From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58320) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cT6pV-0000F1-5v for qemu-devel@nongnu.org; Mon, 16 Jan 2017 07:56:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cT6pS-0006p3-21 for qemu-devel@nongnu.org; Mon, 16 Jan 2017 07:56:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46858) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cT6pR-0006ov-PH for qemu-devel@nongnu.org; Mon, 16 Jan 2017 07:56:05 -0500 Received: from smtp.corp.redhat.com (int-mx16.intmail.prod.int.phx2.redhat.com [10.5.11.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 970704DAF7 for ; Mon, 16 Jan 2017 12:56:05 +0000 (UTC) Date: Mon, 16 Jan 2017 12:55:59 +0000 From: "Daniel P. Berrange" Message-ID: <20170116125559.GH13096@redhat.com> Reply-To: "Daniel P. Berrange" References: <20170113131731.1246-1-pbonzini@redhat.com> <20170113131731.1246-6-pbonzini@redhat.com> <20170116113824.GD14226@lemon.Home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170116113824.GD14226@lemon.Home> Subject: Re: [Qemu-devel] [PATCH 05/16] io: make qio_channel_yield aware of AioContexts List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: Paolo Bonzini , qemu-devel@nongnu.org, stefanha@redhat.com On Mon, Jan 16, 2017 at 07:38:24PM +0800, Fam Zheng wrote: > On Fri, 01/13 14:17, Paolo Bonzini wrote: > > Support separate coroutines for reading and writing, and place the > > read/write handlers on the AioContext that the QIOChannel is registered > > with. > > > > Signed-off-by: Paolo Bonzini > > --- > > include/io/channel.h | 37 ++++++++++++++++++---- > > io/channel.c | 86 ++++++++++++++++++++++++++++++++++++++------------ > > tests/Makefile.include | 2 +- > > 3 files changed, 96 insertions(+), 29 deletions(-) > > > > diff --git a/include/io/channel.h b/include/io/channel.h > > index 665edd7..d7bad94 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; > > #ifdef _WIN32 > > HANDLE event; /* For use with GSource on Win32 */ > > #endif > > @@ -508,13 +507,37 @@ guint qio_channel_add_watch(QIOChannel *ioc, > > > > > > /** > > + * qio_channel_set_aio_context: > > + * @ioc: the channel object > > + * @ctx: the #AioContext to set the handlers on > > + * > > + * Request that qio_channel_yield() sets I/O handlers on > > + * the given #AioContext. If @ctx is %NULL, qio_channel_yield() > > + * uses QEMU's main thread event loop. > > + */ > > +void qio_channel_set_aio_context(QIOChannel *ioc, > > + AioContext *ctx); > > + > > +/** > > + * qio_channel_detach_aio_context: > > + * @ioc: the channel object > > + * > > + * Disable any I/O handlers set by qio_channel_yield(). With the > > + * help of aio_co_schedule(), this allows moving a coroutine that was > > + * paused by qio_channel_yield() to another context. > > + */ > > +void qio_channel_detach_aio_context(QIOChannel *ioc); > > + > > +/** > > * qio_channel_yield: > > * @ioc: the channel object > > * @condition: the I/O condition to wait for > > * > > - * Yields execution from the current coroutine until > > - * the condition indicated by @condition becomes > > - * available. > > + * Yields execution from the current coroutine until the condition > > + * indicated by @condition becomes available. @condition must > > + * be either %G_IO_IN or %G_IO_OUT; it cannot contain both. In > > + * addition, no two coroutine can be waiting on the same condition > > + * and channel at the same time. > > * > > * This must only be called from coroutine context > > */ > > diff --git a/io/channel.c b/io/channel.c > > index ce470d7..1e043bf 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) > > @@ -238,36 +238,80 @@ off_t qio_channel_io_seek(QIOChannel *ioc, > > } > > > > > > -typedef struct QIOChannelYieldData QIOChannelYieldData; > > -struct QIOChannelYieldData { > > - QIOChannel *ioc; > > - Coroutine *co; > > -}; > > +static void qio_channel_set_aio_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_aio_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_aio_fd_handlers(ioc); > > + aio_co_wake(co); > > } > > > > +static void qio_channel_set_aio_fd_handlers(QIOChannel *ioc) > > +{ > > + IOHandler *rd_handler = NULL, *wr_handler = NULL; > > + AioContext *ctx; > > + > > + if (ioc->read_coroutine) { > > + rd_handler = qio_channel_restart_read; > > s/\t/ / > > > + } > > + if (ioc->write_coroutine) { > > + rd_handler = qio_channel_restart_write; > > s/\t/ / > > > + } > > + > > + ctx = ioc->ctx ? ioc->ctx : iohandler_get_aio_context(); > > + qio_channel_set_aio_fd_handler(ioc, ctx, rd_handler, wr_handler, ioc); > > +} > > + > > +void qio_channel_set_aio_context(QIOChannel *ioc, > > + AioContext *ctx) > > +{ > > + AioContext *old_ctx; > > + if (ioc->ctx == ctx) { > > + return; > > + } > > + > > + old_ctx = ioc->ctx ? ioc->ctx : iohandler_get_aio_context(); > > + qio_channel_set_aio_fd_handler(ioc, old_ctx, NULL, NULL, NULL); > > + ioc->ctx = ctx; > > + qio_channel_set_aio_fd_handlers(ioc); > > +} > > + > > +void qio_channel_detach_aio_context(QIOChannel *ioc) > > +{ > > + ioc->read_coroutine = NULL; > > + ioc->write_coroutine = NULL; > > + qio_channel_set_aio_fd_handlers(ioc); > > Why is qio_channel_set_aio_fd_handler not needed here? > > > + ioc->ctx = NULL; > > +} > > > > 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) { > > + assert(!ioc->read_coroutine); > > + ioc->read_coroutine = qemu_coroutine_self(); > > + } else if (condition == G_IO_OUT) { > > + assert(!ioc->write_coroutine); > > + ioc->write_coroutine = qemu_coroutine_self(); > > + } else { > > + abort(); > > + } > > + qio_channel_set_aio_fd_handlers(ioc); > > qemu_coroutine_yield(); > > } > > > > diff --git a/tests/Makefile.include b/tests/Makefile.include > > index 3b8ed9d..7d11bbb 100644 > > --- a/tests/Makefile.include > > +++ b/tests/Makefile.include > > @@ -493,7 +493,7 @@ tests/check-qjson$(EXESUF): tests/check-qjson.o $(test-util-obj-y) > > tests/check-qom-interface$(EXESUF): tests/check-qom-interface.o $(test-qom-obj-y) > > tests/check-qom-proplist$(EXESUF): tests/check-qom-proplist.o $(test-qom-obj-y) > > > > -tests/test-char$(EXESUF): tests/test-char.o qemu-char.o qemu-timer.o $(test-util-obj-y) $(qtest-obj-y) $(test-io-obj-y) > > +tests/test-char$(EXESUF): tests/test-char.o qemu-char.o qemu-timer.o $(test-util-obj-y) $(qtest-obj-y) $(test-io-obj-y) $(test-block-obj-y) > > I guess this is a hint for moving coroutine code into a lower level library like > util. The coroutine code is already in util/, so I'm assuming this is actually for the AioContext stuff. Yes, though, AioContext ought to be moved into util/ as part of this series IMHO, since the io/ channel code shouldn't have a dependancy on block/ layer. 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/ :|