Was added here 43805ad698
But causes segfaults. The issue is hard to understand. At first, it seemed like
the value cached in a v8::Object was persisting through v8::contexts of the
same isolate. Set window.document to the current &document, and in a different
context, it retrieves that cached value (which is now an invalid pointers).
However, upon further investigation, this appears to be limited to a mix of
navigation (which causes a new context to be created, and old values to be
invalidated) + Inspector which continues to send commands to the old context.
Since contextDestroyed is something we're aware of and planning to do shortly,
I think we can disable the cache until that's fixed.
Mem 28MB -> 26MB (currently a 24.1MB)
Time 23 -> 17 (currently at 14)
We've made some memory and performance optimization gains lately. Lowering
these will let us spot incremental changes better.
The idea is that frequently accessed properties, e.g. window.document, can be
cached directly as data properties on the underlying v8::Object, removing the
need for the access call into Zig. This is only used on a handful of properties,
almost all of which are on the Window. It is important that the property be
read-only. For example, window.location cannot be cached this way because
window.location is writable (e.g. window.location.hash = '#blah').
This existed briefly before Zigdom, but was removed as part of the migration.
The implementation has changed. This previously relied on a "postAttach" feature
which no longer exists. It is not integrated in the bridge/callback directly and
lazily applied after the first access.
Previously, we were doing some global setup in the Snapshot, but this was
always being overwritten when creating a context. This meaningless setup in
the snapshot was removed.
The global setup is now done once per isolate, rather than once per context.
Deciding what should be an lp.assert, vs an std.debug.assert, vs a debug-only
assert is a little arbitrary.
debug-only asserts, guarded with an `if (comptime IS_DEBUG)` obviously avoid the
check in release and thus have a performance advantage. We also use them at
library boundaries. If libcurl says it will always emit a header line with a
trailing \r\n, is that really a check we need to do in production? I don't think
so. First, that code path is checked _a lot_ in debug. Second, it feels a bit
like we're testing libcurl (in production!)..why? A debug-only assertion should
be good enough to catch any changes in libcurl.
This adds a crash handler which reports a crash (if telemetry is enabled). On a
crash, this looks for `curl` (using the PATH env), and forks the process to then
call execve. This relies on a new endpoint to be setup to accept the "report".
Also, we include very little data..I figured just knowing about crashes would
be a good place to start.
A panic handler is provided, which override's Zig default handler and hooks
into the crash handler.
An `assert` function is added and hooks into the crash handler. This is
currently only used in one place (Session.zig) to demonstrate its use. In
addition to reporting a failed assert, the assert aborts execution in
ReleaseFast (as opposed to an undefined behavior with std.debug.assert).
I want to hook this into the v8 global error handler, but only after direct_v8
is merged.
Much of this is inspired by bun's code. They have their own assert (1) and
a [more sophisticated] crashHandler (2).
:
(1) beccd01647/src/bun.zig (L2987)
(2) beccd01647/src/crash_handler.zig (L198)
