systemc: Detach child events in the Object destructor.

This way they don't try to detach themselves from a parent object which
no longer exists.

Change-Id: Id4a3f3b2241cf8c67cae9b983bd4c1acbef083e3
Reviewed-on: https://gem5-review.googlesource.com/c/13301
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/core/event.cc

@@ -191,6 +191,16 @@ Event::triggered() const
     return _triggeredStamp == scheduler.changeStamp();
 }
 
+void
+Event::clearParent()
+{
+    if (!parent)
+        return;
+    Object::getFromScObject(parent)->delChildEvent(sc_event());
+    parent = nullptr;
+    topLevelEvents.emplace(topLevelEvents.end(), sc_event());
+}
+
 Events topLevelEvents;
 Events allEvents;
 

src/systemc/core/event.hh

@@ -138,6 +138,8 @@ class Event
         }
     }
 
+    void clearParent();
+
   private:
     sc_core::sc_event *_sc_event;
 

src/systemc/core/object.cc

@@ -145,6 +145,9 @@ Object::~Object()
     }
     children.clear();
 
+    for (auto event: events)
+        Event::getFromScEvent(event)->clearParent();
+
     if (parent)
         popObject(&parent->_gem5_object->children, _name);
     else