feat: add safe_channel pkg

safe_channel/safe_channel.go

@@ -0,0 +1,38 @@
+package safe_channel
+
+import "sync"
+
+type SafeCh[T any] struct {
+	mu     sync.Mutex
+	closed bool
+	ch     chan T
+}
+
+func NewSafeCh[T any](size int) *SafeCh[T] {
+	return &SafeCh[T]{
+		ch: make(chan T, size),
+	}
+}
+
+func (c *SafeCh[T]) Send(e T) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if !c.closed {
+		c.ch <- e
+	}
+}
+
+func (c *SafeCh[T]) GetRcvChan() <-chan T {
+	return c.ch
+}
+
+func (c *SafeCh[T]) Close() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if !c.closed {
+		close(c.ch)
+		c.closed = true
+	}
+}

safe_channel/safe_channel_test.go

@@ -0,0 +1,42 @@
+package safe_channel
+
+import (
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+// Simulate 1 receiver and N(N=2) senders situation
+func TestSafeChannel(t *testing.T) {
+	sCh := NewSafeCh[int](1)
+	wg := sync.WaitGroup{}
+
+	// Two senders
+	wg.Add(2)
+	for i := 0; i < 2; i++ {
+		go func(i int) {
+			if i == 0 {
+				// Case: send after sCh closed
+				time.Sleep(1 * time.Second)
+
+				require.Equal(t, sCh.closed, true)
+				sCh.Send(1) // No panic
+				require.Equal(t, sCh.closed, true)
+			} else {
+				// Case: send success
+				sCh.Send(1)
+				require.Equal(t, sCh.closed, false)
+			}
+			wg.Done()
+		}(i)
+	}
+
+	// One receiver
+	<-sCh.GetRcvChan()
+	sCh.Close()
+	require.Equal(t, sCh.closed, true)
+
+	wg.Wait()
+}