94 lines
1.7 KiB
Go
94 lines
1.7 KiB
Go
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package mutex
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import (
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"context"
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"testing"
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"time"
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"github.com/stretchr/testify/require"
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)
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func TestMutex(t *testing.T) {
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t.Run("starts unlocked", func(t *testing.T) {
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m := New()
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canLock(t, m)
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})
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t.Run("Lock blocks when locked", func(t *testing.T) {
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m := New()
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m.Lock()
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lockIsBlocked(t, m)
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})
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t.Run("Unlock unblocks Lock", func(t *testing.T) {
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m := New()
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m.Lock()
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m.Unlock() // nolint:staticcheck // SA2001 is not relevant here
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canLock(t, m)
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})
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t.Run("TryLock acquires lock", func(t *testing.T) {
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m := New()
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ctx, cancel := context.WithTimeout(context.Background(), time.Second)
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t.Cleanup(cancel)
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require.NoError(t, m.TryLock(ctx))
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lockIsBlocked(t, m)
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})
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t.Run("TryLock blocks until timeout when locked", func(t *testing.T) {
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m := New()
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m.Lock()
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ctx, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
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t.Cleanup(cancel)
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err := m.TryLock(ctx)
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require.Equal(t, err, context.DeadlineExceeded)
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})
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t.Run("TryLock acquires lock before timeout", func(t *testing.T) {
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m := New()
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m.Lock()
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go func() {
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time.Sleep(20 * time.Millisecond)
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m.Unlock()
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}()
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ctx, cancel := context.WithTimeout(context.Background(), time.Second)
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t.Cleanup(cancel)
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err := m.TryLock(ctx)
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require.NoError(t, err)
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})
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}
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func canLock(t *testing.T, m *Mutex) {
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t.Helper()
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chDone := make(chan struct{})
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go func() {
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m.Lock()
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close(chDone)
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}()
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select {
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case <-chDone:
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case <-time.After(20 * time.Millisecond):
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t.Fatal("failed to acquire lock before timeout")
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}
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}
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func lockIsBlocked(t *testing.T, m *Mutex) {
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t.Helper()
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chDone := make(chan struct{})
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go func() {
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m.Lock()
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close(chDone)
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}()
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select {
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case <-chDone:
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t.Fatal("expected Lock to block")
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case <-time.After(20 * time.Millisecond):
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}
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}
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