On Fri, Dec 23, 2016 at 07:26:40PM +0100, Paolo Bonzini wrote:
> Support separate coroutines for reading and writing, and
> restart the coroutine on the AioContext where it was suspended on.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> include/io/channel.h | 7 +++---
> io/channel-socket.c | 12 +++++-----
> io/channel.c | 62
> ++++++++++++++++++++++++++++++++++------------------
> 3 files changed, 50 insertions(+), 31 deletions(-)
>
> diff --git a/include/io/channel.h b/include/io/channel.h
> index 248bc76..3030fdb 100644
> --- a/include/io/channel.h
> +++ b/include/io/channel.h
> @@ -23,6 +23,7 @@
>
> #include "qemu-common.h"
> #include "qom/object.h"
> +#include "qemu/coroutine.h"
> #include "block/aio.h"
>
> #define TYPE_QIO_CHANNEL "qio-channel"
> @@ -59,8 +60,6 @@ typedef gboolean (*QIOChannelFunc)(QIOChannel *ioc,
> GIOCondition condition,
> gpointer data);
>
> -typedef struct QIOChannelRestart QIOChannelRestart;
> -
> /**
> * QIOChannel:
> *
> @@ -84,8 +83,8 @@ struct QIOChannel {
> unsigned int features; /* bitmask of QIOChannelFeatures */
> char *name;
> AioContext *ctx;
> - QIOChannelRestart *read_coroutine;
> - QIOChannelRestart *write_coroutine;
> + Coroutine *read_coroutine;
> + Coroutine *write_coroutine;
Seems this ought to have been squashed into the previous patch
> diff --git a/io/channel-socket.c b/io/channel-socket.c
> index 4d5f180..732ba20 100644
> --- a/io/channel-socket.c
> +++ b/io/channel-socket.c
> @@ -740,14 +740,14 @@ qio_channel_socket_shutdown(QIOChannel *ioc,
> return 0;
> }
>
> -static GSource *qio_channel_socket_set_fd_handler(QIOChannel *ioc,
> - AioContext *ctx,
> - IOHandler *io_read,
> - IOHandler *io_write,
> - void *opaque)
> +static void qio_channel_socket_set_fd_handler(QIOChannel *ioc,
> + AioContext *ctx,
> + IOHandler *io_read,
> + IOHandler *io_write,
> + void *opaque)
> {
> QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
> - aio_set_fd_handler(ctx, sioc->fd, false, io_read, io_write, opaque);
> + aio_set_fd_handler(ctx, sioc->fd, false, io_read, io_write, NULL,
> opaque);
> }
And this ought to be in previous patch too.
>
> diff --git a/io/channel.c b/io/channel.c
> index 9ef683c..d4b3a5a3 100644
> --- a/io/channel.c
> +++ b/io/channel.c
> @@ -21,7 +21,7 @@
> #include "qemu/osdep.h"
> #include "io/channel.h"
> #include "qapi/error.h"
> -#include "qemu/coroutine.h"
> +#include "qemu/main-loop.h"
>
> bool qio_channel_has_feature(QIOChannel *ioc,
> QIOChannelFeature feature)
> @@ -238,22 +238,43 @@ off_t qio_channel_io_seek(QIOChannel *ioc,
> }
>
>
> -typedef struct QIOChannelYieldData QIOChannelYieldData;
> -struct QIOChannelYieldData {
> - QIOChannel *ioc;
> - Coroutine *co;
> -};
> +static void qio_channel_set_fd_handlers(QIOChannel *ioc);
> +
> +static void qio_channel_restart_read(void *opaque)
> +{
> + QIOChannel *ioc = opaque;
> + Coroutine *co = ioc->read_coroutine;
>
> + ioc->read_coroutine = NULL;
> + qio_channel_set_fd_handlers(ioc);
> + aio_co_wake(co);
> +}
>
> -static gboolean qio_channel_yield_enter(QIOChannel *ioc,
> - GIOCondition condition,
> - gpointer opaque)
> +static void qio_channel_restart_write(void *opaque)
> {
> - QIOChannelYieldData *data = opaque;
> - qemu_coroutine_enter(data->co);
> - return FALSE;
> + QIOChannel *ioc = opaque;
> + Coroutine *co = ioc->write_coroutine;
> +
> + ioc->write_coroutine = NULL;
> + qio_channel_set_fd_handlers(ioc);
> + aio_co_wake(co);
> }
>
> +static void qio_channel_set_fd_handlers(QIOChannel *ioc)
> +{
> + IOHandler *rd_handler = NULL, *wr_handler = NULL;
> +
> + if (ioc->read_coroutine) {
> + rd_handler = qio_channel_restart_read;
> + }
> + if (ioc->write_coroutine) {
> + rd_handler = qio_channel_restart_write;
> + }
> +
> + qio_channel_set_fd_handler(ioc,
> + ioc->ctx ? ioc->ctx :
> iohandler_get_aio_context(),
> + rd_handler, wr_handler, ioc);
> +}
ioc->read_coroutine & ioc->write_coroutine can only be non-NULL during
a qio_channel_yield() caller. So it seems that calling
qio_channel_set_fd_handlers() from the qio_channel_set_aio_context()
method in the previous patch is not required, as those two callback
pointers will always be NULL.
> @@ -272,16 +293,15 @@ void qio_channel_set_aio_context(QIOChannel *ioc,
> void coroutine_fn qio_channel_yield(QIOChannel *ioc,
> GIOCondition condition)
> {
> - QIOChannelYieldData data;
> -
> assert(qemu_in_coroutine());
> - data.ioc = ioc;
> - data.co = qemu_coroutine_self();
> - qio_channel_add_watch(ioc,
> - condition,
> - qio_channel_yield_enter,
> - &data,
> - NULL);
> + if (condition == G_IO_IN) {
> + ioc->read_coroutine = qemu_coroutine_self();
> + } else if (condition == G_IO_OUT) {
> + ioc->write_coroutine = qemu_coroutine_self();
> + } else {
> + abort();
> + }
Do we really need this to be an either/or/abort ? It looks like
the qio_channel_set_fd_handlers() method is happy top have both
read_coroutine & write_coroutine set.
If it does need to be exclusive though, can you update the API
docs for this method to mention that.
> + qio_channel_set_fd_handlers(ioc);
> qemu_coroutine_yield();
> }
Regards,
Daniel
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