This patch adds a `-z` option to js and test-js. When run in this mode,
garbage cells are never actually destroyed. We instead keep them around
in a special zombie state.
This allows us to validate that zombies don't get marked in future GC
scans (since there were not supposed to be any more references!) :^)
Cells get notified when they become a zombie (via did_become_zombie())
and this is used by WeakContainer cells to deregister themselves from
the heap.
Make this API take a Span<Cell*> instead of a Vector<Cell*>&.
This is behavior neutral, but stops the API looking like it wants to
do mutable things to the Vector.
This should fix the flaky tests of test-js.
It also fixes the tests when running with the -g flag since the values
will not be garbage collected too soon.
Making userspace provide a global string ID was silly, and made the API
extremely difficult to use correctly in a global profiling context.
Instead, simply make the kernel do the string ID allocation for us.
This also allows us to convert the string storage to a Vector in the
kernel (and an array in the JSON profile data.)
Use this to avoid creating a 16 byte cell allocator on x86_64, where the
size of FreelistEntry is 24 bytes. Every JS::Cell must be at least the
size of the FreelistEntry or things start crashing, so the 16 byte
allocator was wasted on that platform.
So far we only have two states: Live and Dead. In the future, we can
add additional states to support incremental sweeping and/or multi-
stage cell destruction.
Absolutely massive allocations > 1024 bytes would go into the size
class which was 3172 bytes. 3172 happens to not be 8 byte aligned, and
so made UBSAN very sad on x86_64. Change the largest allocator to be
3072 bytes, which is in fact a multiple of 8 :^)
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
