--- /dev/null
+/* $OpenBSD: select.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
+#ifdef _EVENT_HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+#include <sys/queue.h>
+#include <signal.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 "event2/thread.h"
+#include "evthread-internal.h"
+#include "log-internal.h"
+#include "evmap-internal.h"
+
+#ifndef howmany
+#define howmany(x, y) (((x)+((y)-1))/(y))
+#endif
+
+#ifndef _EVENT_HAVE_FD_MASK
+/* This type is mandatory, but Android doesn't define it. */
+#undef NFDBITS
+#define NFDBITS (sizeof(long)*8)
+typedef unsigned long fd_mask;
+#endif
+
+struct selectop {
+ int event_fds; /* Highest fd in fd set */
+ int event_fdsz;
+ int resize_out_sets;
+ fd_set *event_readset_in;
+ fd_set *event_writeset_in;
+ fd_set *event_readset_out;
+ fd_set *event_writeset_out;
+};
+
+static void *select_init(struct event_base *);
+static int select_add(struct event_base *, int, short old, short events, void*);
+static int select_del(struct event_base *, int, short old, short events, void*);
+static int select_dispatch(struct event_base *, struct timeval *);
+static void select_dealloc(struct event_base *);
+
+const struct eventop selectops = {
+ "select",
+ select_init,
+ select_add,
+ select_del,
+ select_dispatch,
+ select_dealloc,
+ 0, /* doesn't need reinit. */
+ EV_FEATURE_FDS,
+ 0,
+};
+
+static int select_resize(struct selectop *sop, int fdsz);
+
+static void *
+select_init(struct event_base *base)
+{
+ struct selectop *sop;
+
+ if (!(sop = mm_calloc(1, sizeof(struct selectop))))
+ return (NULL);
+
+ select_resize(sop, howmany(32 + 1, NFDBITS)*sizeof(fd_mask));
+
+ evsig_init(base);
+
+ return (sop);
+}
+
+#ifdef CHECK_INVARIANTS
+static void
+check_selectop(struct selectop *sop)
+{
+ /* nothing to be done here */
+}
+#else
+#define check_selectop(sop) do { (void) sop; } while (0)
+#endif
+
+static int
+select_dispatch(struct event_base *base, struct timeval *tv)
+{
+ int res=0, i, j, nfds;
+ struct selectop *sop = base->evbase;
+
+ check_selectop(sop);
+ if (sop->resize_out_sets) {
+ fd_set *readset_out=NULL, *writeset_out=NULL;
+ size_t sz = sop->event_fdsz;
+ if (!(readset_out = mm_realloc(sop->event_readset_out, sz)))
+ return (-1);
+ if (!(writeset_out = mm_realloc(sop->event_writeset_out, sz))) {
+ mm_free(readset_out);
+ return (-1);
+ }
+ sop->event_readset_out = readset_out;
+ sop->event_writeset_out = writeset_out;
+ sop->resize_out_sets = 0;
+ }
+
+ memcpy(sop->event_readset_out, sop->event_readset_in,
+ sop->event_fdsz);
+ memcpy(sop->event_writeset_out, sop->event_writeset_in,
+ sop->event_fdsz);
+
+ nfds = sop->event_fds+1;
+
+ EVBASE_RELEASE_LOCK(base, th_base_lock);
+
+ res = select(nfds, sop->event_readset_out,
+ sop->event_writeset_out, NULL, tv);
+
+ EVBASE_ACQUIRE_LOCK(base, th_base_lock);
+
+ check_selectop(sop);
+
+ if (res == -1) {
+ if (errno != EINTR) {
+ event_warn("select");
+ return (-1);
+ }
+
+ return (0);
+ }
+
+ event_debug(("%s: select reports %d", __func__, res));
+
+ check_selectop(sop);
+ i = random() % (nfds+1);
+ for (j = 0; j <= nfds; ++j) {
+ if (++i >= nfds+1)
+ i = 0;
+ res = 0;
+ if (FD_ISSET(i, sop->event_readset_out))
+ res |= EV_READ;
+ if (FD_ISSET(i, sop->event_writeset_out))
+ res |= EV_WRITE;
+
+ if (res == 0)
+ continue;
+
+ evmap_io_active(base, i, res);
+ }
+ check_selectop(sop);
+
+ return (0);
+}
+
+
+static int
+select_resize(struct selectop *sop, int fdsz)
+{
+ fd_set *readset_in = NULL;
+ fd_set *writeset_in = NULL;
+
+ if (sop->event_readset_in)
+ check_selectop(sop);
+
+ if ((readset_in = mm_realloc(sop->event_readset_in, fdsz)) == NULL)
+ goto error;
+ sop->event_readset_in = readset_in;
+ if ((writeset_in = mm_realloc(sop->event_writeset_in, fdsz)) == NULL)
+ goto error;
+ sop->event_writeset_in = writeset_in;
+ sop->resize_out_sets = 1;
+
+ memset((char *)sop->event_readset_in + sop->event_fdsz, 0,
+ fdsz - sop->event_fdsz);
+ memset((char *)sop->event_writeset_in + sop->event_fdsz, 0,
+ fdsz - sop->event_fdsz);
+
+ sop->event_fdsz = fdsz;
+ check_selectop(sop);
+
+ return (0);
+
+ error:
+ event_warn("malloc");
+ return (-1);
+}
+
+
+static int
+select_add(struct event_base *base, int fd, short old, short events, void *p)
+{
+ struct selectop *sop = base->evbase;
+ (void) p;
+
+ EVUTIL_ASSERT((events & EV_SIGNAL) == 0);
+ check_selectop(sop);
+ /*
+ * Keep track of the highest fd, so that we can calculate the size
+ * of the fd_sets for select(2)
+ */
+ if (sop->event_fds < fd) {
+ int fdsz = sop->event_fdsz;
+
+ if (fdsz < (int)sizeof(fd_mask))
+ fdsz = (int)sizeof(fd_mask);
+
+ /* In theory we should worry about overflow here. In
+ * reality, though, the highest fd on a unixy system will
+ * not overflow here. XXXX */
+ while (fdsz <
+ (int) (howmany(fd + 1, NFDBITS) * sizeof(fd_mask)))
+ fdsz *= 2;
+
+ if (fdsz != sop->event_fdsz) {
+ if (select_resize(sop, fdsz)) {
+ check_selectop(sop);
+ return (-1);
+ }
+ }
+
+ sop->event_fds = fd;
+ }
+
+ if (events & EV_READ)
+ FD_SET(fd, sop->event_readset_in);
+ if (events & EV_WRITE)
+ FD_SET(fd, sop->event_writeset_in);
+ check_selectop(sop);
+
+ return (0);
+}
+
+/*
+ * Nothing to be done here.
+ */
+
+static int
+select_del(struct event_base *base, int fd, short old, short events, void *p)
+{
+ struct selectop *sop = base->evbase;
+ (void)p;
+
+ EVUTIL_ASSERT((events & EV_SIGNAL) == 0);
+ check_selectop(sop);
+
+ if (sop->event_fds < fd) {
+ check_selectop(sop);
+ return (0);
+ }
+
+ if (events & EV_READ)
+ FD_CLR(fd, sop->event_readset_in);
+
+ if (events & EV_WRITE)
+ FD_CLR(fd, sop->event_writeset_in);
+
+ check_selectop(sop);
+ return (0);
+}
+
+static void
+select_dealloc(struct event_base *base)
+{
+ struct selectop *sop = base->evbase;
+
+ evsig_dealloc(base);
+ if (sop->event_readset_in)
+ mm_free(sop->event_readset_in);
+ if (sop->event_writeset_in)
+ mm_free(sop->event_writeset_in);
+ if (sop->event_readset_out)
+ mm_free(sop->event_readset_out);
+ if (sop->event_writeset_out)
+ mm_free(sop->event_writeset_out);
+
+ memset(sop, 0, sizeof(struct selectop));
+ mm_free(sop);
+}
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