Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1 | /* |
Tim Peters | 8839617 | 2002-06-30 17:56:40 +0000 | [diff] [blame] | 2 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 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/ |
Neil Schemenauer | a7024e9 | 2008-07-15 19:24:01 +0000 | [diff] [blame] | 12 | |
| 13 | The following mailing list threads provide a historical perspective on |
| 14 | the design of this module. Note that a fair amount of refinement has |
| 15 | occurred since those discussions. |
| 16 | |
| 17 | http://mail.python.org/pipermail/python-dev/2000-March/002385.html |
| 18 | http://mail.python.org/pipermail/python-dev/2000-March/002434.html |
| 19 | http://mail.python.org/pipermail/python-dev/2000-March/002497.html |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 20 | |
| 21 | For a highlevel view of the collection process, read the collect |
| 22 | function. |
| 23 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 24 | */ |
| 25 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 26 | #include "Python.h" |
Christian Heimes | a156e09 | 2008-02-16 07:38:31 +0000 | [diff] [blame] | 27 | #include "frameobject.h" /* for PyFrame_ClearFreeList */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 28 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 29 | /* Get an object's GC head */ |
| 30 | #define AS_GC(o) ((PyGC_Head *)(o)-1) |
| 31 | |
| 32 | /* Get the object given the GC head */ |
| 33 | #define FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1)) |
| 34 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 35 | /*** Global GC state ***/ |
| 36 | |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 37 | struct gc_generation { |
| 38 | PyGC_Head head; |
| 39 | int threshold; /* collection threshold */ |
| 40 | int count; /* count of allocations or collections of younger |
| 41 | generations */ |
| 42 | }; |
| 43 | |
| 44 | #define NUM_GENERATIONS 3 |
| 45 | #define GEN_HEAD(n) (&generations[n].head) |
| 46 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 47 | /* linked lists of container objects */ |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 48 | static struct gc_generation generations[NUM_GENERATIONS] = { |
| 49 | /* PyGC_Head, threshold, count */ |
| 50 | {{{GEN_HEAD(0), GEN_HEAD(0), 0}}, 700, 0}, |
| 51 | {{{GEN_HEAD(1), GEN_HEAD(1), 0}}, 10, 0}, |
| 52 | {{{GEN_HEAD(2), GEN_HEAD(2), 0}}, 10, 0}, |
| 53 | }; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 54 | |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 55 | PyGC_Head *_PyGC_generation0 = GEN_HEAD(0); |
| 56 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 57 | static int enabled = 1; /* automatic collection enabled? */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 58 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 59 | /* true if we are currently running the collector */ |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 60 | static int collecting = 0; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 61 | |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 62 | /* list of uncollectable objects */ |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 63 | static PyObject *garbage = NULL; |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 64 | |
| 65 | /* Python string to use if unhandled exception occurs */ |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 66 | static PyObject *gc_str = NULL; |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 67 | |
Tim Peters | 93ad66d | 2003-04-05 17:15:44 +0000 | [diff] [blame] | 68 | /* Python string used to look for __del__ attribute. */ |
| 69 | static PyObject *delstr = NULL; |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 70 | |
Antoine Pitrou | 14b78f5 | 2009-01-09 22:27:08 +0000 | [diff] [blame] | 71 | /* This is the number of objects who survived the last full collection. It |
| 72 | approximates the number of long lived objects tracked by the GC. |
| 73 | |
| 74 | (by "full collection", we mean a collection of the oldest generation). |
| 75 | */ |
| 76 | static Py_ssize_t long_lived_total = 0; |
| 77 | |
| 78 | /* This is the number of objects who survived all "non-full" collections, |
| 79 | and are awaiting to undergo a full collection for the first time. |
| 80 | |
| 81 | */ |
| 82 | static Py_ssize_t long_lived_pending = 0; |
| 83 | |
| 84 | /* |
| 85 | NOTE: about the counting of long-lived objects. |
| 86 | |
| 87 | To limit the cost of garbage collection, there are two strategies; |
| 88 | - make each collection faster, e.g. by scanning fewer objects |
| 89 | - do less collections |
| 90 | This heuristic is about the latter strategy. |
| 91 | |
| 92 | In addition to the various configurable thresholds, we only trigger a |
| 93 | full collection if the ratio |
| 94 | long_lived_pending / long_lived_total |
| 95 | is above a given value (hardwired to 25%). |
| 96 | |
| 97 | The reason is that, while "non-full" collections (i.e., collections of |
| 98 | the young and middle generations) will always examine roughly the same |
| 99 | number of objects -- determined by the aforementioned thresholds --, |
| 100 | the cost of a full collection is proportional to the total number of |
| 101 | long-lived objects, which is virtually unbounded. |
| 102 | |
