Startup took 44s and 42 of them were one line. Measured from startup.log:
OnStartup 08:42:59 -> MainWindow loaded 08:43:43, with the whole gap inside
LoadLayout, ending at
TRAX: failed to load '\\192.168.50.86\llamaVault\Assets\Music\...':
The network path was not found. (0x80070035)
LoadTrax called MusicPlayer.Load synchronously on the UI thread, and
new MediaFoundationReader(path) does not fail fast on a dead SMB session — it
burns the full ARP/TCP/SMB timeout and only then throws. The NAS had moved to
.87 after the power outage, so an unreachable path became a 40-second frozen
window on every launch.
The rule, from the creator: a probe may time out; a bind should return
immediately. Only one side of that is achievable here, and the reason matters —
an unreachable UNC path has no fast-fail at all, so probing it on the calling
thread is the worst possible probe. (A device open is the opposite: it normally
fails fast on a sharing violation, which is why this bug is network-specific.)
So: IsTrackReachableAsync runs the probe on a thread-pool thread under a
Task.WhenAny ceiling (TraxProbeBudget, 2s) and treats offline/missing/slow as a
normal state rather than an error. Only a probe that passed gets the real bind,
and that bind deliberately stays on the UI thread alongside every other
MusicPlayer mutation — moving the whole load off-thread would have introduced a
race against PlayTrax/PauseTrax that does not exist today. The orphan probe
thread stays parked until SMB gives up; it is not the thread anyone waits on.
One test, per the Good Dog rule: TraxProbeTests.
AHangingProbeIsAbandonedAtTheBudget_AndReportsOffline stands in a probe that
never returns and asserts the caller is released and told "offline". Drop the
ceiling and it fails on elapsed time — which is the frozen window returning.
Suite 381/381, 0 warnings.
gramps