final patches from Neil Schemenauer for garbage collection
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 860030f..003dfdf 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -203,7 +203,6 @@
( (type *) PyObject_InitVar( \
(PyVarObject *) PyObject_MALLOC( _PyObject_VAR_SIZE((typeobj),(n)) ),\
(typeobj), (n)) )
-#define PyObject_DEL(op) PyObject_FREE(op)
/* This example code implements an object constructor with a custom
allocator, where PyObject_New is inlined, and shows the important
@@ -234,11 +233,67 @@
the 1st step is performed automatically for you, so in a C++ class
constructor you would start directly with PyObject_Init/InitVar. */
+/*
+ * Garbage Collection Support
+ * ==========================
+ */
+/* To make a new object participate in garbage collection use
+ PyObject_{New, VarNew, Del} to manage the memory. Set the type flag
+ Py_TPFLAGS_GC and define the type method tp_recurse. You should also
+ add the method tp_clear if your object is mutable. Include
+ PyGC_INFO_SIZE in the calculation of tp_basicsize. Call
+ PyObject_GC_Init after the pointers followed by tp_recurse become
+ valid (usually just before returning the object from the allocation
+ method. Call PyObject_GC_Fini before those pointers become invalid
+ (usually at the top of the deallocation method). */
#ifndef WITH_CYCLE_GC
-#define PyGC_INFO_SIZE 0
-#endif
+
+#define PyGC_HEAD_SIZE 0
+#define PyObject_GC_Init(op)
+#define PyObject_GC_Fini(op)
+#define PyObject_AS_GC(op) (op)
+#define PyObject_FROM_GC(op) (op)
+#define PyObject_DEL(op) PyObject_FREE(op)
+
+#else
+
+/* Add the object into the container set */
+extern DL_IMPORT(void) _PyGC_Insert Py_PROTO((PyObject *));
+
+/* Remove the object from the container set */
+extern DL_IMPORT(void) _PyGC_Remove Py_PROTO((PyObject *));
+
+#define PyObject_GC_Init(op) _PyGC_Insert((PyObject *)op)
+#define PyObject_GC_Fini(op) _PyGC_Remove((PyObject *)op)
+
+/* Structure *prefixed* to container objects participating in GC */
+typedef struct _gc_head {
+ struct _gc_head *gc_next;
+ struct _gc_head *gc_prev;
+ int gc_refs;
+} PyGC_Head;
+
+#define PyGC_HEAD_SIZE sizeof(PyGC_Head)
+
+/* Test if a type has a GC head */
+#define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_GC)
+
+/* Test if an object has a GC head */
+#define PyObject_IS_GC(o) PyType_IS_GC((o)->ob_type)
+
+/* Get an object's GC head */
+#define PyObject_AS_GC(o) ((PyGC_Head *)(o)-1)
+
+/* Get the object given the PyGC_Head */
+#define PyObject_FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1))
+
+#define PyObject_DEL(op) PyObject_FREE( PyObject_IS_GC(op) ? \
+ (ANY *)PyObject_AS_GC(op) : \
+ (ANY *)(op) )
+
+#endif /* WITH_CYCLE_GC */
#ifdef __cplusplus
}
diff --git a/Lib/test/output/test_gc b/Lib/test/output/test_gc
new file mode 100644
index 0000000..c385928
--- /dev/null
+++ b/Lib/test/output/test_gc
@@ -0,0 +1,11 @@
+test_gc
+list 0x831a754
+dict 0x831a754
+list 0x831a754
+tuple 0x831a734
+class 0x831a794
+<test_gc.A instance at 831a754>
+a <test_gc.A instance at 831a754>
+b <test_gc.B instance at 831a95c>
+dict 0x831a9bc
+func 0x831d9e4
diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
new file mode 100644
index 0000000..72253f4
--- /dev/null
+++ b/Lib/test/test_gc.py
@@ -0,0 +1,100 @@
+import gc
+
+def test_list():
+ l = []
+ l.append(l)
+ print 'list 0x%x' % id(l)
+ gc.collect()
+ del l
+ assert gc.collect() == 1
+
+def test_dict():
+ d = {}
+ d[1] = d
+ print 'dict 0x%x' % id(d)
+ gc.collect()
+ del d
+ assert gc.collect() == 1
+
+def test_tuple():
+ l = []
+ t = (l,)
+ l.append(t)
+ print 'list 0x%x' % id(l)
+ print 'tuple 0x%x' % id(t)
+ gc.collect()
+ del t
+ del l
+ assert gc.collect() == 2
+
+def test_class():
+ class A:
+ pass
+ A.a = A
+ print 'class 0x%x' % id(A)
+ gc.collect()
+ del A
+ assert gc.collect() > 0
+
+def test_instance():
+ class A:
+ pass
+ a = A()
+ a.a = a
+ print repr(a)
+ gc.collect()
+ del a
+ assert gc.collect() > 0
+
+def test_method():
+ class A:
+ def __init__(self):
+ self.init = self.__init__
+ a = A()
+ gc.collect()
+ del a
+ assert gc.collect() > 0
+
+def test_finalizer():
+ class A:
+ def __del__(self): pass
+ class B:
+ pass
+ a = A()
+ a.a = a
+ id_a = id(a)
+ b = B()
+ b.b = b
+ print 'a', repr(a)
+ print 'b', repr(b)
+ gc.collect()
+ gc.garbage[:] = []
+ del a
+ del b
+ assert gc.collect() > 0
+ assert id(gc.garbage[0]) == id_a
+
+def test_function():
+ d = {}
+ exec("def f(): pass\n") in d
+ print 'dict 0x%x' % id(d)
+ print 'func 0x%x' % id(d['f'])
+ gc.collect()
+ del d
+ assert gc.collect() == 2
+
+
+def test_all():
+ debug = gc.get_debug()
+ gc.set_debug(gc.DEBUG_LEAK | gc.DEBUG_STATS)
+ test_list()
+ test_dict()
+ test_tuple()
+ test_class()
+ test_instance()
+ test_method()
+ test_finalizer()
+ test_function()
+ gc.set_debug(debug)
+
+test_all()