| 103 | Indeed, it has been remarked that doing a full collection every |
| 104 | <constant number> of object creations entails a dramatic performance |
| 105 | degradation in workloads which consist in creating and storing lots of |
| 106 | long-lived objects (e.g. building a large list of GC-tracked objects would |
| 107 | show quadratic performance, instead of linear as expected: see issue #4074). |
| 108 | |
| 109 | Using the above ratio, instead, yields amortized linear performance in |
| 110 | the total number of objects (the effect of which can be summarized |
| 111 | thusly: "each full garbage collection is more and more costly as the |
| 112 | number of objects grows, but we do fewer and fewer of them"). |
| 113 | |
| 114 | This heuristic was suggested by Martin von Löwis on python-dev in |
| 115 | June 2008. His original analysis and proposal can be found at: |
| 116 | http://mail.python.org/pipermail/python-dev/2008-June/080579.html |
| 117 | */ |
| 118 | |
| 119 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 120 | /* set for debugging information */ |
| 121 | #define DEBUG_STATS (1<<0) /* print collection statistics */ |
| 122 | #define DEBUG_COLLECTABLE (1<<1) /* print collectable objects */ |
| 123 | #define DEBUG_UNCOLLECTABLE (1<<2) /* print uncollectable objects */ |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 124 | #define DEBUG_SAVEALL (1<<5) /* save all garbage in gc.garbage */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 125 | #define DEBUG_LEAK DEBUG_COLLECTABLE | \ |
| 126 | DEBUG_UNCOLLECTABLE | \ |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 127 | DEBUG_SAVEALL |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 128 | static int debug; |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 129 | static PyObject *tmod = NULL; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 130 | |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 131 | /*-------------------------------------------------------------------------- |
| 132 | gc_refs values. |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 133 | |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 134 | Between collections, every gc'ed object has one of two gc_refs values: |
| 135 | |
| 136 | GC_UNTRACKED |
| 137 | The initial state; objects returned by PyObject_GC_Malloc are in this |
| 138 | state. The object doesn't live in any generation list, and its |
| 139 | tp_traverse slot must not be called. |
| 140 | |
| 141 | GC_REACHABLE |
| 142 | The object lives in some generation list, and its tp_traverse is safe to |
| 143 | call. An object transitions to GC_REACHABLE when PyObject_GC_Track |
| 144 | is called. |
| 145 | |
| 146 | During a collection, gc_refs can temporarily take on other states: |
| 147 | |
| 148 | >= 0 |
| 149 | At the start of a collection, update_refs() copies the true refcount |
| 150 | to gc_refs, for each object in the generation being collected. |
| 151 | subtract_refs() then adjusts gc_refs so that it equals the number of |
| 152 | times an object is referenced directly from outside the generation |
| 153 | being collected. |
Martin v. Löwis | 774348c | 2002-11-09 19:54:06 +0000 | [diff] [blame] | 154 | gc_refs remains >= 0 throughout these steps. |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 155 | |
| 156 | GC_TENTATIVELY_UNREACHABLE |
| 157 | move_unreachable() then moves objects not reachable (whether directly or |
| 158 | indirectly) from outside the generation into an "unreachable" set. |
| 159 | Objects that are found to be reachable have gc_refs set to GC_REACHABLE |
| 160 | again. Objects that are found to be unreachable have gc_refs set to |
| 161 | GC_TENTATIVELY_UNREACHABLE. It's "tentatively" because the pass doing |
| 162 | this can't be sure until it ends, and GC_TENTATIVELY_UNREACHABLE may |
| 163 | transition back to GC_REACHABLE. |
| 164 | |
| 165 | Only objects with GC_TENTATIVELY_UNREACHABLE still set are candidates |
| 166 | for collection. If it's decided not to collect such an object (e.g., |
| 167 | it has a __del__ method), its gc_refs is restored to GC_REACHABLE again. |
| 168 | ---------------------------------------------------------------------------- |
| 169 | */ |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 170 | #define GC_UNTRACKED _PyGC_REFS_UNTRACKED |
| 171 | #define GC_REACHABLE _PyGC_REFS_REACHABLE |
| 172 | #define GC_TENTATIVELY_UNREACHABLE _PyGC_REFS_TENTATIVELY_UNREACHABLE |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 173 | |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 174 | #define IS_TRACKED(o) ((AS_GC(o))->gc.gc_refs != GC_UNTRACKED) |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 175 | #define IS_REACHABLE(o) ((AS_GC(o))->gc.gc_refs == GC_REACHABLE) |
| 176 | #define IS_TENTATIVELY_UNREACHABLE(o) ( \ |
| 177 | (AS_GC(o))->gc.gc_refs == GC_TENTATIVELY_UNREACHABLE) |
Neil Schemenauer | a2b11ec | 2002-05-21 15:53:24 +0000 | [diff] [blame] | 178 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 179 | /*** list functions ***/ |
| 180 | |
| 181 | static void |
| 182 | gc_list_init(PyGC_Head *list) |
| 183 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 184 | list->gc.gc_prev = list; |
| 185 | list->gc.gc_next = list; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 186 | } |
