Re: [lwip-users] Is netconn_write blocking or not

[Dimax]

HI,

Some time ago I have asked a question below 

It is not clear from the API documentation if netconn_write function is blocking or not?

Did not actually get an answer but looking inside the code I got to the understanding that it is not blocking function if there are enough resources to send data.

But my problem is as following. I want to use netconn_write with NETCONN_NOCOPY flag. This requires fro the data to be stable during transmission. But I can't know for sure when transmission ends and the buffer can be used again. I need to implement something like that:

fill_buffer( buf, DATA_0, sz );

netconn_write( netconn, buf, sz, NETCONN_NOCOPY );

BLOCK_WAITING_FOR_COMPLETION

fill_buffer( buf, DATA_1, sz );

netconn_write( netconn, buf, sz, NETCONN_NOCOPY );

BLOCK_WAITING_FOR_COMPLETION

and so on.

How the "BLOCK_WAITING_FOR_COMPLETION" can be implemented? Without it a sequence shown about sends two buffers with DATA_1 both as DATA_0 buffer is overridden with DATA_1 before it got sent.