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 /*

  * Copyright 2007-2012 Niels Provos and Nick Mathewson

  * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>

  * Copyright 2003 Michael A. Davis <mike@datanerds.net>

  *

  * 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 <winsock2.h>

 #include <windows.h>

 #include <sys/types.h>

 #include <sys/queue.h>

 #include <limits.h>

 #include <signal.h>

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

 #include <errno.h>

 #include "event2/util.h"

 #include "event2/event-config.h"

 #include "util-internal.h"

 #include "log-internal.h"

 #include "event2/event.h"

 #include "event-internal.h"

 #include "evmap-internal.h"

 #include "event2/thread.h"

 #include "evthread-internal.h"

 #define XFREE(ptr) do { if (ptr) mm_free(ptr); } while (0)

 extern struct event_list timequeue;

 extern struct event_list addqueue;

 struct win_fd_set {

 	u_int fd_count;

 	SOCKET fd_array[1];

 };

 /* MSDN says this is required to handle SIGFPE */

 volatile double SIGFPE_REQ = 0.0f;

 struct idx_info {

 	int read_pos_plus1;

 	int write_pos_plus1;

 };

 struct win32op {

 	unsigned num_fds_in_fd_sets;

 	int resize_out_sets;

 	struct win_fd_set *readset_in;

 	struct win_fd_set *writeset_in;

 	struct win_fd_set *readset_out;

 	struct win_fd_set *writeset_out;

 	struct win_fd_set *exset_out;

 	unsigned signals_are_broken : 1;

 };

 static void *win32_init(struct event_base *);

 static int win32_add(struct event_base *, evutil_socket_t, short old, short events, void *_idx);

 static int win32_del(struct event_base *, evutil_socket_t, short old, short events, void *_idx);

 static int win32_dispatch(struct event_base *base, struct timeval *);

 static void win32_dealloc(struct event_base *);

 struct eventop win32ops = {

 	"win32",

 	win32_init,

 	win32_add,

 	win32_del,

 	win32_dispatch,

 	win32_dealloc,

 	0, /* doesn't need reinit */

 	0, /* No features supported. */

 	sizeof(struct idx_info),

 };

 #define FD_SET_ALLOC_SIZE(n) ((sizeof(struct win_fd_set) + ((n)-1)*sizeof(SOCKET)))

 static int

 grow_fd_sets(struct win32op *op, unsigned new_num_fds)

 {

 	size_t size;

 	EVUTIL_ASSERT(new_num_fds >= op->readset_in->fd_count &&

 	       new_num_fds >= op->writeset_in->fd_count);

 	EVUTIL_ASSERT(new_num_fds >= 1);

 	size = FD_SET_ALLOC_SIZE(new_num_fds);

 	if (!(op->readset_in = mm_realloc(op->readset_in, size)))

 		return (-1);

 	if (!(op->writeset_in = mm_realloc(op->writeset_in, size)))

 		return (-1);

 	op->resize_out_sets = 1;

 	op->num_fds_in_fd_sets = new_num_fds;

 	return (0);

 }

 static int

 do_fd_set(struct win32op *op, struct idx_info *ent, evutil_socket_t s, int read)

 {

 	struct win_fd_set *set = read ? op->readset_in : op->writeset_in;

 	if (read) {

 		if (ent->read_pos_plus1 > 0)

 			return (0);

 	} else {

 		if (ent->write_pos_plus1 > 0)

 			return (0);

 	}

 	if (set->fd_count == op->num_fds_in_fd_sets) {

 		if (grow_fd_sets(op, op->num_fds_in_fd_sets*2))

 			return (-1);

 		/* set pointer will have changed and needs reiniting! */

 		set = read ? op->readset_in : op->writeset_in;

 	}

 	set->fd_array[set->fd_count] = s;

 	if (read)

 		ent->read_pos_plus1 = set->fd_count+1;

 	else

 		ent->write_pos_plus1 = set->fd_count+1;

 	return (set->fd_count++);

 }

 static int

 do_fd_clear(struct event_base *base,

 			struct win32op *op, struct idx_info *ent, int read)