| 187 | |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 188 | static int |
| 189 | gc_list_is_empty(PyGC_Head *list) |
| 190 | { |
| 191 | return (list->gc.gc_next == list); |
| 192 | } |
| 193 | |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 194 | #if 0 |
| 195 | /* This became unused after gc_list_move() was introduced. */ |
| 196 | /* Append `node` to `list`. */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 197 | static void |
| 198 | gc_list_append(PyGC_Head *node, PyGC_Head *list) |
| 199 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 200 | node->gc.gc_next = list; |
| 201 | node->gc.gc_prev = list->gc.gc_prev; |
| 202 | node->gc.gc_prev->gc.gc_next = node; |
| 203 | list->gc.gc_prev = node; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 204 | } |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 205 | #endif |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 206 | |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 207 | /* Remove `node` from the gc list it's currently in. */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 208 | static void |
| 209 | gc_list_remove(PyGC_Head *node) |
| 210 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 211 | node->gc.gc_prev->gc.gc_next = node->gc.gc_next; |
| 212 | node->gc.gc_next->gc.gc_prev = node->gc.gc_prev; |
| 213 | node->gc.gc_next = NULL; /* object is not currently tracked */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 214 | } |
| 215 | |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 216 | /* Move `node` from the gc list it's currently in (which is not explicitly |
| 217 | * named here) to the end of `list`. This is semantically the same as |
| 218 | * gc_list_remove(node) followed by gc_list_append(node, list). |
| 219 | */ |
| 220 | static void |
| 221 | gc_list_move(PyGC_Head *node, PyGC_Head *list) |
| 222 | { |
Tim Peters | bc1d1b8 | 2004-11-01 16:39:57 +0000 | [diff] [blame] | 223 | PyGC_Head *new_prev; |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 224 | PyGC_Head *current_prev = node->gc.gc_prev; |
| 225 | PyGC_Head *current_next = node->gc.gc_next; |
Tim Peters | bc1d1b8 | 2004-11-01 16:39:57 +0000 | [diff] [blame] | 226 | /* Unlink from current list. */ |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 227 | current_prev->gc.gc_next = current_next; |
| 228 | current_next->gc.gc_prev = current_prev; |
Tim Peters | bc1d1b8 | 2004-11-01 16:39:57 +0000 | [diff] [blame] | 229 | /* Relink at end of new list. */ |
| 230 | new_prev = node->gc.gc_prev = list->gc.gc_prev; |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 231 | new_prev->gc.gc_next = list->gc.gc_prev = node; |
Tim Peters | bc1d1b8 | 2004-11-01 16:39:57 +0000 | [diff] [blame] | 232 | node->gc.gc_next = list; |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 233 | } |
| 234 | |
| 235 | /* append list `from` onto list `to`; `from` becomes an empty list */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 236 | static void |
| 237 | gc_list_merge(PyGC_Head *from, PyGC_Head *to) |
| 238 | { |
| 239 | PyGC_Head *tail; |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 240 | assert(from != to); |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 241 | if (!gc_list_is_empty(from)) { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 242 | tail = to->gc.gc_prev; |
| 243 | tail->gc.gc_next = from->gc.gc_next; |
| 244 | tail->gc.gc_next->gc.gc_prev = tail; |
| 245 | to->gc.gc_prev = from->gc.gc_prev; |
| 246 | to->gc.gc_prev->gc.gc_next = to; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 247 | } |
| 248 | gc_list_init(from); |
| 249 | } |
| 250 | |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 251 | static Py_ssize_t |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 252 | gc_list_size(PyGC_Head *list) |
| 253 | { |
| 254 | PyGC_Head *gc; |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 255 | Py_ssize_t n = 0; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 256 | 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] | 257 | n++; |
| 258 | } |
| 259 | return n; |
| 260 | } |
| 261 | |
Tim Peters | 259272b | 2003-04-06 19:41:39 +0000 | [diff] [blame] | 262 | /* Append objects in a GC list to a Python list. |
| 263 | * Return 0 if all OK, < 0 if error (out of memory for list). |
| 264 | */ |
| 265 | static int |
| 266 | append_objects(PyObject *py_list, PyGC_Head *gc_list) |
| 267 | { |
| 268 | PyGC_Head *gc; |
| 269 | for (gc = gc_list->gc.gc_next; gc != gc_list; gc = gc->gc.gc_next) { |
| 270 | PyObject *op = FROM_GC(gc); |
| 271 | if (op != py_list) { |
| 272 | if (PyList_Append(py_list, op)) { |
| 273 | return -1; /* exception */ |
| 274 | } |
| 275 | } |
| 276 | } |
| 277 | return 0; |
| 278 | } |
| 279 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 280 | /*** end of list stuff ***/ |
| 281 | |
| 282 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 283 | /* Set all gc_refs = ob_refcnt. After this, gc_refs is > 0 for all objects |
| 284 | * in containers, and is GC_REACHABLE for all tracked gc objects not in |
| 285 | * containers. |
Tim Peters | 8839617 | 2002-06-30 17:56:40 +0000 | [diff] [blame] | 286 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 287 | static void |
| 288 | update_refs(PyGC_Head *containers) |