diff --git a/Modules/Setup.thread.in b/Modules/Setup.thread.in
index d532156..7360144 100644
--- a/Modules/Setup.thread.in
+++ b/Modules/Setup.thread.in
@@ -10,3 +10,6 @@
# support threads.
@USE_THREAD_MODULE@thread threadmodule.c
+
+# Garbage collection enabled with --with-cycle-gc
+@USE_GC_MODULE@gc gcmodule.c
diff --git a/Modules/cPickle.c b/Modules/cPickle.c
index 0d91936..f9ef78f 100644
--- a/Modules/cPickle.c
+++ b/Modules/cPickle.c
@@ -2892,7 +2892,7 @@
Py_DECREF(inst);
goto err;
}
-
+ PyObject_GC_Init(inst);
return (PyObject *)inst;
}
Py_DECREF(__getinitargs__);
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
new file mode 100644
index 0000000..8c0dc3d
--- /dev/null
+++ b/Modules/gcmodule.c
@@ -0,0 +1,679 @@
+/*
+
+ Reference Cycle Garbage Collection
+ ==================================
+
+ Neil Schemenauer <nascheme@enme.ucalgary.ca>
+
+ Based on a post on the python-dev list. Ideas from Guido van Rossum,
+ Eric Tiedemann, and various others.
+
+ http://www.enme.calgary.ca/~nascheme/python/gc.html
+ http://www.python.org/pipermail/python-dev/2000-March/003869.html
+ http://www.python.org/pipermail/python-dev/2000-March/004010.html
+ http://www.python.org/pipermail/python-dev/2000-March/004022.html
+
+ For a highlevel view of the collection process, read the collect
+ function.
+
+ TODO:
+ use a different interface for set_debug() (keywords)?
+ tune parameters
+
+*/
+
+
+#include "Python.h"
+
+#ifdef WITH_CYCLE_GC
+
+/* magic gc_refs value */
+#define GC_MOVED -1
+
+/*** Global GC state ***/
+
+/* linked lists of container objects */
+static PyGC_Head generation0 = {&generation0, &generation0, 0};
+static PyGC_Head generation1 = {&generation1, &generation1, 0};
+static PyGC_Head generation2 = {&generation2, &generation2, 0};
+static int generation = 0; /* current generation being collected */
+
+/* collection frequencies, XXX tune these */
+static int threshold0 = 100; /* net new containers before collection */
+static int threshold1 = 10; /* generation0 collections before collecting 1 */
+static int threshold2 = 10; /* generation1 collections before collecting 2 */
+
+/* net new objects allocated since last collection */
+static int allocated;
+
+/* set for debugging information */
+#define DEBUG_STATS (1<<0) /* print collection statistics */
+#define DEBUG_COLLECTABLE (1<<1) /* print collectable objects */
+#define DEBUG_UNCOLLECTABLE (1<<2) /* print uncollectable objects */
+#define DEBUG_INSTANCES (1<<3) /* print instances */
+#define DEBUG_OBJECTS (1<<4) /* print other objects */
+#define DEBUG_LEAK DEBUG_COLLECTABLE | \
+ DEBUG_UNCOLLECTABLE | \
+ DEBUG_INSTANCES | \
+ DEBUG_OBJECTS
+static int debug;
+
+/* list of uncollectable objects */
+static PyObject *garbage;
+
+
+/*** list functions ***/
+
+static void
+gc_list_init(PyGC_Head *list)
+{
+ list->gc_prev = list;
+ list->gc_next = list;
+}
+
+static void
+gc_list_append(PyGC_Head *node, PyGC_Head *list)
+{
+ node->gc_next = list;
+ node->gc_prev = list->gc_prev;
+ node->gc_prev->gc_next = node;
+ list->gc_prev = node;
+}
+
+static void
+gc_list_remove(PyGC_Head *node)
+{
+ node->gc_prev->gc_next = node->gc_next;
+ node->gc_next->gc_prev = node->gc_prev;
+#ifdef Py_DEBUG
+ node->gc_prev = NULL;
+ node->gc_next = NULL;
+#endif
+}
+
+static void
+gc_list_move(PyGC_Head *from, PyGC_Head *to)
+{
+ if (from->gc_next == from) {
+ /* empty from list */
+ gc_list_init(to);
+ } else {
+ to->gc_next = from->gc_next;
+ to->gc_next->gc_prev = to;
+ to->gc_prev = from->gc_prev;
+ to->gc_prev->gc_next = to;
+ }
+ gc_list_init(from);
+}
+
+/* append a list onto another list, from becomes an empty list */
+static void
+gc_list_merge(PyGC_Head *from, PyGC_Head *to)
+{
+ PyGC_Head *tail;
+ if (from->gc_next != from) {
+ tail = to->gc_prev;
+ tail->gc_next = from->gc_next;
+ tail->gc_next->gc_prev = tail;
+ to->gc_prev = from->gc_prev;
+ to->gc_prev->gc_next = to;
+ }
+ gc_list_init(from);
+}
+
+static long
+gc_list_size(PyGC_Head *list)
+{
+ PyGC_Head *gc;
+ long n = 0;
+ for (gc = list->gc_next; gc != list; gc = gc->gc_next) {
+ n++;
+ }
+ return n;
+}
+
+/*** end of list stuff ***/
