Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1 | /* |
| 2 | |
| 3 | Reference Cycle Garbage Collection |
| 4 | ================================== |
| 5 | |
Neil Schemenauer | b2c2c9e | 2000-10-04 16:34:09 +0000 | [diff] [blame] | 6 | Neil Schemenauer <nas@arctrix.com> |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 7 | |
| 8 | Based on a post on the python-dev list. Ideas from Guido van Rossum, |
| 9 | Eric Tiedemann, and various others. |
| 10 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 11 | http://www.arctrix.com/nas/python/gc/ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 12 | http://www.python.org/pipermail/python-dev/2000-March/003869.html |
| 13 | http://www.python.org/pipermail/python-dev/2000-March/004010.html |
| 14 | http://www.python.org/pipermail/python-dev/2000-March/004022.html |
| 15 | |
| 16 | For a highlevel view of the collection process, read the collect |
| 17 | function. |
| 18 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 19 | */ |
| 20 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 21 | #include "Python.h" |
| 22 | |
| 23 | #ifdef WITH_CYCLE_GC |
| 24 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 25 | /* Get an object's GC head */ |
| 26 | #define AS_GC(o) ((PyGC_Head *)(o)-1) |
| 27 | |
| 28 | /* Get the object given the GC head */ |
| 29 | #define FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1)) |
| 30 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 31 | |
| 32 | /*** Global GC state ***/ |
| 33 | |
| 34 | /* linked lists of container objects */ |
Guido van Rossum | bca8c2e | 2001-10-12 20:52:48 +0000 | [diff] [blame] | 35 | PyGC_Head _PyGC_generation0 = {{&_PyGC_generation0, &_PyGC_generation0, 0}}; |
| 36 | static PyGC_Head generation1 = {{&generation1, &generation1, 0}}; |
| 37 | static PyGC_Head generation2 = {{&generation2, &generation2, 0}}; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 38 | static int generation = 0; /* current generation being collected */ |
| 39 | |
| 40 | /* collection frequencies, XXX tune these */ |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 41 | static int enabled = 1; /* automatic collection enabled? */ |
Jeremy Hylton | 3263dc2b | 2000-09-05 15:44:50 +0000 | [diff] [blame] | 42 | static int threshold0 = 700; /* net new containers before collection */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 43 | static int threshold1 = 10; /* generation0 collections before collecting 1 */ |
| 44 | static int threshold2 = 10; /* generation1 collections before collecting 2 */ |
| 45 | |
| 46 | /* net new objects allocated since last collection */ |
| 47 | static int allocated; |
| 48 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 49 | /* true if we are currently running the collector */ |
| 50 | static int collecting; |
| 51 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 52 | /* set for debugging information */ |
| 53 | #define DEBUG_STATS (1<<0) /* print collection statistics */ |
| 54 | #define DEBUG_COLLECTABLE (1<<1) /* print collectable objects */ |
| 55 | #define DEBUG_UNCOLLECTABLE (1<<2) /* print uncollectable objects */ |
| 56 | #define DEBUG_INSTANCES (1<<3) /* print instances */ |
| 57 | #define DEBUG_OBJECTS (1<<4) /* print other objects */ |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 58 | #define DEBUG_SAVEALL (1<<5) /* save all garbage in gc.garbage */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 59 | #define DEBUG_LEAK DEBUG_COLLECTABLE | \ |
| 60 | DEBUG_UNCOLLECTABLE | \ |
| 61 | DEBUG_INSTANCES | \ |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 62 | DEBUG_OBJECTS | \ |
| 63 | DEBUG_SAVEALL |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 64 | static int debug; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 65 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 66 | /* Special gc_refs value */ |
| 67 | #define GC_MOVED -123 |
| 68 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 69 | /* list of uncollectable objects */ |
| 70 | static PyObject *garbage; |
| 71 | |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 72 | /* Python string to use if unhandled exception occurs */ |
| 73 | static PyObject *gc_str; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 74 | |
| 75 | /*** list functions ***/ |
| 76 | |
| 77 | static void |
| 78 | gc_list_init(PyGC_Head *list) |
| 79 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 80 | list->gc.gc_prev = list; |
| 81 | list->gc.gc_next = list; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 82 | } |
| 83 | |
| 84 | static void |
| 85 | gc_list_append(PyGC_Head *node, PyGC_Head *list) |
| 86 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 87 | node->gc.gc_next = list; |
| 88 | node->gc.gc_prev = list->gc.gc_prev; |
| 89 | node->gc.gc_prev->gc.gc_next = node; |
| 90 | list->gc.gc_prev = node; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | static void |
| 94 | gc_list_remove(PyGC_Head *node) |
| 95 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 96 | node->gc.gc_prev->gc.gc_next = node->gc.gc_next; |
| 97 | node->gc.gc_next->gc.gc_prev = node->gc.gc_prev; |
| 98 | node->gc.gc_next = NULL; /* object is not currently tracked */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 99 | } |
| 100 | |
| 101 | static void |
| 102 | gc_list_move(PyGC_Head *from, PyGC_Head *to) |
