GF
Go Foundation API
lock API

lock

package

API reference for the lock package.

Imports

(5)
INT github.com/mirkobrombin/go-foundation/v2/core/contracts STD context STD time STD sync STD testing
I
interface

Lease

Locker defines the interface for distributed or local locks.

core/lock/locker.go:18-21 
type Lease interface

Example 

// Assuming a RedisLocker implementation
locker := NewRedisLocker(redisClient)
lease, err := locker.Acquire(ctx, "my-resource", 5*time.Second)
if err == nil {
	defer lease.Release(ctx)
}

Methods

Key
Method

Returns

string 
func Key(...)
Release
Method

Parameters

ctx context.Context

Returns

error 
func Release(...)
I
interface

Locker

core/lock/locker.go:23-30 
type Locker interface

Methods

Acquire
Method

Parameters

ctx context.Context
key string
ttl time.Duration

Returns

Lease
error 
func Acquire(...)
TryLock
Method

Parameters

ctx context.Context
key string
ttl time.Duration

Returns

Lease
bool
error 
func TryLock(...)
S
struct •
Implements: Locker

InMemoryLocker

InMemoryLocker implements Locker using in-process mutexes.

core/lock/memory.go:10-14 
type InMemoryLocker struct

Methods

Acquire
Method

Parameters

ctx context.Context
key string
ttl time.Duration

Returns

Lease
error 
func (*InMemoryLocker) Acquire(ctx context.Context, key string, ttl time.Duration) (Lease, error)
{
	ticker := time.NewTicker(10 * time.Millisecond)
	defer ticker.Stop()

	for {
		lease, ok, err := l.TryLock(ctx, key, ttl)
		if err != nil {
			return nil, err
		}
		if ok {
			return lease, nil
		}
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-ticker.C:
		}
	}
}
TryLock
Method

Parameters

ctx context.Context
key string
ttl time.Duration

Returns

Lease
bool
error 
func (*InMemoryLocker) TryLock(ctx context.Context, key string, ttl time.Duration) (Lease, bool, error)
{
	if err := ctx.Err(); err != nil {
		return nil, false, err
	}
	l.mu.Lock()
	if _, exists := l.locks[key]; exists {
		l.mu.Unlock()
		return nil, false, nil
	}
	l.next++
	owner := l.next
	state := &lockState{owner: owner}
	l.locks[key] = state
	if ttl > 0 {
		state.timer = time.AfterFunc(ttl, func() {
			l.release(key, owner)
		})
	}
	l.mu.Unlock()
	return &memoryLease{locker: l, key: key, owner: owner}, true, nil
}
release
Method

Parameters

key string
owner uint64 
func (*InMemoryLocker) release(key string, owner uint64)
{
	l.mu.Lock()
	defer l.mu.Unlock()
	state, ok := l.locks[key]
	if !ok || state.owner != owner {
		return
	}
	if state.timer != nil {
		state.timer.Stop()
	}
	delete(l.locks, key)
}

Fields

Name Type Description
mu sync.Mutex
locks map[string]*lockState
next uint64
S
struct

lockState

core/lock/memory.go:16-19 
type lockState struct

Fields

Name Type Description
owner uint64
timer *time.Timer
S
struct

memoryLease

core/lock/memory.go:21-26 
type memoryLease struct

Methods

Key
Method

Returns

string 
func (*memoryLease) Key() string
{
	return l.key
}
Release
Method

Parameters

_ context.Context

Returns

error 
func (*memoryLease) Release(_ context.Context) error
{
	l.once.Do(func() {
		l.locker.release(l.key, l.owner)
	})
	return nil
}

Fields

Name Type Description
locker *InMemoryLocker
key string
owner uint64
once sync.Once
F
function

NewInMemoryLocker

NewInMemoryLocker creates a new in-process Locker.

Returns

*InMemoryLocker
core/lock/memory.go:40-44 
func NewInMemoryLocker() *InMemoryLocker

{
	return &InMemoryLocker{
		locks: make(map[string]*lockState),
	}
}
F
function

TestInMemoryLocker_TryLock

Parameters

t
*testing.T
core/lock/memory_test.go:10-28 
func TestInMemoryLocker_TryLock(t *testing.T)

{
	l := NewInMemoryLocker()
	lease, ok, err := l.TryLock(context.Background(), "key1", 0)
	if err != nil {
		t.Fatalf("TryLock failed: %v", err)
	}
	if !ok {
		t.Fatal("expected lock acquired")
	}
	defer lease.Release(context.Background())

