Function TestCacheGetEntriesLocking

fs/cachefs/cache_test.go:251–298

Simple test for getEntries() locking/unlocking. Related to PRs #130 and #132.

(t *testing.T)

// Simple test for getEntries() locking/unlocking. Related to PRs #130 and #132.
func TestCacheGetEntriesLocking(t *testing.T) {
	ctx := testlogging.Context(t)
	c := NewCache(&Options{
		MaxCachedDirectories: 4,
		MaxCachedEntries:     100,
	})
	lock := &lockState{l: c.mu}
	c.mu = lock // allow checking the lock state below

	if len(c.data) != 0 || c.totalDirectoryEntries != 0 || c.head != nil || c.tail != nil {
		t.Errorf("invalid initial state: %v %v %v %v", c.data, c.totalDirectoryEntries, c.head, c.tail)
	}

	cs := newCacheSource()
	cv := cacheVerifier{cacheSource: cs, cache: c}

	const id1 = "1"

	cs.setEntryCount(id1, 1)

	// fetch non-existing entry, the loader will return an error
	actualEs, err := c.getEntries(ctx, id1, expirationTime, cs.get("foo"), identityWrapper)
	if err == nil {
		t.Fatal("Expected non-nil error when retrieving non-existing cache entry")
	}

	const expectedEsLength = 0

	actualEsLength := len(actualEs)
	if actualEsLength != expectedEsLength {
		t.Fatal("Expected empty entries, got: ", actualEsLength)
	}
	// cache must be unlocked at this point: See #130
	if !lock.Unlocked() {
		t.Fatal("Cache is locked after returning from getEntries")
	}

	// fetch id1
	_, _ = c.getEntries(ctx, id1, expirationTime, cs.get(id1), identityWrapper)
	cv.verifyCacheMiss(t, id1)
	// fetch id1 again - cache hit, no change
	_, _ = c.getEntries(ctx, id1, expirationTime, cs.get(id1), identityWrapper)
	cv.verifyCacheHit(t, id1)
	// cache must be unlocked and there should be no double unlock: See #132
	if !lock.Unlocked() {
		t.Fatal("Cache is locked after returning from getEntries")
	}
}