+
+
+/* Set all gc_refs = ob_refcnt */
+static void
+update_refs(PyGC_Head *containers)
+{
+ PyGC_Head *gc = containers->gc_next;
+ for (; gc != containers; gc=gc->gc_next) {
+ gc->gc_refs = PyObject_FROM_GC(gc)->ob_refcnt;
+ }
+}
+
+static int
+visit_decref(PyObject *op, void *data)
+{
+ if (op && PyObject_IS_GC(op)) {
+ PyObject_AS_GC(op)->gc_refs--;
+ }
+ return 0;
+}
+
+/* Subtract internal references from gc_refs */
+static void
+subtract_refs(PyGC_Head *containers)
+{
+ traverseproc traverse;
+ PyGC_Head *gc = containers->gc_next;
+ for (; gc != containers; gc=gc->gc_next) {
+ traverse = PyObject_FROM_GC(gc)->ob_type->tp_traverse;
+ (void) traverse(PyObject_FROM_GC(gc),
+ (visitproc)visit_decref,
+ NULL);
+ }
+}
+
+/* Append objects with gc_refs > 0 to roots list */
+static void
+move_roots(PyGC_Head *containers, PyGC_Head *roots)
+{
+ PyGC_Head *next;
+ PyGC_Head *gc = containers->gc_next;
+ while (gc != containers) {
+ next = gc->gc_next;
+ if (gc->gc_refs > 0) {
+ gc_list_remove(gc);
+ gc_list_append(gc, roots);
+ gc->gc_refs = GC_MOVED;
+ }
+ gc = next;
+ }
+}
+
+static int
+visit_reachable(PyObject *op, PyGC_Head *roots)
+{
+ if (PyObject_IS_GC(op)) {
+ PyGC_Head *gc = PyObject_AS_GC(op);
+ if (gc && gc->gc_refs != GC_MOVED) {
+ gc_list_remove(gc);
+ gc_list_append(gc, roots);
+ gc->gc_refs = GC_MOVED;
+ }
+ }
+ return 0;
+}
+
+/* Move objects referenced from reachable to reachable set. */
+static void
+move_root_reachable(PyGC_Head *reachable)
+{
+ traverseproc traverse;
+ PyGC_Head *gc = reachable->gc_next;
+ for (; gc != reachable; gc=gc->gc_next) {
+ /* careful, reachable list is growing here */
+ PyObject *op = PyObject_FROM_GC(gc);
+ traverse = op->ob_type->tp_traverse;
+ (void) traverse(op,
+ (visitproc)visit_reachable,
+ (void *)reachable);
+ }
+}
+
+/* move all objects with finalizers (instances with __del__) */
+static void
+move_finalizers(PyGC_Head *unreachable, PyGC_Head *finalizers)
+{
+ PyGC_Head *next;
+ PyGC_Head *gc = unreachable->gc_next;
+ static PyObject *delstr;
+ if (delstr == NULL) {
+ delstr = PyString_InternFromString("__del__");
+ }
+ for (; gc != unreachable; gc=next) {
+ PyObject *op = PyObject_FROM_GC(gc);
+ next = gc->gc_next;
+ if (PyInstance_Check(op) && PyObject_HasAttr(op, delstr)) {
+ gc_list_remove(gc);
+ gc_list_append(gc, finalizers);
+ }
+ }
+}
+
+
+/* called by tp_traverse */
+static int
+visit_finalizer_reachable(PyObject *op, PyGC_Head *finalizers)
+{
+ if (PyObject_IS_GC(op)) {
+ PyGC_Head *gc = PyObject_AS_GC(op);
+ if (gc && gc->gc_refs != GC_MOVED) {
+ gc_list_remove(gc);
+ gc_list_append(gc, finalizers);
+ gc->gc_refs = GC_MOVED;
+ }
+ }
+ return 0;
+}
+
+/* Move objects referenced from roots to roots */
+static void
+move_finalizer_reachable(PyGC_Head *finalizers)
+{
+ traverseproc traverse;
+ PyGC_Head *gc = finalizers->gc_next;
+ for (; gc != finalizers; gc=gc->gc_next) {
+ /* careful, finalizers list is growing here */
+ traverse = PyObject_FROM_GC(gc)->ob_type->tp_traverse;
+ (void) traverse(PyObject_FROM_GC(gc),
+ (visitproc)visit_finalizer_reachable,
+ (void *)finalizers);
+ }
+}
+
+static void
+debug_instance(PyObject *output, char *msg, PyInstanceObject *inst)
+{
+ char buf[200];
+ char *cname;
+ /* be careful not to create new dictionaries */
+ PyObject *classname = inst->in_class->cl_name;
+ if (classname != NULL && PyString_Check(classname))
+ cname = PyString_AsString(classname);
+ else
+ cname = "?";
+ sprintf(buf, "gc: %s<%.100s instance at %lx>\n",
+ msg, cname, (long)inst);
+ PyFile_WriteString(buf, output);
+}
+
+static void
+debug_cycle(PyObject *output, char *msg, PyObject *op)
+{
+ if ((debug & DEBUG_INSTANCES) && PyInstance_Check(op)) {
+ debug_instance(output, msg, (PyInstanceObject *)op);
+ } else if (debug & DEBUG_OBJECTS) {
+ char buf[200];
+ sprintf(buf, "gc: %s<%s 0x%x>\n",
+ msg,
+ op->ob_type->tp_name,
+ (long)op);
+ PyFile_WriteString(buf, output);
+ }
+}
+
+/* Handle uncollectable garbage (cycles with finalizers). */
+static void
+handle_finalizers(PyGC_Head *finalizers, PyGC_Head *old)
+{
+ PyGC_Head *gc;
+ if (garbage == NULL) {