| 289 | { |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 290 | PyGC_Head *gc = containers->gc.gc_next; |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 291 | for (; gc != containers; gc = gc->gc.gc_next) { |
| 292 | assert(gc->gc.gc_refs == GC_REACHABLE); |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 293 | gc->gc.gc_refs = Py_REFCNT(FROM_GC(gc)); |
Tim Peters | 780c497 | 2003-11-14 00:01:17 +0000 | [diff] [blame] | 294 | /* Python's cyclic gc should never see an incoming refcount |
| 295 | * of 0: if something decref'ed to 0, it should have been |
| 296 | * deallocated immediately at that time. |
| 297 | * Possible cause (if the assert triggers): a tp_dealloc |
| 298 | * routine left a gc-aware object tracked during its teardown |
| 299 | * phase, and did something-- or allowed something to happen -- |
| 300 | * that called back into Python. gc can trigger then, and may |
| 301 | * see the still-tracked dying object. Before this assert |
| 302 | * was added, such mistakes went on to allow gc to try to |
| 303 | * delete the object again. In a debug build, that caused |
| 304 | * a mysterious segfault, when _Py_ForgetReference tried |
| 305 | * to remove the object from the doubly-linked list of all |
| 306 | * objects a second time. In a release build, an actual |
| 307 | * double deallocation occurred, which leads to corruption |
| 308 | * of the allocator's internal bookkeeping pointers. That's |
| 309 | * so serious that maybe this should be a release-build |
| 310 | * check instead of an assert? |
| 311 | */ |
| 312 | assert(gc->gc.gc_refs != 0); |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 313 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 314 | } |
| 315 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 316 | /* A traversal callback for subtract_refs. */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 317 | static int |
| 318 | visit_decref(PyObject *op, void *data) |
| 319 | { |
Tim Peters | 93cd83e | 2002-06-30 21:31:03 +0000 | [diff] [blame] | 320 | assert(op != NULL); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 321 | if (PyObject_IS_GC(op)) { |
| 322 | PyGC_Head *gc = AS_GC(op); |
| 323 | /* We're only interested in gc_refs for objects in the |
| 324 | * generation being collected, which can be recognized |
| 325 | * because only they have positive gc_refs. |
| 326 | */ |
Tim Peters | aab713b | 2002-07-02 22:15:28 +0000 | [diff] [blame] | 327 | assert(gc->gc.gc_refs != 0); /* else refcount was too small */ |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 328 | if (gc->gc.gc_refs > 0) |
| 329 | gc->gc.gc_refs--; |
| 330 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 331 | return 0; |
| 332 | } |
| 333 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 334 | /* Subtract internal references from gc_refs. After this, gc_refs is >= 0 |
| 335 | * for all objects in containers, and is GC_REACHABLE for all tracked gc |
| 336 | * objects not in containers. The ones with gc_refs > 0 are directly |
| 337 | * reachable from outside containers, and so can't be collected. |
| 338 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 339 | static void |
| 340 | subtract_refs(PyGC_Head *containers) |
| 341 | { |
| 342 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 343 | PyGC_Head *gc = containers->gc.gc_next; |
| 344 | for (; gc != containers; gc=gc->gc.gc_next) { |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 345 | traverse = Py_TYPE(FROM_GC(gc))->tp_traverse; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 346 | (void) traverse(FROM_GC(gc), |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 347 | (visitproc)visit_decref, |
| 348 | NULL); |
| 349 | } |
| 350 | } |
| 351 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 352 | /* A traversal callback for move_unreachable. */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 353 | static int |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 354 | visit_reachable(PyObject *op, PyGC_Head *reachable) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 355 | { |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 356 | if (PyObject_IS_GC(op)) { |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 357 | PyGC_Head *gc = AS_GC(op); |
Martin v. Löwis | 6db0e00 | 2006-03-01 16:56:25 +0000 | [diff] [blame] | 358 | const Py_ssize_t gc_refs = gc->gc.gc_refs; |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 359 | |
| 360 | if (gc_refs == 0) { |
| 361 | /* This is in move_unreachable's 'young' list, but |
| 362 | * the traversal hasn't yet gotten to it. All |
| 363 | * we need to do is tell move_unreachable that it's |
| 364 | * reachable. |
| 365 | */ |
| 366 | gc->gc.gc_refs = 1; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 367 | } |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 368 | else if (gc_refs == GC_TENTATIVELY_UNREACHABLE) { |
| 369 | /* This had gc_refs = 0 when move_unreachable got |
| 370 | * to it, but turns out it's reachable after all. |
| 371 | * Move it back to move_unreachable's 'young' list, |
| 372 | * and move_unreachable will eventually get to it |
| 373 | * again. |
| 374 | */ |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 375 | gc_list_move(gc, reachable); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 376 | gc->gc.gc_refs = 1; |