| 103 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 104 | if (from->gc.gc_next == from) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 105 | /* empty from list */ |
| 106 | gc_list_init(to); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 107 | } |
| 108 | else { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 109 | to->gc.gc_next = from->gc.gc_next; |
| 110 | to->gc.gc_next->gc.gc_prev = to; |
| 111 | to->gc.gc_prev = from->gc.gc_prev; |
| 112 | to->gc.gc_prev->gc.gc_next = to; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 113 | } |
| 114 | gc_list_init(from); |
| 115 | } |
| 116 | |
| 117 | /* append a list onto another list, from becomes an empty list */ |
| 118 | static void |
| 119 | gc_list_merge(PyGC_Head *from, PyGC_Head *to) |
| 120 | { |
| 121 | PyGC_Head *tail; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 122 | if (from->gc.gc_next != from) { |
| 123 | tail = to->gc.gc_prev; |
| 124 | tail->gc.gc_next = from->gc.gc_next; |
| 125 | tail->gc.gc_next->gc.gc_prev = tail; |
| 126 | to->gc.gc_prev = from->gc.gc_prev; |
| 127 | to->gc.gc_prev->gc.gc_next = to; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 128 | } |
| 129 | gc_list_init(from); |
| 130 | } |
| 131 | |
| 132 | static long |
| 133 | gc_list_size(PyGC_Head *list) |
| 134 | { |
| 135 | PyGC_Head *gc; |
| 136 | long n = 0; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 137 | for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 138 | n++; |
| 139 | } |
| 140 | return n; |
| 141 | } |
| 142 | |
| 143 | /*** end of list stuff ***/ |
| 144 | |
| 145 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 146 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 147 | /* Set all gc_refs = ob_refcnt */ |
| 148 | static void |
| 149 | update_refs(PyGC_Head *containers) |
| 150 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 151 | PyGC_Head *gc = containers->gc.gc_next; |
| 152 | for (; gc != containers; gc=gc->gc.gc_next) { |
| 153 | gc->gc.gc_refs = FROM_GC(gc)->ob_refcnt; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 154 | } |
| 155 | } |
| 156 | |
| 157 | static int |
| 158 | visit_decref(PyObject *op, void *data) |
| 159 | { |
| 160 | if (op && PyObject_IS_GC(op)) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 161 | PyGC_Head *gc = AS_GC(op); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 162 | if (gc->gc.gc_next != NULL) |
| 163 | AS_GC(op)->gc.gc_refs--; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 164 | } |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | /* Subtract internal references from gc_refs */ |
| 169 | static void |
| 170 | subtract_refs(PyGC_Head *containers) |
| 171 | { |
| 172 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 173 | PyGC_Head *gc = containers->gc.gc_next; |
| 174 | for (; gc != containers; gc=gc->gc.gc_next) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 175 | traverse = FROM_GC(gc)->ob_type->tp_traverse; |
| 176 | (void) traverse(FROM_GC(gc), |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 177 | (visitproc)visit_decref, |
| 178 | NULL); |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | /* Append objects with gc_refs > 0 to roots list */ |
| 183 | static void |
| 184 | move_roots(PyGC_Head *containers, PyGC_Head *roots) |
| 185 | { |
| 186 | PyGC_Head *next; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 187 | PyGC_Head *gc = containers->gc.gc_next; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 188 | while (gc != containers) { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 189 | next = gc->gc.gc_next; |
| 190 | if (gc->gc.gc_refs > 0) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 191 | gc_list_remove(gc); |
| 192 | gc_list_append(gc, roots); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 193 | gc->gc.gc_refs = GC_MOVED; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 194 | } |
| 195 | gc = next; |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | static int |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 200 | visit_move(PyObject *op, PyGC_Head *tolist) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 201 | { |
| 202 | if (PyObject_IS_GC(op)) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 203 | PyGC_Head *gc = AS_GC(op); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 204 | if (gc->gc.gc_next != NULL && gc->gc.gc_refs != GC_MOVED) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 205 | gc_list_remove(gc); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 206 | gc_list_append(gc, tolist); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 207 | gc->gc.gc_refs = GC_MOVED; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 208 | } |
| 209 | } |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | /* Move objects referenced from reachable to reachable set. */ |
| 214 | static void |
| 215 | move_root_reachable(PyGC_Head *reachable) |
| 216 | { |
| 217 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 218 | PyGC_Head *gc = reachable->gc.gc_next; |
| 219 | for (; gc != reachable; gc=gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 220 | /* careful, reachable list is growing here */ |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 221 | PyObject *op = FROM_GC(gc); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 222 | traverse = op->ob_type->tp_traverse; |
| 223 | (void) traverse(op, |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 224 | (visitproc)visit_move, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 225 | (void *)reachable); |
