Subject: Re: Generic Properties
To: Michael K. Sanders <msanders@confusion.net>
From: None <cgd@broadcom.com>
List: tech-kern
Date: 09/27/2001 10:27:09
"Michael K. Sanders" <msanders@confusion.net> writes:
> cgd@broadcom.com writes:
> >It's not stated here, but PROP_CONST is a flag.
> ...
> >as your basic types, then have 'array' be a flag.
> 
> Would it make sense for the wait argument to also be a flag?  Should
> the flags be a separate argument?  Cf. malloc(9).

these flags are flags in the 'type' field of the entries.  go back and
read the previous discussions.  8-)


> >> size_t getprop(kdatabase_t db, opaque_t object, const char *name, 
> >> 	void *val, size_t len, int *type);
> 
> >uh, why do the 'val != NULL' check if anything other than diagnostic?
> 
> How do you know the appropriate size to allocate for val?

same way you do for all of the similar interfaces: it returns the size
you need, so you can pass in a len of 0 (and who cares what the buffer
is), or pass in a good buffer and a length that may or may not be long
enough...


> If that's the case, maybe there should be a separate lookup function
> instead of overloading getprop to do both.  

there is no shortage of interfaces that work exactly the way this one
does.


cgd