mirror of https://github.com/python/cpython
955 lines
23 KiB
C
955 lines
23 KiB
C
/*
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Reference Cycle Garbage Collection
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==================================
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Neil Schemenauer <nas@arctrix.com>
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Based on a post on the python-dev list. Ideas from Guido van Rossum,
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Eric Tiedemann, and various others.
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http://www.arctrix.com/nas/python/gc/
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http://www.python.org/pipermail/python-dev/2000-March/003869.html
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http://www.python.org/pipermail/python-dev/2000-March/004010.html
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http://www.python.org/pipermail/python-dev/2000-March/004022.html
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For a highlevel view of the collection process, read the collect
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function.
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*/
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#include "Python.h"
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#ifdef WITH_CYCLE_GC
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/* Get an object's GC head */
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#define AS_GC(o) ((PyGC_Head *)(o)-1)
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/* Get the object given the GC head */
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#define FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1))
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/* True if an object is tracked by the GC */
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#define IS_TRACKED(o) ((AS_GC(o))->gc.gc_next != NULL)
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/*** Global GC state ***/
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struct gc_generation {
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PyGC_Head head;
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int threshold; /* collection threshold */
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int count; /* count of allocations or collections of younger
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generations */
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};
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#define NUM_GENERATIONS 3
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#define GEN_HEAD(n) (&generations[n].head)
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/* linked lists of container objects */
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static struct gc_generation generations[NUM_GENERATIONS] = {
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/* PyGC_Head, threshold, count */
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{{{GEN_HEAD(0), GEN_HEAD(0), 0}}, 700, 0},
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{{{GEN_HEAD(1), GEN_HEAD(1), 0}}, 10, 0},
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{{{GEN_HEAD(2), GEN_HEAD(2), 0}}, 10, 0},
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};
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PyGC_Head *_PyGC_generation0 = GEN_HEAD(0);
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static int enabled = 1; /* automatic collection enabled? */
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/* true if we are currently running the collector */
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static int collecting;
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/* set for debugging information */
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#define DEBUG_STATS (1<<0) /* print collection statistics */
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#define DEBUG_COLLECTABLE (1<<1) /* print collectable objects */
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#define DEBUG_UNCOLLECTABLE (1<<2) /* print uncollectable objects */
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#define DEBUG_INSTANCES (1<<3) /* print instances */
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#define DEBUG_OBJECTS (1<<4) /* print other objects */
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#define DEBUG_SAVEALL (1<<5) /* save all garbage in gc.garbage */
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#define DEBUG_LEAK DEBUG_COLLECTABLE | \
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DEBUG_UNCOLLECTABLE | \
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DEBUG_INSTANCES | \
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DEBUG_OBJECTS | \
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DEBUG_SAVEALL
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static int debug;
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/* Special gc_refs value */
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#define GC_MOVED -123
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/* True if an object has been moved to the older generation */
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#define IS_MOVED(o) ((AS_GC(o))->gc.gc_refs == GC_MOVED)
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/* list of uncollectable objects */
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static PyObject *garbage;
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/* Python string to use if unhandled exception occurs */
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static PyObject *gc_str;
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/*** list functions ***/
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static void
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gc_list_init(PyGC_Head *list)
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{
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list->gc.gc_prev = list;
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list->gc.gc_next = list;
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}
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static int
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gc_list_is_empty(PyGC_Head *list)
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{
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return (list->gc.gc_next == list);
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}
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static void
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gc_list_append(PyGC_Head *node, PyGC_Head *list)
