[plt-scheme] synchronizing pthread with MzScheme thread

Hi,

On Mac OS X or Unix, am I correct that the way to coordinate between  
the MzScheme thread and another OS-level thread is to make Scheme  
wait on a file descriptor, by calling `scheme_block_until' or reading  
from a port created with `scheme_make_fd_input_port'?

The only way I know to make file descriptors suitable for this is to  
use the `socket' and `pipe' system calls.  Is that how it's usually  
done?

Also, the "Inside PLT MzScheme" manual mentions `object-wait- 
multiple'.  I assume that is an old name for `sync'?

In my specific case I'm embedding MzScheme in a Cocoa app, and I'm  
trying a design with 2 OS-level threads -- one for Cocoa and one for  
Scheme.

thanks,
Rob