michael@0: /*
michael@0:  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  * 3. The name of the author may not be used to endorse or promote products
michael@0:  *    derived from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
michael@0:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
michael@0:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
michael@0:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
michael@0:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
michael@0:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: 
michael@0: /**
michael@0:    @file buffer_iocp.c
michael@0: 
michael@0:    This module implements overlapped read and write functions for evbuffer
michael@0:    objects on Windows.
michael@0: */
michael@0: 
michael@0: #include "event2/buffer.h"
michael@0: #include "event2/buffer_compat.h"
michael@0: #include "event2/util.h"
michael@0: #include "event2/thread.h"
michael@0: #include "event2/event-config.h"
michael@0: #include "util-internal.h"
michael@0: #include "evthread-internal.h"
michael@0: #include "evbuffer-internal.h"
michael@0: #include "iocp-internal.h"
michael@0: #include "mm-internal.h"
michael@0: 
michael@0: #include <winsock2.h>
michael@0: #include <windows.h>
michael@0: #include <stdio.h>
michael@0: 
michael@0: #define MAX_WSABUFS 16
michael@0: 
michael@0: /** An evbuffer that can handle overlapped IO. */
michael@0: struct evbuffer_overlapped {
michael@0: 	struct evbuffer buffer;
michael@0: 	/** The socket that we're doing overlapped IO on. */
michael@0: 	evutil_socket_t fd;
michael@0: 
michael@0: 	/** pending I/O type */
michael@0: 	unsigned read_in_progress : 1;
michael@0: 	unsigned write_in_progress : 1;
michael@0: 
michael@0: 	/** The first pinned chain in the buffer. */
michael@0: 	struct evbuffer_chain *first_pinned;
michael@0: 
michael@0: 	/** How many chains are pinned; how many of the fields in buffers
michael@0: 	 * are we using. */
michael@0: 	int n_buffers;
michael@0: 	WSABUF buffers[MAX_WSABUFS];
michael@0: };
michael@0: 
michael@0: /** Given an evbuffer, return the correponding evbuffer structure, or NULL if
michael@0:  * the evbuffer isn't overlapped. */
michael@0: static inline struct evbuffer_overlapped *
michael@0: upcast_evbuffer(struct evbuffer *buf)
michael@0: {
michael@0: 	if (!buf || !buf->is_overlapped)
michael@0: 		return NULL;
michael@0: 	return EVUTIL_UPCAST(buf, struct evbuffer_overlapped, buffer);
michael@0: }
michael@0: 
michael@0: /** Unpin all the chains noted as pinned in 'eo'. */
michael@0: static void
michael@0: pin_release(struct evbuffer_overlapped *eo, unsigned flag)
michael@0: {
michael@0: 	int i;
michael@0: 	struct evbuffer_chain *next, *chain = eo->first_pinned;
michael@0: 
michael@0: 	for (i = 0; i < eo->n_buffers; ++i) {
michael@0: 		EVUTIL_ASSERT(chain);
michael@0: 		next = chain->next;
michael@0: 		_evbuffer_chain_unpin(chain, flag);
michael@0: 		chain = next;
michael@0: 	}
michael@0: }
michael@0: 
michael@0: void
michael@0: evbuffer_commit_read(struct evbuffer *evbuf, ev_ssize_t nBytes)
michael@0: {
michael@0: 	struct evbuffer_overlapped *buf = upcast_evbuffer(evbuf);
michael@0: 	struct evbuffer_chain **chainp;
michael@0: 	size_t remaining, len;
michael@0: 	unsigned i;
michael@0: 
michael@0: 	EVBUFFER_LOCK(evbuf);
michael@0: 	EVUTIL_ASSERT(buf->read_in_progress && !buf->write_in_progress);
michael@0: 	EVUTIL_ASSERT(nBytes >= 0); /* XXXX Can this be false? */
michael@0: 
michael@0: 	evbuffer_unfreeze(evbuf, 0);
michael@0: 
michael@0: 	chainp = evbuf->last_with_datap;
michael@0: 	if (!((*chainp)->flags & EVBUFFER_MEM_PINNED_R))
michael@0: 		chainp = &(*chainp)->next;
michael@0: 	remaining = nBytes;
