Re: [PATCH 1/2] aio: allow to wait for coroutine pool from different coroutine - please ignore

["Denis V. Lunev" <den@openvz.org>]

On 6/10/20 9:58 PM, Denis V. Lunev wrote:
> The patch preserves the constraint that the only waiter is allowed.
>
> The patch renames AioTaskPool->main_co to wake_co and removes
> AioTaskPool->waiting flag. wake_co keeps coroutine, which is
> waiting for wakeup on worker completion. Thus 'waiting' flag
> in this semantics is equivalent to 'wake_co != NULL'.
>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Kevin Wolf <kwolf@redhat.com>
> CC: Max Reitz <mreitz@redhat.com>
> CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> CC: Denis Plotnikov <dplotnikov@virtuozzo.com>
> ---
>  block/aio_task.c | 17 ++++++++---------
>  1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/block/aio_task.c b/block/aio_task.c
> index 88989fa248..5183b0729d 100644
> --- a/block/aio_task.c
> +++ b/block/aio_task.c
> @@ -27,11 +27,10 @@
>  #include "block/aio_task.h"
>  
>  struct AioTaskPool {
> -    Coroutine *main_co;
> +    Coroutine *wake_co;
>      int status;
>      int max_busy_tasks;
>      int busy_tasks;
> -    bool waiting;
>  };
>  
>  static void coroutine_fn aio_task_co(void *opaque)
> @@ -52,21 +51,21 @@ static void coroutine_fn aio_task_co(void *opaque)
>  
>      g_free(task);
>  
> -    if (pool->waiting) {
> -        pool->waiting = false;
> -        aio_co_wake(pool->main_co);
> +    if (pool->wake_co != NULL) {
> +        aio_co_wake(pool->wake_co);
> +        pool->wake_co = NULL;
>      }
>  }
>  
>  void coroutine_fn aio_task_pool_wait_one(AioTaskPool *pool)
>  {
>      assert(pool->busy_tasks > 0);
> -    assert(qemu_coroutine_self() == pool->main_co);
> +    assert(pool->wake_co == NULL);
>  
> -    pool->waiting = true;
> +    pool->wake_co = qemu_coroutine_self();
>      qemu_coroutine_yield();
>  
> -    assert(!pool->waiting);
> +    assert(pool->wake_co == NULL);
>      assert(pool->busy_tasks < pool->max_busy_tasks);
>  }
>  
> @@ -98,7 +97,7 @@ AioTaskPool *coroutine_fn aio_task_pool_new(int max_busy_tasks)
>  {
>      AioTaskPool *pool = g_new0(AioTaskPool, 1);
>  
> -    pool->main_co = qemu_coroutine_self();
> +    pool->wake_co = NULL;
>      pool->max_busy_tasks = max_busy_tasks;
>  
>      return pool;
please ignore