+ garbage = PyList_New(0);
+ }
+ for (gc = finalizers->gc_next; gc != finalizers;
+ gc = finalizers->gc_next) {
+ PyObject *op = PyObject_FROM_GC(gc);
+ /* Add all instances to a Python accessible list of garbage */
+ if (PyInstance_Check(op)) {
+ PyList_Append(garbage, op);
+ }
+ /* We assume that all objects in finalizers are reachable from
+ * instances. Once we add the instances to the garbage list
+ * everything is reachable from Python again. */
+ gc_list_remove(gc);
+ gc_list_append(gc, old);
+ }
+}
+
+/* Break reference cycles by clearing the containers involved. This is
+ * tricky business as the lists can be changing and we don't know which
+ * objects may be freed. It is possible I screwed something up here. */
+static void
+delete_garbage(PyGC_Head *unreachable, PyGC_Head *old)
+{
+ inquiry clear;
+
+ while (unreachable->gc_next != unreachable) {
+ PyGC_Head *gc = unreachable->gc_next;
+ PyObject *op = PyObject_FROM_GC(gc);
+ /*
+ PyList_Append(garbage, op);
+ */
+ if ((clear = op->ob_type->tp_clear) != NULL) {
+ Py_INCREF(op);
+ clear((PyObject *)op);
+ Py_DECREF(op);
+ }
+ /* only try to call tp_clear once for each object */
+ if (unreachable->gc_next == gc) {
+ /* still alive, move it, it may die later */
+ gc_list_remove(gc);
+ gc_list_append(gc, old);
+ }
+ }
+}
+
+/* This is the main function. Read this to understand how the
+ * collection process works. */
+static long
+collect(PyGC_Head *young, PyGC_Head *old)
+{
+ long n = 0;
+ long m = 0;
+ PyGC_Head reachable;
+ PyGC_Head unreachable;
+ PyGC_Head finalizers;
+ PyGC_Head *gc;
+ PyObject *output = NULL;
+
+ if (debug) {
+ output = PySys_GetObject("stderr");
+ }
+ if (debug & DEBUG_STATS) {
+ char buf[100];
+ sprintf(buf, "gc: collecting generation %d...\n", generation);
+ PyFile_WriteString(buf,output);
+ sprintf(buf, "gc: objects in each generation: %d %d %d\n",
+ gc_list_size(&generation0),
+ gc_list_size(&generation1),
+ gc_list_size(&generation2));
+ PyFile_WriteString(buf,output);
+ }
+
+ /* Using ob_refcnt and gc_refs, calculate which objects in the
+ * container set are reachable from outside the set (ie. have a
+ * refcount greater than 0 when all the references within the
+ * set are taken into account */
+ update_refs(young);
+ subtract_refs(young);
+
+ /* Move everything reachable from outside the set into the
+ * reachable set (ie. gc_refs > 0). Next, move everything
+ * reachable from objects in the reachable set. */
+ gc_list_init(&reachable);
+ move_roots(young, &reachable);
+ move_root_reachable(&reachable);
+
+ /* move unreachable objects to a temporary list, new objects can be
+ * allocated after this point */
+ gc_list_init(&unreachable);
+ gc_list_move(young, &unreachable);
+
+ /* move reachable objects to next generation */
+ gc_list_merge(&reachable, old);
+
+ /* Move objects reachable from finalizers, we can't safely delete
+ * them. Python programmers should take care not to create such
+ * things. For Python finalizers means instance objects with
+ * __del__ methods. */
+ gc_list_init(&finalizers);
+ move_finalizers(&unreachable, &finalizers);
+ move_finalizer_reachable(&finalizers);
+
+ /* Collect statistics on collectable objects found and print
+ * debugging information. */
+ for (gc = unreachable.gc_next; gc != &unreachable;
+ gc = gc->gc_next) {
+ m++;
+ if (output != NULL && (debug & DEBUG_COLLECTABLE)) {
+ debug_cycle(output, "collectable ", PyObject_FROM_GC(gc));
+ }
+ }
+ /* call tp_clear on objects in the collectable set. This will cause
+ * the reference cycles to be broken. It may also cause some objects in
+ * finalizers to be freed */
+ delete_garbage(&unreachable, old);
+
+ /* Collect statistics on uncollectable objects found and print
+ * debugging information. */
+ for (gc = finalizers.gc_next; gc != &finalizers;
+ gc = gc->gc_next) {
+ n++;
+ if (output != NULL && (debug & DEBUG_UNCOLLECTABLE)) {
+ debug_cycle(output, "uncollectable ", PyObject_FROM_GC(gc));
+ }
+ }
+ if (output != NULL && (debug & DEBUG_STATS)) {
+ if (m == 0 && n == 0) {
+ PyFile_WriteString("gc: done.\n", output);
+ } else {
+ char buf[200];