| 226 | } |
| 227 | } |
| 228 | |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame^] | 229 | /* return true of object has a finalization method */ |
| 230 | static int |
| 231 | has_finalizer(PyObject *op) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 232 | { |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 233 | static PyObject *delstr = NULL; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 234 | if (delstr == NULL) { |
| 235 | delstr = PyString_InternFromString("__del__"); |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 236 | if (delstr == NULL) |
| 237 | Py_FatalError("PyGC: can't initialize __del__ string"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 238 | } |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame^] | 239 | if ((PyInstance_Check(op) || |
| 240 | PyType_HasFeature(op->ob_type, Py_TPFLAGS_HEAPTYPE)) && |
| 241 | PyObject_HasAttr(op, delstr)) { |
| 242 | return 1; |
| 243 | } |
| 244 | else { |
| 245 | return 0; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /* Move all objects with finalizers (instances with __del__) */ |
| 250 | static void |
| 251 | move_finalizers(PyGC_Head *unreachable, PyGC_Head *finalizers) |
| 252 | { |
| 253 | PyGC_Head *next; |
| 254 | PyGC_Head *gc = unreachable->gc.gc_next; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 255 | for (; gc != unreachable; gc=next) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 256 | PyObject *op = FROM_GC(gc); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 257 | next = gc->gc.gc_next; |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame^] | 258 | if (has_finalizer(op)) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 259 | gc_list_remove(gc); |
| 260 | gc_list_append(gc, finalizers); |
| 261 | } |
| 262 | } |
| 263 | } |
| 264 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 265 | /* Move objects referenced from roots to roots */ |
| 266 | static void |
| 267 | move_finalizer_reachable(PyGC_Head *finalizers) |
| 268 | { |
| 269 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 270 | PyGC_Head *gc = finalizers->gc.gc_next; |
| 271 | for (; gc != finalizers; gc=gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 272 | /* careful, finalizers list is growing here */ |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 273 | traverse = FROM_GC(gc)->ob_type->tp_traverse; |
| 274 | (void) traverse(FROM_GC(gc), |
| 275 | (visitproc)visit_move, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 276 | (void *)finalizers); |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | static void |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 281 | debug_instance(char *msg, PyInstanceObject *inst) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 282 | { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 283 | char *cname; |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame^] | 284 | /* simple version of instance_repr */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 285 | PyObject *classname = inst->in_class->cl_name; |
| 286 | if (classname != NULL && PyString_Check(classname)) |
| 287 | cname = PyString_AsString(classname); |
| 288 | else |
| 289 | cname = "?"; |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 290 | PySys_WriteStderr("gc: %.100s <%.100s instance at %p>\n", |
| 291 | msg, cname, inst); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | static void |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 295 | debug_cycle(char *msg, PyObject *op) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 296 | { |
| 297 | if ((debug & DEBUG_INSTANCES) && PyInstance_Check(op)) { |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 298 | debug_instance(msg, (PyInstanceObject *)op); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 299 | } |
| 300 | else if (debug & DEBUG_OBJECTS) { |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 301 | PySys_WriteStderr("gc: %.100s <%.100s %p>\n", |
| 302 | msg, op->ob_type->tp_name, op); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 303 | } |
| 304 | } |
| 305 | |
| 306 | /* Handle uncollectable garbage (cycles with finalizers). */ |
| 307 | static void |
| 308 | handle_finalizers(PyGC_Head *finalizers, PyGC_Head *old) |
| 309 | { |
| 310 | PyGC_Head *gc; |
| 311 | if (garbage == NULL) { |
| 312 | garbage = PyList_New(0); |
| 313 | } |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 314 | for (gc = finalizers->gc.gc_next; gc != finalizers; |
| 315 | gc = finalizers->gc.gc_next) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 316 | PyObject *op = FROM_GC(gc); |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame^] | 317 | if ((debug & DEBUG_SAVEALL) || has_finalizer(op)) { |
| 318 | /* If SAVEALL is not set then just append objects with |
| 319 | * finalizers to the list of garbage. All objects in |
| 320 | * the finalizers list are reachable from those |
| 321 | * objects. */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 322 | PyList_Append(garbage, op); |
| 323 | } |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 324 | /* object is now reachable again */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 325 | gc_list_remove(gc); |
| 326 | gc_list_append(gc, old); |
| 327 | } |
| 328 | } |