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{
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node->gc.gc_next = list;
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node->gc.gc_prev = list->gc.gc_prev;
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node->gc.gc_prev->gc.gc_next = node;
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list->gc.gc_prev = node;
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}
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static void
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gc_list_remove(PyGC_Head *node)
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{
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node->gc.gc_prev->gc.gc_next = node->gc.gc_next;
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node->gc.gc_next->gc.gc_prev = node->gc.gc_prev;
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node->gc.gc_next = NULL; /* object is not currently tracked */
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}
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static void
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gc_list_move(PyGC_Head *from, PyGC_Head *to)
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{
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if (gc_list_is_empty(from)) {
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gc_list_init(to);
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}
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else {
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to->gc.gc_next = from->gc.gc_next;
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to->gc.gc_next->gc.gc_prev = to;
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to->gc.gc_prev = from->gc.gc_prev;
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to->gc.gc_prev->gc.gc_next = to;
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}
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gc_list_init(from);
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}
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/* append a list onto another list, from becomes an empty list */
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static void
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gc_list_merge(PyGC_Head *from, PyGC_Head *to)
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{
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PyGC_Head *tail;
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if (!gc_list_is_empty(from)) {
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tail = to->gc.gc_prev;
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tail->gc.gc_next = from->gc.gc_next;
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tail->gc.gc_next->gc.gc_prev = tail;
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to->gc.gc_prev = from->gc.gc_prev;
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to->gc.gc_prev->gc.gc_next = to;
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}
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gc_list_init(from);
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}
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static long
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gc_list_size(PyGC_Head *list)
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{
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PyGC_Head *gc;
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long n = 0;
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for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) {
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n++;
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}
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return n;
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}
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/*** end of list stuff ***/
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/* Set all gc_refs = ob_refcnt */
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static void
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update_refs(PyGC_Head *containers)
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{
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PyGC_Head *gc = containers->gc.gc_next;
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for (; gc != containers; gc=gc->gc.gc_next) {
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gc->gc.gc_refs = FROM_GC(gc)->ob_refcnt;
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}
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}
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static int
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visit_decref(PyObject *op, void *data)
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{
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if (op && PyObject_IS_GC(op)) {
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if (IS_TRACKED(op))
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AS_GC(op)->gc.gc_refs--;
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}
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return 0;
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}
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/* Subtract internal references from gc_refs */
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static void
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subtract_refs(PyGC_Head *containers)
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{
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traverseproc traverse;
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PyGC_Head *gc = containers->gc.gc_next;
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for (; gc != containers; gc=gc->gc.gc_next) {
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traverse = FROM_GC(gc)->ob_type->tp_traverse;
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(void) traverse(FROM_GC(gc),
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(visitproc)visit_decref,
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NULL);
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}
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}
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/* Append objects with gc_refs > 0 to roots list */
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static void
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move_roots(PyGC_Head *containers, PyGC_Head *roots)
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{
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PyGC_Head *next;
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PyGC_Head *gc = containers->gc.gc_next;
