// A LRWMutex is a mutual exclusion lock with timeouts.
type LRWMutex struct {
	id          string
	source      string
	isWriteLock bool
	ref         int
	mu          sync.Mutex // Mutex to prevent multiple simultaneous locks
}

// NewLRWMutex - initializes a new lsync RW mutex.
func NewLRWMutex() *LRWMutex {
	return &LRWMutex{}
}

// Lock holds a write lock on lm.
//
// If the lock is already in use, the calling go routine

distribution that disables transparent huge pages altogether.

Go 1.22 added contention on runtime-internal locks to the [`mutex`
profile](/pkg/runtime/pprof#Profile). Contention on these locks is always
reported at `runtime._LostContendedRuntimeLock`. Complete stack traces of
runtime locks can be enabled with the [`runtimecontentionstacks`
setting](/pkg/runtime#hdr-Environment_Variables). These stack traces have

	"github.com/minio/minio/internal/logger"
)

// localMetacacheMgr is the *local* manager for this peer.
// It should never be used directly since buckets are
// distributed deterministically.
// Therefore no cluster locks are required.
var localMetacacheMgr = &metacacheManager{
	buckets: make(map[string]*bucketMetacache),
	trash:   make(map[string]metacache),
}

type metacacheManager struct {
	mu      sync.RWMutex
	init    sync.Once

    int added = 0;
    while (added < numElements) {
      // we could rely solely on #poll, but #drainTo might be more efficient when there are multiple
      // elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
      added += q.drainTo(buffer, numElements - added);
      if (added < numElements) { // not enough elements immediately available; will have to poll
        E e = q.poll(deadline - System.nanoTime(), NANOSECONDS);

import java.util.concurrent.Future;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import org.jspecify.annotations.Nullable;

/**
 * Utilities for treating interruptible operations as uninterruptible. In all cases, if a thread is

import java.nio.channels.spi.AbstractInterruptibleChannel;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.locks.LockSupport;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

@NullUnmarked
public final class InterruptibleTaskTest extends TestCase {

}

// keepAlive will continuously update lastHandout until ctx is canceled.
func (m metacache) keepAlive(ctx context.Context, rpc *peerRESTClient) {
	// we intentionally operate on a copy of m, so we can update without locks.
	t := time.NewTicker(metacacheMaxClientWait / 10)
	defer t.Stop()
	for {
		select {
		case <-ctx.Done():
			// Request is done, stop updating.
			return
		case <-t.C:
			m.lastHandout = time.Now()

    }
}
```

### 4.3 Lease Manager
```java
package jcifs.internal.smb2.lease;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import jcifs.CIFSContext;

public class LeaseManager {
    private final ConcurrentHashMap<Smb2LeaseKey, LeaseEntry> leases;

    int added = 0;
    while (added < numElements) {
      // we could rely solely on #poll, but #drainTo might be more efficient when there are multiple
      // elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
      added += q.drainTo(buffer, numElements - added);
      if (added < numElements) { // not enough elements immediately available; will have to poll
        E e = q.poll(deadline - System.nanoTime(), NANOSECONDS);

    }
}
```

### 4.2 Directory Cache Entry
```java
package jcifs.internal.smb2.lease;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

public class DirectoryCacheEntry {
    private final String directoryPath;
    private final Smb2LeaseKey leaseKey;
    private final long createTime;