 {

 	int i;

 	struct win_fd_set *set = read ? op->readset_in : op->writeset_in;

 	if (read) {

 		i = ent->read_pos_plus1 - 1;

 		ent->read_pos_plus1 = 0;

 	} else {

 		i = ent->write_pos_plus1 - 1;

 		ent->write_pos_plus1 = 0;

 	}

 	if (i < 0)

 		return (0);

 	if (--set->fd_count != (unsigned)i) {

 		struct idx_info *ent2;

 		SOCKET s2;

 		s2 = set->fd_array[i] = set->fd_array[set->fd_count];

 		ent2 = evmap_io_get_fdinfo(&base->io, s2);

 		if (!ent2) /* This indicates a bug. */

 			return (0);

 		if (read)

 			ent2->read_pos_plus1 = i+1;

 		else

 			ent2->write_pos_plus1 = i+1;

 	}

 	return (0);

 }

 #define NEVENT 32

 void *

 win32_init(struct event_base *_base)

 {

 	struct win32op *winop;

 	size_t size;

 	if (!(winop = mm_calloc(1, sizeof(struct win32op))))

 		return NULL;

 	winop->num_fds_in_fd_sets = NEVENT;

 	size = FD_SET_ALLOC_SIZE(NEVENT);

 	if (!(winop->readset_in = mm_malloc(size)))

 		goto err;

 	if (!(winop->writeset_in = mm_malloc(size)))

 		goto err;

 	if (!(winop->readset_out = mm_malloc(size)))

 		goto err;

 	if (!(winop->writeset_out = mm_malloc(size)))

 		goto err;

 	if (!(winop->exset_out = mm_malloc(size)))

 		goto err;

 	winop->readset_in->fd_count = winop->writeset_in->fd_count = 0;

 	winop->readset_out->fd_count = winop->writeset_out->fd_count

 		= winop->exset_out->fd_count = 0;

 	if (evsig_init(_base) < 0)

 		winop->signals_are_broken = 1;

 	return (winop);

  err:

 	XFREE(winop->readset_in);

 	XFREE(winop->writeset_in);

 	XFREE(winop->readset_out);

 	XFREE(winop->writeset_out);

 	XFREE(winop->exset_out);

 	XFREE(winop);

 	return (NULL);

 }

 int

 win32_add(struct event_base *base, evutil_socket_t fd,

 			 short old, short events, void *_idx)

 {

 	struct win32op *win32op = base->evbase;

 	struct idx_info *idx = _idx;

 	if ((events & EV_SIGNAL) && win32op->signals_are_broken)

 		return (-1);

 	if (!(events & (EV_READ|EV_WRITE)))

 		return (0);

 	event_debug(("%s: adding event for %d", __func__, (int)fd));

 	if (events & EV_READ) {

 		if (do_fd_set(win32op, idx, fd, 1)<0)

 			return (-1);

 	}

 	if (events & EV_WRITE) {

 		if (do_fd_set(win32op, idx, fd, 0)<0)

 			return (-1);

 	}

 	return (0);

 }

 int

 win32_del(struct event_base *base, evutil_socket_t fd, short old, short events,

 		  void *_idx)

 {

 	struct win32op *win32op = base->evbase;

 	struct idx_info *idx = _idx;

 	event_debug(("%s: Removing event for "EV_SOCK_FMT,

 		__func__, EV_SOCK_ARG(fd)));

 	if (events & EV_READ)

 		do_fd_clear(base, win32op, idx, 1);

 	if (events & EV_WRITE)

 		do_fd_clear(base, win32op, idx, 0);

 	return 0;

 }

 static void

 fd_set_copy(struct win_fd_set *out, const struct win_fd_set *in)

 {

 	out->fd_count = in->fd_count;

 	memcpy(out->fd_array, in->fd_array, in->fd_count * (sizeof(SOCKET)));

 }

 /*

   static void dump_fd_set(struct win_fd_set *s)

