File Descriptor RX Buffer Count and TCP Preread

[addonray]

Does anyone know of an "under the hood" way to determine the incoming count of bytes for a file descriptor? My post a few days ago regarding dataavail() hasn't been answered so I'm wondering if there is a direct buffer count way of doing it. I'm porting a Rabbit project that had some handy methods of knowing the incoming counts (prior to calling a read), and trying not to rewrite all of that. On a similar note, the Rabbit TCP stack has a "preread" type of function that lets you keep the RX buffer intact but peek at any count of data in there. Anything like that hidden in the NB libs?

Thanks,

Ray

[pbreed]

#include <tcp.h>


WORD TcpGetRxBufferSpaceUsed( int fd )



Just noted that the comment text in tcp.h is wrong.
Looks like there was a comment copy and paste that was mis edited.

Looked at the underlying code and it does what is requested/expected.

Paul

[addonray]

Thank you, Paul. Any idea how (or if possible) to do the same thing with the UARTS, using the fifo_buffer_storage SpaceUsed() construct?

Regards,

Ray

[pbreed]

You can write a function that uses the similar function from the buffer storage on the serial driver...

At some level this approach bothers me a little, because it implies that you are testing things in a loop

I think in general its probably better to put each group of reads in a task and use select to pend on the reads.
That way a task only wakes up and is busy if it has something to do....


Paul

[addonray]

Thanks for that advice, Paul. I'll do some experiments with Select. I'm porting from a Round-Robin system so much is sure to change.

Regards,

Ray