[Qemu-block] [PATCH v2 03/17] aio-wait: Increase num_waiters even in home thread

[Kevin Wolf]

Even if AIO_WAIT_WHILE() is called in the home context of the
AioContext, we still want to allow the condition to change depending on
other threads as long as they kick the AioWait. Specfically block jobs
can be running in an I/O thread and should then be able to kick a drain
in the main loop context.

Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
---
 include/block/aio-wait.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
index c85a62f798..46ba7f9111 100644
--- a/include/block/aio-wait.h
+++ b/include/block/aio-wait.h
@@ -77,10 +77,12 @@ typedef struct {
     AioWait *wait_ = (wait);                                       \
     AioContext *ctx_ = (ctx);                                      \
     if (ctx_ && in_aio_context_home_thread(ctx_)) {                \
+        atomic_inc(&wait_->num_waiters);                           \
         while ((cond)) {                                           \
             aio_poll(ctx_, true);                                  \
             waited_ = true;                                        \
         }                                                          \
+        atomic_dec(&wait_->num_waiters);                           \
     } else {                                                       \
         assert(qemu_get_current_aio_context() ==                   \
                qemu_get_aio_context());                            \
-- 
2.13.6