refactor(debug): move watchpoint slot state into the session

debug/watchpoint_linux_arm64.go

@@ -22,9 +22,6 @@ const (
 	WatchRead  WatchpointType = 3
 )
 
-// wpSlots tracks watchpoint slot occupancy.
-var wpSlots [16]bool // arm64 supports up to 16 watchpoints
-
 const maxWatchpoints = 16
 
 // hwBreakState mirrors the kernel's struct user_hwdebug_state.
@@ -45,7 +42,7 @@ const (
 
 func (s *Session) FindFreeWatchpointSlot() int {
 	for i := range maxWatchpoints {
-		if !wpSlots[i] {
+		if !s.wpSlots[i] {
 			return i
 		}
 	}
@@ -56,7 +53,7 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot >= maxWatchpoints {
 		return false
 	}
-	return wpSlots[slot]
+	return s.wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint on the given address.
@@ -64,7 +61,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if wpSlots[slot] {
+	if s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 
@@ -105,7 +102,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 		return fmt.Errorf("debug: set watchpoint: %w", err)
 	}
 
-	wpSlots[slot] = true
+	s.wpSlots[slot] = true
 	return nil
 }
 
@@ -113,7 +110,7 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if !wpSlots[slot] {
+	if !s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
 
@@ -126,13 +123,13 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if err := s.setHWBreakState(state); err != nil {
 		return err
 	}
-	wpSlots[slot] = false
+	s.wpSlots[slot] = false
 	return nil
 }
 
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := 0; slot < maxWatchpoints; slot++ {
-		if wpSlots[slot] {
+		if s.wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}