The premise was wrong. deno_core 0.350's run_event_loop is:
pub async fn run_event_loop(&mut self, opts) -> Result<(), CoreError> {
poll_fn(|cx| self.poll_event_loop(cx, opts)).await
}
so replacing `timeout(budget, run_event_loop())` with a hand-rolled
`poll_fn(poll_event_loop)` loop is the same code with the same cancellation
semantics, not safer ones. The mechanism I described cannot happen either:
`poll` is a synchronous `&mut self` call, a future can only be dropped between
polls, and the HandleScope/ContextScope live inside poll_event_loop as stack
locals that are destroyed before it returns. The isolate is exited between
polls both before and after that change.
What actually fixes#430 is confining each connection's isolates to their own
OS thread, which the next commits do. The regression test still reproduces the
abort on the pre-thread-per-connection tree and still passes here without this
commit, so nothing depended on it.
It was not merely a no-op. Two regressions it introduced:
- resolve_promises_until inverted the meaning of tick_ms. It was "pump the
event loop for up to tick_ms, returning early on idle"; it became one single
poll followed by an unconditional sleep(tick_ms). With the 1->50ms backoff
that settles at 20 event-loop turns per second, so an awaited promise chain
needing many turns crawls, and past the budget the caller silently reads a
stale __obscura_await_meta.
- drive_module_eval replaced `e?` with `let _ = poll_event_loop(...)`,
discarding event-loop errors. A module stalled on a top-level await used to
exit immediately with a logged error; it instead spun for the whole budget
logging nothing -- the exact #374 starvation the surrounding comment claims
to prevent.
Keep the drive_module_eval extraction (it genuinely dedupes load_module and
load_inline_module) but restore the original select!-based body.
Refs #430.
sycatle
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