+ sprintf(buf,
+ "gc: done, %d unreachable, %d uncollectable.\n",
+ n+m, n);
+ PyFile_WriteString(buf, output);
+ }
+ }
+
+ /* Append instances in the uncollectable set to a Python
+ * reachable list of garbage. The programmer has to deal with
+ * this if they insist on creating this type of structure. */
+ handle_finalizers(&finalizers, old);
+
+ allocated = 0;
+ PyErr_Clear(); /* in case writing to sys.stderr failed */
+ return n+m;
+}
+
+static long
+collect_generations(void)
+{
+ static long collections0 = 0;
+ static long collections1 = 0;
+ long n;
+
+
+ if (collections1 > threshold2) {
+ generation = 2;
+ gc_list_merge(&generation0, &generation2);
+ gc_list_merge(&generation1, &generation2);
+ if (generation2.gc_next != &generation2) {
+ n = collect(&generation2, &generation2);
+ }
+ collections1 = 0;
+ } else if (collections0 > threshold1) {
+ generation = 1;
+ collections1++;
+ gc_list_merge(&generation0, &generation1);
+ if (generation1.gc_next != &generation1) {
+ n = collect(&generation1, &generation2);
+ }
+ collections0 = 0;
+ } else {
+ generation = 0;
+ collections0++;
+ if (generation0.gc_next != &generation0) {
+ n = collect(&generation0, &generation1);
+ }
+ }
+ return n;
+}
+
+void
+_PyGC_Insert(PyObject *op)
+{
+ /* collection lock since collecting may cause allocations */
+ static int collecting = 0;
+
+#ifdef Py_DEBUG
+ if (!PyObject_IS_GC(op)) {
+ abort();
+ }
+#endif
+ if (threshold0 && allocated > threshold0 && !collecting) {
+ collecting++;
+ collect_generations();
+ collecting--;
+ }
+ allocated++;
+ gc_list_append(PyObject_AS_GC(op), &generation0);
+}
+
+void
+_PyGC_Remove(PyObject *op)
+{
+ PyGC_Head *g = PyObject_AS_GC(op);
+#ifdef Py_DEBUG
+ if (!PyObject_IS_GC(op)) {
+ abort();
+ }
+#endif
+ gc_list_remove(g);
+ if (allocated > 0) {
+ allocated--;
+ }
+}
+
+
+static char collect__doc__[] =
+"collect() -> n\n"
+"\n"
+"Run a full collection. The number of unreachable objects is returned.\n"
+;
+
+static PyObject *
+Py_collect(self, args)
+ PyObject *self;
+ PyObject *args;
+{
+ long n;
+
+ if(!PyArg_ParseTuple(args, "")) /* check no args */
+ return NULL;
+
+ generation = 2;
+ gc_list_merge(&generation0, &generation2);
+ gc_list_merge(&generation1, &generation2);
+ n = collect(&generation2, &generation2);
+
+ return Py_BuildValue("i", n);
+}
+
+static char set_debug__doc__[] =
+"set_debug(flags) -> None\n"
+"\n"
+"Set the garbage collection debugging flags. Debugging information is\n"
+"written to sys.stderr.\n"
+"\n"
+"flags is an integer and can have the following bits turned on:\n"
+"\n"
+" DEBUG_STATS - Print statistics during collection.\n"
+" DEBUG_COLLECTABLE - Print collectable objects found.\n"
+" DEBUG_UNCOLLECTABLE - Print unreachable but uncollectable objects found.\n"
+" DEBUG_INSTANCES - Print instance objects.\n"
+" DEBUG_OBJECTS - Print objects other than instances.\n"
+" DEBUG_LEAK - Debug leaking programs (everything but STATS).\n"
+;
+
+static PyObject *
+Py_set_debug(self, args)
+ PyObject *self;
+ PyObject *args;
+{
+ if (!PyArg_ParseTuple(args, "l", &debug))
+ return NULL;
+
+ Py_INCREF(Py_None);
+ return Py_None;
+}
+
+static char get_debug__doc__[] =
+"get_debug() -> flags\n"
+"\n"
+"Get the garbage collection debugging flags.\n"
+;
+
+static PyObject *
+Py_get_debug(self, args)
+ PyObject *self;
+ PyObject *args;
+{
+ if(!PyArg_ParseTuple(args, "")) /* no args */
+ return NULL;
+
+ return Py_BuildValue("i", debug);
+}
+
+static char set_thresh__doc__[] =
+"set_threshold(threshold0, [threhold1, threshold2]) -> None\n"
+"\n"
+"Sets the collection thresholds. Setting threshold0 to zero disables\n"
+"collection.\n"
+;
+
+static PyObject *
+Py_set_thresh(self, args)
+ PyObject *self;
+ PyObject *args;
+{
+ if (!PyArg_ParseTuple(args, "i|ii", &threshold0,
+ &threshold1, &threshold2))
+ return NULL;
+
+ Py_INCREF(Py_None);
+ return Py_None;
+}
+
+static char get_thresh__doc__[] =
+"get_threshold() -> (threshold0, threshold1, threshold2)\n"
+"\n"
+"Return the current collection thresholds\n"
+;
+
+static PyObject *
+Py_get_thresh(self, args)
+ PyObject *self;
+ PyObject *args;
