sim: fix reference counting of PythonEvent

When gem5 is a slave to another simulator and the Python is only used
to initialize the configuration (and not perform actual simulation), a
"debug start" (--debug-start) event will get freed during or immediately
after the initial Python frame's execution rather than remaining in the
event queue. This tricky patch fixes the GC issue causing this.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/python/swig/pyevent.hh b/src/python/swig/pyevent.hh
index f34fbd996..f668c1d9a 100644
--- a/src/python/swig/pyevent.hh
+++ b/src/python/swig/pyevent.hh
@@ -37,9 +37,10 @@
 class PythonEvent : public Event
 {
   private:
-    PyObject *object;
-
+    PyObject *eventCode; // PyObject to call to perform event
   public:
+    PyObject *object;    // PyObject wrapping this PythonEvent
+
     PythonEvent(PyObject *obj, Event::Priority priority);
     ~PythonEvent();