| 329 | |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 330 | /* Break reference cycles by clearing the containers involved. This is |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 331 | * tricky business as the lists can be changing and we don't know which |
| 332 | * objects may be freed. It is possible I screwed something up here. */ |
| 333 | static void |
| 334 | delete_garbage(PyGC_Head *unreachable, PyGC_Head *old) |
| 335 | { |
| 336 | inquiry clear; |
| 337 | |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 338 | while (unreachable->gc.gc_next != unreachable) { |
| 339 | PyGC_Head *gc = unreachable->gc.gc_next; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 340 | PyObject *op = FROM_GC(gc); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 341 | if (debug & DEBUG_SAVEALL) { |
| 342 | PyList_Append(garbage, op); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 343 | } |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 344 | else { |
| 345 | if ((clear = op->ob_type->tp_clear) != NULL) { |
| 346 | Py_INCREF(op); |
| 347 | clear((PyObject *)op); |
| 348 | Py_DECREF(op); |
| 349 | } |
| 350 | } |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 351 | if (unreachable->gc.gc_next == gc) { |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 352 | /* object is still alive, move it, it may die later */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 353 | gc_list_remove(gc); |
| 354 | gc_list_append(gc, old); |
| 355 | } |
| 356 | } |
| 357 | } |
| 358 | |
| 359 | /* This is the main function. Read this to understand how the |
| 360 | * collection process works. */ |
| 361 | static long |
| 362 | collect(PyGC_Head *young, PyGC_Head *old) |
| 363 | { |
| 364 | long n = 0; |
| 365 | long m = 0; |
| 366 | PyGC_Head reachable; |
| 367 | PyGC_Head unreachable; |
| 368 | PyGC_Head finalizers; |
| 369 | PyGC_Head *gc; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 370 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 371 | if (debug & DEBUG_STATS) { |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 372 | PySys_WriteStderr( |
| 373 | "gc: collecting generation %d...\n" |
| 374 | "gc: objects in each generation: %ld %ld %ld\n", |
| 375 | generation, |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 376 | gc_list_size(&_PyGC_generation0), |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 377 | gc_list_size(&generation1), |
| 378 | gc_list_size(&generation2)); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 379 | } |
| 380 | |
| 381 | /* Using ob_refcnt and gc_refs, calculate which objects in the |
| 382 | * container set are reachable from outside the set (ie. have a |
| 383 | * refcount greater than 0 when all the references within the |
| 384 | * set are taken into account */ |
| 385 | update_refs(young); |
| 386 | subtract_refs(young); |
| 387 | |
| 388 | /* Move everything reachable from outside the set into the |
| 389 | * reachable set (ie. gc_refs > 0). Next, move everything |
| 390 | * reachable from objects in the reachable set. */ |
| 391 | gc_list_init(&reachable); |
| 392 | move_roots(young, &reachable); |
| 393 | move_root_reachable(&reachable); |
| 394 | |
| 395 | /* move unreachable objects to a temporary list, new objects can be |
| 396 | * allocated after this point */ |
| 397 | gc_list_init(&unreachable); |
| 398 | gc_list_move(young, &unreachable); |
| 399 | |
| 400 | /* move reachable objects to next generation */ |
| 401 | gc_list_merge(&reachable, old); |
| 402 | |
| 403 | /* Move objects reachable from finalizers, we can't safely delete |
| 404 | * them. Python programmers should take care not to create such |
| 405 | * things. For Python finalizers means instance objects with |
| 406 | * __del__ methods. */ |
| 407 | gc_list_init(&finalizers); |
| 408 | move_finalizers(&unreachable, &finalizers); |
| 409 | move_finalizer_reachable(&finalizers); |
| 410 | |
| 411 | /* Collect statistics on collectable objects found and print |
| 412 | * debugging information. */ |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 413 | for (gc = unreachable.gc.gc_next; gc != &unreachable; |
| 414 | gc = gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 415 | m++; |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 416 | if (debug & DEBUG_COLLECTABLE) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 417 | debug_cycle("collectable", FROM_GC(gc)); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 418 | } |
| 419 | } |
| 420 | /* call tp_clear on objects in the collectable set. This will cause |
| 421 | * the reference cycles to be broken. It may also cause some objects in |
| 422 | * finalizers to be freed */ |
| 423 | delete_garbage(&unreachable, old); |
| 424 | |
| 425 | /* Collect statistics on uncollectable objects found and print |
| 426 | * debugging information. */ |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 427 | for (gc = finalizers.gc.gc_next; gc != &finalizers; |
| 428 | gc = gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 429 | n++; |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 430 | if (debug & DEBUG_UNCOLLECTABLE) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 431 | debug_cycle("uncollectable", FROM_GC(gc)); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 432 | } |
| 433 | } |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 434 | if (debug & DEBUG_STATS) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 435 | if (m == 0 && n == 0) { |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 436 | PySys_WriteStderr("gc: done.\n"); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 437 | } |
