The FFI's weak table of callback procedures (to map Racket procedures
to FFI callback objects) suffered from the classic key-in-value
problem.
Closes PR 12228, probably
Merge to 5.2
Macros and other tools that need syntax privilege used
`(current-code-inspector)' at the module top-level to try to
capture the right code inspector at load time. It's more
consistent to instead use the enclosing module's declaration-time
inspector, and `var-ref->mod-decl-insp' provides that. The
new function works only on references to anonymous variables,
which limits access to the inspector.
The real function name is longer, of course.
The target of the change is actually `hack-argument-replacement' in
`mred/private/coco/queue'. The replaced method can get called in
a different OS-level thread than the main thread.
Closes PR 12086
- the `lam' structure from `compiler/zo-struct' changed to include a
`toplevel-map' field
This change helps solve a finalization problem in `racket/draw',
which in turn sigificantly reduces the peak memory use of `raco setup'
during the doc-building phase (because some documents load `racket/draw'
to render images, and multiple copies of `racket/draw' were retained
before finalization was fixed).
The change is an extreme way to solve a specific finalization
problem, but it's a kind of space-safety improvement; space safety
almost never matters, but when it does, then working around a lack of
space safety is practically impossible. In this case, it's not clear
how to otherwise solve the `racket/draw' finalization problem.
The improvement doesn't change the representation of closures, but it
requires special cooperation with the GC. All closures in a module
continue to share the same array of globals (plus syntax objects);
that is, instead of completely flat closures, Racket uses a two-level
environment where top-/module-level variables are grouped
together. The code half of a closure now records which
top-/module-level variables the body code actually uses, and the mark
phase of GC consults this information to retain only parts of the
top-/module-level environment frame that are actually used by some
closure (or all of the frame if it is accessible through some other
route). In other words, the GC supports a kind of "dependent
reference" to an array that is indexed by positions into the array
--- except that the code is more in the "Racket" directory instead of
the "GC" directory, since it's so specific to the closure
representation.
