Method TestLBCache_ShutdownTimer_New_Race

balancer/grpclb/grpclb_util_test.go:228–267

Test that if the timer to shut down a SubConn fires at the same time NewSubConn cancels the timer, it doesn't cause deadlock.

(t *testing.T)

// Test that if the timer to shut down a SubConn fires at the same time
// NewSubConn cancels the timer, it doesn't cause deadlock.
func (s) TestLBCache_ShutdownTimer_New_Race(t *testing.T) {
	mcc := newMockClientConn()
	if err := checkMockCC(mcc, 0); err != nil {
		t.Fatal(err)
	}

	ccc := newLBCacheClientConn(mcc)
	ccc.timeout = time.Nanosecond
	if err := checkCacheCC(ccc, 0, 0); err != nil {
		t.Fatal(err)
	}

	sc, _ := ccc.NewSubConn([]resolver.Address{{Addr: "address1"}}, balancer.NewSubConnOptions{})
	// One subconn in MockCC.
	if err := checkMockCC(mcc, 1); err != nil {
		t.Fatal(err)
	}
	// No subconn being deleted, and one in CacheCC.
	if err := checkCacheCC(ccc, 0, 1); err != nil {
		t.Fatal(err)
	}

	done := make(chan struct{})

	go func() {
		for i := 0; i < 1000; i++ {
			// Shutdown starts a timer with 1 ns timeout, the NewSubConn will
			// race with the timer.
			sc.Shutdown()
			sc, _ = ccc.NewSubConn([]resolver.Address{{Addr: "address1"}}, balancer.NewSubConnOptions{})
		}
		close(done)
	}()

	select {
	case <-time.After(time.Second):
		t.Fatalf("Test didn't finish within 1 second. Deadlock")
	case <-done:
	}
}