[07/12] aio-wait: draw equivalence between AIO_WAIT_WHILE() and AIO_WAIT_WHILE_UNLOCKED()

Commit Message

Stefan Hajnoczi Nov. 29, 2023, 7:55 p.m. UTC

Now that the AioContext lock no longer exists, AIO_WAIT_WHILE() and
AIO_WAIT_WHILE_UNLOCKED() are equivalent.

A future patch will get rid of AIO_WAIT_WHILE_UNLOCKED().

Signed-off-by: Stefan Hajnoczi <[e-mail]>
---
 include/block/aio-wait.h | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

Comments

Eric Blake Nov. 30, 2023, 9:39 p.m. UTC | #1

On Wed, Nov 29, 2023 at 02:55:48PM -0500, Stefan Hajnoczi wrote:
> Now that the AioContext lock no longer exists, AIO_WAIT_WHILE() and
> AIO_WAIT_WHILE_UNLOCKED() are equivalent.
> 
> A future patch will get rid of AIO_WAIT_WHILE_UNLOCKED().
> 
> Signed-off-by: Stefan Hajnoczi <[e-mail]>
> ---
>  include/block/aio-wait.h | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
>

Reviewed-by: Eric Blake <[e-mail]>

Patch

diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
index 5449b6d742..157f105916 100644
--- a/include/block/aio-wait.h
+++ b/include/block/aio-wait.h
@@ -63,9 +63,6 @@  extern AioWait global_aio_wait;
  * @ctx: the aio context, or NULL if multiple aio contexts (for which the
  *       caller does not hold a lock) are involved in the polling condition.
  * @cond: wait while this conditional expression is true
- * @unlock: whether to unlock and then lock again @ctx. This applies
- * only when waiting for another AioContext from the main loop.
- * Otherwise it's ignored.
  *
  * Wait while a condition is true.  Use this to implement synchronous
  * operations that require event loop activity.
@@ -78,7 +75,7 @@  extern AioWait global_aio_wait;
  * wait on conditions between two IOThreads since that could lead to deadlock,
  * go via the main loop instead.
  */
-#define AIO_WAIT_WHILE_INTERNAL(ctx, cond, unlock) ({              \
+#define AIO_WAIT_WHILE_INTERNAL(ctx, cond) ({                      \
     bool waited_ = false;                                          \
     AioWait *wait_ = &global_aio_wait;                             \
     AioContext *ctx_ = (ctx);                                      \
@@ -95,13 +92,7 @@  extern AioWait global_aio_wait;
         assert(qemu_get_current_aio_context() ==                   \
                qemu_get_aio_context());                            \
         while ((cond)) {                                           \
-            if (unlock && ctx_) {                                  \
-                aio_context_release(ctx_);                         \
-            }                                                      \
             aio_poll(qemu_get_aio_context(), true);                \
-            if (unlock && ctx_) {                                  \
-                aio_context_acquire(ctx_);                         \
-            }                                                      \
             waited_ = true;                                        \
         }                                                          \
     }                                                              \
@@ -109,10 +100,11 @@  extern AioWait global_aio_wait;
     waited_; })
 
 #define AIO_WAIT_WHILE(ctx, cond)                                  \
-    AIO_WAIT_WHILE_INTERNAL(ctx, cond, true)
+    AIO_WAIT_WHILE_INTERNAL(ctx, cond)
 
+/* TODO replace this with AIO_WAIT_WHILE() in a future patch */
 #define AIO_WAIT_WHILE_UNLOCKED(ctx, cond)                         \
-    AIO_WAIT_WHILE_INTERNAL(ctx, cond, false)
+    AIO_WAIT_WHILE_INTERNAL(ctx, cond)
 
 /**
  * aio_wait_kick: