The set of all prototype shapes was a process-global static, which
meant that Shape::invalidate_all_prototype_chains_leading_to_this()
had to iterate over every prototype shape from every Realm in the
process.
This was catastrophic for pages that load many SVG-as-img resources,
since each SVG image creates its own Realm with a full set of JS
intrinsics and web prototypes. With N SVG images, each adding ~100
properties to their ObjectPrototype, this became O(N * 100 * M)
where M is the total number of prototype shapes across all Realms.
Since prototype chains never cross Realm boundaries, we can scope
the tracking to each Realm, making the invalidation cost independent
of the number of Realms in the process.
Realm now caches a direct pointer to the global declarative
environment record, updated when set_global_environment() is called.
This avoids an extra pointer chase through GlobalEnvironment in hot
paths like the asmint's GetGlobal/SetGlobal handlers.
Instead of storing a list of builtin function objects with the realm,
just move the builtin field from NativeFunction up to FunctionObject.
Now you can ask any FunctionObject for its builtin(), and we no longer
need the get_builtin_value() API.
Fixes 10 test262 tests that were querying the realm builtins at a
bad time.
Regressed in 54b755126c.
This reverts commit c14173f651. We
should only annotate the minimum number of symbols that external
consumers actually use, so I am starting from scratch to do that
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
Now that the heap has no knowledge about a JavaScript realm and is
purely for managing the memory of the heap, it does not make sense
to name this function to say that it is a non-realm variant.
The main motivation behind this is to remove JS specifics of the Realm
from the implementation of the Heap.
As a side effect of this change, this is a bit nicer to read than the
previous approach, and in my opinion, also makes it a little more clear
that this method is specific to a JavaScript Realm.
