The docs say:
Note that while correct uses of TryLock do exist, they are rare,
and use of TryLock is often a sign of a deeper problem in a particular use of mutexes.
Rare code! Or bad code! Who can tell!
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The Windows CI machine experiences significant random execution delays.
For example, in this code from watchdog.go:
done := make(chan bool)
go func() {
start := time.Now()
mu.Lock()
There was a 500ms delay from initializing done to locking mu.
This test checks that we receive a sufficient number of events quickly enough.
In the face of random 500ms delays, unsurprisingly, the test fails.
There's not much principled we can do about it.
We could build a system of retries or attempt to detect these random delays,
but that game isn't worth the candle.
Skip the test.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
This allows us to check lock invariants.
It was proposed upstream and rejected in:
https://github.com/golang/go/issues/1366
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
