[M3commit] how to switch userthreads on/off

[Jay]

> I realize maybe there is a strong counteropinion, like, whatever 
> inefficiences are >implied by dynamic linking are to be "fought" 
> against with aggressive/creative/even fragile optimization techniques.  
 
 
I realize I argue for optimizing PushEFrame and for deoptimizing e.g. lock.
PushEFrame is presumably more common...except that it probably occurs most often with lock? I don't know, I have no numbers.
 
 
I'm not sure yet what to do here.
Swapping .so files might or might not work.
If it does, that's a step but doesn't enable everything.
 
 
For example when I just switch compilation back and forth without "clean", I get errors about types missing. Maybe that'll occur at runtime, maybe not? Maybe these are different? Depends somewhat on what "reveal" does? 
Maybe Thread.T/Mutex/Condition should be ADDRESS and never revealed, but loopholed to escape these problems?? ("These problems" are partly that I don't fully understand the Modula-3 object model, e.g. what does "reveal" do, at a low level? What does "brand" do, at a low level? I looked into it some and brand doesn't seem to affect objects at all, only out of band typeinfo.)
 
 
Maybe just leave it as an option in m3core's m3makefile and people can twiddle it if they want and rebuild the entire system like it is today?
That is a bit onerous, but maybe it's all userthreads deserve?
?
 
 
Anyone who actually wanted to switch back and forth (Mika) would just have two installs and two source trees?
 
 
 - Jay