From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45986) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cT5cQ-0005JI-CJ for qemu-devel@nongnu.org; Mon, 16 Jan 2017 06:38:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cT5cN-0004jG-6m for qemu-devel@nongnu.org; Mon, 16 Jan 2017 06:38:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54078) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cT5cM-0004jB-UV for qemu-devel@nongnu.org; Mon, 16 Jan 2017 06:38:31 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (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 EDDE0624CF for ; Mon, 16 Jan 2017 11:38:30 +0000 (UTC) Date: Mon, 16 Jan 2017 19:38:24 +0800 From: Fam Zheng Message-ID: <20170116113824.GD14226@lemon.Home> References: <20170113131731.1246-1-pbonzini@redhat.com> <20170113131731.1246-6-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170113131731.1246-6-pbonzini@redhat.com> 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: Paolo Bonzini Cc: qemu-devel@nongnu.org, stefanha@redhat.com 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) $(test-block-obj-y) I guess this is a hint for moving coroutine code into a lower level library like util. Fam > tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(test-block-obj-y) > tests/test-aio$(EXESUF): tests/test-aio.o $(test-block-obj-y) > tests/test-aio-multithread$(EXESUF): tests/test-aio-multithread.o $(test-block-obj-y) > -- > 2.9.3 > >