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while (gc != containers) {
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next = gc->gc.gc_next;
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if (gc->gc.gc_refs > 0) {
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gc_list_remove(gc);
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gc_list_append(gc, roots);
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gc->gc.gc_refs = GC_MOVED;
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}
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gc = next;
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}
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}
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static int
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visit_move(PyObject *op, PyGC_Head *tolist)
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{
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if (PyObject_IS_GC(op)) {
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if (IS_TRACKED(op) && !IS_MOVED(op)) {
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PyGC_Head *gc = AS_GC(op);
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gc_list_remove(gc);
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gc_list_append(gc, tolist);
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gc->gc.gc_refs = GC_MOVED;
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}
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}
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return 0;
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}
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/* Move objects referenced from reachable to reachable set. */
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static void
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move_root_reachable(PyGC_Head *reachable)
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{
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traverseproc traverse;
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PyGC_Head *gc = reachable->gc.gc_next;
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for (; gc != reachable; gc=gc->gc.gc_next) {
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/* careful, reachable list is growing here */
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PyObject *op = FROM_GC(gc);
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traverse = op->ob_type->tp_traverse;
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(void) traverse(op,
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(visitproc)visit_move,
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(void *)reachable);
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}
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}
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/* return true of object has a finalization method */
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static int
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has_finalizer(PyObject *op)
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{
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static PyObject *delstr = NULL;
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if (delstr == NULL) {
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delstr = PyString_InternFromString("__del__");
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if (delstr == NULL)
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Py_FatalError("PyGC: can't initialize __del__ string");
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}
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return (PyInstance_Check(op) ||
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PyType_HasFeature(op->ob_type, Py_TPFLAGS_HEAPTYPE))
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&& PyObject_HasAttr(op, delstr);
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}
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/* Move all objects with finalizers (instances with __del__) */
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static void
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move_finalizers(PyGC_Head *unreachable, PyGC_Head *finalizers)
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{
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PyGC_Head *next;
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PyGC_Head *gc = unreachable->gc.gc_next;
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for (; gc != unreachable; gc=next) {
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PyObject *op = FROM_GC(gc);
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next = gc->gc.gc_next;
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if (has_finalizer(op)) {
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gc_list_remove(gc);
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gc_list_append(gc, finalizers);
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}
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}
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}
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/* Move objects referenced from roots to roots */
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static void
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move_finalizer_reachable(PyGC_Head *finalizers)
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{
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traverseproc traverse;
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PyGC_Head *gc = finalizers->gc.gc_next;
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for (; gc != finalizers; gc=gc->gc.gc_next) {
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/* careful, finalizers list is growing here */
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traverse = FROM_GC(gc)->ob_type->tp_traverse;
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(void) traverse(FROM_GC(gc),
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(visitproc)visit_move,
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(void *)finalizers);
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}
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}
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static void
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debug_instance(char *msg, PyInstanceObject *inst)
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{
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char *cname;
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/* simple version of instance_repr */
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PyObject *classname = inst->in_class->cl_name;
