Sometimes constraints are questionable

[Stuart Marks]

On 6/2/20 11:49 PM, David Holmes wrote:
> IIUC what you are saying is that MAX_ARRAY_LENGTH is treated as a soft-limit. A 
> request for prefGrowth won't be allowed to exceed it. But if minGrowth takes the 
> length passed it then the code tries to do the allocation that large anyway. If 
> it succeeds we win, and if we get OOME that is what we would have thrown anyway 
> if we rejected the request as too big.

Yes, that's a good, succinct summary.

> So my misunderstanding in this was that MAX_ARRAY_LENGTH is not attempting to 
> define the actual VM hard limit, just a large value close to that which is 
> expected to always be valid (actual memory permitting).

Exactly. And sorry for this misunderstanding -- revisiting this I see that the 
name MAX_ARRAY_LENGTH is quite misleading. Maybe I should have pushed harder to 
change this when Ivan and I went through this code last year. We had improved 
some things, I think, but we had already gone through half a dozen rounds of 
review and I think we were both getting tired. :-)

s'marks