wip: Py_TPFLAGS_HAVE_GC was suggested. doesn't work yet

4 files changed, 29 insertions, 16 deletions

diff --git a/coverage/collector.py b/coverage/collector.py
index 1466222d..89ba66ba 100644
--- a/coverage/collector.py
+++ b/coverage/collector.py
@@ -262,8 +262,6 @@ class Collector:
             tracer.switch_context = self.switch_context
         if hasattr(tracer, 'disable_plugin'):
             tracer.disable_plugin = self.disable_plugin
-        tracer.another1 = object()
-        tracer.another2 = self._installation_trace
 
         fn = tracer.start()
         self.tracers.append(tracer)
diff --git a/coverage/ctracer/tracer.c b/coverage/ctracer/tracer.c
index e8e7e2f3..6e6702dc 100644
--- a/coverage/ctracer/tracer.c
+++ b/coverage/ctracer/tracer.c
@@ -104,8 +104,6 @@ CTracer_dealloc(CTracer *self)
     Py_XDECREF(self->switch_context);
     Py_XDECREF(self->context);
     Py_XDECREF(self->disable_plugin);
-    Py_XDECREF(self->another1);
-    Py_XDECREF(self->another2);
 
     DataStack_dealloc(&self->stats, &self->data_stack);
     if (self->data_stacks) {
@@ -120,6 +118,22 @@ CTracer_dealloc(CTracer *self)
     Py_TYPE(self)->tp_free((PyObject*)self);
 }
 
+static int
+CTracer_traverse(CTracer *self, visitproc visit, void *arg)
+{
+    Py_VISIT(self->switch_context);
+    Py_VISIT(self->disable_plugin);
+    return 0;
+}
+
+static int
+CTracer_clear(CTracer *self)
+{
+    Py_CLEAR(self->switch_context);
+    Py_CLEAR(self->disable_plugin);
+    return 0;
+}
+
 #if TRACE_LOG
 static const char *
 indent(int n)
@@ -1023,9 +1037,6 @@ CTracer_members[] = {
     { "disable_plugin",     T_OBJECT, offsetof(CTracer, disable_plugin), 0,
             PyDoc_STR("Function for disabling a plugin.") },
 
-    { "another1", T_OBJECT, offsetof(CTracer, another1), 0, PyDoc_STR("blah") },
-    { "another2", T_OBJECT, offsetof(CTracer, another2), 0, PyDoc_STR("blah") },
-
     { NULL }
 };
 
@@ -1055,7 +1066,8 @@ CTracerType = {
     "coverage.CTracer",        /*tp_name*/
     sizeof(CTracer),           /*tp_basicsize*/
     0,                         /*tp_itemsize*/
-    (destructor)CTracer_dealloc, /*tp_dealloc*/
+    (destructor)CTracer_dealloc,
+                               /*tp_dealloc*/
     0,                         /*tp_print*/
     0,                         /*tp_getattr*/
     0,                         /*tp_setattr*/
@@ -1070,10 +1082,12 @@ CTracerType = {
     0,                         /*tp_getattro*/
     0,                         /*tp_setattro*/
     0,                         /*tp_as_buffer*/
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
+                               /*tp_flags*/
     "CTracer objects",         /* tp_doc */
-    0,                         /* tp_traverse */
-    0,                         /* tp_clear */
+    (traverseproc)CTracer_traverse,
+                               /* tp_traverse */
+    (inquiry)CTracer_clear,    /* tp_clear */
     0,                         /* tp_richcompare */
     0,                         /* tp_weaklistoffset */
     0,                         /* tp_iter */
diff --git a/coverage/ctracer/tracer.h b/coverage/ctracer/tracer.h
index 51bd07f9..65d748ca 100644
--- a/coverage/ctracer/tracer.h
+++ b/coverage/ctracer/tracer.h
@@ -28,8 +28,6 @@ typedef struct CTracer {
     PyObject * should_start_context;
     PyObject * switch_context;
     PyObject * disable_plugin;
-    PyObject * another1;
-    PyObject * another2;
 
     /* Has the tracer been started? */
     BOOL started;
diff --git a/tests/test_oddball.py b/tests/test_oddball.py
index 7f65e827..e1f12978 100644
--- a/tests/test_oddball.py
+++ b/tests/test_oddball.py
@@ -217,7 +217,6 @@ class MemoryLeakTest(CoverageTest):
             for i in range(3):
                 work()
                 gc_collect()
-                n.append(len(gc.get_objects()))
                 objs = gc.get_objects()
                 n.append(len(objs))
                 for obj in objs:
@@ -225,8 +224,12 @@ class MemoryLeakTest(CoverageTest):
                         meths[i][id(obj)] = obj
                 del objs
 
-            print("diff 0-1", [meths[1][k] for k in set(meths[1]) - set(meths[0])])
-            print("diff 1-2", [meths[2][k] for k in set(meths[2]) - set(meths[1])])
+            import pprint
+            print("diff 0-1:")
+            pprint.pprint([meths[1][k] for k in set(meths[1]) - set(meths[0])])
+            print("diff 1-2:")
+            pprint.pprint([meths[2][k] for k in set(meths[2]) - set(meths[1])])
+            print(f"gc.garbage has {len(gc.garbage)} things")
             assert (
                 n[0] == n[1] == n[2]
             ), f"objects leaked: {n[1] - n[0]}, {n[2] - n[1]}"