}
}

func TestSimpleWriteLockTimedOut(t *testing.T) {
	locked := testSimpleWriteLock(t, time.Second)

	expected := false
	if locked != expected {
		t.Errorf("TestSimpleWriteLockTimedOut(): \nexpected %#v\ngot      %#v", expected, locked)
	}
}

func testDualWriteLock(t *testing.T, duration time.Duration) (locked bool) {
	ctx := t.Context()
	lrwm := NewLRWMutex()

	expected := true
	if locked != expected {
		t.Errorf("TestSimpleWriteLockAcquired(): \nexpected %#v\ngot      %#v", expected, locked)
	}
}

func TestSimpleWriteLockTimedOut(t *testing.T) {
	locked := testSimpleWriteLock(t, testDrwMutexAcquireTimeout)

	expected := false
	if locked != expected {
		t.Errorf("TestSimpleWriteLockTimedOut(): \nexpected %#v\ngot      %#v", expected, locked)
	}
}

			lm.ref = 1
			lm.isWriteLock = true
			locked = true
		}
	} else {
		if !lm.isWriteLock {
			lm.ref++
			locked = true
		}
	}

	return locked
}

const (
	lockRetryInterval = 50 * time.Millisecond
)

// lockLoop will acquire either a read or a write lock
//
// The call will block until the lock is granted using a built-in
// timing randomized back-off algorithm to try again until successful

// open file descriptor.
package lock

import (
	"errors"
	"os"
	"sync"
)

// ErrAlreadyLocked is returned if the underlying fd is already locked.
var ErrAlreadyLocked = errors.New("file already locked")

// RLockedFile represents a read locked file, implements a special
// closer which only closes the associated *os.File when the ref count.
// has reached zero, i.e when all the readers have given up their locks.

	}

	// blocking on locked file
	locked := make(chan struct{}, 1)
	go func() {
		bl, blerr := LockedOpenFile(f.Name(), os.O_WRONLY, 0o600)
		if blerr != nil {
			t.Error(blerr)
			return
		}
		locked <- struct{}{}
		if blerr = bl.Close(); blerr != nil {
			t.Error(blerr)
			return
		}
	}()

	select {
	case <-locked:
		t.Error("unexpected unblocking")

	}
	nsLk.ref++
	n.lockMap[resource] = nsLk
	n.lockMapMutex.Unlock()

	// Locking here will block (until timeout).
	if readLock {
		locked = nsLk.GetRLock(ctx, opsID, lockSource, timeout)
	} else {
		locked = nsLk.GetLock(ctx, opsID, lockSource, timeout)
	}

	if !locked { // We failed to get the lock
		// Decrement ref count since we failed to get the lock
		n.lockMapMutex.Lock()
		n.lockMap[resource].ref--

type LockArgs struct {
	// Unique ID of lock/unlock request.
	UID string

	// Resources contains single or multiple entries to be locked/unlocked.
	Resources []string

	// Owner represents unique ID for this instance, an owner who originally requested
	// the locked resource, useful primarily in figuring out stale locks.
	Owner string

	// Source contains the line number, function and file name of the code

	default:
		atomic.StoreInt64(&m.LastPing, time.Now().Unix())
		return pongMsg{}
	}
}

// disconnect will disconnect the mux.
// m.recvMu must be locked when calling this function.
func (m *muxServer) disconnect(msg string, locked bool) {
	if debugPrint {
		fmt.Println("Mux", m.ID, "disconnecting. Reason:", msg)
	}
	if msg != "" {

package clause

const (
	LockingStrengthUpdate    = "UPDATE"
	LockingStrengthShare     = "SHARE"
	LockingOptionsSkipLocked = "SKIP LOCKED"
	LockingOptionsNoWait     = "NOWAIT"
)

type Locking struct {
	Strength string
	Table    Table
	Options  string
}

// Name where clause name
func (locking Locking) Name() string {
	return "FOR"
}

// Build build where clause
func (locking Locking) Build(builder Builder) {

		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsSkipLocked}},
			"SELECT * FROM `users` FOR UPDATE SKIP LOCKED", nil,
		},
	}

	for idx, result := range results {
		t.Run(fmt.Sprintf("case #%v", idx), func(t *testing.T) {
			checkBuildClauses(t, result.Clauses, result.Result, result.Vars)
		})
	}