   {

   unsigned int i;

   printf("[ ");

   for(i=0;i<s->fd_count;++i)

   printf("%d ",(int)s->fd_array[i]);

   printf("]\n");

   }

 */

 int

 win32_dispatch(struct event_base *base, struct timeval *tv)

 {

 	struct win32op *win32op = base->evbase;

 	int res = 0;

 	unsigned j, i;

 	int fd_count;

 	SOCKET s;

 	if (win32op->resize_out_sets) {

 		size_t size = FD_SET_ALLOC_SIZE(win32op->num_fds_in_fd_sets);

 		if (!(win32op->readset_out = mm_realloc(win32op->readset_out, size)))

 			return (-1);

 		if (!(win32op->exset_out = mm_realloc(win32op->exset_out, size)))

 			return (-1);

 		if (!(win32op->writeset_out = mm_realloc(win32op->writeset_out, size)))

 			return (-1);

 		win32op->resize_out_sets = 0;

 	}

 	fd_set_copy(win32op->readset_out, win32op->readset_in);

 	fd_set_copy(win32op->exset_out, win32op->writeset_in);

 	fd_set_copy(win32op->writeset_out, win32op->writeset_in);

 	fd_count =

 	    (win32op->readset_out->fd_count > win32op->writeset_out->fd_count) ?

 	    win32op->readset_out->fd_count : win32op->writeset_out->fd_count;

 	if (!fd_count) {

 		long msec = tv ? evutil_tv_to_msec(tv) : LONG_MAX;

 		/* Sleep's DWORD argument is unsigned long */

 		if (msec < 0)

 			msec = LONG_MAX;

 		/* Windows doesn't like you to call select() with no sockets */

 		Sleep(msec);

 		return (0);

 	}

 	EVBASE_RELEASE_LOCK(base, th_base_lock);

 	res = select(fd_count,

 		     (struct fd_set*)win32op->readset_out,

 		     (struct fd_set*)win32op->writeset_out,

 		     (struct fd_set*)win32op->exset_out, tv);

 	EVBASE_ACQUIRE_LOCK(base, th_base_lock);

 	event_debug(("%s: select returned %d", __func__, res));

 	if (res <= 0) {

 		return res;

 	}

 	if (win32op->readset_out->fd_count) {

 		i = rand() % win32op->readset_out->fd_count;

 		for (j=0; j<win32op->readset_out->fd_count; ++j) {

 			if (++i >= win32op->readset_out->fd_count)

 				i = 0;

 			s = win32op->readset_out->fd_array[i];

 			evmap_io_active(base, s, EV_READ);

 		}

 	}

 	if (win32op->exset_out->fd_count) {

 		i = rand() % win32op->exset_out->fd_count;

 		for (j=0; j<win32op->exset_out->fd_count; ++j) {

 			if (++i >= win32op->exset_out->fd_count)

 				i = 0;

 			s = win32op->exset_out->fd_array[i];

 			evmap_io_active(base, s, EV_WRITE);

 		}

 	}

 	if (win32op->writeset_out->fd_count) {

 		SOCKET s;

 		i = rand() % win32op->writeset_out->fd_count;

 		for (j=0; j<win32op->writeset_out->fd_count; ++j) {

 			if (++i >= win32op->writeset_out->fd_count)

 				i = 0;

 			s = win32op->writeset_out->fd_array[i];

 			evmap_io_active(base, s, EV_WRITE);

 		}

 	}

 	return (0);

 }

 void

 win32_dealloc(struct event_base *_base)

 {

 	struct win32op *win32op = _base->evbase;

 	evsig_dealloc(_base);

 	if (win32op->readset_in)

 		mm_free(win32op->readset_in);

 	if (win32op->writeset_in)

 		mm_free(win32op->writeset_in);

 	if (win32op->readset_out)

 		mm_free(win32op->readset_out);

 	if (win32op->writeset_out)

 		mm_free(win32op->writeset_out);

 	if (win32op->exset_out)

 		mm_free(win32op->exset_out);

 	/* XXXXX free the tree. */

 	memset(win32op, 0, sizeof(win32op));

 	mm_free(win32op);

 }