perfSessionEndHook top-level property
Command that closes a measurement session, turning wind's counting back off.
It exists because perfSessionBeginHook turns counting on, and something
has to turn it off again. WindParser.parse is the hottest path in the
framework and runs on every build of every W-widget, so leaving counting
enabled after a session would tax every later frame in the app for numbers
nobody asked for. It is the same discipline ext.dusk.perf_end already
applies to the debugProfile* flags it restores.
Counters are deliberately NOT zeroed here: perf_end reads them to build
its report, and a hook that cleared them would have to run after the read,
which is a coupling worth avoiding. The next session's
perfSessionBeginHook zeroes them instead.
Defaults to a no-op.
Hosts wire the real thing by writing:
perfSessionEndHook = () {
WindPerfCounters.enabled = false;
};
Contract: set-once-per-isolate from MagicPerfIntegration.install().
Reset to this no-op default by MagicPerfIntegration.resetForTesting().
Implementation
void Function() perfSessionEndHook = () {};