| 377 | } |
| 378 | /* Else there's nothing to do. |
| 379 | * If gc_refs > 0, it must be in move_unreachable's 'young' |
| 380 | * list, and move_unreachable will eventually get to it. |
| 381 | * If gc_refs == GC_REACHABLE, it's either in some other |
| 382 | * generation so we don't care about it, or move_unreachable |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 383 | * already dealt with it. |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 384 | * If gc_refs == GC_UNTRACKED, it must be ignored. |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 385 | */ |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 386 | else { |
| 387 | assert(gc_refs > 0 |
| 388 | || gc_refs == GC_REACHABLE |
| 389 | || gc_refs == GC_UNTRACKED); |
| 390 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 391 | } |
| 392 | return 0; |
| 393 | } |
| 394 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 395 | /* Move the unreachable objects from young to unreachable. After this, |
| 396 | * all objects in young have gc_refs = GC_REACHABLE, and all objects in |
| 397 | * unreachable have gc_refs = GC_TENTATIVELY_UNREACHABLE. All tracked |
| 398 | * gc objects not in young or unreachable still have gc_refs = GC_REACHABLE. |
| 399 | * All objects in young after this are directly or indirectly reachable |
| 400 | * from outside the original young; and all objects in unreachable are |
| 401 | * not. |
Tim Peters | 8839617 | 2002-06-30 17:56:40 +0000 | [diff] [blame] | 402 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 403 | static void |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 404 | move_unreachable(PyGC_Head *young, PyGC_Head *unreachable) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 405 | { |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 406 | PyGC_Head *gc = young->gc.gc_next; |
| 407 | |
| 408 | /* Invariants: all objects "to the left" of us in young have gc_refs |
| 409 | * = GC_REACHABLE, and are indeed reachable (directly or indirectly) |
| 410 | * from outside the young list as it was at entry. All other objects |
| 411 | * from the original young "to the left" of us are in unreachable now, |
| 412 | * and have gc_refs = GC_TENTATIVELY_UNREACHABLE. All objects to the |
| 413 | * left of us in 'young' now have been scanned, and no objects here |
| 414 | * or to the right have been scanned yet. |
| 415 | */ |
| 416 | |
| 417 | while (gc != young) { |
| 418 | PyGC_Head *next; |
| 419 | |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 420 | if (gc->gc.gc_refs) { |
| 421 | /* gc is definitely reachable from outside the |
| 422 | * original 'young'. Mark it as such, and traverse |
| 423 | * its pointers to find any other objects that may |
| 424 | * be directly reachable from it. Note that the |
| 425 | * call to tp_traverse may append objects to young, |
| 426 | * so we have to wait until it returns to determine |
| 427 | * the next object to visit. |
| 428 | */ |
| 429 | PyObject *op = FROM_GC(gc); |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 430 | traverseproc traverse = Py_TYPE(op)->tp_traverse; |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 431 | assert(gc->gc.gc_refs > 0); |
| 432 | gc->gc.gc_refs = GC_REACHABLE; |
| 433 | (void) traverse(op, |
| 434 | (visitproc)visit_reachable, |
| 435 | (void *)young); |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 436 | next = gc->gc.gc_next; |
| 437 | if (PyTuple_CheckExact(op)) { |
| 438 | _PyTuple_MaybeUntrack(op); |
| 439 | } |
| 440 | else if (PyDict_CheckExact(op)) { |
| 441 | _PyDict_MaybeUntrack(op); |
| 442 | } |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 443 | } |
| 444 | else { |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 445 | /* This *may* be unreachable. To make progress, |
| 446 | * assume it is. gc isn't directly reachable from |
| 447 | * any object we've already traversed, but may be |
| 448 | * reachable from an object we haven't gotten to yet. |
| 449 | * visit_reachable will eventually move gc back into |
| 450 | * young if that's so, and we'll see it again. |
| 451 | */ |
| 452 | next = gc->gc.gc_next; |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 453 | gc_list_move(gc, unreachable); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 454 | gc->gc.gc_refs = GC_TENTATIVELY_UNREACHABLE; |
| 455 | } |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 456 | gc = next; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 457 | } |
| 458 | } |
| 459 | |
Amaury Forgeot d'Arc | ad8dcd5 | 2007-12-10 23:58:35 +0000 | [diff] [blame] | 460 | /* Return true if object has a finalization method. */ |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame] | 461 | static int |
| 462 | has_finalizer(PyObject *op) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 463 | { |
Guido van Rossum | 50e9fb9 | 2006-08-17 05:42:55 +0000 | [diff] [blame] | 464 | if (PyGen_CheckExact(op)) |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 465 | return PyGen_NeedsFinalizing((PyGenObject *)op); |
| 466 | else |
Thomas Wouters | 3dfc3c1 | 2006-08-21 22:15:41 +0000 | [diff] [blame] | 467 | return op->ob_type->tp_del != NULL; |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame] | 468 | } |