| 438 | else { |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 439 | PySys_WriteStderr( |
| 440 | "gc: done, %ld unreachable, %ld uncollectable.\n", |
| 441 | n+m, n); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 442 | } |
| 443 | } |
| 444 | |
| 445 | /* Append instances in the uncollectable set to a Python |
| 446 | * reachable list of garbage. The programmer has to deal with |
| 447 | * this if they insist on creating this type of structure. */ |
| 448 | handle_finalizers(&finalizers, old); |
| 449 | |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 450 | if (PyErr_Occurred()) { |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 451 | if (gc_str == NULL) { |
| 452 | gc_str = PyString_FromString("garbage collection"); |
| 453 | } |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 454 | PyErr_WriteUnraisable(gc_str); |
| 455 | Py_FatalError("unexpected exception during garbage collection"); |
| 456 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 457 | allocated = 0; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 458 | return n+m; |
| 459 | } |
| 460 | |
| 461 | static long |
| 462 | collect_generations(void) |
| 463 | { |
| 464 | static long collections0 = 0; |
| 465 | static long collections1 = 0; |
Vladimir Marangozov | b16714b | 2000-07-10 05:37:39 +0000 | [diff] [blame] | 466 | long n = 0; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 467 | |
| 468 | |
| 469 | if (collections1 > threshold2) { |
| 470 | generation = 2; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 471 | gc_list_merge(&_PyGC_generation0, &generation2); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 472 | gc_list_merge(&generation1, &generation2); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 473 | if (generation2.gc.gc_next != &generation2) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 474 | n = collect(&generation2, &generation2); |
| 475 | } |
| 476 | collections1 = 0; |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 477 | } |
| 478 | else if (collections0 > threshold1) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 479 | generation = 1; |
| 480 | collections1++; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 481 | gc_list_merge(&_PyGC_generation0, &generation1); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 482 | if (generation1.gc.gc_next != &generation1) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 483 | n = collect(&generation1, &generation2); |
| 484 | } |
| 485 | collections0 = 0; |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 486 | } |
| 487 | else { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 488 | generation = 0; |
| 489 | collections0++; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 490 | if (_PyGC_generation0.gc.gc_next != &_PyGC_generation0) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 491 | n = collect(&_PyGC_generation0, &generation1); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 492 | } |
| 493 | } |
| 494 | return n; |
| 495 | } |
| 496 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 497 | static char gc_enable__doc__[] = |
| 498 | "enable() -> None\n" |
| 499 | "\n" |
| 500 | "Enable automatic garbage collection.\n" |
| 501 | ; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 502 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 503 | static PyObject * |
| 504 | gc_enable(PyObject *self, PyObject *args) |
| 505 | { |
| 506 | |
| 507 | if (!PyArg_ParseTuple(args, ":enable")) /* check no args */ |
| 508 | return NULL; |
| 509 | |
| 510 | enabled = 1; |
| 511 | |
| 512 | Py_INCREF(Py_None); |
| 513 | return Py_None; |
| 514 | } |
| 515 | |
| 516 | static char gc_disable__doc__[] = |
| 517 | "disable() -> None\n" |
| 518 | "\n" |
| 519 | "Disable automatic garbage collection.\n" |
| 520 | ; |
| 521 | |
| 522 | static PyObject * |
| 523 | gc_disable(PyObject *self, PyObject *args) |
| 524 | { |
| 525 | |
| 526 | if (!PyArg_ParseTuple(args, ":disable")) /* check no args */ |
| 527 | return NULL; |
| 528 | |
| 529 | enabled = 0; |
| 530 | |
| 531 | Py_INCREF(Py_None); |
| 532 | return Py_None; |
| 533 | } |
| 534 | |
| 535 | static char gc_isenabled__doc__[] = |
| 536 | "isenabled() -> status\n" |
| 537 | "\n" |
| 538 | "Returns true if automatic garbage collection is enabled.\n" |
| 539 | ; |
| 540 | |
| 541 | static PyObject * |
| 542 | gc_isenabled(PyObject *self, PyObject *args) |
| 543 | { |
| 544 | |
| 545 | if (!PyArg_ParseTuple(args, ":isenabled")) /* check no args */ |
| 546 | return NULL; |
| 547 | |
| 548 | return Py_BuildValue("i", enabled); |
| 549 | } |
| 550 | |
| 551 | static char gc_collect__doc__[] = |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 552 | "collect() -> n\n" |
| 553 | "\n" |
| 554 | "Run a full collection. The number of unreachable objects is returned.\n" |
| 555 | ; |
| 556 | |
| 557 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 558 | gc_collect(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 559 | { |
| 560 | long n; |
| 561 | |
Fred Drake | cc1be24 | 2000-07-12 04:42:23 +0000 | [diff] [blame] | 562 | if (!PyArg_ParseTuple(args, ":collect")) /* check no args */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 563 | return NULL; |
| 564 | |
Neil Schemenauer | e8c40cb | 2001-10-31 23:09:35 +0000 | [diff] [blame] | 565 | if (collecting) { |
