The situation is exactly what you said at last sentence. The real situation in wine-client view is below : GetQueuedCompletionStatus waits for 16 overlapped WSARecv. After one IO Completion is processed, it does not wake up. async_reselect() should be called after list_remove to receive POLLIN event again. async_waiting() only checks about the first entry in the queue. Before calling list_remove(), async_waiting() returns false. These stuff was done in async_destroy() on wine-6.7, and I let the contents of async remained so that async_destroy() handles it. Apparently, as you said, test bot says there is a problem in this patch. What about calling async_reselect() again right after calling list_remove()? if (async->queue) { list_remove( &async->queue_entry ); async_reselect(async); async->fd = NULL; async->queue = NULL; release_object( async ); } It does not cause assertion about handle_count and make GetQueuedCompletionStatus wake up after IO completions.