michael@0: 	for (i = 0; remaining > 0 && i < (unsigned)buf->n_buffers; ++i) {
michael@0: 		EVUTIL_ASSERT(*chainp);
michael@0: 		len = buf->buffers[i].len;
michael@0: 		if (remaining < len)
michael@0: 			len = remaining;
michael@0: 		(*chainp)->off += len;
michael@0: 		evbuf->last_with_datap = chainp;
michael@0: 		remaining -= len;
michael@0: 		chainp = &(*chainp)->next;
michael@0: 	}
michael@0: 
michael@0: 	pin_release(buf, EVBUFFER_MEM_PINNED_R);
michael@0: 
michael@0: 	buf->read_in_progress = 0;
michael@0: 
michael@0: 	evbuf->total_len += nBytes;
michael@0: 	evbuf->n_add_for_cb += nBytes;
michael@0: 
michael@0: 	evbuffer_invoke_callbacks(evbuf);
michael@0: 
michael@0: 	_evbuffer_decref_and_unlock(evbuf);
michael@0: }
michael@0: 
michael@0: void
michael@0: evbuffer_commit_write(struct evbuffer *evbuf, ev_ssize_t nBytes)
michael@0: {
michael@0: 	struct evbuffer_overlapped *buf = upcast_evbuffer(evbuf);
michael@0: 
michael@0: 	EVBUFFER_LOCK(evbuf);
michael@0: 	EVUTIL_ASSERT(buf->write_in_progress && !buf->read_in_progress);
michael@0: 	evbuffer_unfreeze(evbuf, 1);
michael@0: 	evbuffer_drain(evbuf, nBytes);
michael@0: 	pin_release(buf,EVBUFFER_MEM_PINNED_W);
michael@0: 	buf->write_in_progress = 0;
michael@0: 	_evbuffer_decref_and_unlock(evbuf);
michael@0: }
michael@0: 
michael@0: struct evbuffer *
michael@0: evbuffer_overlapped_new(evutil_socket_t fd)
michael@0: {
michael@0: 	struct evbuffer_overlapped *evo;
michael@0: 
michael@0: 	evo = mm_calloc(1, sizeof(struct evbuffer_overlapped));
michael@0: 	if (!evo)
michael@0: 		return NULL;
michael@0: 
michael@0: 	TAILQ_INIT(&evo->buffer.callbacks);
michael@0: 	evo->buffer.refcnt = 1;
michael@0: 	evo->buffer.last_with_datap = &evo->buffer.first;
michael@0: 
michael@0: 	evo->buffer.is_overlapped = 1;
michael@0: 	evo->fd = fd;
michael@0: 
michael@0: 	return &evo->buffer;
michael@0: }
michael@0: 
michael@0: int
michael@0: evbuffer_launch_write(struct evbuffer *buf, ev_ssize_t at_most,
michael@0: 		struct event_overlapped *ol)
michael@0: {
michael@0: 	struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
michael@0: 	int r = -1;
michael@0: 	int i;
michael@0: 	struct evbuffer_chain *chain;
michael@0: 	DWORD bytesSent;
michael@0: 
michael@0: 	if (!buf) {
michael@0: 		/* No buffer, or it isn't overlapped */
michael@0: 		return -1;
michael@0: 	}
michael@0: 
michael@0: 	EVBUFFER_LOCK(buf);
michael@0: 	EVUTIL_ASSERT(!buf_o->read_in_progress);
michael@0: 	if (buf->freeze_start || buf_o->write_in_progress)
michael@0: 		goto done;
michael@0: 	if (!buf->total_len) {
michael@0: 		/* Nothing to write */
michael@0: 		r = 0;
michael@0: 		goto done;
michael@0: 	} else if (at_most < 0 || (size_t)at_most > buf->total_len) {
michael@0: 		at_most = buf->total_len;
michael@0: 	}
michael@0: 	evbuffer_freeze(buf, 1);
michael@0: 
michael@0: 	buf_o->first_pinned = NULL;
michael@0: 	buf_o->n_buffers = 0;
michael@0: 	memset(buf_o->buffers, 0, sizeof(buf_o->buffers));
michael@0: 
michael@0: 	chain = buf_o->first_pinned = buf->first;
michael@0: 
michael@0: 	for (i=0; i < MAX_WSABUFS && chain; ++i, chain=chain->next) {
michael@0: 		WSABUF *b = &buf_o->buffers[i];
michael@0: 		b->buf = (char*)( chain->buffer + chain->misalign );
michael@0: 		_evbuffer_chain_pin(chain, EVBUFFER_MEM_PINNED_W);
michael@0: 
michael@0: 		if ((size_t)at_most > chain->off) {
michael@0: 			/* XXXX Cast is safe for now, since win32 has no
michael@0: 			   mmaped chains.  But later, we need to have this
michael@0: 			   add more WSAbufs if chain->off is greater than
michael@0: 			   ULONG_MAX */
michael@0: 			b->len = (unsigned long)chain->off;
michael@0: 			at_most -= chain->off;
michael@0: 		} else {
