aio: introduce AioContext, move bottom halves there

Start introducing AioContext, which will let us remove globals from
aio.c/async.c, and introduce multiple I/O threads.

The bottom half functions now take an additional AioContext argument.
A bottom half is created with a specific AioContext that remains the
same throughout the lifetime.  qemu_bh_new is just a wrapper that
uses a global context.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/main-loop.c b/main-loop.c
index baefe41..40fdbd3 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -26,6 +26,7 @@
 #include "qemu-timer.h"
 #include "slirp/slirp.h"
 #include "main-loop.h"
+#include "qemu-aio.h"
 
 #ifndef _WIN32
 
@@ -199,6 +200,8 @@ static int qemu_signal_init(void)
 }
 #endif
 
+static AioContext *qemu_aio_context;
+
 int qemu_init_main_loop(void)
 {
     int ret;
@@ -218,6 +221,7 @@ int qemu_init_main_loop(void)
         return ret;
     }
 
+    qemu_aio_context = aio_context_new();
     return 0;
 }
 
@@ -481,7 +485,7 @@ int main_loop_wait(int nonblocking)
     if (nonblocking) {
         timeout = 0;
     } else {
-        qemu_bh_update_timeout(&timeout);
+        aio_bh_update_timeout(qemu_aio_context, &timeout);
     }
 
     /* poll any events */
@@ -510,3 +514,15 @@ int main_loop_wait(int nonblocking)
 
     return ret;
 }
+
+/* Functions to operate on the main QEMU AioContext.  */
+
+QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
+{
+    return aio_bh_new(qemu_aio_context, cb, opaque);
+}
+
+int qemu_bh_poll(void)
+{
+    return aio_bh_poll(qemu_aio_context);
+}