// TestMutexSessionRelock ensures that acquiring the same lock with the same
// session will not result in deadlock.
func TestMutexSessionRelock(t *testing.T) {
clus := NewClusterV3(t, &ClusterConfig{Size: 3})
defer clus.Terminate(t)
cli := clus.RandClient()
m := concurrency.NewMutex(cli, "test-mutex")
if err := m.Lock(context.TODO()); err != nil {
t.Fatal(err)
}
m2 := concurrency.NewMutex(cli, "test-mutex")
if err := m2.Lock(context.TODO()); err != nil {
t.Fatal(err)
}
}
func doSTM(ctx context.Context, client *v3.Client, requests <-chan stmApply) {
defer wg.Done()
var m *v3sync.Mutex
if stmMutex {
m = v3sync.NewMutex(client, "stmlock")
}
for applyf := range requests {
st := time.Now()
if m != nil {
m.Lock(context.TODO())
}
_, err := mkSTM(context.TODO(), client, applyf)
if m != nil {
m.Unlock(context.TODO())
}
var errStr string
if err != nil {
errStr = err.Error()
}
results <- result{errStr: errStr, duration: time.Since(st), happened: time.Now()}
bar.Increment()
}
}
func doSTM(client *v3.Client, requests <-chan stmApply, results chan<- report.Result) {
defer wg.Done()
var m *v3sync.Mutex
if stmMutex {
s, err := v3sync.NewSession(client)
if err != nil {
panic(err)
}
m = v3sync.NewMutex(s, "stmlock")
}
for applyf := range requests {
st := time.Now()
if m != nil {
m.Lock(context.TODO())
}
_, err := mkSTM(context.TODO(), client, applyf)
if m != nil {
m.Unlock(context.TODO())
}
results <- report.Result{Err: err, Start: st, End: time.Now()}
bar.Increment()
}
}
func testMutex(t *testing.T, waiters int, chooseClient func() *clientv3.Client) {
// stream lock acquisitions
lockedC := make(chan *concurrency.Mutex)
for i := 0; i < waiters; i++ {
go func() {
m := concurrency.NewMutex(chooseClient(), "test-mutex")
if err := m.Lock(context.TODO()); err != nil {
t.Fatalf("could not wait on lock (%v)", err)
}
lockedC <- m
}()
}
// unlock locked mutexes
timerC := time.After(time.Duration(waiters) * time.Second)
for i := 0; i < waiters; i++ {
select {
case <-timerC:
t.Fatalf("timed out waiting for lock %d", i)
case m := <-lockedC:
// lock acquired with m
select {
case <-lockedC:
t.Fatalf("lock %d followers did not wait", i)
default:
}
if err := m.Unlock(); err != nil {
t.Fatalf("could not release lock (%v)", err)
}
}
}
}
func runRacer(getClient getClientFunc, round int) {
rcs := make([]roundClient, 15)
ctx := context.Background()
cnt := 0
for i := range rcs {
rcs[i].c = getClient()
var (
s *concurrency.Session
err error
)
for {
s, err = concurrency.NewSession(rcs[i].c)
if err == nil {
break
}
}
m := concurrency.NewMutex(s, "racers")
rcs[i].acquire = func() error { return m.Lock(ctx) }
rcs[i].validate = func() error {
if cnt++; cnt != 1 {
return fmt.Errorf("bad lock; count: %d", cnt)
}
return nil
}
rcs[i].release = func() error {
if err := m.Unlock(ctx); err != nil {
return err
}
cnt = 0
return nil
}
}
doRounds(rcs, round)
}
func lockUntilSignal(c *clientv3.Client, lockname string) error {
s, err := concurrency.NewSession(c)
if err != nil {
return err
}
m := concurrency.NewMutex(s, lockname)
ctx, cancel := context.WithCancel(context.TODO())
// unlock in case of ordinary shutdown
donec := make(chan struct{})
sigc := make(chan os.Signal, 1)
signal.Notify(sigc, os.Interrupt, os.Kill)
go func() {
<-sigc
cancel()
close(donec)
}()
s, serr := concurrency.NewSession(c)
if serr != nil {
return serr
}
if err := m.Lock(ctx); err != nil {
return err
}
k, kerr := c.Get(ctx, m.Key())
if kerr != nil {
return kerr
}
if len(k.Kvs) == 0 {
return errors.New("lock lost on init")
}
display.Get(*k)
select {
case <-donec:
return m.Unlock(context.TODO())
case <-s.Done():
}
return errors.New("session expired")
}
func (e *EtcdClient) LockPath(path string) (KVLocker, error) {
e.lockPathsMU.Lock()
if e.lockPaths[path] == nil {
e.lockPaths[path] = &sync.Mutex{}
}
e.lockPathsMU.Unlock()
log.Debugf("Locking path %s", path)
// First we lock the local lock for this path
e.lockPaths[path].Lock()
e.sessionMU.RLock()
mu := concurrency.NewMutex(e.session, path)
e.sessionMU.RUnlock()
// Then we lock the global lock
err := mu.Lock(ctx.Background())
if err != nil {
e.lockPaths[path].Unlock()
return nil, fmt.Errorf("Error while locking path %s: %s", path, err)
}
log.Debugf("Locked path %s", path)
return &EtcdLocker{mutex: mu, path: path, localLock: e.lockPaths[path]}, nil
}
func runRacer(eps []string, round int) {
rcs := make([]roundClient, 15)
ctx := context.Background()
cnt := 0
for i := range rcs {
rcs[i].c = randClient(eps)
m := concurrency.NewMutex(rcs[i].c, "racers")
rcs[i].acquire = func() error { return m.Lock(ctx) }
rcs[i].validate = func() error {
if cnt++; cnt != 1 {
return fmt.Errorf("bad lock; count: %d", cnt)
}
return nil
}
rcs[i].release = func() error {
if err := m.Unlock(ctx); err != nil {
return err
}
cnt = 0
return nil
}
}
doRounds(rcs, round)
}
