Trickle bandwidth shaper

[Daniel J. Luke]

On Jul 20, 2011, at 3:58 PM, Brandon Allbery wrote:
> 
> On Wed, Jul 20, 2011 at 15:37, Ralph Seichter <macports-ml at seichter.de> wrote:
> On 20.07.11 00:51, Arno Hautala wrote:
> > I'd enjoy using trickle as well, but I doubt it's possible without
> > significant rewrites..
> 
> Well, perhaps ipfw-based traffic shaping is the proper way to do things
> with OS X. Randal Schwartz has suggested this direction aswell. I think
> I will give it a try, although I'd still prefer an approach which can be
> targeted on single applications instead of a given port or machine.
> 
> I don't think OSX's dynamic linking supports runtime overrides the way ELF with weak symbols does.  
> 
> Actually, it looks like it does to some extent, but only if the programs you're linking into use flat namespaces; Leopard and Snow Leopard default to 2-level namespaces.  See the "-flat_namespace" and "-force_flat_namespace" options to ld(1).  Looks to me like a program has to be linked with the latter option to support it.  That's going to severely restrict what you can use it with.

well, if it's just for testing, one might be able to use DYLD_FORCE_FLAT_NAMESPACE (and DYLD_INSERT_LIBRARIES) ... but really ipfw traffic shaper (dummynet) is probably a better way to go.
--
Daniel J. Luke                                                                   
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