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 <pbonz...@redhat.com>
---
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;
+ }
+ if (ioc->write_coroutine) {
+ rd_handler = qio_channel_restart_write;
+ }
+
+ 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);
+ 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) $(test-block-obj-y)
tests/test-coroutine$(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
