add comments

internal/syncx/mutex_test.go

@@ -5,6 +5,9 @@ import (
 	"time"
 )
 
+// TestClosableMutex_TryLock tests the TryLock functionality of ClosableMutex.
+// It verifies that TryLock succeeds when the mutex is unlocked, fails when already locked,
+// succeeds after unlocking, and fails after the mutex is closed.
 func TestClosableMutex_TryLock(t *testing.T) {
 	cm := NewClosableMutex()
 	if !cm.TryLock() {
@@ -23,6 +26,8 @@ func TestClosableMutex_TryLock(t *testing.T) {
 	}
 }
 
+// TestClosableMutex_MustLock tests the MustLock functionality of ClosableMutex.
+// It verifies that MustLock succeeds when the mutex is unlocked and panics when already locked.
 func TestClosableMutex_MustLock(t *testing.T) {
 	cm := NewClosableMutex()
 	cm.MustLock()
@@ -34,6 +39,8 @@ func TestClosableMutex_MustLock(t *testing.T) {
 	cm.MustLock()
 }
 
+// TestClosableMutex_Unlock tests the Unlock functionality of ClosableMutex.
+// It verifies that Unlock succeeds when the mutex is locked and panics when already unlocked.
 func TestClosableMutex_Unlock(t *testing.T) {
 	cm := NewClosableMutex()
 	cm.MustLock()
@@ -46,6 +53,8 @@ func TestClosableMutex_Unlock(t *testing.T) {
 	cm.Unlock()
 }
 
+// TestClosableMutex_Close tests the Close functionality of ClosableMutex.
+// It verifies that Close succeeds when the mutex is locked and panics when already closed.
 func TestClosableMutex_Close(t *testing.T) {
 	cm := NewClosableMutex()
 	cm.MustLock()
@@ -58,20 +67,23 @@ func TestClosableMutex_Close(t *testing.T) {
 	cm.Close()
 }
 
+// TestClosableMutex_Concurrent tests the concurrent behavior of ClosableMutex.
+// It verifies that TryLock fails when the mutex is locked by another goroutine
+// and succeeds after the other goroutine unlocks it.
 func TestClosableMutex_Concurrent(t *testing.T) {
 	cm := NewClosableMutex()
 	done := make(chan struct{})
 	go func() {
 		cm.MustLock()
-		time.Sleep(100 * time.Millisecond)
+		time.Sleep(100 * time.Millisecond) // Simulate work while holding the lock
 		cm.Unlock()
 		close(done)
 	}()
-	time.Sleep(50 * time.Millisecond)
+	time.Sleep(50 * time.Millisecond) // Wait for the goroutine to acquire the lock
 	if cm.TryLock() {
 		t.Fatal("expected TryLock to fail when locked by another goroutine")
 	}
-	<-done
+	<-done // Wait for the goroutine to release the lock
 	if !cm.TryLock() {
 		t.Fatal("expected TryLock to succeed after other goroutine unlocks")
 	}