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

// all of it to the socket. This behavior is similar to the Write
// step of an io.Copy in userspace.
func splicePump(sock *FD, pipefd int, inPipe int) (int, error) {
	if err := sock.writeLock(); err != nil {
		return 0, err
	}
	defer sock.writeUnlock()
	if err := sock.pd.prepareWrite(sock.isFile); err != nil {
		return 0, err
	}
	written := 0
	for inPipe > 0 {

        }
    }

    def 'invokes locking provider on writeLocks with visited modules'() {
        given:
        def identifier = newId(mid, '1.1')
        startWithoutLockState()
        addVisitedNode(identifier)

        when:
        visitor.writeLocks()

        then:

// maxOutBufHeapLen limits the growth of the heap area.
const maxOutBufHeapLen = 10 << 20

// writeLoc determines the write location if a buffer is mmaped.
// We maintain two write buffers, an mmapped section, and a heap section for
// writing. When the mmapped section is full, we switch over the heap memory
// for writing.
func (out *OutBuf) writeLoc(lenToWrite int64) (int64, []byte) {
	// See if we have enough space in the mmaped area.

// 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{

// 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

//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 {

	if err := ob.Mmap(1 << 20); err != nil {
		t.Errorf("error mmapping file %v", err)
	}
	if !ob.isMmapped() {
		t.Errorf("should be mmapped")
	}
}

// TestWriteLoc ensures that the math surrounding writeLoc is correct.
func TestWriteLoc(t *testing.T) {
	tests := []struct {
		bufLen          int
		off             int64
		heapLen         int
		lenToWrite      int64
		expectedHeapLen int
		writePos        int64

        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) {

    Lock readLock = striped.get(key).readLock();
    WeakReference<Object> garbage = new WeakReference<>(new Object());
    GcFinalization.awaitClear(garbage);
    Lock writeLock = striped.get(key).writeLock();
    readLock.lock();
    assertFalse(writeLock.tryLock());
    readLock.unlock();
  }

  @AndroidIncompatible // Presumably GC doesn't trigger, despite our efforts.
  public void testStrongImplementations() {