Refactor aio callback allocation to use an aiocb pool (Avi Kivity)

Move the AIOCB allocation code to use a dedicate structure, AIOPool.  AIOCB
specific information, such as the AIOCB size and cancellation routine, is
moved into the pool.

At present, there is exactly one pool per block format driver, maintaining
the status quo.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6870 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 27 insertions, 15 deletions

diff --git a/block.c b/block.c
index 3f262fa590..1aa3de573b 100644
--- a/block.c
+++ b/block.c
@@ -141,6 +141,7 @@ static void bdrv_register(BlockDriver *bdrv)
         bdrv->bdrv_read = bdrv_read_em;
         bdrv->bdrv_write = bdrv_write_em;
     }
+    aio_pool_init(&bdrv->aio_pool, bdrv->aiocb_size, bdrv->bdrv_aio_cancel);
     bdrv->next = first_drv;
     first_drv = bdrv;
 }
@@ -1443,14 +1444,12 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
 
 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
 {
-    BlockDriver *drv = acb->bs->drv;
-
     if (acb->cb == bdrv_aio_rw_vector_cb) {
         VectorTranslationState *s = acb->opaque;
         acb = s->aiocb;
     }
 
-    drv->bdrv_aio_cancel(acb);
+    acb->pool->cancel(acb);
 }
 
 
@@ -1568,18 +1567,25 @@ void bdrv_init(void)
     bdrv_register(&bdrv_nbd);
 }
 
-void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
-                   void *opaque)
+void aio_pool_init(AIOPool *pool, int aiocb_size,
+                   void (*cancel)(BlockDriverAIOCB *acb))
+{
+    pool->aiocb_size = aiocb_size;
+    pool->cancel = cancel;
+    pool->free_aiocb = NULL;
+}
+
+void *qemu_aio_get_pool(AIOPool *pool, BlockDriverState *bs,
+                        BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BlockDriver *drv;
     BlockDriverAIOCB *acb;
 
-    drv = bs->drv;
-    if (drv->free_aiocb) {
-        acb = drv->free_aiocb;
-        drv->free_aiocb = acb->next;
+    if (pool->free_aiocb) {
+        acb = pool->free_aiocb;
+        pool->free_aiocb = acb->next;
     } else {
-        acb = qemu_mallocz(drv->aiocb_size);
+        acb = qemu_mallocz(pool->aiocb_size);
+        acb->pool = pool;
     }
     acb->bs = bs;
     acb->cb = cb;
@@ -1587,12 +1593,18 @@ void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
     return acb;
 }
 
+void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
+                   void *opaque)
+{
+    return qemu_aio_get_pool(&bs->drv->aio_pool, bs, cb, opaque);
+}
+
 void qemu_aio_release(void *p)
 {
-    BlockDriverAIOCB *acb = p;
-    BlockDriver *drv = acb->bs->drv;
-    acb->next = drv->free_aiocb;
-    drv->free_aiocb = acb;
+    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
+    AIOPool *pool = acb->pool;
+    acb->next = pool->free_aiocb;
+    pool->free_aiocb = acb;
 }
 
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