+{
+ if(!PyArg_ParseTuple(args, "")) /* no args */
+ return NULL;
+
+ return Py_BuildValue("(iii)", threshold0, threshold1, threshold2);
+}
+
+
+static char gc__doc__ [] =
+"This module provides access to the garbage collector for reference cycles.\n"
+"\n"
+"collect() -- Do a full collection right now.\n"
+"set_debug() -- Set debugging flags.\n"
+"get_debug() -- Get debugging flags.\n"
+"set_threshold() -- Set the collection thresholds.\n"
+"get_threshold() -- Return the current the collection thresholds.\n"
+;
+
+static PyMethodDef GcMethods[] = {
+ {"set_debug", Py_set_debug, METH_VARARGS, set_debug__doc__},
+ {"get_debug", Py_get_debug, METH_VARARGS, get_debug__doc__},
+ {"set_threshold", Py_set_thresh, METH_VARARGS, set_thresh__doc__},
+ {"get_threshold", Py_get_thresh, METH_VARARGS, get_thresh__doc__},
+ {"collect", Py_collect, METH_VARARGS, collect__doc__},
+ {NULL, NULL} /* Sentinel */
+};
+
+void
+initgc(void)
+{
+ PyObject *m;
+ PyObject *d;
+
+ m = Py_InitModule4("gc",
+ GcMethods,
+ gc__doc__,
+ NULL,
+ PYTHON_API_VERSION);
+ d = PyModule_GetDict(m);
+ if (garbage == NULL) {
+ garbage = PyList_New(0);
+ }
+ PyDict_SetItemString(d, "garbage", garbage);
+ PyDict_SetItemString(d, "DEBUG_STATS",
+ PyInt_FromLong(DEBUG_STATS));
+ PyDict_SetItemString(d, "DEBUG_COLLECTABLE",
+ PyInt_FromLong(DEBUG_COLLECTABLE));
+ PyDict_SetItemString(d, "DEBUG_UNCOLLECTABLE",
+ PyInt_FromLong(DEBUG_UNCOLLECTABLE));
+ PyDict_SetItemString(d, "DEBUG_INSTANCES",
+ PyInt_FromLong(DEBUG_INSTANCES));
+ PyDict_SetItemString(d, "DEBUG_OBJECTS",
+ PyInt_FromLong(DEBUG_OBJECTS));
+ PyDict_SetItemString(d, "DEBUG_LEAK",
+ PyInt_FromLong(DEBUG_LEAK));
+}
+
+#endif /* WITH_CYCLE_GC */
diff --git a/Modules/newmodule.c b/Modules/newmodule.c
index fa0dc8b..d35896c 100644
--- a/Modules/newmodule.c
+++ b/Modules/newmodule.c
@@ -56,6 +56,7 @@
Py_INCREF(dict);
inst->in_class = (PyClassObject *)klass;
inst->in_dict = dict;
+ PyObject_GC_Init(inst);
return (PyObject *)inst;
}
diff --git a/Objects/classobject.c b/Objects/classobject.c
index f1dabfe..4653d27 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -132,6 +132,7 @@
Py_XINCREF(op->cl_getattr);
Py_XINCREF(op->cl_setattr);
Py_XINCREF(op->cl_delattr);
+ PyObject_GC_Init(op);
return (PyObject *) op;
}
@@ -141,6 +142,7 @@
class_dealloc(op)
PyClassObject *op;
{
+ PyObject_GC_Fini(op);
Py_DECREF(op->cl_bases);
Py_DECREF(op->cl_dict);
Py_XDECREF(op->cl_name);
@@ -428,7 +430,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"class",
- sizeof(PyClassObject) + PyGC_INFO_SIZE,
+ sizeof(PyClassObject) + PyGC_HEAD_SIZE,
0,
(destructor)class_dealloc, /*tp_dealloc*/
0, /*tp_print*/
@@ -490,6 +492,7 @@
if (inst == NULL)
return NULL;
inst->in_dict = PyDict_New();
+ PyObject_GC_Init(inst);
if (inst->in_dict == NULL) {
PyObject_DEL(inst);
return NULL;
@@ -539,11 +542,12 @@
PyObject *error_type, *error_value, *error_traceback;
PyObject *del;
static PyObject *delstr;
+ extern long _Py_RefTotal;
+ PyObject_GC_Fini(inst);
/* Call the __del__ method if it exists. First temporarily
revive the object and save the current exception, if any. */
#ifdef Py_TRACE_REFS
/* much too complicated if Py_TRACE_REFS defined */
- extern long _Py_RefTotal;
inst->ob_type = &PyInstance_Type;
_Py_NewReference((PyObject *)inst);
_Py_RefTotal--; /* compensate for increment in NEWREF */
@@ -591,6 +595,7 @@
#ifdef COUNT_ALLOCS
inst->ob_type->tp_free--;
#endif
+ PyObject_GC_Init((PyObject *)inst);
return; /* __del__ added a reference; don't delete now */
}
#ifdef Py_TRACE_REFS
@@ -598,7 +603,9 @@
inst->ob_type->tp_free--; /* compensate for increment in UNREF */
#endif
_Py_ForgetReference((PyObject *)inst);
+#ifndef WITH_CYCLE_GC
inst->ob_type = NULL;
+#endif
#endif /* Py_TRACE_REFS */
Py_DECREF(inst->in_class);
Py_XDECREF(inst->in_dict);
@@ -1510,7 +1517,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"instance",
- sizeof(PyInstanceObject) + PyGC_INFO_SIZE,
+ sizeof(PyInstanceObject) + PyGC_HEAD_SIZE,
0,
(destructor)instance_dealloc, /*tp_dealloc*/
0, /*tp_print*/
@@ -1568,6 +1575,7 @@
im->im_self = self;
Py_INCREF(class);
