Limit free list of method and builtin function objects to 256 entries each.

1 files changed, 17 insertions, 3 deletions

diff --git a/Objects/methodobject.c b/Objects/methodobject.c
index 3daa9dd70d..17e905be4b 100644
--- a/Objects/methodobject.c
+++ b/Objects/methodobject.c
@@ -4,7 +4,12 @@
 #include "Python.h"
 #include "structmember.h"
 
+/* Free list for method objects to safe malloc/free overhead
+ * The m_self element is used to chain the objects.
+ */
 static PyCFunctionObject *free_list = NULL;
+static int numfree = 0;
+#define MAXFREELIST 256
 
 PyObject *
 PyCFunction_NewEx(PyMethodDef *ml, PyObject *self, PyObject *module)
@@ -14,6 +19,7 @@ PyCFunction_NewEx(PyMethodDef *ml, PyObject *self, PyObject *module)
 	if (op != NULL) {
 		free_list = (PyCFunctionObject *)(op->m_self);
 		PyObject_INIT(op, &PyCFunction_Type);
+		numfree--;
 	}
 	else {
 		op = PyObject_GC_New(PyCFunctionObject, &PyCFunction_Type);
@@ -125,8 +131,14 @@ meth_dealloc(PyCFunctionObject *m)
 	_PyObject_GC_UNTRACK(m);
 	Py_XDECREF(m->m_self);
 	Py_XDECREF(m->m_module);
-	m->m_self = (PyObject *)free_list;
-	free_list = m;
+	if (numfree < MAXFREELIST) {
+		m->m_self = (PyObject *)free_list;
+		free_list = m;
+		numfree++;
+	}
+	else {
+		PyObject_GC_Del(m);
+	}
 }
 
 static PyObject *
@@ -346,14 +358,16 @@ PyCFunction_Fini(void)
 		PyCFunctionObject *v = free_list;
 		free_list = (PyCFunctionObject *)(v->m_self);
 		PyObject_GC_Del(v);
+		numfree--;
 	}
+	assert(numfree == 0);
 }
 
 /* PyCFunction_New() is now just a macro that calls PyCFunction_NewEx(),
    but it's part of the API so we need to keep a function around that
    existing C extensions can call.
 */
-   
+
 #undef PyCFunction_New
 PyAPI_FUNC(PyObject *) PyCFunction_New(PyMethodDef *, PyObject *);