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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* 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 "chardev/char-io.h"
typedef struct IOWatchPoll {
GSource parent;
QIOChannel *ioc;
GSource *src;
IOCanReadHandler *fd_can_read;
GSourceFunc fd_read;
void *opaque;
GMainContext *context;
} IOWatchPoll;
static IOWatchPoll *io_watch_poll_from_source(GSource *source)
{
return container_of(source, IOWatchPoll, parent);
}
static gboolean io_watch_poll_prepare(GSource *source,
gint *timeout)
{
IOWatchPoll *iwp = io_watch_poll_from_source(source);
bool now_active = iwp->fd_can_read(iwp->opaque) > 0;
bool was_active = iwp->src != NULL;
if (was_active == now_active) {
return FALSE;
}
/*
* We do not register the QIOChannel watch as a child GSource.
* The 'prepare' function on the parent GSource will be
* skipped if a child GSource's 'prepare' function indicates
* readiness. We need this prepare function be guaranteed
* to run on *every* iteration of the main loop, because
* it is critical to ensure we remove the QIOChannel watch
* if 'fd_can_read' indicates the frontend cannot receive
* more data.
*/
if (now_active) {
iwp->src = qio_channel_create_watch(
iwp->ioc, G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL);
g_source_set_callback(iwp->src, iwp->fd_read, iwp->opaque, NULL);
g_source_attach(iwp->src, iwp->context);
} else {
g_source_destroy(iwp->src);
g_source_unref(iwp->src);
iwp->src = NULL;
}
return FALSE;
}
static gboolean io_watch_poll_check(GSource *source)
{
return FALSE;
}
static gboolean io_watch_poll_dispatch(GSource *source, GSourceFunc callback,
gpointer user_data)
{
abort();
}
static void io_watch_poll_finalize(GSource *source)
{
/*
* Due to a glib bug, removing the last reference to a source
* inside a finalize callback causes recursive locking (and a
* deadlock). This is not a problem inside other callbacks,
* including dispatch callbacks, so we call io_remove_watch_poll
* to remove this source. At this point, iwp->src must
* be NULL, or we would leak it.
*/
IOWatchPoll *iwp = io_watch_poll_from_source(source);
assert(iwp->src == NULL);
}
static GSourceFuncs io_watch_poll_funcs = {
.prepare = io_watch_poll_prepare,
.check = io_watch_poll_check,
.dispatch = io_watch_poll_dispatch,
.finalize = io_watch_poll_finalize,
};
GSource *io_add_watch_poll(Chardev *chr,
QIOChannel *ioc,
IOCanReadHandler *fd_can_read,
QIOChannelFunc fd_read,
gpointer user_data,
GMainContext *context)
{
IOWatchPoll *iwp;
char *name;
iwp = (IOWatchPoll *) g_source_new(&io_watch_poll_funcs,
sizeof(IOWatchPoll));
iwp->fd_can_read = fd_can_read;
iwp->opaque = user_data;
iwp->ioc = ioc;
iwp->fd_read = (GSourceFunc) fd_read;
iwp->src = NULL;
iwp->context = context;
name = g_strdup_printf("chardev-iowatch-%s", chr->label);
g_source_set_name((GSource *)iwp, name);
g_free(name);
g_source_attach(&iwp->parent, context);
g_source_unref(&iwp->parent);
return (GSource *)iwp;
}
static void io_remove_watch_poll(GSource *source)
{
IOWatchPoll *iwp;
iwp = io_watch_poll_from_source(source);
if (iwp->src) {
g_source_destroy(iwp->src);
g_source_unref(iwp->src);
iwp->src = NULL;
}
g_source_destroy(&iwp->parent);
}
void remove_fd_in_watch(Chardev *chr)
{
if (chr->gsource) {
io_remove_watch_poll(chr->gsource);
chr->gsource = NULL;
}
}
int io_channel_send_full(QIOChannel *ioc,
const void *buf, size_t len,
int *fds, size_t nfds)
{
size_t offset = 0;
while (offset < len) {
ssize_t ret = 0;
struct iovec iov = { .iov_base = (char *)buf + offset,
.iov_len = len - offset };
ret = qio_channel_writev_full(
ioc, &iov, 1,
fds, nfds, 0, NULL);
if (ret == QIO_CHANNEL_ERR_BLOCK) {
if (offset) {
return offset;
}
errno = EAGAIN;
return -1;
} else if (ret < 0) {
errno = EINVAL;
return -1;
}
offset += ret;
}
return offset;
}
int io_channel_send(QIOChannel *ioc, const void *buf, size_t len)
{
return io_channel_send_full(ioc, buf, len, NULL, 0);
}
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