im->im_class = class;
+ PyObject_GC_Init(im);
return (PyObject *)im;
}
@@ -1643,6 +1651,7 @@
instancemethod_dealloc(im)
register PyMethodObject *im;
{
+ PyObject_GC_Fini(im);
Py_DECREF(im->im_func);
Py_XDECREF(im->im_self);
Py_DECREF(im->im_class);
@@ -1745,7 +1754,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"instance method",
- sizeof(PyMethodObject) + PyGC_INFO_SIZE,
+ sizeof(PyMethodObject) + PyGC_HEAD_SIZE,
0,
(destructor)instancemethod_dealloc, /*tp_dealloc*/
0, /*tp_print*/
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index ce38f11..ea3af48 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -129,6 +129,7 @@
mp->ma_table = NULL;
mp->ma_fill = 0;
mp->ma_used = 0;
+ PyObject_GC_Init(mp);
return (PyObject *)mp;
}
@@ -481,6 +482,7 @@
register int i;
register dictentry *ep;
Py_TRASHCAN_SAFE_BEGIN(mp)
+ PyObject_GC_Fini(mp);
for (i = 0, ep = mp->ma_table; i < mp->ma_size; i++, ep++) {
if (ep->me_key != NULL) {
Py_DECREF(ep->me_key);
@@ -1087,7 +1089,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"dictionary",
- sizeof(dictobject) + PyGC_INFO_SIZE,
+ sizeof(dictobject) + PyGC_HEAD_SIZE,
0,
(destructor)dict_dealloc, /*tp_dealloc*/
(printfunc)dict_print, /*tp_print*/
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index d9ce027..2736d65 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -63,6 +63,7 @@
Py_INCREF(doc);
op->func_doc = doc;
}
+ PyObject_GC_Init(op);
return (PyObject *)op;
}
@@ -186,6 +187,7 @@
func_dealloc(op)
PyFunctionObject *op;
{
+ PyObject_GC_Fini(op);
Py_DECREF(op->func_code);
Py_DECREF(op->func_globals);
Py_DECREF(op->func_name);
@@ -277,7 +279,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"function",
- sizeof(PyFunctionObject) + PyGC_INFO_SIZE,
+ sizeof(PyFunctionObject) + PyGC_HEAD_SIZE,
0,
(destructor)func_dealloc, /*tp_dealloc*/
0, /*tp_print*/
diff --git a/Objects/listobject.c b/Objects/listobject.c
index e9f12ab..a75100e 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -72,10 +72,11 @@
}
/* PyObject_NewVar is inlined */
op = (PyListObject *) PyObject_MALLOC(sizeof(PyListObject)
- + PyGC_INFO_SIZE);
+ + PyGC_HEAD_SIZE);
if (op == NULL) {
return PyErr_NoMemory();
}
+ op = (PyListObject *) PyObject_FROM_GC(op);
if (size <= 0) {
op->ob_item = NULL;
}
@@ -89,6 +90,7 @@
PyObject_INIT_VAR(op, &PyList_Type, size);
for (i = 0; i < size; i++)
op->ob_item[i] = NULL;
+ PyObject_GC_Init(op);
return (PyObject *) op;
}
@@ -216,6 +218,7 @@
{
int i;
Py_TRASHCAN_SAFE_BEGIN(op)
+ PyObject_GC_Fini(op);
if (op->ob_item != NULL) {
/* Do it backwards, for Christian Tismer.
There's a simple test case where somehow this reduces
@@ -1498,7 +1501,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"list",
- sizeof(PyListObject) + PyGC_INFO_SIZE,
+ sizeof(PyListObject) + PyGC_HEAD_SIZE,
0,
(destructor)list_dealloc, /*tp_dealloc*/
(printfunc)list_print, /*tp_print*/
@@ -1577,7 +1580,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"list (immutable, during sort)",
- sizeof(PyListObject) + PyGC_INFO_SIZE,
+ sizeof(PyListObject) + PyGC_HEAD_SIZE,
0,
0, /*tp_dealloc*/ /* Cannot happen */
(printfunc)list_print, /*tp_print*/
diff --git a/Objects/object.c b/Objects/object.c
index 9ed03b2..6eaff67 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -124,6 +124,10 @@
"NULL object passed to PyObject_Init");
return op;
}
+#ifdef WITH_CYCLE_GC
+ if (PyType_IS_GC(tp))
+ op = (PyObject *) PyObject_FROM_GC(op);
+#endif
/* Any changes should be reflected in PyObject_INIT (objimpl.h) */
op->ob_type = tp;
_Py_NewReference(op);
@@ -141,6 +145,10 @@
"NULL object passed to PyObject_InitVar");
return op;
}
+#ifdef WITH_CYCLE_GC
+ if (PyType_IS_GC(tp))
+ op = (PyVarObject *) PyObject_FROM_GC(op);
+#endif
/* Any changes should be reflected in PyObject_INIT_VAR */
op->ob_size = size;
op->ob_type = tp;
@@ -156,6 +164,10 @@
op = (PyObject *) PyObject_MALLOC(_PyObject_SIZE(tp));
if (op == NULL)
return PyErr_NoMemory();
+#ifdef WITH_CYCLE_GC
+ if (PyType_IS_GC(tp))
+ op = (PyObject *) PyObject_FROM_GC(op);
+#endif
return PyObject_INIT(op, tp);
}
@@ -168,6 +180,10 @@
op = (PyVarObject *) PyObject_MALLOC(_PyObject_VAR_SIZE(tp, size));