| 469 | |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 470 | /* Move the objects in unreachable with __del__ methods into `finalizers`. |
| 471 | * Objects moved into `finalizers` have gc_refs set to GC_REACHABLE; the |
| 472 | * objects remaining in unreachable are left at GC_TENTATIVELY_UNREACHABLE. |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 473 | */ |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame] | 474 | static void |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 475 | move_finalizers(PyGC_Head *unreachable, PyGC_Head *finalizers) |
Neil Schemenauer | a765c12 | 2001-11-01 17:35:23 +0000 | [diff] [blame] | 476 | { |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 477 | PyGC_Head *gc; |
| 478 | PyGC_Head *next; |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 479 | |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 480 | /* March over unreachable. Move objects with finalizers into |
| 481 | * `finalizers`. |
| 482 | */ |
| 483 | for (gc = unreachable->gc.gc_next; gc != unreachable; gc = next) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 484 | PyObject *op = FROM_GC(gc); |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 485 | |
Tim Peters | f6ae7a4 | 2003-04-05 18:40:50 +0000 | [diff] [blame] | 486 | assert(IS_TENTATIVELY_UNREACHABLE(op)); |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 487 | next = gc->gc.gc_next; |
Tim Peters | f6ae7a4 | 2003-04-05 18:40:50 +0000 | [diff] [blame] | 488 | |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 489 | if (has_finalizer(op)) { |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 490 | gc_list_move(gc, finalizers); |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 491 | gc->gc.gc_refs = GC_REACHABLE; |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 492 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 493 | } |
| 494 | } |
| 495 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 496 | /* A traversal callback for move_finalizer_reachable. */ |
| 497 | static int |
| 498 | visit_move(PyObject *op, PyGC_Head *tolist) |
| 499 | { |
| 500 | if (PyObject_IS_GC(op)) { |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 501 | if (IS_TENTATIVELY_UNREACHABLE(op)) { |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 502 | PyGC_Head *gc = AS_GC(op); |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 503 | gc_list_move(gc, tolist); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 504 | gc->gc.gc_refs = GC_REACHABLE; |
| 505 | } |
| 506 | } |
| 507 | return 0; |
| 508 | } |
| 509 | |
| 510 | /* Move objects that are reachable from finalizers, from the unreachable set |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 511 | * into finalizers set. |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 512 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 513 | static void |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 514 | move_finalizer_reachable(PyGC_Head *finalizers) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 515 | { |
| 516 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 517 | PyGC_Head *gc = finalizers->gc.gc_next; |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 518 | for (; gc != finalizers; gc = gc->gc.gc_next) { |
| 519 | /* Note that the finalizers list may grow during this. */ |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 520 | traverse = Py_TYPE(FROM_GC(gc))->tp_traverse; |
Tim Peters | 8839617 | 2002-06-30 17:56:40 +0000 | [diff] [blame] | 521 | (void) traverse(FROM_GC(gc), |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 522 | (visitproc)visit_move, |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 523 | (void *)finalizers); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 524 | } |
| 525 | } |
| 526 | |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 527 | /* Clear all weakrefs to unreachable objects, and if such a weakref has a |
| 528 | * callback, invoke it if necessary. Note that it's possible for such |
| 529 | * weakrefs to be outside the unreachable set -- indeed, those are precisely |
| 530 | * the weakrefs whose callbacks must be invoked. See gc_weakref.txt for |
| 531 | * overview & some details. Some weakrefs with callbacks may be reclaimed |
| 532 | * directly by this routine; the number reclaimed is the return value. Other |
| 533 | * weakrefs with callbacks may be moved into the `old` generation. Objects |
| 534 | * moved into `old` have gc_refs set to GC_REACHABLE; the objects remaining in |
| 535 | * unreachable are left at GC_TENTATIVELY_UNREACHABLE. When this returns, |
| 536 | * no object in `unreachable` is weakly referenced anymore. |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 537 | */ |
| 538 | static int |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 539 | handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old) |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 540 | { |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 541 | PyGC_Head *gc; |
| 542 | PyObject *op; /* generally FROM_GC(gc) */ |
| 543 | PyWeakReference *wr; /* generally a cast of op */ |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 544 | PyGC_Head wrcb_to_call; /* weakrefs with callbacks to call */ |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 545 | PyGC_Head *next; |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 546 | int num_freed = 0; |
