aio: introduce qemu_get_current_aio_context

This will be used by BDRV_POLL_WHILE (and thus by bdrv_drain)
to choose how to wait for I/O completion.

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-12-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/iothread.c b/iothread.c
index fbeb8de..62c8796 100644
--- a/iothread.c
+++ b/iothread.c
@@ -20,6 +20,7 @@
 #include "qmp-commands.h"
 #include "qemu/error-report.h"
 #include "qemu/rcu.h"
+#include "qemu/main-loop.h"
 
 typedef ObjectClass IOThreadClass;
 
@@ -28,6 +29,13 @@ typedef ObjectClass IOThreadClass;
 #define IOTHREAD_CLASS(klass) \
    OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
 
+static __thread IOThread *my_iothread;
+
+AioContext *qemu_get_current_aio_context(void)
+{
+    return my_iothread ? my_iothread->ctx : qemu_get_aio_context();
+}
+
 static void *iothread_run(void *opaque)
 {
     IOThread *iothread = opaque;
@@ -35,6 +43,7 @@ static void *iothread_run(void *opaque)
 
     rcu_register_thread();
 
+    my_iothread = iothread;
     qemu_mutex_lock(&iothread->init_done_lock);
     iothread->thread_id = qemu_get_thread_id();
     qemu_cond_signal(&iothread->init_done_cond);