Re: ws2_32: implement AcceptEx and GetAcceptExSockaddrs (try 2)

[Alexandre Julliard]

Mike Kaplinskiy  writes:
> - wsa->read = HeapAlloc( GetProcessHeap(), 0, sizeof(*wsa->read) );
> - if (!wsa->read)
> - {
> -
>    status = STATUS_NO_MEMORY;
> -
>    goto finish;
> - }
> - wsa->read->hSocket     = wsa->accept_socket;
> - wsa->read->flags       = 0;
> - wsa->read->addr        = NULL;
> - wsa->read->addrlen.ptr = NULL;
> - wsa->read->n_iovecs    = 1;
> - wsa->read->first_iovec = 0;
> - /* Includes 1 iovec, and that's all we need */
> - wsa->read->iovec[0].iov_base = wsa->buf;
> - wsa->read->iovec[0].iov_len  = wsa->data_len;
> - SERVER_START_REQ( register_async )
> - {
> -
>    req->type           = ASYNC_TYPE_READ;
> -
>    req->async.handle   = wine_server_obj_handle( wsa->accept_socket );
> -
>    req->async.callback = wine_server_client_ptr( WS2_async_recv_accept );
> -
>    req->async.iosb     = wine_server_client_ptr( iosb );
> -
>    req->async.arg      = wine_server_client_ptr( wsa );
> -
>    status = wine_server_call( req );
> - }
> - SERVER_END_REQ;
> -
> - if (status != STATUS_PENDING)
> -
>    goto finish;
> -
> - return STATUS_SUCCESS;
> -
>
> +finish:
> - iosb->u.Status = status;
> - iosb->Information = 0;
> -
> - if (wsa->user_overlapped->hEvent)
> -
>    SetEvent(wsa->user_overlapped->hEvent);
> - if (wsa->cvalue)
> -
>    WS_AddCompletion( HANDLE2SOCKET(wsa->listen_socket), wsa->cvalue, iosb->u.Status, iosb->Information );
> - HeapFree( GetProcessHeap(), 0, wsa->read );
> - HeapFree( GetProcessHeap(), 0, wsa );
> -
> - return status;
>
> +}

You cannot allocate or free memory in an async callback, because it can
be called from a signal handler. All needed memory needs to be allocated
beforehand, and freed in the user apc callback.