/*
* Coroutine-aware I/O functions
*
* Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation.
* Copyright (c) 2011, Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/sockets.h"
#include "qemu/coroutine.h"
#include "qemu/iov.h"
#include "qemu/main-loop.h"
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)
{
size_t done = 0;
ssize_t ret;
while (done < bytes) {
ret = iov_send_recv(sockfd, iov, iov_cnt,
offset + done, bytes - done, do_send);
if (ret > 0) {
done += ret;
} else if (ret < 0) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
qemu_coroutine_yield();
} else if (done == 0) {
return -errno;
} else {
break;
}
} else if (ret == 0 && !do_send) {
/* write (send) should never return 0.
* read (recv) returns 0 for end-of-file (-data).
* In both cases there's little point retrying,
* but we do for write anyway, just in case */
break;
}
}
return done;
}
ssize_t coroutine_fn
qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
{
struct iovec iov = { .iov_base = buf, .iov_len = bytes };
return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send);
}
typedef struct {
AioContext *ctx;
Coroutine *co;
int fd;
} FDYieldUntilData;
static void fd_coroutine_enter(void *opaque)
{
FDYieldUntilData *data = opaque;
aio_set_fd_handler(data->ctx, data->fd, false, NULL, NULL, NULL, NULL);
qemu_coroutine_enter(data->co);
}
void coroutine_fn yield_until_fd_readable(int fd)
{
FDYieldUntilData data;
assert(qemu_in_coroutine());
data.ctx = qemu_get_current_aio_context();
data.co = qemu_coroutine_self();
data.fd = fd;
aio_set_fd_handler(
data.ctx, fd, false, fd_coroutine_enter, NULL, NULL, &data);
qemu_coroutine_yield();
}
