+++ /dev/null
-/* $OpenBSD: poll.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */
-
-/*
- * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>
- * Copyright 2007-2010 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 <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"
-
-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);
-
- 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 = random() % 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))
- 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);
-}
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