Hi, I try to add support for NBD in MinGW. Basicalyl this means adding support for win32 sockets to aio-win32.c. What I did was rewrite the file (attachment provided). problem here is that revents for the node related to the nbd socket is always 0 after g_poll() even when I see that data is returned from and nbd server (file attached).
What am I doing wrong ? This was done against QEMU-1.6.0 Thanks, Or
dumpfile.pcap
Description: Binary data
/*
* QEMU aio implementation
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aligu...@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu-common.h"
#include "block/block.h"
#include "qemu/queue.h"
#include "qemu/sockets.h"
struct AioHandler
{
GPollFD pfd;
EventNotifier *e;
int socket;
GIOChannel *channel;
IOHandler *io_read;
IOHandler *io_write;
EventNotifierHandler *io_notify;
AioFlushHandler *io_flush;
int deleted;
int pollfds_idx;
void *opaque;
QLIST_ENTRY(AioHandler) node;
};
static AioHandler *find_aio_handler(AioContext *ctx, int socket)
{
AioHandler *node;
QLIST_FOREACH(node, &ctx->aio_handlers, node) {
if (node->socket == socket)
if (!node->deleted)
return node;
}
return NULL;
}
void aio_set_fd_handler(AioContext *ctx,
int fd,
IOHandler *io_read,
IOHandler *io_write,
AioFlushHandler *io_flush,
void *opaque)
{
AioHandler *node;
node = find_aio_handler(ctx, fd);
/* Are we deleting the fd handler? */
if (!io_read && !io_write) {
if (node) {
g_source_remove_poll(&ctx->source, &node->pfd);
g_io_channel_unref(node->channel);
/* If the lock is held, just mark the node as deleted */
if (ctx->walking_handlers) {
node->deleted = 1;
node->pfd.revents = 0;
} else {
/* Otherwise, delete it for real. We can't just mark it as
* deleted because deleted nodes are only cleaned up after
* releasing the walking_handlers lock.
*/
QLIST_REMOVE(node, node);
g_free(node);
}
}
} else {
if (node == NULL) {
/* Alloc and insert if it's not already there */
node = g_malloc0(sizeof(AioHandler));
node->socket = fd;
node->channel = g_io_channel_win32_new_socket(fd);
g_io_channel_win32_make_pollfd(node->channel,
(io_read ? G_IO_IN | G_IO_HUP | G_IO_ERR : 0)|(io_write ? G_IO_OUT | G_IO_ERR : 0),
&node->pfd);
QLIST_INSERT_HEAD(&ctx->aio_handlers, node, node);
g_source_add_poll(&ctx->source, &node->pfd);
}
/* Update handler with latest information */
node->io_read = io_read;
node->io_write = io_write;
node->io_flush = io_flush;
node->opaque = opaque;
node->pollfds_idx = -1;
}
aio_notify(ctx);
}
void aio_set_event_notifier(AioContext *ctx,
EventNotifier *notifier,
EventNotifierHandler *io_notify,
AioFlushEventNotifierHandler *io_flush)
{
AioHandler *node;
QLIST_FOREACH(node, &ctx->aio_handlers, node) {
if (node->e == notifier && !node->deleted) {
break;
}
}
/* Are we deleting the fd handler? */
if (!io_notify) {
if (node) {
g_source_remove_poll(&ctx->source, &node->pfd);
/* If the lock is held, just mark the node as deleted */
if (ctx->walking_handlers) {
node->deleted = 1;
node->pfd.revents = 0;
} else {
/* Otherwise, delete it for real. We can't just mark it as
* deleted because deleted nodes are only cleaned up after
* releasing the walking_handlers lock.
