In Blink's version of Oilpan, GCInfo objects would reside in .bss and
a table would translate between an index and the .bss address. Upon
retrieving a GCInfoIndex, the slow path merely passes a .bss pointer
to a slow path setup method to create the table mapping.
In cppgc, we set up GCInfo entries directly in the table. This is
slightly faster for actually using GCInfo objects as there's no
indirection between table and .bss, and it also saves one pointer (the
indirection) per type that is set up. The downside of this approach is
that individual components of a GCInfo objects, that are all
type-dependent, need to be passed to the conditional setup method.
Since GCInfo indices must be retrieved on each allocation, this
pollutes the fast path with additional instructions.
However, GCInfo components are actually known at compile-time for many
objects. In such cases, we can use a compile-time static dispatch to
encode the known parameters in different functions. This saves around
40KiB of memory on ChromePublic.apk and also creates a more compact
fast path for allocation.
Bug: chromium:1238884, chromium:1056170
Change-Id: Iedd809a8baefcc02f131d2b2c77d341b0abe43bb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3094007
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76291}
A human-readable name is in Blink only available for C++ types with
JS wrapper objects and for manually annotated types that are interesting
for the snapshot. Return the proper C++ shallow size of the object in
this case. (Merge nodes will have their JS+C++ sizes added.)
Bug: chromium:1228411, chromium:1056170
Change-Id: Ib2b1b7b9dec80e5cccccb1aad8c4c035715612ec
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3021169
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75698}
Adds NameProvider to allow specifying names of objects. The
corresponding internal NameTrait is registered with the GCInfo object.
Use name infrastructure to provide a hint on encountering an unmarked
object in the marking verifier.
Bug: chromium:1056170
Change-Id: I95bb290660f5905500f861bd5cc85148a1b47184
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2454087
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70400}
