tree 23f75fa455ec333677650198cd889b187228b735
parent 2fc6b55dae7a120b4272ca0e9c356d1f96053bd9
author Roberto Ierusalimschy <roberto@inf.puc-rio.br> 1541089260 -0300
committer Roberto Ierusalimschy <roberto@inf.puc-rio.br> 1541089260 -0300

Removed internal cache for closures

The mechanism of "caching the last closure created for a prototype to
try to reuse it the next time a closure for that prototype is created"
was removed. There are several reasons:

- It is hard to find a natural example where this cache has a measurable
impact on performance.

- Programmers already perceive closure creation as something slow,
so they tend to avoid it inside hot paths. (Any case where the cache
could reuse a closure can be rewritten predefining the closure in some
variable and using that variable.)

- The implementation was somewhat complex, due to a bad interaction
with the generational collector. (Typically, new closures are new,
while prototypes are old. So, the cache breaks the invariant that
old objects should not point to new ones.)