| 566 | n = 0; /* already collecting, don't do anything */ |
| 567 | } |
| 568 | else { |
| 569 | collecting = 1; |
| 570 | generation = 2; |
| 571 | gc_list_merge(&_PyGC_generation0, &generation2); |
| 572 | gc_list_merge(&generation1, &generation2); |
| 573 | n = collect(&generation2, &generation2); |
| 574 | collecting = 0; |
| 575 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 576 | |
Neil Schemenauer | 7760cff | 2000-09-22 22:35:36 +0000 | [diff] [blame] | 577 | return Py_BuildValue("l", n); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 578 | } |
| 579 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 580 | static char gc_set_debug__doc__[] = |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 581 | "set_debug(flags) -> None\n" |
| 582 | "\n" |
| 583 | "Set the garbage collection debugging flags. Debugging information is\n" |
| 584 | "written to sys.stderr.\n" |
| 585 | "\n" |
| 586 | "flags is an integer and can have the following bits turned on:\n" |
| 587 | "\n" |
| 588 | " DEBUG_STATS - Print statistics during collection.\n" |
| 589 | " DEBUG_COLLECTABLE - Print collectable objects found.\n" |
| 590 | " DEBUG_UNCOLLECTABLE - Print unreachable but uncollectable objects found.\n" |
| 591 | " DEBUG_INSTANCES - Print instance objects.\n" |
| 592 | " DEBUG_OBJECTS - Print objects other than instances.\n" |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 593 | " DEBUG_SAVEALL - Save objects to gc.garbage rather than freeing them.\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 594 | " DEBUG_LEAK - Debug leaking programs (everything but STATS).\n" |
| 595 | ; |
| 596 | |
| 597 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 598 | gc_set_debug(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 599 | { |
Neil Schemenauer | 7760cff | 2000-09-22 22:35:36 +0000 | [diff] [blame] | 600 | if (!PyArg_ParseTuple(args, "i:set_debug", &debug)) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 601 | return NULL; |
| 602 | |
| 603 | Py_INCREF(Py_None); |
| 604 | return Py_None; |
| 605 | } |
| 606 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 607 | static char gc_get_debug__doc__[] = |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 608 | "get_debug() -> flags\n" |
| 609 | "\n" |
| 610 | "Get the garbage collection debugging flags.\n" |
| 611 | ; |
| 612 | |
| 613 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 614 | gc_get_debug(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 615 | { |
Fred Drake | cc1be24 | 2000-07-12 04:42:23 +0000 | [diff] [blame] | 616 | if (!PyArg_ParseTuple(args, ":get_debug")) /* no args */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 617 | return NULL; |
| 618 | |
| 619 | return Py_BuildValue("i", debug); |
| 620 | } |
| 621 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 622 | static char gc_set_thresh__doc__[] = |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 623 | "set_threshold(threshold0, [threhold1, threshold2]) -> None\n" |
| 624 | "\n" |
| 625 | "Sets the collection thresholds. Setting threshold0 to zero disables\n" |
| 626 | "collection.\n" |
| 627 | ; |
| 628 | |
| 629 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 630 | gc_set_thresh(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 631 | { |
Fred Drake | cc1be24 | 2000-07-12 04:42:23 +0000 | [diff] [blame] | 632 | if (!PyArg_ParseTuple(args, "i|ii:set_threshold", &threshold0, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 633 | &threshold1, &threshold2)) |
| 634 | return NULL; |
| 635 | |
| 636 | Py_INCREF(Py_None); |
| 637 | return Py_None; |
| 638 | } |
| 639 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 640 | static char gc_get_thresh__doc__[] = |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 641 | "get_threshold() -> (threshold0, threshold1, threshold2)\n" |
| 642 | "\n" |
| 643 | "Return the current collection thresholds\n" |
| 644 | ; |
| 645 | |
| 646 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 647 | gc_get_thresh(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 648 | { |
Fred Drake | cc1be24 | 2000-07-12 04:42:23 +0000 | [diff] [blame] | 649 | if (!PyArg_ParseTuple(args, ":get_threshold")) /* no args */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 650 | return NULL; |
| 651 | |
| 652 | return Py_BuildValue("(iii)", threshold0, threshold1, threshold2); |
| 653 | } |
| 654 | |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 655 | static int |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 656 | referentsvisit(PyObject* obj, PyObject *objs) |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 657 | { |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 658 | if (PySequence_Contains(objs, obj)) { |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 659 | return 1; |
| 660 | } |
| 661 | return 0; |
| 662 | } |
| 663 | |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 664 | static int |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 665 | gc_referents_for(PyObject *objs, PyGC_Head *list, PyObject *resultlist) |
| 666 | { |
| 667 | PyGC_Head *gc; |
| 668 | PyObject *obj; |
| 669 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 670 | for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 671 | obj = FROM_GC(gc); |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 672 | traverse = obj->ob_type->tp_traverse; |
| 673 | if (obj == objs || obj == resultlist) |