*/
QLIST_REMOVE(node, node);
g_free(node);
}
}
} else {
if (node == NULL) {
/* Alloc and insert if it's not already there */
node = g_malloc0(sizeof(AioHandler));
node->e = notifier;
node->pfd.fd = (uintptr_t)event_notifier_get_handle(notifier);
node->pfd.events = G_IO_IN;
QLIST_INSERT_HEAD(&ctx->aio_handlers, node, node);
g_source_add_poll(&ctx->source, &node->pfd);
}
/* Update handler with latest information */
node->io_notify = io_notify;
node->io_flush = io_flush;
}
aio_notify(ctx);
}
bool aio_pending(AioContext *ctx)
{
AioHandler *node;
QLIST_FOREACH(node, &ctx->aio_handlers, node) {
// HANDLE ?
if (node->pfd.revents && node->io_notify) {
return true;
}
// SOCKET ?
int revents;
revents = node->pfd.revents & node->pfd.events;
if ((revents & G_IO_IN) && node->io_read) {
return true;
}
if ((revents & G_IO_OUT) && node->io_write) {
return true;
}
}
return false;
}
static bool aio_dispatch(AioContext *ctx)
{
AioHandler *node;
bool progress = false;
/*
* We have to walk very carefully in case qemu_aio_set_fd_handler is
* called while we're walking.
*/
node = QLIST_FIRST(&ctx->aio_handlers);
while (node) {
AioHandler *tmp = node;
ctx->walking_handlers++;
if (!node->deleted) {
// HANDLE ?
if (node->pfd.revents && node->io_notify) {
node->pfd.revents = 0;
node->io_notify(node->e);
/* aio_notify() does not count as progress */
if (node->e != &ctx->notifier) {
progress = true;
}
}
// SOCKET ?
int revents = node->pfd.revents & node->pfd.events;
node->pfd.revents = 0;
if ((revents & G_IO_IN) && node->io_read) {
node->io_read(node->opaque);
/* aio_notify() does not count as progress */
if (node->opaque != &ctx->notifier) {
progress = true;
}
}
if ((revents & G_IO_OUT) && node->io_write) {
node->io_write(node->opaque);
progress = true;
}
}
node = QLIST_NEXT(node, node);
ctx->walking_handlers--;
if (!ctx->walking_handlers && tmp->deleted) {
QLIST_REMOVE(tmp, node);
g_free(tmp);
}
}
return progress;
}
bool aio_poll(AioContext *ctx, bool blocking)
{
AioHandler *node;
int ret;
bool busy, progress;
progress = false;
/*
* If there are callbacks left that have been queued, we need to call them.
* Do not call select in this case, because it is possible that the caller
* does not need a complete flush (as is the case for qemu_aio_wait loops).
*/
if (aio_bh_poll(ctx)) {
blocking = false;
progress = true;
}
if (aio_dispatch(ctx)) {
progress = true;
}
if (progress && !blocking) {
return true;
}
ctx->walking_handlers++;
g_array_set_size(ctx->pollfds, 0);
/* fill pollfds */
busy = false;
QLIST_FOREACH(node, &ctx->aio_handlers, node) {
if (node->deleted)
continue;
node->pollfds_idx = -1;
/* If there aren't pending AIO operations, don't invoke callbacks.
* Otherwise, if there are no AIO requests, qemu_aio_wait() would
* wait indefinitely.
*/
if (node->io_flush) {
if (node->opaque != NULL &&
node->io_flush(node->opaque) == 0)
continue;
else if (node->opaque == NULL &&
node->io_flush(node->e) == 0)
continue;
busy = true;
}
if (!node->deleted && node->pfd.events) {
GPollFD pfd = {
.fd = node->pfd.fd,
.events = node->pfd.events,
};
node->pollfds_idx = ctx->pollfds->len;
g_array_append_val(ctx->pollfds, pfd);
}
}
ctx->walking_handlers--;
/* No AIO operations? Get us out of here */
if (!busy) {
return progress;
}
/* wait until next event */
ret = g_poll((GPollFD *)ctx->pollfds->data,
ctx->pollfds->len,
blocking ? -1 : 0);
/* if we have any readable fds, dispatch event */
if (ret > 0) {
QLIST_FOREACH(node, &ctx->aio_handlers, node) {
if (node->pollfds_idx != -1) {
GPollFD *pfd = &g_array_index(ctx->pollfds, GPollFD,
node->pollfds_idx);
node->pfd.revents = pfd->revents;
}
}
if (aio_dispatch(ctx)) {
progress = true;
}
}
assert(progress || busy);
return true;
}
