* @throws FileIntegrityViolationException If the integrity of the file cannot be guaranteed (i.e. {@link #writeFile(Runnable)} has never been called)
     * @throws InsufficientLockModeException If the held lock is not at least a shared lock (e.g. LockMode.NONE)
     */
    <T> T readFile(Callable<? extends T> action) throws LockTimeoutException, FileIntegrityViolationException, InsufficientLockModeException;

    /**

// the syntax.
//
// "a < b" means a must be acquired before b if both are held
// (or, if b is held, a cannot be acquired).
//
// "NONE < a" means no locks may be held when a is acquired.
//
// If a lock is not given a rank, then it is assumed to be a leaf
// lock, which means no other lock can be acquired while it is held.
// Therefore, leaf locks do not need to be given an explicit rank.
//

    for (int i = 0; i < length; i++) {
      Object key = new Object();
      // TODO(b/145386688): This access should be guarded by 'this.segment', which is not currently
      // held
      chain = segment.newEntry(key, cache.hash(key), chain);
      if (i == 0) {
        head = chain;
      }
    }
  }

  @SuppressWarnings("GuardedBy")
  @Benchmark
  int time(int reps) {
    int dummy = 0;
    for (int i = 0; i < reps; i++) {

	defer l.mutex.Unlock()
	var locksHeld int64
	if locksHeld, reply = l.lockMap[args.Resources[0]]; !reply { // No lock is held on the given name
		return false, fmt.Errorf("RUnlock attempted on an unlocked entity: %s", args.Resources[0])
	}
	if reply = locksHeld != WriteLock; !reply { // A write-lock is held, cannot release a read lock
		return false, fmt.Errorf("RUnlock attempted on a write locked entity: %s", args.Resources[0])
	}

import java.util.function.Consumer;

@ServiceScope(Scope.Global.class)
public interface FileLockManager {
    /**
     * Creates a lock for the given file with the given mode. Acquires a lock with the given mode, which is held until the lock is
     * released by calling {@link FileLock#close()}. This method blocks until the lock can be acquired.
     *
     * @param target The file to be locked.
     * @param options The lock options.

}

// flush empties out unallocated free pages in the given cache
// into s. Then, it clears the cache, such that empty returns
// true.
//
// p.mheapLock must be held.
//
// Must run on the system stack because p.mheapLock must be held.
//
//go:systemstack
func (c *pageCache) flush(p *pageAlloc) {
	assertLockHeld(p.mheapLock)

	if c.empty() {
		return
	}
	ci := chunkIndex(c.base)

 * corresponding started event has returned.
 *
 * Implementations may retain the notification values beyond the method that passed them.
 * Started notifications maybe held until a corresponding finished notification, and slightly after.
 * Finished notifications maybe held for a short time after the return of the finished signal for
 * off thread processing.
 *
 * Implementations must not error from either signal.

    boolean lockIsHeld(final ResourceLock resourceLock) {
        MutableBoolean held = new MutableBoolean()
        coordinationService.withStateLock(new InternalTransformer<ResourceLockState.Disposition, ResourceLockState>() {
            @Override
            ResourceLockState.Disposition transform(ResourceLockState resourceLockState) {
                held.set(resourceLock.locked && resourceLock.isLockedByCurrentThread())

	select {
	case bfr.retry <- struct{}{}:
	default:
	}
}

// assumes the lock is not held
func (bfr *BoundedFrequencyRunner) stop() {
	bfr.mu.Lock()
	defer bfr.mu.Unlock()
	bfr.limiter.Stop()
	bfr.timer.Stop()
}

// assumes the lock is not held
func (bfr *BoundedFrequencyRunner) doRetry() {
	bfr.mu.Lock()
	defer bfr.mu.Unlock()
	bfr.retryMu.Lock()

//
// Semantic ranking is represented by acquiring readRank during read lock and
// writeRank during write lock.
//
// wLock is held for the duration of a write lock, so it uses writeRank
// directly, both for semantic and internal ranking. rLock is only held
// temporarily inside the rlock/lock methods, so it uses readRankInternal to
// represent internal ranking. Semantic ranking is represented by a separate