| 674 | continue; |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 675 | if (traverse(obj, (visitproc)referentsvisit, objs)) { |
| 676 | if (PyList_Append(resultlist, obj) < 0) |
| 677 | return 0; /* error */ |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 678 | } |
| 679 | } |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 680 | return 1; /* no error */ |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 681 | } |
| 682 | |
| 683 | static char gc_get_referents__doc__[]= |
| 684 | "get_referents(*objs) -> list\n\ |
| 685 | Return the list of objects that directly refer to any of objs."; |
| 686 | |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 687 | static PyObject * |
| 688 | gc_get_referents(PyObject *self, PyObject *args) |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 689 | { |
| 690 | PyObject *result = PyList_New(0); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 691 | if (!(gc_referents_for(args, &_PyGC_generation0, result) && |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 692 | gc_referents_for(args, &generation1, result) && |
| 693 | gc_referents_for(args, &generation2, result))) { |
| 694 | Py_DECREF(result); |
| 695 | return NULL; |
| 696 | } |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 697 | return result; |
| 698 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 699 | |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 700 | static char gc_get_objects__doc__[] = |
| 701 | "get_objects() -> [...]\n" |
| 702 | "\n" |
| 703 | "Return a list of objects tracked by the collector (excluding the list\n" |
| 704 | "returned).\n" |
| 705 | ; |
| 706 | |
| 707 | /* appending objects in a GC list to a Python list */ |
| 708 | static void |
| 709 | append_objects(PyObject *py_list, PyGC_Head *gc_list) |
| 710 | { |
| 711 | PyGC_Head *gc; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 712 | for (gc = gc_list->gc.gc_next; gc != gc_list; gc = gc->gc.gc_next) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 713 | PyObject *op = FROM_GC(gc); |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 714 | if (op != py_list) { |
| 715 | Py_INCREF(op); |
| 716 | PyList_Append(py_list, op); |
| 717 | } |
| 718 | } |
| 719 | } |
| 720 | |
| 721 | static PyObject * |
| 722 | gc_get_objects(PyObject *self, PyObject *args) |
| 723 | { |
| 724 | PyObject* result; |
| 725 | |
| 726 | if (!PyArg_ParseTuple(args, ":get_objects")) /* check no args */ |
| 727 | return NULL; |
| 728 | result = PyList_New(0); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 729 | append_objects(result, &_PyGC_generation0); |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 730 | append_objects(result, &generation1); |
| 731 | append_objects(result, &generation2); |
| 732 | return result; |
| 733 | } |
| 734 | |
| 735 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 736 | static char gc__doc__ [] = |
| 737 | "This module provides access to the garbage collector for reference cycles.\n" |
| 738 | "\n" |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 739 | "enable() -- Enable automatic garbage collection.\n" |
| 740 | "disable() -- Disable automatic garbage collection.\n" |
| 741 | "isenabled() -- Returns true if automatic collection is enabled.\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 742 | "collect() -- Do a full collection right now.\n" |
| 743 | "set_debug() -- Set debugging flags.\n" |
| 744 | "get_debug() -- Get debugging flags.\n" |
| 745 | "set_threshold() -- Set the collection thresholds.\n" |
| 746 | "get_threshold() -- Return the current the collection thresholds.\n" |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 747 | "get_objects() -- Return a list of all objects tracked by the collector.\n" |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 748 | "get_referents() -- Return the list of objects that refer to an object.\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 749 | ; |
| 750 | |
| 751 | static PyMethodDef GcMethods[] = { |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 752 | {"enable", gc_enable, METH_VARARGS, gc_enable__doc__}, |
| 753 | {"disable", gc_disable, METH_VARARGS, gc_disable__doc__}, |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 754 | {"isenabled", gc_isenabled, METH_VARARGS, gc_isenabled__doc__}, |
| 755 | {"set_debug", gc_set_debug, METH_VARARGS, gc_set_debug__doc__}, |
| 756 | {"get_debug", gc_get_debug, METH_VARARGS, gc_get_debug__doc__}, |
| 757 | {"set_threshold", gc_set_thresh, METH_VARARGS, gc_set_thresh__doc__}, |
| 758 | {"get_threshold", gc_get_thresh, METH_VARARGS, gc_get_thresh__doc__}, |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 759 | {"collect", gc_collect, METH_VARARGS, gc_collect__doc__}, |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 760 | {"get_objects", gc_get_objects,METH_VARARGS, gc_get_objects__doc__}, |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 761 | {"get_referents", gc_get_referents, METH_VARARGS, |
| 762 | gc_get_referents__doc__}, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 763 | {NULL, NULL} /* Sentinel */ |
| 764 | }; |
| 765 | |
| 766 | void |
| 767 | initgc(void) |
| 768 | { |
| 769 | PyObject *m; |
| 770 | PyObject *d; |
| 771 | |
| 772 | m = Py_InitModule4("gc", |
| 773 | GcMethods, |
| 774 | gc__doc__, |
| 775 | NULL, |
| 776 | PYTHON_API_VERSION); |
| 777 | d = PyModule_GetDict(m); |
| 778 | if (garbage == NULL) { |
| 779 | garbage = PyList_New(0); |
