diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/block_int.h | 2 | ||||
| -rw-r--r-- | include/qemu/coroutine.h | 18 |
2 files changed, 19 insertions, 1 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h index 669a2797fd..5c6b761d81 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -324,7 +324,7 @@ struct BlockDriver { * Drain and stop any internal sources of requests in the driver, and * remain so until next I/O callback (e.g. bdrv_co_writev) is called. */ - void (*bdrv_drain)(BlockDriverState *bs); + void coroutine_fn (*bdrv_co_drain)(BlockDriverState *bs); void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child, Error **errp); diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index a4509bd977..9aff9a735e 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -229,6 +229,24 @@ void qemu_co_rwlock_init(CoRwlock *lock); void qemu_co_rwlock_rdlock(CoRwlock *lock); /** + * Write Locks the CoRwlock from a reader. This is a bit more efficient than + * @qemu_co_rwlock_unlock followed by a separate @qemu_co_rwlock_wrlock. + * However, if the lock cannot be upgraded immediately, control is transferred + * to the caller of the current coroutine. Also, @qemu_co_rwlock_upgrade + * only overrides CoRwlock fairness if there are no concurrent readers, so + * another writer might run while @qemu_co_rwlock_upgrade blocks. + */ +void qemu_co_rwlock_upgrade(CoRwlock *lock); + +/** + * Downgrades a write-side critical section to a reader. Downgrading with + * @qemu_co_rwlock_downgrade never blocks, unlike @qemu_co_rwlock_unlock + * followed by @qemu_co_rwlock_rdlock. This makes it more efficient, but + * may also sometimes be necessary for correctness. + */ +void qemu_co_rwlock_downgrade(CoRwlock *lock); + +/** * Write Locks the mutex. If the lock cannot be taken immediately because * of a parallel reader, control is transferred to the caller of the current * coroutine. |