From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55732) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOpCr-0000FE-48 for qemu-devel@nongnu.org; Wed, 04 Jan 2017 12:18:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cOpCn-0001Bj-Pe for qemu-devel@nongnu.org; Wed, 04 Jan 2017 12:18:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35558) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cOpCn-0001BW-HM for qemu-devel@nongnu.org; Wed, 04 Jan 2017 12:18:29 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8A9F64D68E for ; Wed, 4 Jan 2017 17:18:29 +0000 (UTC) Date: Wed, 4 Jan 2017 17:18:23 +0000 From: "Daniel P. Berrange" Message-ID: <20170104171823.GJ10541@redhat.com> Reply-To: "Daniel P. Berrange" References: <20161223182641.2718-1-pbonzini@redhat.com> <20161223182641.2718-3-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20161223182641.2718-3-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/3] io: make qio_channel_yield aware of AioContexts List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org 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 > --- > 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 -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|