| 780 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 781 | PyDict_SetItemString(d, "garbage", garbage); |
| 782 | PyDict_SetItemString(d, "DEBUG_STATS", |
| 783 | PyInt_FromLong(DEBUG_STATS)); |
| 784 | PyDict_SetItemString(d, "DEBUG_COLLECTABLE", |
| 785 | PyInt_FromLong(DEBUG_COLLECTABLE)); |
| 786 | PyDict_SetItemString(d, "DEBUG_UNCOLLECTABLE", |
| 787 | PyInt_FromLong(DEBUG_UNCOLLECTABLE)); |
| 788 | PyDict_SetItemString(d, "DEBUG_INSTANCES", |
| 789 | PyInt_FromLong(DEBUG_INSTANCES)); |
| 790 | PyDict_SetItemString(d, "DEBUG_OBJECTS", |
| 791 | PyInt_FromLong(DEBUG_OBJECTS)); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 792 | PyDict_SetItemString(d, "DEBUG_SAVEALL", |
| 793 | PyInt_FromLong(DEBUG_SAVEALL)); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 794 | PyDict_SetItemString(d, "DEBUG_LEAK", |
| 795 | PyInt_FromLong(DEBUG_LEAK)); |
| 796 | } |
| 797 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 798 | /* for debugging */ |
| 799 | void _PyGC_Dump(PyGC_Head *g) |
| 800 | { |
| 801 | _PyObject_Dump(FROM_GC(g)); |
| 802 | } |
| 803 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 804 | #endif /* WITH_CYCLE_GC */ |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 805 | |
| 806 | /* extension modules might be compiled with GC support so these |
| 807 | functions must always be available */ |
| 808 | |
| 809 | void |
| 810 | _PyObject_GC_Track(PyObject *op) |
| 811 | { |
| 812 | _PyObject_GC_TRACK(op); |
| 813 | } |
| 814 | |
| 815 | void |
| 816 | _PyObject_GC_UnTrack(PyObject *op) |
| 817 | { |
| 818 | _PyObject_GC_UNTRACK(op); |
| 819 | } |
| 820 | |
| 821 | PyObject * |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 822 | _PyObject_GC_Malloc(PyTypeObject *tp, int nitems) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 823 | { |
| 824 | PyObject *op; |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 825 | const size_t basicsize = _PyObject_VAR_SIZE(tp, nitems); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 826 | #ifdef WITH_CYCLE_GC |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 827 | const size_t nbytes = sizeof(PyGC_Head) + basicsize; |
| 828 | PyGC_Head *g = PyObject_MALLOC(nbytes); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 829 | if (g == NULL) |
| 830 | return (PyObject *)PyErr_NoMemory(); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 831 | g->gc.gc_next = NULL; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 832 | allocated++; |
| 833 | if (allocated > threshold0 && |
| 834 | enabled && |
| 835 | threshold0 && |
| 836 | !collecting && |
| 837 | !PyErr_Occurred()) { |
| 838 | collecting = 1; |
| 839 | collect_generations(); |
| 840 | collecting = 0; |
| 841 | } |
| 842 | op = FROM_GC(g); |
| 843 | #else |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 844 | op = PyObject_MALLOC(basicsize); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 845 | if (op == NULL) |
| 846 | return (PyObject *)PyErr_NoMemory(); |
| 847 | |
| 848 | #endif |
| 849 | return op; |
| 850 | } |
| 851 | |
| 852 | PyObject * |
| 853 | _PyObject_GC_New(PyTypeObject *tp) |
| 854 | { |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 855 | PyObject *op = _PyObject_GC_Malloc(tp, 0); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 856 | return PyObject_INIT(op, tp); |
| 857 | } |
| 858 | |
| 859 | PyVarObject * |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 860 | _PyObject_GC_NewVar(PyTypeObject *tp, int nitems) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 861 | { |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 862 | PyVarObject *op = (PyVarObject *) _PyObject_GC_Malloc(tp, nitems); |
| 863 | return PyObject_INIT_VAR(op, tp, nitems); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 864 | } |
| 865 | |
| 866 | PyVarObject * |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 867 | _PyObject_GC_Resize(PyVarObject *op, int nitems) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 868 | { |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 869 | const size_t basicsize = _PyObject_VAR_SIZE(op->ob_type, nitems); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 870 | #ifdef WITH_CYCLE_GC |
| 871 | PyGC_Head *g = AS_GC(op); |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 872 | g = PyObject_REALLOC(g, sizeof(PyGC_Head) + basicsize); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 873 | if (g == NULL) |
| 874 | return (PyVarObject *)PyErr_NoMemory(); |
| 875 | op = (PyVarObject *) FROM_GC(g); |
| 876 | #else |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 877 | op = PyObject_REALLOC(op, basicsize); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 878 | if (op == NULL) |
| 879 | return (PyVarObject *)PyErr_NoMemory(); |
| 880 | #endif |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 881 | op->ob_size = nitems; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 882 | return op; |
| 883 | } |
| 884 | |
| 885 | void |
| 886 | _PyObject_GC_Del(PyObject *op) |
| 887 | { |
| 888 | #ifdef WITH_CYCLE_GC |
| 889 | PyGC_Head *g = AS_GC(op); |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 890 | if (g->gc.gc_next != NULL) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 891 | gc_list_remove(g); |
| 892 | if (allocated > 0) { |
| 893 | allocated--; |
| 894 | } |
| 895 | PyObject_FREE(g); |
| 896 | #else |
| 897 | PyObject_FREE(op); |
| 898 | #endif |
| 899 | } |
| 900 | |