110817bf0SDaniel P. Berrange /*
210817bf0SDaniel P. Berrange * Coroutine-aware I/O functions
310817bf0SDaniel P. Berrange *
410817bf0SDaniel P. Berrange * Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation.
510817bf0SDaniel P. Berrange * Copyright (c) 2011, Red Hat, Inc.
610817bf0SDaniel P. Berrange *
710817bf0SDaniel P. Berrange * Permission is hereby granted, free of charge, to any person obtaining a copy
810817bf0SDaniel P. Berrange * of this software and associated documentation files (the "Software"), to deal
910817bf0SDaniel P. Berrange * in the Software without restriction, including without limitation the rights
1010817bf0SDaniel P. Berrange * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
1110817bf0SDaniel P. Berrange * copies of the Software, and to permit persons to whom the Software is
1210817bf0SDaniel P. Berrange * furnished to do so, subject to the following conditions:
1310817bf0SDaniel P. Berrange *
1410817bf0SDaniel P. Berrange * The above copyright notice and this permission notice shall be included in
1510817bf0SDaniel P. Berrange * all copies or substantial portions of the Software.
1610817bf0SDaniel P. Berrange *
1710817bf0SDaniel P. Berrange * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1810817bf0SDaniel P. Berrange * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1910817bf0SDaniel P. Berrange * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
2010817bf0SDaniel P. Berrange * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
2110817bf0SDaniel P. Berrange * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
2210817bf0SDaniel P. Berrange * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
2310817bf0SDaniel P. Berrange * THE SOFTWARE.
2410817bf0SDaniel P. Berrange */
25aafd7584SPeter Maydell #include "qemu/osdep.h"
2610817bf0SDaniel P. Berrange #include "qemu/sockets.h"
2710817bf0SDaniel P. Berrange #include "qemu/coroutine.h"
2810817bf0SDaniel P. Berrange #include "qemu/iov.h"
2910817bf0SDaniel P. Berrange #include "qemu/main-loop.h"
3010817bf0SDaniel P. Berrange
3110817bf0SDaniel P. Berrange ssize_t coroutine_fn
qemu_co_sendv_recvv(int sockfd,struct iovec * iov,unsigned iov_cnt,size_t offset,size_t bytes,bool do_send)3210817bf0SDaniel P. Berrange qemu_co_sendv_recvv(int sockfd, struct iovec *iov, unsigned iov_cnt,
3310817bf0SDaniel P. Berrange size_t offset, size_t bytes, bool do_send)
3410817bf0SDaniel P. Berrange {
3510817bf0SDaniel P. Berrange size_t done = 0;
3610817bf0SDaniel P. Berrange ssize_t ret;
3710817bf0SDaniel P. Berrange while (done < bytes) {
3810817bf0SDaniel P. Berrange ret = iov_send_recv(sockfd, iov, iov_cnt,
3910817bf0SDaniel P. Berrange offset + done, bytes - done, do_send);
4010817bf0SDaniel P. Berrange if (ret > 0) {
4110817bf0SDaniel P. Berrange done += ret;
4210817bf0SDaniel P. Berrange } else if (ret < 0) {
43b16a44e1SDaniel P. Berrange if (errno == EAGAIN || errno == EWOULDBLOCK) {
4410817bf0SDaniel P. Berrange qemu_coroutine_yield();
4510817bf0SDaniel P. Berrange } else if (done == 0) {
46b16a44e1SDaniel P. Berrange return -errno;
4710817bf0SDaniel P. Berrange } else {
4810817bf0SDaniel P. Berrange break;
4910817bf0SDaniel P. Berrange }
5010817bf0SDaniel P. Berrange } else if (ret == 0 && !do_send) {
5110817bf0SDaniel P. Berrange /* write (send) should never return 0.
5210817bf0SDaniel P. Berrange * read (recv) returns 0 for end-of-file (-data).
5310817bf0SDaniel P. Berrange * In both cases there's little point retrying,
5410817bf0SDaniel P. Berrange * but we do for write anyway, just in case */
5510817bf0SDaniel P. Berrange break;
5610817bf0SDaniel P. Berrange }
5710817bf0SDaniel P. Berrange }
5810817bf0SDaniel P. Berrange return done;
5910817bf0SDaniel P. Berrange }
6010817bf0SDaniel P. Berrange
6110817bf0SDaniel P. Berrange ssize_t coroutine_fn
qemu_co_send_recv(int sockfd,void * buf,size_t bytes,bool do_send)6210817bf0SDaniel P. Berrange qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
6310817bf0SDaniel P. Berrange {
6410817bf0SDaniel P. Berrange struct iovec iov = { .iov_base = buf, .iov_len = bytes };
6510817bf0SDaniel P. Berrange return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send);
6610817bf0SDaniel P. Berrange }
6710817bf0SDaniel P. Berrange
6810817bf0SDaniel P. Berrange typedef struct {
69d154ef37SDietmar Maurer AioContext *ctx;
7010817bf0SDaniel P. Berrange Coroutine *co;
7110817bf0SDaniel P. Berrange int fd;
7210817bf0SDaniel P. Berrange } FDYieldUntilData;
7310817bf0SDaniel P. Berrange
fd_coroutine_enter(void * opaque)7410817bf0SDaniel P. Berrange static void fd_coroutine_enter(void *opaque)
7510817bf0SDaniel P. Berrange {
7610817bf0SDaniel P. Berrange FDYieldUntilData *data = opaque;
77*60f782b6SStefan Hajnoczi aio_set_fd_handler(data->ctx, data->fd, NULL, NULL, NULL, NULL, NULL);
780b8b8753SPaolo Bonzini qemu_coroutine_enter(data->co);
7910817bf0SDaniel P. Berrange }
8010817bf0SDaniel P. Berrange
yield_until_fd_readable(int fd)8110817bf0SDaniel P. Berrange void coroutine_fn yield_until_fd_readable(int fd)
8210817bf0SDaniel P. Berrange {
8310817bf0SDaniel P. Berrange FDYieldUntilData data;
8410817bf0SDaniel P. Berrange
8510817bf0SDaniel P. Berrange assert(qemu_in_coroutine());
86d154ef37SDietmar Maurer data.ctx = qemu_get_current_aio_context();
8710817bf0SDaniel P. Berrange data.co = qemu_coroutine_self();
8810817bf0SDaniel P. Berrange data.fd = fd;
89*60f782b6SStefan Hajnoczi aio_set_fd_handler(data.ctx, fd, fd_coroutine_enter, NULL, NULL, NULL,
90*60f782b6SStefan Hajnoczi &data);
9110817bf0SDaniel P. Berrange qemu_coroutine_yield();
9210817bf0SDaniel P. Berrange }
93