if (op == NULL)
return (PyVarObject *)PyErr_NoMemory();
+#ifdef WITH_CYCLE_GC
+ if (PyType_IS_GC(tp))
+ op = (PyVarObject *) PyObject_FROM_GC(op);
+#endif
return PyObject_INIT_VAR(op, tp, size);
}
@@ -175,9 +191,23 @@
_PyObject_Del(op)
PyObject *op;
{
- PyObject_FREE(op);
+#ifdef WITH_CYCLE_GC
+ if (PyType_IS_GC(op->ob_type)) {
+ PyGC_Head *g = PyObject_AS_GC(op);
+ PyObject_FREE(g);
+ } else
+#endif
+ {
+ PyObject_FREE(op);
+ }
}
+#ifndef WITH_CYCLE_GC
+/* extension modules might need these */
+void _PyGC_Insert(PyObject *op) { }
+void _PyGC_Remove(PyObject *op) { }
+#endif
+
int
PyObject_Print(op, fp, flags)
PyObject *op;
@@ -917,8 +947,10 @@
{
destructor dealloc = op->ob_type->tp_dealloc;
_Py_ForgetReference(op);
+#ifndef WITH_CYCLE_GC
if (_PyTrash_delete_nesting < PyTrash_UNWIND_LEVEL-1)
op->ob_type = NULL;
+#endif
(*dealloc)(op);
}
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 73e3304..46e67a8 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -94,7 +94,7 @@
/* Check for overflow */
if (nbytes / sizeof(PyObject *) != (size_t)size ||
(nbytes += sizeof(PyTupleObject) - sizeof(PyObject *)
- + PyGC_INFO_SIZE)
+ + PyGC_HEAD_SIZE)
<= 0)
{
return PyErr_NoMemory();
@@ -103,7 +103,7 @@
op = (PyTupleObject *) PyObject_MALLOC(nbytes);
if (op == NULL)
return PyErr_NoMemory();
-
+ op = (PyTupleObject *) PyObject_FROM_GC(op);
PyObject_INIT_VAR(op, &PyTuple_Type, size);
}
for (i = 0; i < size; i++)
@@ -115,6 +115,7 @@
Py_INCREF(op); /* extra INCREF so that this is never freed */
}
#endif
+ PyObject_GC_Init(op);
return (PyObject *) op;
}
@@ -181,6 +182,7 @@
register int i;
register int len = op->ob_size;
Py_TRASHCAN_SAFE_BEGIN(op)
+ PyObject_GC_Fini(op);
if (len > 0) {
i = len;
while (--i >= 0)
@@ -453,7 +455,7 @@
PyObject_HEAD_INIT(&PyType_Type)
0,
"tuple",
- sizeof(PyTupleObject) - sizeof(PyObject *) + PyGC_INFO_SIZE,
+ sizeof(PyTupleObject) - sizeof(PyObject *) + PyGC_HEAD_SIZE,
sizeof(PyObject *),
(destructor)tupledealloc, /*tp_dealloc*/
(printfunc)tupleprint, /*tp_print*/
@@ -557,12 +559,27 @@
} else
#endif
{
+#ifdef WITH_CYCLE_GC
+ PyGC_Head *g = PyObject_AS_GC((PyObject *)v);
+ PyObject_GC_Fini((PyObject *)v);
+ sv = (PyTupleObject *)
+ PyObject_REALLOC((char *)g, sizeof(PyTupleObject)
+ + PyGC_HEAD_SIZE
+ + newsize * sizeof(PyObject *));
+ if (g == NULL) {
+ sv = NULL;
+ } else {
+ sv = (PyTupleObject *)PyObject_FROM_GC(g);
+ }
+#else
sv = (PyTupleObject *)
PyObject_REALLOC((char *)v, sizeof(PyTupleObject)
- + PyGC_INFO_SIZE
+ + PyGC_HEAD_SIZE
+ newsize * sizeof(PyObject *));
+#endif
*pv = (PyObject *) sv;
if (sv == NULL) {
+ PyObject_GC_Init((PyObject *)v);
PyObject_DEL(v);
PyErr_NoMemory();
return -1;
@@ -578,6 +595,7 @@
sv->ob_item[i - sizediff] = NULL;
}
}
+ PyObject_GC_Init(sv);
sv->ob_size = newsize;
return 0;
}
diff --git a/PC/config.c b/PC/config.c
index f295f85..0ff4c93 100644
--- a/PC/config.c
+++ b/PC/config.c
@@ -43,6 +43,9 @@
#endif
extern void initcmath();
extern void initerrno();
+#ifdef WITH_CYCLE_GC
+extern void initgc();
+#endif
#ifndef MS_WIN64
extern void initimageop();
#endif
@@ -89,6 +92,9 @@
#endif
{"cmath", initcmath},
{"errno", initerrno},
+#ifdef WITH_CYCLE_GC
+ {"gc", initgc},
+#endif
#ifndef MS_WIN64
{"imageop", initimageop},
#endif
diff --git a/PC/config.h b/PC/config.h
index dfe5118..43bb35f 100644
--- a/PC/config.h
+++ b/PC/config.h
@@ -451,6 +451,9 @@
/* Define if you want to use the GNU readline library */
/* #define WITH_READLINE 1 */
+/* Define if you want cycle garbage collection */
+/* #define WITH_CYCLE_GC 1 */
+
/* Define if you have clock. */
/* #define HAVE_CLOCK */
diff --git a/PCbuild/python16.dsp b/PCbuild/python16.dsp
index 4c75302..34ec9ef 100644
--- a/PCbuild/python16.dsp
+++ b/PCbuild/python16.dsp
@@ -659,6 +659,20 @@
# End Source File
# Begin Source File
+SOURCE=..\Modules\gcmodule.c
+
+!IF "$(CFG)" == "python16 - Win32 Release"
+
+!ELSEIF "$(CFG)" == "python16 - Win32 Debug"
+
+!ELSEIF "$(CFG)" == "python16 - Win32 Alpha Debug"
+
+!ELSEIF "$(CFG)" == "python16 - Win32 Alpha Release"
+
+!ENDIF
+
+# End Source File
+# Begin Source File
SOURCE=..\Python\getargs.c