- Rebuild `message_arena` during self-heal to prevent memory accumulation.
- Optimize `minify` comptime performance by avoiding string concatenation.
- Update `extractText` to use `runEval` and sentinels for better reliability.
- Add logging for long environment variable names in `lookupLpEnv`.
Worker scripts can call importScripts(), which performs a synchronous
HTTP request via HttpClient.syncRequest. To stay responsive during a
long fetch, syncRequest pumps the CDP socket (cdp.blocking_read) while
waiting. If a CDP message such as Target.closeTarget arrives on that
socket mid-fetch, the previous code path tore down the page
immediately:
Worker JS -> importScripts -> syncRequest -> blocking_read
-> CDP dispatch -> Target.closeTarget
-> Session.removePage -> Page.deinit -> Frame.deinit
-> Worker.deinit (frees worker arena + identity_map)
When control unwound back into the worker's eval, the next operation
that hit ctx.identity.identity_map.getOrPut dereferenced the freed
metadata pointer and segfaulted (sometimes immediately, sometimes a
few connections later as the arena got recycled).
Reproducer: any URL that loads dedicated workers calling importScripts
during initial eval, driven via puppeteer-core's connectOverCDP. The
allbirds.com product page (which loads ~8 web-pixel workers each
calling importScripts) reliably triggered it within ~10 connections.
Session.removePage already deferred when the frame's own
ScriptManager.is_evaluating was set; that guard never tripped because
worker scripts don't go through the frame's ScriptManager. Fix:
* Worker.loadInitialScript now sets the worker's own
_worker_scope._script_manager.is_evaluating around the eval, with
save/restore so nested worker evals compose correctly.
* WorkerGlobalScope.importScript also sets its own
_script_manager.is_evaluating around the syncRequest +
runMacrotasks. The typical caller (Worker.loadInitialScript)
already sets this around its outer eval, so the outer guard
usually covers us; the inner mark is defense-in-depth for callers
that reach importScripts() from a setTimeout / microtask outside
the loadInitialScript scope.
* New Frame.anyScriptEvaluating method walks the frame tree (frame
ScriptManager + every worker's ScriptManager + child frames) and
returns true if any is mid-eval. Session.removePage and
CDP.disposeBrowserContext use this in place of the frame-only
check, deferring teardown until all evals unwind. Final cleanup
happens at CDP.deinit on connection close, matching the existing
deferred-teardown contract.
Verified by running the puppeteer-core repro back-to-back against a
single Lightpanda serve; all returned 200 with the right title, no
UAF crashes (was previously crashing within 1-10 runs). All 521 unit
tests still pass.
Note: a separate, pre-existing latent V8 issue surfaces under stress
on this same code path. After many iterations a Runtime.evaluate
promise tracked by V8's inspector PromiseHandlerTracker is discarded
during garbage collection's first-pass weak callbacks; the discard
sends a failure response which triggers v8::String::NewFromOneByte,
hitting the debug-only assertion AllowHeapAllocation::IsAllowed() in
heap-allocator-inl.h:79 (no allocations allowed during weak callbacks).
This reproduces on a baseline build of this PR commit and on a
baseline build of just the original two-line is_evaluating fix \u2014
i.e. it is not introduced by the deferral logic. The deferral makes
it more visible because inspector callbacks now live longer before
teardown, so they are more likely to be alive during a GC. Tracking
this as a follow-up; the fix here still resolves the UAF that was
crashing the server immediately.
Use `std.json.Value` directly for tool arguments instead of
stringifying and reparsing. This optimizes the hot replay path
in the agent and MCP server.
When http_client.request fails synchronously (e.g. RobotsLayer returning
RobotsBlocked because robots.txt is already cached), Client.request
invokes our error_callback before returning the error. httpErrorCallback
rejects the promise and releases response._arena. Letting the error
propagate from Fetch.init also fires the `errdefer response.deinit`,
double-freeing the arena and corrupting the arena pool — eventually
surfacing as a malloc abort during teardown.
Fixes#2403.
Give scheduler a 500ms timeslice to run per queue (high/low priority).
A site can load hundreds of timeouts to all execute at the same time. These
can be relatively expensive (e.g. lots of calls directly or indirectly to
getBoundingClientRect). As-is, the scheduler drains its queue to completion and
other timeouts, like --wait-ms can't do what they're meant to do. By adding
timeslice, we prevent many tasks all scheduled for the same time to go
unchecked.
I was initially planning on putting this higher in runMacrotasks, but that could
lead to starvation, i.e. if the first context used up all the time. Having it
per context is more fair, at the cost of running 500ms * context. But, (a) the
number of context we allow is fixed and (b) the reality is that most sites have
few contexts and normally only the first one is doing anything interesting.