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if (classname != NULL && PyString_Check(classname))
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cname = PyString_AsString(classname);
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else
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cname = "?";
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PySys_WriteStderr("gc: %.100s <%.100s instance at %p>\n",
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msg, cname, inst);
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}
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static void
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debug_cycle(char *msg, PyObject *op)
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{
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if ((debug & DEBUG_INSTANCES) && PyInstance_Check(op)) {
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debug_instance(msg, (PyInstanceObject *)op);
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}
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else if (debug & DEBUG_OBJECTS) {
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PySys_WriteStderr("gc: %.100s <%.100s %p>\n",
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msg, op->ob_type->tp_name, op);
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}
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}
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/* Handle uncollectable garbage (cycles with finalizers). */
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static void
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handle_finalizers(PyGC_Head *finalizers, PyGC_Head *old)
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{
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PyGC_Head *gc;
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if (garbage == NULL) {
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garbage = PyList_New(0);
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}
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for (gc = finalizers->gc.gc_next; gc != finalizers;
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gc = finalizers->gc.gc_next) {
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PyObject *op = FROM_GC(gc);
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if ((debug & DEBUG_SAVEALL) || has_finalizer(op)) {
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/* If SAVEALL is not set then just append objects with
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* finalizers to the list of garbage. All objects in
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* the finalizers list are reachable from those
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* objects. */
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PyList_Append(garbage, op);
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}
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/* object is now reachable again */
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gc_list_remove(gc);
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gc_list_append(gc, old);
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}
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}
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/* Break reference cycles by clearing the containers involved. This is
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* tricky business as the lists can be changing and we don't know which
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* objects may be freed. It is possible I screwed something up here. */
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static void
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delete_garbage(PyGC_Head *unreachable, PyGC_Head *old)
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{
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inquiry clear;
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while (!gc_list_is_empty(unreachable)) {
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PyGC_Head *gc = unreachable->gc.gc_next;
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PyObject *op = FROM_GC(gc);
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if (debug & DEBUG_SAVEALL) {
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PyList_Append(garbage, op);
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}
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else {
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if ((clear = op->ob_type->tp_clear) != NULL) {
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Py_INCREF(op);
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clear(op);
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Py_DECREF(op);
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}
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}
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if (unreachable->gc.gc_next == gc) {
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/* object is still alive, move it, it may die later */
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gc_list_remove(gc);
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gc_list_append(gc, old);
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}
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}
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}
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/* This is the main function. Read this to understand how the
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* collection process works. */
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static long
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collect(int generation)
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{
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int i;
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long n = 0;
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long m = 0;
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PyGC_Head *young; /* the generation we are examining */
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PyGC_Head *old; /* next older generation */
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PyGC_Head reachable;
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PyGC_Head unreachable;
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PyGC_Head finalizers;
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PyGC_Head *gc;
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if (debug & DEBUG_STATS) {
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PySys_WriteStderr("gc: collecting generation %d...\n",
