probeSocket
function probeSocket(sockPath, timeoutMs?): Promise<boolean>;Defined in: src/launcher/state.ts:198
Probe whether a worker is listening on sockPath.
A listener whose accept queue is full is alive, only busy – and a false
“dead” here is destructive, because launch() then unlinks the socket
out from under the live worker and spawns a duplicate (and gcStateDir
reaps a live worker’s files). A 32-process run of the Python reference
produced 64 workers for 2 commands that way.
So one connect is classified three ways:
- connected, or
EAGAIN/EWOULDBLOCK(Linux’s report of a full queue on a non-blocking AF_UNIX connect) – alive; ECONNREFUSED– re-probed after 50, 100 and 200 ms before it is believed, because a full queue can report as a refusal too, indistinguishable from no listener at all;- anything else (absent, timed out, unreachable) – dead.
Which runtimes can tell a full queue from a refusal is measured, not
assumed: on Linux, Node reports it as EAGAIN, but Bun (1.4.2) reports it as
ECONNREFUSED, exactly like macOS does for every runtime – except Bun 1.3
on macOS, which says ENOENT for a socket file that exists; that counts as
a refusal too. Under Bun, then, a
busy worker is recognised only if it frees a slot within the re-probe window
– the same guarantee the reference gives on macOS.
This asks “is anything listening”, not “is it responsive”: a connect lands in
the queue of a worker that never accepts, so a successful one never proved
that either. timeoutMs bounds each connect. Mirrors vgi_rpc.launcher._probe
and the C++ launcher’s ProbeAlive.
Parameters
Section titled “Parameters”| Parameter | Type | Default value |
|---|---|---|
sockPath |
string |
undefined |
timeoutMs |
number |
2000 |
Returns
Section titled “Returns”Promise<boolean>