type IAMStorageAPI interface {
	// The role of the read-write lock is to prevent go routines from
	// concurrently reading and writing the IAM storage. The (r)lock()
	// functions return the iamCache. The cache can be safely written to
	// only when returned by `lock()`.
	lock() *iamCache
	unlock()
	rlock() *iamCache
	runlock()
	getUsersSysType() UsersSysType

	return false
}

// Close closes the underlying socket file descriptor.
func (restClient *ReconnectRESTClient) Close() error {
	return nil
}

var (
	errLockConflict = errors.New("lock conflict")
	errLockNotFound = errors.New("lock not found")
)

func toLockError(err error) error {
	if err == nil {
		return nil
	}

	switch err.Error() {
	case errLockConflict.Error():
		return errLockConflict

func (list *TargetList) incCurrentSendCalls(id TargetID) {
	list.statLock.Lock()
	defer list.statLock.Unlock()

	stats, ok := list.targetStats[id]
	if !ok {
		stats = targetStat{}
	}

	stats.currentSendCalls++
	list.targetStats[id] = stats
	return
}

func (list *TargetList) decCurrentSendCalls(id TargetID) {
	list.statLock.Lock()
	defer list.statLock.Unlock()

	stats, ok := list.targetStats[id]

		if m.cancelFn != nil {
			m.cancelFn(context.Canceled)
		}
		// Wait for senders to release.
		m.respMu.Lock()
	}

	defer m.respMu.Unlock()
	m.closeLocked()
}

func (m *muxClient) closeLocked() {
	if m.closed {
		return
	}
	// We hold the lock, so nobody can modify m.respWait while we're closing.
	if m.respWait != nil {
		xioutil.SafeClose(m.respWait)
		m.respWait = nil
	}

}

func (t *tierMetrics) logSuccess(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.success++
	t.requestsCount[tier] = stat
}

func (t *tierMetrics) logFailure(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.failure++
	t.requestsCount[tier] = stat
}

		return err
	}

	// if no update is needed return right away.
	if !update {
		z.poolMetaMutex.Lock()
		z.poolMeta = meta
		z.poolMetaMutex.Unlock()
	} else {
		newMeta := newPoolMeta(z, meta)
		if err = newMeta.save(ctx, z.serverPools); err != nil {
			return err
		}
		z.poolMetaMutex.Lock()
		z.poolMeta = newMeta
		z.poolMetaMutex.Unlock()
	}

	pools := meta.returnResumablePools()

sleep 10

./mc alias set myminio1 http://localhost:9001 minioadmin minioadmin
./mc alias set myminio2 http://localhost:9101 minioadmin minioadmin

sleep 1

./mc mb myminio1/testbucket/ --with-lock
./mc mb myminio2/testbucket/ --with-lock

./mc encrypt set sse-s3 my-minio-key myminio1/testbucket/
./mc encrypt set sse-s3 my-minio-key myminio2/testbucket/

// found, otherwise use default parameters
func newSrvConfig(objAPI ObjectLayer) error {
	// Initialize server config.
	srvCfg := newServerConfig()

	// hold the mutex lock before a new config is assigned.
	globalServerConfigMu.Lock()
	globalServerConfig = srvCfg
	globalServerConfigMu.Unlock()

	// Save config into file.
	return saveServerConfig(GlobalContext, objAPI, srvCfg)
}

	var funcReturned bool
	var funcReturnedMu sync.Mutex
	defer func() {
		funcReturnedMu.Lock()
		funcReturned = true
		funcReturnedMu.Unlock()
	}()
	// Write listing to results and saver.
	go func() {
		var returned bool
		for entry := range inCh {
			if !returned {
				funcReturnedMu.Lock()
				returned = funcReturned
				funcReturnedMu.Unlock()
				outCh <- entry
				if returned {

type Target struct {
	status int32

	totalMessages  int64
	failedMessages int64

	wg sync.WaitGroup

	// Channel of log entries.
	// Reading logCh must hold read lock on logChMu (to avoid read race)
	// Sending a value on logCh must hold read lock on logChMu (to avoid closing)
	logCh   chan interface{}
	logChMu sync.RWMutex

	// store to persist and replay the logs to the target