| 547 | |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 548 | gc_list_init(&wrcb_to_call); |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 549 | |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 550 | /* Clear all weakrefs to the objects in unreachable. If such a weakref |
| 551 | * also has a callback, move it into `wrcb_to_call` if the callback |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 552 | * needs to be invoked. Note that we cannot invoke any callbacks until |
| 553 | * all weakrefs to unreachable objects are cleared, lest the callback |
| 554 | * resurrect an unreachable object via a still-active weakref. We |
| 555 | * make another pass over wrcb_to_call, invoking callbacks, after this |
| 556 | * pass completes. |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 557 | */ |
| 558 | for (gc = unreachable->gc.gc_next; gc != unreachable; gc = next) { |
| 559 | PyWeakReference **wrlist; |
| 560 | |
| 561 | op = FROM_GC(gc); |
| 562 | assert(IS_TENTATIVELY_UNREACHABLE(op)); |
| 563 | next = gc->gc.gc_next; |
| 564 | |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 565 | if (! PyType_SUPPORTS_WEAKREFS(Py_TYPE(op))) |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 566 | continue; |
| 567 | |
| 568 | /* It supports weakrefs. Does it have any? */ |
| 569 | wrlist = (PyWeakReference **) |
| 570 | PyObject_GET_WEAKREFS_LISTPTR(op); |
| 571 | |
| 572 | /* `op` may have some weakrefs. March over the list, clear |
| 573 | * all the weakrefs, and move the weakrefs with callbacks |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 574 | * that must be called into wrcb_to_call. |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 575 | */ |
| 576 | for (wr = *wrlist; wr != NULL; wr = *wrlist) { |
| 577 | PyGC_Head *wrasgc; /* AS_GC(wr) */ |
| 578 | |
| 579 | /* _PyWeakref_ClearRef clears the weakref but leaves |
| 580 | * the callback pointer intact. Obscure: it also |
| 581 | * changes *wrlist. |
| 582 | */ |
| 583 | assert(wr->wr_object == op); |
| 584 | _PyWeakref_ClearRef(wr); |
| 585 | assert(wr->wr_object == Py_None); |
| 586 | if (wr->wr_callback == NULL) |
| 587 | continue; /* no callback */ |
| 588 | |
| 589 | /* Headache time. `op` is going away, and is weakly referenced by |
| 590 | * `wr`, which has a callback. Should the callback be invoked? If wr |
| 591 | * is also trash, no: |
| 592 | * |
| 593 | * 1. There's no need to call it. The object and the weakref are |
| 594 | * both going away, so it's legitimate to pretend the weakref is |
| 595 | * going away first. The user has to ensure a weakref outlives its |
| 596 | * referent if they want a guarantee that the wr callback will get |
| 597 | * invoked. |
| 598 | * |
| 599 | * 2. It may be catastrophic to call it. If the callback is also in |
| 600 | * cyclic trash (CT), then although the CT is unreachable from |
| 601 | * outside the current generation, CT may be reachable from the |
| 602 | * callback. Then the callback could resurrect insane objects. |
| 603 | * |
| 604 | * Since the callback is never needed and may be unsafe in this case, |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 605 | * wr is simply left in the unreachable set. Note that because we |
| 606 | * already called _PyWeakref_ClearRef(wr), its callback will never |
| 607 | * trigger. |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 608 | * |
| 609 | * OTOH, if wr isn't part of CT, we should invoke the callback: the |
| 610 | * weakref outlived the trash. Note that since wr isn't CT in this |
| 611 | * case, its callback can't be CT either -- wr acted as an external |
| 612 | * root to this generation, and therefore its callback did too. So |
| 613 | * nothing in CT is reachable from the callback either, so it's hard |
| 614 | * to imagine how calling it later could create a problem for us. wr |
| 615 | * is moved to wrcb_to_call in this case. |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 616 | */ |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 617 | if (IS_TENTATIVELY_UNREACHABLE(wr)) |
| 618 | continue; |
| 619 | assert(IS_REACHABLE(wr)); |
| 620 | |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 621 | /* Create a new reference so that wr can't go away |
| 622 | * before we can process it again. |
| 623 | */ |
| 624 | Py_INCREF(wr); |
| 625 | |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 626 | /* Move wr to wrcb_to_call, for the next pass. */ |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 627 | wrasgc = AS_GC(wr); |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 628 | assert(wrasgc != next); /* wrasgc is reachable, but |
| 629 | next isn't, so they can't |
| 630 | be the same */ |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 631 | gc_list_move(wrasgc, &wrcb_to_call); |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 632 | } |
| 633 | } |
| 634 | |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 635 | /* Invoke the callbacks we decided to honor. It's safe to invoke them |
| 636 | * because they can't reference unreachable objects. |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 637 | */ |
| 638 | while (! gc_list_is_empty(&wrcb_to_call)) { |
