lnpeer/write_buffer_pool_test: adds basic write buffer pool test

lnpeer/write_buffer_pool_test.go

@@ -0,0 +1,67 @@
+package lnpeer_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/lightningnetwork/lnd/lnpeer"
+)
+
+// TestWriteBufferPool verifies that buffer pool properly resets used write
+// buffers.
+func TestWriteBufferPool(t *testing.T) {
+	const (
+		gcInterval     = time.Second
+		expiryInterval = 250 * time.Millisecond
+	)
+
+	bp := lnpeer.NewWriteBufferPool(gcInterval, expiryInterval)
+
+	// Take a fresh write buffer from the pool.
+	writeBuf := bp.Take()
+
+	// Dirty the write buffer.
+	for i := range writeBuf[:] {
+		writeBuf[i] = 0xff
+	}
+
+	// Return the buffer to the pool.
+	bp.Return(writeBuf)
+
+	// Take buffers from the pool until we find the original. We expect at
+	// most two, in the even that a fresh buffer is populated after the
+	// first is taken.
+	for i := 0; i < 2; i++ {
+		// Wait a small duration to ensure the tests behave reliable,
+		// and don't activate the non-blocking case unintentionally.
+		<-time.After(time.Millisecond)
+
+		// Take a buffer, skipping those whose pointer does not match
+		// the one we dirtied.
+		writeBuf2 := bp.Take()
+		if writeBuf2 != writeBuf {
+			continue
+		}
+
+		// Finally, verify that the buffer has been properly cleaned.
+		for i := range writeBuf2[:] {
+			if writeBuf2[i] != 0 {
+				t.Fatalf("buffer was not recycled")
+			}
+		}
+
+		return
+	}
+
+	t.Fatalf("original buffer not found")
+}
+
+// BenchmarkWriteBufferRecycle tests how quickly a WriteBuffer can be zeroed.
+func BenchmarkWriteBufferRecycle(b *testing.B) {
+	b.ReportAllocs()
+
+	buffer := new(lnpeer.WriteBuffer)
+	for i := 0; i < b.N; i++ {
+		buffer.Recycle()
+	}
+}