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generation);
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PySys_WriteStderr("gc: objects in each generation:");
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for (i = 0; i < NUM_GENERATIONS; i++) {
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PySys_WriteStderr(" %ld", gc_list_size(GEN_HEAD(i)));
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}
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PySys_WriteStderr("\n");
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}
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/* update collection and allocation counters */
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if (generation+1 < NUM_GENERATIONS)
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generations[generation+1].count += 1;
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for (i = 0; i <= generation; i++)
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generations[generation].count = 0;
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/* merge younger generations with one we are currently collecting */
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for (i = 0; i < generation; i++) {
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gc_list_merge(GEN_HEAD(i), GEN_HEAD(generation));
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}
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/* handy references */
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young = GEN_HEAD(generation);
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if (generation < NUM_GENERATIONS-1) {
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old = GEN_HEAD(generation+1);
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} else {
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old = GEN_HEAD(NUM_GENERATIONS-1);
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}
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/* Using ob_refcnt and gc_refs, calculate which objects in the
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* container set are reachable from outside the set (ie. have a
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* refcount greater than 0 when all the references within the
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* set are taken into account */
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update_refs(young);
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subtract_refs(young);
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/* Move everything reachable from outside the set into the
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* reachable set (ie. gc_refs > 0). Next, move everything
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* reachable from objects in the reachable set. */
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gc_list_init(&reachable);
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move_roots(young, &reachable);
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move_root_reachable(&reachable);
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/* move unreachable objects to a temporary list, new objects can be
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* allocated after this point */
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gc_list_init(&unreachable);
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gc_list_move(young, &unreachable);
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/* move reachable objects to next generation */
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gc_list_merge(&reachable, old);
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/* Move objects reachable from finalizers, we can't safely delete
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* them. Python programmers should take care not to create such
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* things. For Python finalizers means instance objects with
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* __del__ methods. */
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gc_list_init(&finalizers);
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move_finalizers(&unreachable, &finalizers);
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move_finalizer_reachable(&finalizers);
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/* Collect statistics on collectable objects found and print
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* debugging information. */
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for (gc = unreachable.gc.gc_next; gc != &unreachable;
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gc = gc->gc.gc_next) {
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m++;
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if (debug & DEBUG_COLLECTABLE) {
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debug_cycle("collectable", FROM_GC(gc));
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}
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}
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/* call tp_clear on objects in the collectable set. This will cause
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* the reference cycles to be broken. It may also cause some objects in
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* finalizers to be freed */
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delete_garbage(&unreachable, old);
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/* Collect statistics on uncollectable objects found and print
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* debugging information. */
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for (gc = finalizers.gc.gc_next; gc != &finalizers;
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gc = gc->gc.gc_next) {
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n++;
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if (debug & DEBUG_UNCOLLECTABLE) {
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debug_cycle("uncollectable", FROM_GC(gc));
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}
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}
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if (debug & DEBUG_STATS) {
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if (m == 0 && n == 0) {
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PySys_WriteStderr("gc: done.\n");
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}
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else {
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PySys_WriteStderr(
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"gc: done, %ld unreachable, %ld uncollectable.\n",