michael@0: 			b->len = (unsigned long)at_most;
michael@0: 			++i;
michael@0: 			break;
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	buf_o->n_buffers = i;
michael@0: 	_evbuffer_incref(buf);
michael@0: 	if (WSASend(buf_o->fd, buf_o->buffers, i, &bytesSent, 0,
michael@0: 		&ol->overlapped, NULL)) {
michael@0: 		int error = WSAGetLastError();
michael@0: 		if (error != WSA_IO_PENDING) {
michael@0: 			/* An actual error. */
michael@0: 			pin_release(buf_o, EVBUFFER_MEM_PINNED_W);
michael@0: 			evbuffer_unfreeze(buf, 1);
michael@0: 			evbuffer_free(buf); /* decref */
michael@0: 			goto done;
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	buf_o->write_in_progress = 1;
michael@0: 	r = 0;
michael@0: done:
michael@0: 	EVBUFFER_UNLOCK(buf);
michael@0: 	return r;
michael@0: }
michael@0: 
michael@0: int
michael@0: evbuffer_launch_read(struct evbuffer *buf, size_t at_most,
michael@0: 		struct event_overlapped *ol)
michael@0: {
michael@0: 	struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
michael@0: 	int r = -1, i;
michael@0: 	int nvecs;
michael@0: 	int npin=0;
michael@0: 	struct evbuffer_chain *chain=NULL, **chainp;
michael@0: 	DWORD bytesRead;
michael@0: 	DWORD flags = 0;
michael@0: 	struct evbuffer_iovec vecs[MAX_WSABUFS];
michael@0: 
michael@0: 	if (!buf_o)
michael@0: 		return -1;
michael@0: 	EVBUFFER_LOCK(buf);
michael@0: 	EVUTIL_ASSERT(!buf_o->write_in_progress);
michael@0: 	if (buf->freeze_end || buf_o->read_in_progress)
michael@0: 		goto done;
michael@0: 
michael@0: 	buf_o->first_pinned = NULL;
michael@0: 	buf_o->n_buffers = 0;
michael@0: 	memset(buf_o->buffers, 0, sizeof(buf_o->buffers));
michael@0: 
michael@0: 	if (_evbuffer_expand_fast(buf, at_most, MAX_WSABUFS) == -1)
michael@0: 		goto done;
michael@0: 	evbuffer_freeze(buf, 0);
michael@0: 
michael@0: 	nvecs = _evbuffer_read_setup_vecs(buf, at_most,
michael@0: 	    vecs, MAX_WSABUFS, &chainp, 1);
michael@0: 	for (i=0;i<nvecs;++i) {
michael@0: 		WSABUF_FROM_EVBUFFER_IOV(
michael@0: 			&buf_o->buffers[i],
michael@0: 			&vecs[i]);
michael@0: 	}
michael@0: 
michael@0: 	buf_o->n_buffers = nvecs;
michael@0: 	buf_o->first_pinned = chain = *chainp;
michael@0: 
michael@0: 	npin=0;
michael@0: 	for ( ; chain; chain = chain->next) {
michael@0: 		_evbuffer_chain_pin(chain, EVBUFFER_MEM_PINNED_R);
michael@0: 		++npin;
michael@0: 	}
michael@0: 	EVUTIL_ASSERT(npin == nvecs);
michael@0: 
michael@0: 	_evbuffer_incref(buf);
michael@0: 	if (WSARecv(buf_o->fd, buf_o->buffers, nvecs, &bytesRead, &flags,
michael@0: 		    &ol->overlapped, NULL)) {
michael@0: 		int error = WSAGetLastError();
michael@0: 		if (error != WSA_IO_PENDING) {
michael@0: 			/* An actual error. */
michael@0: 			pin_release(buf_o, EVBUFFER_MEM_PINNED_R);
michael@0: 			evbuffer_unfreeze(buf, 0);
michael@0: 			evbuffer_free(buf); /* decref */
michael@0: 			goto done;
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	buf_o->read_in_progress = 1;
michael@0: 	r = 0;
michael@0: done:
michael@0: 	EVBUFFER_UNLOCK(buf);
michael@0: 	return r;
michael@0: }
michael@0: 
michael@0: evutil_socket_t
michael@0: _evbuffer_overlapped_get_fd(struct evbuffer *buf)
michael@0: {
michael@0: 	struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
michael@0: 	return buf_o ? buf_o->fd : -1;
michael@0: }
michael@0: 
michael@0: void
michael@0: _evbuffer_overlapped_set_fd(struct evbuffer *buf, evutil_socket_t fd)
michael@0: {
michael@0: 	struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
michael@0: 	EVBUFFER_LOCK(buf);
michael@0: 	/* XXX is this right?, should it cancel current I/O operations? */
michael@0: 	if (buf_o)
michael@0: 		buf_o->fd = fd;
michael@0: 	EVBUFFER_UNLOCK(buf);
michael@0: }