Faster floating point allocator, same idea as the int allocator.

By Aaron Watters.

diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index d66bf8534b714095bfcd842c3834cda310fdf8ac..7f7f50786bc47766a1abebf5ab8bdaea6deee712 100644 (file)
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -83,6 +83,25 @@ extern double fmod Py_PROTO((double, double));
 extern double pow Py_PROTO((double, double));
 #endif
 
+/* Special free list -- see comments for same code in intobject.c. */
+static PyFloatObject *free_list = NULL;
+#define BLOCK_SIZE     1000    /* 1K less typical malloc overhead */
+#define N_FLOATOBJECTS (BLOCK_SIZE / sizeof(PyFloatObject))
+
+static PyFloatObject *
+fill_free_list()
+{
+       PyFloatObject *p, *q;
+       p = PyMem_NEW(PyFloatObject, N_FLOATOBJECTS);
+       if (p == NULL)
+               return (PyFloatObject *)PyErr_NoMemory();
+       q = p + N_FLOATOBJECTS;
+       while (--q > p)
+               *(PyFloatObject **)q = q-1;
+       *(PyFloatObject **)q = NULL;
+       return p + N_FLOATOBJECTS - 1;
+}
+
 PyObject *
 #ifdef __SC__
 PyFloat_FromDouble(double fval)
@@ -91,11 +110,13 @@ PyFloat_FromDouble(fval)
        double fval;
 #endif
 {
-       /* For efficiency, this code is copied from newobject() */
-       register PyFloatObject *op =
-               (PyFloatObject *) malloc(sizeof(PyFloatObject));
-       if (op == NULL)
-               return PyErr_NoMemory();
+       register PyFloatObject *op;
+       if (free_list == NULL) {
+               if ((free_list = fill_free_list()) == NULL)
+                       return NULL;
+       }
+       op = free_list;
+       free_list = *(PyFloatObject **)free_list;
        op->ob_type = &PyFloat_Type;
        op->ob_fval = fval;
        _Py_NewReference(op);
@@ -104,9 +125,10 @@ PyFloat_FromDouble(fval)
 
 static void
 float_dealloc(op)
-       PyObject *op;
+       PyFloatObject *op;
 {
-       PyMem_DEL(op);
+       *(PyFloatObject **)op = free_list;
+       free_list = op;
 }
 
 double