// reference.
func (file *file) readUnlock() {
	if file.fdmu.ReadUnlock() {
		file.destroy()
	}
}

// writeLock adds a reference to the file and locks it for writing.
// It returns an error if the file is already closed.
func (file *file) writeLock() error {
	if !file.fdmu.WriteLock() {
		return ErrClosed
	}
	return nil
}

// writeUnlock removes a reference from the file and unlocks it for writing.

  private ReentrantReadWriteLock.ReadLock readLockB;
  private ReentrantReadWriteLock.ReadLock readLockC;
  private ReentrantReadWriteLock.WriteLock writeLockA;
  private ReentrantReadWriteLock.WriteLock writeLockB;
  private ReentrantReadWriteLock.WriteLock writeLockC;
  private ReentrantLock lock1;
  private ReentrantLock lock2;
  private ReentrantLock lock3;
  private ReentrantLock lock01;

  private ReentrantReadWriteLock.ReadLock readLockB;
  private ReentrantReadWriteLock.ReadLock readLockC;
  private ReentrantReadWriteLock.WriteLock writeLockA;
  private ReentrantReadWriteLock.WriteLock writeLockB;
  private ReentrantReadWriteLock.WriteLock writeLockC;
  private ReentrantLock lock1;
  private ReentrantLock lock2;
  private ReentrantLock lock3;
  private ReentrantLock lock01;

		subrouter.Methods(http.MethodPost).Path("/v1/force-unlock").HandlerFunc(lockServer.ForceUnlockHandler)

		nodes[i] = httptest.NewServer(router)
	}
}

const WriteLock = -1

type lockServer struct {
	mutex sync.Mutex
	// Map of locks, with negative value indicating (exclusive) write lock
	// and positive values indicating number of read locks
	lockMap map[string]int64

					continue
				}
			}
		}
		err = fd.eofError(n, err)
		return n, oobn, sysflags, err
	}
}

// Write implements io.Writer.
func (fd *FD) Write(p []byte) (int, error) {
	if err := fd.writeLock(); err != nil {
		return 0, err
	}
	defer fd.writeUnlock()
	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
		return 0, err
	}
	var nn int
	for {
		max := len(p)

// unspecified.
//
// Closing the file may or may not release the lock promptly. Callers should
// ensure that Unlock is always called when Lock succeeds.
func Lock(f File) error {
	return lock(f, writeLock)
}

// RLock places an advisory read lock on the file, blocking until it can be locked.
//
// If RLock returns nil, no other process will be able to place a write lock on

// license that can be found in the LICENSE file.

//go:build !unix && !windows

package filelock

import (
	"errors"
	"io/fs"
)

type lockType int8

const (
	readLock = iota + 1
	writeLock
)

func lock(f File, lt lockType) error {
	return &fs.PathError{
		Op:   lt.String(),
		Path: f.Name(),
		Err:  errors.ErrUnsupported,
	}
}

func unlock(f File) error {
	return &fs.PathError{

//go:build darwin || dragonfly || freebsd || illumos || linux || netbsd || openbsd

package filelock

import (
	"io/fs"
	"syscall"
)

type lockType int16

const (
	readLock  lockType = syscall.LOCK_SH
	writeLock lockType = syscall.LOCK_EX
)

func lock(f File, lt lockType) (err error) {
	for {
		err = syscall.Flock(int(f.Fd()), int(lt))
		if err != syscall.EINTR {
			break
		}
	}
	if err != nil {

func SendFile(dstFD *FD, src int, remain int64) (written int64, err error, handled bool) {
	defer func() {
		TestHookDidSendFile(dstFD, src, written, err, handled)
	}()
	if err := dstFD.writeLock(); err != nil {
		return 0, err, false
	}
	defer dstFD.writeUnlock()

	if err := dstFD.pd.prepareWrite(dstFD.isFile); err != nil {
		return 0, err, false
	}

	dst := dstFD.Sysfd
	for remain > 0 {

        persistentCache.withFileLock(() -> {
            // Additional locking necessary because of https://github.com/gradle/gradle/issues/3537
            lock.writeLock().lock();
            try {
                storeInsideLock(key, file);
            } finally {
                lock.writeLock().unlock();
            }
        });
    }

    private void storeInsideLock(HashCode key, File sourceFile) {