RTOS/EK-TM4C129EXL: NDK Stack -reg

Hi todd,

      I may use BSD sockets also. I am able to get the data from the client but I don't know how to read that data.. Refereing to the NDK manual I  had found an API

 int NDK_recv(SOCKET s, void *pbuf, int size, int flags);

       I don't know where to include this API in the code to read the data. Do I need to create a separate task (I mean a separate function) to read the Data ???  or  To include the NDK_recv() API in tcpWorker part of the  code??

Hi Naveen,

Were you able to run the tcpEcho example?

Naveen Kumar29 said:

Is there any sequence using api like NDK_connect(), NDK_recv() to receieve data

Yes, there is a certain order to make the socket API calls in, depending on whether or not your code is a client or a server.

A server will typically call bind(), listen() and accept() to wait for connections before it can send() and recv() data.

A client will call connect() to connect to a server before it can send() and recv() data.

The following diagram I found with a Google search may help you. Note that you can substitute the API names in the diagram for their NDK equivalents (e.g. "connect()" in the diagram would be equivalent to "NDK_connect()" and so on).

Naveen Kumar29 said:

What are the things that I need to edit in tcpHandler.c to receive data from the Client.

The TCP echo example is a TCP server. It has a companion application that acts as a client, which is run from a PC (please refer to the README file in the tcpEcho example for guidance).

If you follow the code of the tcpEcho example, starting first with the tcpHandler task, and then the tcpWorker task, you should see how its socket API calls map to the server part of the above diagram.

Naveen Kumar29 said:

I am able to get the data from the client but I don't know how to read that data.. Refereing to the NDK manual I  had found an API

?

1	int NDK_recv(SOCKET s, void *pbuf, int size, int flags);

Yes, the NDK_recv() function is used to receive (read) data from a socket. You have to give this API a buffer to copy the data that's read into (this is the pbuf argument of the API).

Once the NDK_recv() function returns (successfully), you should be able to access the data that was read within the pbuf buffer.

Naveen Kumar29 said:

       I don't know where to include this API in the code to read the data. Do I need to create a separate task (I mean a separate function) to read the Data ???  or  To include the NDK_recv() API in tcpWorker part of the  code??

In the tcpEcho example, the recv() calls can be found within the tcpWorker task function.

If you're trying to figure out in general where/when to call recv(), then the above diagram should help you with that.

Steve