aio: extract aio_dispatch() from aio_poll()

We will need to loop over AioHandlers calling ->io_read()/->io_write()
when aio_poll() is converted from select(2) to g_poll(2).

Luckily the code for this already exists, extract it into the new
aio_dispatch() function.

Two small changes:

 * aio_poll() checks !node->deleted to avoid calling handlers that have
   been deleted.

 * Fix typo 'then' -> 'them' in aio_poll() comment.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1361356113-11049-9-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Stefan Hajnoczi 2013-02-20 11:28:31 +01:00 committed by Anthony Liguori
parent 9cbaacf999
commit d0c8d2c05f
1 changed files with 35 additions and 22 deletions

View File

@ -129,30 +129,12 @@ bool aio_pending(AioContext *ctx)
return false;
}
bool aio_poll(AioContext *ctx, bool blocking)
static bool aio_dispatch(AioContext *ctx)
{
static struct timeval tv0;
AioHandler *node;
fd_set rdfds, wrfds;
int max_fd = -1;
int ret;
bool busy, progress;
progress = false;
bool progress = false;
/*
* If there are callbacks left that have been queued, we need to call then.
* 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;
}
/*
* Then dispatch any pending callbacks from the GSource.
*
* We have to walk very carefully in case qemu_aio_set_fd_handler is
* called while we're walking.
*/
@ -167,11 +149,15 @@ bool aio_poll(AioContext *ctx, bool blocking)
node->pfd.revents = 0;
/* See comment in aio_pending. */
if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR) && node->io_read) {
if (!node->deleted &&
(revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) &&
node->io_read) {
node->io_read(node->opaque);
progress = true;
}
if (revents & (G_IO_OUT | G_IO_ERR) && node->io_write) {
if (!node->deleted &&
(revents & (G_IO_OUT | G_IO_ERR)) &&
node->io_write) {
node->io_write(node->opaque);
progress = true;
}
@ -186,6 +172,33 @@ bool aio_poll(AioContext *ctx, bool blocking)
g_free(tmp);
}
}
return progress;
}
bool aio_poll(AioContext *ctx, bool blocking)
{
static struct timeval tv0;
AioHandler *node;
fd_set rdfds, wrfds;
int max_fd = -1;
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;