// For each call, unfreezeServices must be called once.
func freezeServices() {
	// Use atomics for globalServiceFreeze, so we can read without locking.
	// We need a lock since we are need the 2 atomic values to remain in sync.
	globalServiceFreezeMu.Lock()
	// If multiple calls, first one creates channel.
	globalServiceFreezeCnt++
	if globalServiceFreezeCnt == 1 {
		globalServiceFreeze.Store(make(chan struct{}))
	}

	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

func (d *disconnectReader) Close() error {
	d.mu.Lock()
	d.r = nil
	d.mu.Unlock()
	return nil
}

package dsync

// Dsync represents dsync client object which is initialized with
// authenticated clients, used to initiate lock REST calls.
type Dsync struct {
	// List of rest client objects, one per lock server.
	GetLockers func() ([]NetLocker, string)

	// Timeouts to apply.
	Timeouts Timeouts

	activeConnections uint64
	sync.RWMutex
}

func (n *netPerfRX) Connect() {
	n.Lock()
	defer n.Unlock()
	n.activeConnections++
	atomic.StoreUint64(&n.RX, 0)
	n.lastToConnect = time.Now()
}

func (n *netPerfRX) Disconnect() {
	n.Lock()
	defer n.Unlock()
	n.activeConnections--
	if n.firstToDisconnect.IsZero() {
		n.RXSample = atomic.LoadUint64(&n.RX)

		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()

	if o.Bucket != b.bucket {
		logger.Info("bucketMetacache.findCache: bucket %s does not match this bucket %s", o.Bucket, b.bucket)
		debug.PrintStack()
		return metacache{}
	}

	// Grab a write lock, since we create one if we cannot find one.
	b.mu.Lock()
	defer b.mu.Unlock()

	// Check if exists already.
	if c, ok := b.caches[o.ID]; ok {
		c.lastHandout = time.Now()
		b.caches[o.ID] = c
		b.debugf("returning existing %v", o.ID)

package lifecycle

import (
	"fmt"
	"time"

	objlock "github.com/minio/minio/internal/bucket/object/lock"
	"github.com/minio/minio/internal/bucket/replication"
)

// Evaluator - evaluates lifecycle policy on objects for the given lifecycle
// configuration, lock retention configuration and replication configuration.
type Evaluator struct {
	policy        Lifecycle
	lockRetention *objlock.Retention

	sync.Mutex
}

func (l *logOnceType) logOnceConsoleIf(ctx context.Context, subsystem string, err error, id string, errKind ...any) {
	if err == nil {
		return
	}

	nerr := unwrapErrs(err)
	l.Lock()
	shouldLog := true
	prev, ok := l.IDMap[id]
	if !ok {
		l.IDMap[id] = onceErr{
			Err:   nerr,
			Count: 1,
		}
	} else if prev.Err.Error() == nerr.Error() {
		// if errors are equal do not log.

func (r *ReqInfo) AppendTags(key, val string) *ReqInfo {
	if r == nil {
		return nil
	}
	r.Lock()
	defer r.Unlock()
	r.tags = append(r.tags, KeyVal{key, val})
	return r
}

// SetTags - sets key/val to ReqInfo.tags
func (r *ReqInfo) SetTags(key, val string) *ReqInfo {
	if r == nil {
		return nil
	}
	r.Lock()
	defer r.Unlock()
	// Search of tag key already exists in tags
	var updated bool

	globalAuthPluginMutex.Lock()
	defer globalAuthPluginMutex.Unlock()
	return globalAuthNPlugin
}

func newGlobalAuthZPluginFn() *polplugin.AuthZPlugin {
	globalAuthPluginMutex.Lock()
	defer globalAuthPluginMutex.Unlock()
	return globalAuthZPlugin
}

func setGlobalAuthNPlugin(authn *idplugin.AuthNPlugin) {
	globalAuthPluginMutex.Lock()
	globalAuthNPlugin = authn