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

debug/watchpoint_linux_amd64.go

@@ -20,14 +20,11 @@ const (
 	WatchRead  WatchpointType = 3 // trigger on read or write
 )
 
-// wpSlots tracks watchpoint slot occupancy (DR0-DR3).
-var wpSlots [4]bool
-
 // FindFreeWatchpointSlot returns the index of the first free watchpoint slot
 // (0-3), or -1 if all four hardware watchpoints are in use.
 func (s *Session) FindFreeWatchpointSlot() int {
 	for i := range 4 {
-		if !wpSlots[i] {
+		if !s.wpSlots[i] {
 			return i
 		}
 	}
@@ -39,7 +36,7 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot > 3 {
 		return false
 	}
-	return wpSlots[slot]
+	return s.wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint on the given address.
@@ -47,7 +44,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if slot < 0 || slot > 3 {
 		return fmt.Errorf("debug: watchpoint slot must be 0-3")
 	}
-	if wpSlots[slot] {
+	if s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 
@@ -96,7 +93,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if err := ptracePokeUser(s.pid, 0x38, dr7); err != nil {
 		return fmt.Errorf("debug: set DR7: %w", err)
 	}
-	wpSlots[slot] = true
+	s.wpSlots[slot] = true
 	return nil
 }
 
@@ -105,7 +102,7 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot > 3 {
 		return fmt.Errorf("debug: watchpoint slot must be 0-3")
 	}
-	if !wpSlots[slot] {
+	if !s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
 	dr7, err := ptracePeekUser(s.pid, 0x38)
@@ -116,14 +113,14 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if err := ptracePokeUser(s.pid, 0x38, dr7); err != nil {
 		return err
 	}
-	wpSlots[slot] = false
+	s.wpSlots[slot] = false
 	return nil
 }
 
 // ClearAllWatchpoints removes all hardware watchpoints.
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := range 4 {
-		if wpSlots[slot] {
+		if s.wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}