Using memnet and synctest removes flakiness caused by real networking
and subtle timing differences.
Additionally, remove the `t.Logf` call inside the server's shutdown
goroutine that was causing a false positive data race detection.
The race detector is flagging a double write during this `t.Logf` call.
This is a common pattern, noted in golang/go#40343 and elsehwere in
this file, where using `t.Logf` after a test has finished can interact
poorly with the test runner.
This is a long-standing issue which became more common after rewriting
this test to use memnet and synctest.
Fixed#17355
Signed-off-by: Alex Chan <alexc@tailscale.com>
Alex ChanandAlex Chan
7dfa26778e