIN;
|
||
|
|
poll_check_ok(pop);
|
||
|
|
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Nothing to be done here.
|
||
|
|
*/
|
||
|
|
|
||
|
|
static int
|
||
|
|
poll_del(struct event_base *base, int fd, short old, short events, void *idx_)
|
||
|
|
{
|
||
|
|
struct pollop *pop = base->evbase;
|
||
|
|
struct pollfd *pfd = NULL;
|
||
|
|
struct pollidx *idx = idx_;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
EVUTIL_ASSERT((events & EV_SIGNAL) == 0);
|
||
|
|
if (!(events & (EV_READ|EV_WRITE)))
|
||
|
|
return (0);
|
||
|
|
|
||
|
|
poll_check_ok(pop);
|
||
|
|
i = idx->idxplus1 - 1;
|
||
|
|
if (i < 0)
|
||
|
|
return (-1);
|
||
|
|
|
||
|
|
/* Do we still want to read or write? */
|
||
|
|
pfd = &pop->event_set[i];
|
||
|
|
if (events & EV_READ)
|
||
|
|
pfd->events &= ~POLLIN;
|
||
|
|
if (events & EV_WRITE)
|
||
|
|
pfd->events &= ~POLLOUT;
|
||
|
|
poll_check_ok(pop);
|
||
|
|
if (pfd->events)
|
||
|
|
/* Another event cares about that fd. */
|
||
|
|
return (0);
|
||
|
|
|
||
|
|
/* Okay, so we aren't interested in that fd anymore. */
|
||
|
|
idx->idxplus1 = 0;
|
||
|
|
|
||
|
|
--pop->nfds;
|
||
|
|
if (i != pop->nfds) {
|
||
|
|
/*
|
||
|
|
* Shift the last pollfd down into the now-unoccupied
|
||
|
|
* position.
|
||
|
|
*/
|
||
|
|
memcpy(&pop->event_set[i], &pop->event_set[pop->nfds],
|
||
|
|
sizeof(struct pollfd));
|
||
|
|
idx = evmap_io_get_fdinfo_(&base->io, pop->event_set[i].fd);
|
||
|
|
EVUTIL_ASSERT(idx);
|
||
|
|
EVUTIL_ASSERT(idx->idxplus1 == pop->nfds + 1);
|
||
|
|
idx->idxplus1 = i + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
poll_check_ok(pop);
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void
|
||
|
|
poll_dealloc(struct event_base *base)
|
||
|
|
{
|
||
|
|
struct pollop *pop = base->evbase;
|
||
|
|
|
||
|
|
evsig_dealloc_(base);
|
||
|
|
if (pop->event_set)
|
||
|
|
mm_free(pop->event_set);
|
||
|
|
if (pop->event_set_copy)
|
||
|
|
mm_free(pop->event_set_copy);
|
||
|
|
|
||
|
|
memset(pop, 0, sizeof(struct pollop));
|
||
|
|
mm_free(pop);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* EVENT__HAVE_POLL */
|