Segmented stack

[Chris Williams via Digitalmars-d]

On Thursday, 16 October 2014 at 19:46:42 UTC, Shucai wrote:
> I am doing research on segmented stack mechanisms, and in 
> addition to academic papers, I am surveying whether segmented 
> stack mechanism is still useful on 64-bit machines. On 64 bit 
> machines, why  they don’t just use a big enough stack, for 
> example, 1GB or even larger?  Are segmented stacks only useful 
> for 32 bit machines?  Are there other reasons for segmented 
> stacks on 64 bit machines?
>
> Any response is appreciated, thanks, Shucai

While the implementation isn't guaranteed, I think that Java 
mandates that the VM behave like every function receives a fresh 
stack. I imagine that the advantage of this was that it allows 
the VM to supply only the minimal necessary memory for a function 
to operate, at any given time. On small devices, it can swap the 
stack out to disk. On large devices, it can just keep everything 
in memory. Optimization for size/speed is handled for you, making 
your code more portable. (Theoretically.)

Another possibility is that, while I can't think of the 
application, being able to preserve discarded chunks of the stack 
might be useful in some way. In a traditional stack arrangement, 
a new function entry will generally cause the data from the 
previous function entry to be overwritten. If you're allocating 
each new entry as its own thing, then all of the old functions 
continue to sit around to be processed by another thread, until 
you're ready to completely get rid of them.