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n+m, n);
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}
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}
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/* Append instances in the uncollectable set to a Python
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* reachable list of garbage. The programmer has to deal with
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* this if they insist on creating this type of structure. */
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handle_finalizers(&finalizers, old);
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if (PyErr_Occurred()) {
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if (gc_str == NULL) {
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gc_str = PyString_FromString("garbage collection");
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}
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PyErr_WriteUnraisable(gc_str);
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Py_FatalError("unexpected exception during garbage collection");
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}
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return n+m;
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}
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static long
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collect_generations(void)
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{
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int i;
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long n = 0;
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/* Find the oldest generation (higest numbered) where the count
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* exceeds the threshold. Objects in the that generation and
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* generations younger than it will be collected. */
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for (i = NUM_GENERATIONS-1; i >= 0; i--) {
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if (generations[i].count > generations[i].threshold) {
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n = collect(i);
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break;
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}
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}
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return n;
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}
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PyDoc_STRVAR(gc_enable__doc__,
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"enable() -> None\n"
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"\n"
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"Enable automatic garbage collection.\n");
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static PyObject *
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gc_enable(PyObject *self, PyObject *args)
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{
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if (!PyArg_ParseTuple(args, ":enable")) /* check no args */
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return NULL;
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enabled = 1;
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Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_disable__doc__,
|
|
"disable() -> None\n"
|
|
"\n"
|
|
"Disable automatic garbage collection.\n");
|
|
|
|
static PyObject *
|
|
gc_disable(PyObject *self, PyObject *args)
|
|
{
|
|
|
|
if (!PyArg_ParseTuple(args, ":disable")) /* check no args */
|
|
return NULL;
|
|
|
|
enabled = 0;
|
|
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_isenabled__doc__,
|
|
"isenabled() -> status\n"
|
|
"\n"
|
|
"Returns true if automatic garbage collection is enabled.\n");
|
|
|
|
static PyObject *
|
|
gc_isenabled(PyObject *self, PyObject *args)
|
|
{
|
|
|
|
if (!PyArg_ParseTuple(args, ":isenabled")) /* check no args */
|
|
return NULL;
|
|
|
|
return Py_BuildValue("i", enabled);
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_collect__doc__,
|
|
"collect() -> n\n"
|
|
"\n"
|
|
"Run a full collection. The number of unreachable objects is returned.\n");
|
|
|
|
static PyObject *
|
|
gc_collect(PyObject *self, PyObject *args)
|
|
{
|
|
long n;
|
|
|
|
if (!PyArg_ParseTuple(args, ":collect")) /* check no args */
|
|
return NULL;
|
|
|
|
if (collecting) {
|
|
n = 0; /* already collecting, don't do anything */
|
|
}
|
|
else {
|
|
collecting = 1;
|
|
n = collect(NUM_GENERATIONS - 1);
|
|
collecting = 0;
|
|
}
|
|
|
|
return Py_BuildValue("l", n);
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_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_SAVEALL - Save objects to gc.garbage rather than freeing them.\n"
|
|
" DEBUG_LEAK - Debug leaking programs (everything but STATS).\n");
|
|
|
|
static PyObject *
|
|
gc_set_debug(PyObject *self, PyObject *args)
|
|
{
|
|
if (!PyArg_ParseTuple(args, "i:set_debug", &debug))
|
|
return NULL;
|
|
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_get_debug__doc__,
|
|
"get_debug() -> flags\n"
|
|
"\n"
|
|
"Get the garbage collection debugging flags.\n");
|
|
|
|
static PyObject *
|
|
gc_get_debug(PyObject *self, PyObject *args)
|
|
{
|
|
if (!PyArg_ParseTuple(args, ":get_debug")) /* no args */
|
|
return NULL;
|
|
|
|
return Py_BuildValue("i", debug);
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_set_thresh__doc__,
|
|
"set_threshold(threshold0, [threshold1, threshold2]) -> None\n"
|
|
"\n"
|
|
"Sets the collection thresholds. Setting threshold0 to zero disables\n"
|
|
"collection.\n");
|
|
|
|
static PyObject *
|
|
gc_set_thresh(PyObject *self, PyObject *args)
|
|
{
|
|
int i;
|
|
if (!PyArg_ParseTuple(args, "i|ii:set_threshold",
|
|
&generations[0].threshold,
|
|
&generations[1].threshold,
|
|
&generations[2].threshold))
|
|
return NULL;
|
|
for (i = 2; i < NUM_GENERATIONS; i++) {
|
|
/* generations higher than 2 get the same threshold */
|
|
generations[i].threshold = generations[2].threshold;
|
|
}
|
|
|
|
Py_INCREF(Py_None);
|
|
return Py_None;
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_get_thresh__doc__,
|
|
"get_threshold() -> (threshold0, threshold1, threshold2)\n"
|
|
"\n"
|
|
"Return the current collection thresholds\n");
|
|
|
|
static PyObject *
|
|
gc_get_thresh(PyObject *self, PyObject *args)
|
|
{
|
|
if (!PyArg_ParseTuple(args, ":get_threshold")) /* no args */
|
|
return NULL;
|
|
|
|
return Py_BuildValue("(iii)",
|
|
generations[0].threshold,
|
|
generations[1].threshold,
|
|
generations[2].threshold);
|
|
}
|
|
|
|
static int
|
|
