Commit Graph

8 Commits

Author SHA1 Message Date
Josh Bleecher Snyder d3ba860ffd syncs: stop running TestWatchMultipleValues on CI
It's flaky, and not just on Windows.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-05-04 10:21:21 -07:00
Josh Bleecher Snyder 0807e3e2f7 syncs: disable TestWatchMultipleValues on Windows CI builds
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>
2021-03-27 13:25:33 -07:00
Brad Fitzpatrick 77ec80538a syncs: add Semaphore
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-23 12:39:28 -07:00
Dmytro Tananayskiy c431382720 Fix receiver in order to be consistent: syncs.WaitGroupChan
Signed-off-by: Dmytro Tananayskiy <dmitriyminer@gmail.com>
2020-11-24 17:20:34 -08:00
Josh Bleecher Snyder 9ab2b32569 syncs: add Watch, for monitoring mutex contention
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-09-11 11:36:07 -07:00
Josh Bleecher Snyder bf24d54143 syncs: add AssertLocked
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>
2020-09-09 12:27:52 -07:00
Brad Fitzpatrick d3134ad0c8 syncs: add AtomicBool 2020-05-29 12:41:30 -07:00
Brad Fitzpatrick b4d02a251a syncs: add new package for extra sync types 2020-03-12 11:13:33 -07:00