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On Wednesday, 28. February 2001 17:34, Schruefer Wolfgang wrote:
> Hi Andreas,
>
> if you really want to hear more comments, I'll try my best...
>
> 1) Error Codes
> These are not very good supported yet.

Yes, you are right, and I regret that. The return values are neither very
consequent, nor do they always say what happened. I have tried to
give comments in the documentation, though, and for now I will not
change that (because I would have to change more then throughout the
entire source code), and there are more important things to be done
before that.

If you send me a couple of small (!), clean easy to understand patches
(after release of a version 1.0) though, I am willing to change that, though.

> There should be sctp specific errorcodes (via #define or typedef enum),
> e.g.:
> #define SCTP_SUCCESS 0
> #define SCTP_UNSPECIFIED_ERROR -1 /*look at errno*/
> #define SCTP_ASSOC_NOT_EXISTING -2
> #define SCTP_PATH_NOT_EXISTING -3
> #define SCTP_INVALID_ADDRESS -4
> #define SCTP_LACK_OF_RESOURCES -5
> #define SCTP_SEND_QUEUE_FULL -6
> #define SCTP_WRONG_STATE -7
> #define SCTP_INVALID_PARAMETERS -8
> #define ...
>
> And (as "i-Tüpfelchen") you provide for error-reporting a stringified
> representation by a new helper function, e.g.: char *
> sctp_errcode2string(int);

Well, again, there are much more important things to be done first.

> 2) Memory Management
>
> Goals:
> - no memory copy at the interfaces to ULP and IP (already implemented)
> - clear memory assignement to one specific layer.
> - usage of different memory pools might be necessary e.g. for protection
> mechanisms, cache behaviour, interprocess communication ...

Well, first thing will be to get rid of the dll_main.c module (to avoid
copying multiple times).
And for that I would start by creating a unified data structure for a
chunk, that will be used in the streamengine-module, and other
modules that handle the real "data flow" (i.e. flow-control, reliable
transfer, bundling etc.)
So, really for that I have to start off with the stream-engine and
that means: rewrite it. Which I will do later, because I do not entirely
understand the code that has been written there.

> Therefore I would divide the memory in 3 parts:
> I) ulp_memory used by SCTP and ULP
> II) network_memory used by SCTP and IP-layer
> III) internal_memory

I would suggest doing the above mentioned changes, and then look
with a profiler, where performance hot spots are.
THEN these would be attacked...actually at this stage of the implementation
it would be way too early to start optimization.
I know that at least 50% of the performance is simply wasted by
unnecessarily copying and allocating/deallocating memory.

> 3) sctp_associate(): (again)
> parameter "pointer to ULP data"
> You said it's trivial to implement, so I think you should do it. It is
> easier for the ULP to provide it twice than to search through all its
> associations.

Okay, agreed.

> 4) ulpCallbacks: sendFailureNotif instead of sentFailureNotif
Yup, well.... that must have been written on a tired evening :-)

Andreas Jungmaier

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• Re: AW: [SCTP-Discussion] Update on API definition (sctp.h), Andreas Jungmaier, 03/01/2001

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