	_, ok, err = l.TryLock(context.Background(), "key1", 0)
	if err != nil {
		t.Fatalf("TryLock second call: %v", err)
	}
	if ok {
		t.Fatal("expected lock not acquired (already held)")
	}
}
F
function

TestInMemoryLocker_Release

Parameters

t
*testing.T
core/lock/memory_test.go:30-46 
func TestInMemoryLocker_Release(t *testing.T)

{
	l := NewInMemoryLocker()
	lease, _, _ := l.TryLock(context.Background(), "k", 0)

	err := lease.Release(context.Background())
	if err != nil {
		t.Fatalf("Release failed: %v", err)
	}

	_, ok, err := l.TryLock(context.Background(), "k", 0)
	if err != nil {
		t.Fatalf("TryLock after release: %v", err)
	}
	if !ok {
		t.Fatal("expected lock acquired after release")
	}
}
F
function

TestInMemoryLocker_Acquire

Parameters

t
*testing.T
core/lock/memory_test.go:48-69 
func TestInMemoryLocker_Acquire(t *testing.T)

{
	l := NewInMemoryLocker()

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		lease, _, _ := l.TryLock(context.Background(), "shared", 0)
		time.Sleep(50 * time.Millisecond)
		lease.Release(context.Background())
	}()

	time.Sleep(5 * time.Millisecond)
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()

	_, err := l.Acquire(ctx, "shared", 0)
	if err != nil {
		t.Fatalf("Acquire failed: %v", err)
	}
	wg.Wait()
}
F
function

TestInMemoryLocker_AcquireContextCancel

Parameters

t
*testing.T
core/lock/memory_test.go:71-83 
func TestInMemoryLocker_AcquireContextCancel(t *testing.T)

{
	l := NewInMemoryLocker()
	lease, _, _ := l.TryLock(context.Background(), "blocked", 0)
	defer lease.Release(context.Background())

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Millisecond)
	defer cancel()

	_, err := l.Acquire(ctx, "blocked", 0)
	if err == nil {
		t.Fatal("expected error from cancelled context")
	}
}
F
function

TestInMemoryLocker_DifferentKeys

Parameters

t
*testing.T
core/lock/memory_test.go:85-94 
func TestInMemoryLocker_DifferentKeys(t *testing.T)

{
	l := NewInMemoryLocker()
	lease1, ok1, _ := l.TryLock(context.Background(), "a", 0)
	lease2, ok2, _ := l.TryLock(context.Background(), "b", 0)
	defer lease1.Release(context.Background())
	defer lease2.Release(context.Background())
	if !ok1 || !ok2 {
		t.Fatal("different keys should not conflict")
	}
}
F
function

TestInMemoryLocker_TTLReleasesLock

Parameters

t
*testing.T
core/lock/memory_test.go:96-110 
func TestInMemoryLocker_TTLReleasesLock(t *testing.T)

{
	l := NewInMemoryLocker()
	_, ok, err := l.TryLock(context.Background(), "expiring", 10*time.Millisecond)
	if err != nil || !ok {
		t.Fatalf("TryLock() = %v, %v, want true, nil", ok, err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	lease, err := l.Acquire(ctx, "expiring", 0)
	if err != nil {
		t.Fatalf("Acquire() after TTL: %v", err)
	}
	defer lease.Release(context.Background())
}
F
function

TestInMemoryLocker_ExpiredOwnerDoesNotReleaseNewLock

Parameters

t
*testing.T
core/lock/memory_test.go:112-139 
func TestInMemoryLocker_ExpiredOwnerDoesNotReleaseNewLock(t *testing.T)

{
	l := NewInMemoryLocker()
	first, ok, err := l.TryLock(context.Background(), "reused", 40*time.Millisecond)
	if err != nil || !ok {
		t.Fatalf("first TryLock() = %v, %v", ok, err)
	}
	if err := first.Release(context.Background()); err != nil {
		t.Fatal(err)
	}
	second, ok, err := l.TryLock(context.Background(), "reused", 0)
	if err != nil || !ok {
		t.Fatalf("second TryLock() = %v, %v", ok, err)
	}
	if err := first.Release(context.Background()); err != nil {
		t.Fatal(err)
	}
	time.Sleep(60 * time.Millisecond)
	_, ok, err = l.TryLock(context.Background(), "reused", 0)
	if err != nil {
		t.Fatal(err)
	}
	if ok {
		t.Fatal("expired owner released a newer lock")
	}
	if err := second.Release(context.Background()); err != nil {
		t.Fatal(err)
	}
}