referrersvisit(PyObject* obj, PyObject *objs)
|
|
{
|
|
int i;
|
|
for (i = 0; i < PyTuple_GET_SIZE(objs); i++)
|
|
if (PyTuple_GET_ITEM(objs, i) == obj)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
gc_referrers_for(PyObject *objs, PyGC_Head *list, PyObject *resultlist)
|
|
{
|
|
PyGC_Head *gc;
|
|
PyObject *obj;
|
|
traverseproc traverse;
|
|
for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) {
|
|
obj = FROM_GC(gc);
|
|
traverse = obj->ob_type->tp_traverse;
|
|
if (obj == objs || obj == resultlist)
|
|
continue;
|
|
if (traverse(obj, (visitproc)referrersvisit, objs)) {
|
|
if (PyList_Append(resultlist, obj) < 0)
|
|
return 0; /* error */
|
|
}
|
|
}
|
|
return 1; /* no error */
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_get_referrers__doc__,
|
|
"get_referrers(*objs) -> list\n\
|
|
Return the list of objects that directly refer to any of objs.");
|
|
|
|
static PyObject *
|
|
gc_get_referrers(PyObject *self, PyObject *args)
|
|
{
|
|
int i;
|
|
PyObject *result = PyList_New(0);
|
|
for (i = 0; i < NUM_GENERATIONS; i++) {
|
|
if (!(gc_referrers_for(args, GEN_HEAD(i), result))) {
|
|
Py_DECREF(result);
|
|
return NULL;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
PyDoc_STRVAR(gc_get_objects__doc__,
|
|
"get_objects() -> [...]\n"
|
|
"\n"
|
|
"Return a list of objects tracked by the collector (excluding the list\n"
|
|
"returned).\n");
|
|
|
|
/* appending objects in a GC list to a Python list */
|
|
static int
|
|
append_objects(PyObject *py_list, PyGC_Head *gc_list)
|
|
{
|
|
PyGC_Head *gc;
|
|
for (gc = gc_list->gc.gc_next; gc != gc_list; gc = gc->gc.gc_next) {
|
|
PyObject *op = FROM_GC(gc);
|
|
if (op != py_list) {
|
|
if (PyList_Append(py_list, op)) {
|
|
return -1; /* exception */
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static PyObject *
|
|
gc_get_objects(PyObject *self, PyObject *args)
|
|
{
|
|
int i;
|
|
PyObject* result;
|
|
|
|
if (!PyArg_ParseTuple(args, ":get_objects")) /* check no args */
|
|
return NULL;
|
|
result = PyList_New(0);
|
|
if (result == NULL) {
|
|
return NULL;
|
|
}
|
|
for (i = 0; i < NUM_GENERATIONS; i++) {
|
|
if (append_objects(result, GEN_HEAD(i))) {
|
|
Py_DECREF(result);
|
|
return NULL;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
PyDoc_STRVAR(gc__doc__,
|
|
"This module provides access to the garbage collector for reference cycles.\n"
|
|
"\n"
|
|
"enable() -- Enable automatic garbage collection.\n"
|
|
"disable() -- Disable automatic garbage collection.\n"
|
|
"isenabled() -- Returns true if automatic collection is enabled.\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"
|
|
"get_objects() -- Return a list of all objects tracked by the collector.\n"
|
|
"get_referrers() -- Return the list of objects that refer to an object.\n");
|
|
|
|
static PyMethodDef GcMethods[] = {
|
|
{"enable", gc_enable, METH_VARARGS, gc_enable__doc__},
|
|
{"disable", gc_disable, METH_VARARGS, gc_disable__doc__},
|
|
{"isenabled", gc_isenabled, METH_VARARGS, gc_isenabled__doc__},
|
|
{"set_debug", gc_set_debug, METH_VARARGS, gc_set_debug__doc__},
|
|
{"get_debug", gc_get_debug, METH_VARARGS, gc_get_debug__doc__},
|
|
{"set_threshold", gc_set_thresh, METH_VARARGS, gc_set_thresh__doc__},
|
|
{"get_threshold", gc_get_thresh, METH_VARARGS, gc_get_thresh__doc__},
|
|
{"collect", gc_collect, METH_VARARGS, gc_collect__doc__},
|
|
{"get_objects", gc_get_objects,METH_VARARGS, gc_get_objects__doc__},
|
|
{"get_referrers", gc_get_referrers, METH_VARARGS,
|
|
gc_get_referrers__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_SAVEALL",
|
|
PyInt_FromLong(DEBUG_SAVEALL));
|
|
PyDict_SetItemString(d, "DEBUG_LEAK",
|
|
PyInt_FromLong(DEBUG_LEAK));
|
|
}
|
|
|
|
/* for debugging */
|
|
void _PyGC_Dump(PyGC_Head *g)
|
|
{
|
|
_PyObject_Dump(FROM_GC(g));
|
|
}
|
|
|
|
#endif /* WITH_CYCLE_GC */
|
|
|
|
/* extension modules might be compiled with GC support so these
|
|
functions must always be available */
|
|
|
|
#undef PyObject_GC_Track
|
|
#undef PyObject_GC_UnTrack
|
|
#undef PyObject_GC_Del
|
|
#undef _PyObject_GC_Malloc
|
|
|
|
void
|
|
PyObject_GC_Track(void *op)
|
|
{
|
|
_PyObject_GC_TRACK(op);
|
|
}
|
|
|
|
/* for binary compatibility with 2.2 */
|
|
void
|
|
_PyObject_GC_Track(PyObject *op)
|
|
{
|
|
PyObject_GC_Track(op);
|
|
}
|
|
|
|
void
|
|
PyObject_GC_UnTrack(void *op)
|
|
{
|
|
#ifdef WITH_CYCLE_GC
|
|
if (IS_TRACKED(op))
|
|
_PyObject_GC_UNTRACK(op);
|
|
#endif
|
|
}
|
|
|
|
/* for binary compatibility with 2.2 */
|
|
void
|
|
_PyObject_GC_UnTrack(PyObject *op)
|
|
{
|
|
PyObject_GC_UnTrack(op);
|
|
}
|
|
|
|
PyObject *
|
|
_PyObject_GC_Malloc(size_t basicsize)
|
|
{
|
|
PyObject *op;
|
|
#ifdef WITH_CYCLE_GC
|
|
PyGC_Head *g = PyObject_MALLOC(sizeof(PyGC_Head) + basicsize);
|
|
if (g == NULL)
|
|
return PyErr_NoMemory();
|
|
g->gc.gc_next = NULL;
|
|
generations[0].count++; /* number of allocated GC objects */
|
|
if (generations[0].count > generations[0].threshold &&
|
|
enabled &&
|
|
generations[0].threshold &&
|
|
!collecting &&
|
|
!PyErr_Occurred()) {
|
|
collecting = 1;
|
|
collect_generations();
|
|
collecting = 0;
|
|
}
|
|
op = FROM_GC(g);
|
|
#else
|
|
op = PyObject_MALLOC(basicsize);
|
|
if (op == NULL)
|
|
return PyErr_NoMemory();
|
|
|
|
#endif
|
|
return op;
|
|
}
|
|
|
|
PyObject *
|
|
_PyObject_GC_New(PyTypeObject *tp)
|
|
{
|
|
PyObject *op = _PyObject_GC_Malloc(_PyObject_SIZE(tp));
|
|
if (op != NULL)
|
|
op = PyObject_INIT(op, tp);
|
|
return op;
|
|
}
|
|
|
|
PyVarObject *
|
|
_PyObject_GC_NewVar(PyTypeObject *tp, int nitems)
|
|
{
|
|
const size_t size = _PyObject_VAR_SIZE(tp, nitems);
|
|
PyVarObject *op = (PyVarObject *) _PyObject_GC_Malloc(size);
|
|
if (op != NULL)
|
|
op = PyObject_INIT_VAR(op, tp, nitems);
|
|
return op;
|
|
}
|
|
|
|
PyVarObject *
|
|
_PyObject_GC_Resize(PyVarObject *op, int nitems)
|
|
{
|
|
const size_t basicsize = _PyObject_VAR_SIZE(op->ob_type, nitems);
|
|
#ifdef WITH_CYCLE_GC
|
|
PyGC_Head *g = AS_GC(op);
|
|
g = PyObject_REALLOC(g, sizeof(PyGC_Head) + basicsize);
|
|
if (g == NULL)
|
|
return (PyVarObject *)PyErr_NoMemory();
|
|
op = (PyVarObject *) FROM_GC(g);
|
|
#else
|
|
op = PyObject_REALLOC(op, basicsize);
|
|
if (op == NULL)
|
|
return (PyVarObject *)PyErr_NoMemory();
|
|
#endif
|
|
op->ob_size = nitems;
|
|
return op;
|
|
}
|
|
|
|
void
|
|
PyObject_GC_Del(void *op)
|
|
{
|
|
#ifdef WITH_CYCLE_GC
|
|
PyGC_Head *g = AS_GC(op);
|
|
if (IS_TRACKED(op))
|
|
gc_list_remove(g);
|
|
if (generations[0].count > 0) {
|
|
generations[0].count--;
|
|
}
|
|
PyObject_FREE(g);
|
|
#else
|
|
PyObject_FREE(op);
|
|
#endif
|
|
}
|
|
|
|
/* for binary compatibility with 2.2 */
|
|
#undef _PyObject_GC_Del
|
|
void
|
|
_PyObject_GC_Del(PyObject *op)
|
|
{
|
|
PyObject_GC_Del(op);
|
|
}
|