| 639 | PyObject *temp; |
| 640 | PyObject *callback; |
| 641 | |
| 642 | gc = wrcb_to_call.gc.gc_next; |
| 643 | op = FROM_GC(gc); |
| 644 | assert(IS_REACHABLE(op)); |
| 645 | assert(PyWeakref_Check(op)); |
| 646 | wr = (PyWeakReference *)op; |
| 647 | callback = wr->wr_callback; |
| 648 | assert(callback != NULL); |
| 649 | |
| 650 | /* copy-paste of weakrefobject.c's handle_callback() */ |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 651 | temp = PyObject_CallFunctionObjArgs(callback, wr, NULL); |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 652 | if (temp == NULL) |
| 653 | PyErr_WriteUnraisable(callback); |
| 654 | else |
| 655 | Py_DECREF(temp); |
| 656 | |
| 657 | /* Give up the reference we created in the first pass. When |
| 658 | * op's refcount hits 0 (which it may or may not do right now), |
Tim Peters | cc2a866 | 2004-10-31 22:12:43 +0000 | [diff] [blame] | 659 | * op's tp_dealloc will decref op->wr_callback too. Note |
| 660 | * that the refcount probably will hit 0 now, and because this |
| 661 | * weakref was reachable to begin with, gc didn't already |
| 662 | * add it to its count of freed objects. Example: a reachable |
| 663 | * weak value dict maps some key to this reachable weakref. |
| 664 | * The callback removes this key->weakref mapping from the |
| 665 | * dict, leaving no other references to the weakref (excepting |
| 666 | * ours). |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 667 | */ |
| 668 | Py_DECREF(op); |
| 669 | if (wrcb_to_call.gc.gc_next == gc) { |
| 670 | /* object is still alive -- move it */ |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 671 | gc_list_move(gc, old); |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 672 | } |
| 673 | else |
| 674 | ++num_freed; |
| 675 | } |
| 676 | |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 677 | return num_freed; |
| 678 | } |
| 679 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 680 | static void |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 681 | debug_cycle(char *msg, PyObject *op) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 682 | { |
Amaury Forgeot d'Arc | ad8dcd5 | 2007-12-10 23:58:35 +0000 | [diff] [blame] | 683 | PySys_WriteStderr("gc: %.100s <%.100s %p>\n", |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 684 | msg, Py_TYPE(op)->tp_name, op); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 685 | } |
| 686 | |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 687 | /* Handle uncollectable garbage (cycles with finalizers, and stuff reachable |
| 688 | * only from such cycles). |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 689 | * If DEBUG_SAVEALL, all objects in finalizers are appended to the module |
| 690 | * garbage list (a Python list), else only the objects in finalizers with |
| 691 | * __del__ methods are appended to garbage. All objects in finalizers are |
| 692 | * merged into the old list regardless. |
Tim Peters | 259272b | 2003-04-06 19:41:39 +0000 | [diff] [blame] | 693 | * Returns 0 if all OK, <0 on error (out of memory to grow the garbage list). |
| 694 | * The finalizers list is made empty on a successful return. |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 695 | */ |
Tim Peters | 259272b | 2003-04-06 19:41:39 +0000 | [diff] [blame] | 696 | static int |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 697 | handle_finalizers(PyGC_Head *finalizers, PyGC_Head *old) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 698 | { |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 699 | PyGC_Head *gc = finalizers->gc.gc_next; |
| 700 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 701 | if (garbage == NULL) { |
| 702 | garbage = PyList_New(0); |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 703 | if (garbage == NULL) |
| 704 | Py_FatalError("gc couldn't create gc.garbage list"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 705 | } |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 706 | for (; gc != finalizers; gc = gc->gc.gc_next) { |
| 707 | PyObject *op = FROM_GC(gc); |
| 708 | |
| 709 | if ((debug & DEBUG_SAVEALL) || has_finalizer(op)) { |
| 710 | if (PyList_Append(garbage, op) < 0) |
| 711 | return -1; |
| 712 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 713 | } |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 714 | |
Tim Peters | 259272b | 2003-04-06 19:41:39 +0000 | [diff] [blame] | 715 | gc_list_merge(finalizers, old); |
| 716 | return 0; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 717 | } |
| 718 | |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 719 | /* Break reference cycles by clearing the containers involved. This is |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 720 | * tricky business as the lists can be changing and we don't know which |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 721 | * objects may be freed. It is possible I screwed something up here. |
| 722 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 723 | static void |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 724 | delete_garbage(PyGC_Head *collectable, PyGC_Head *old) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 725 | { |
| 726 | inquiry clear; |
| 727 | |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 728 | while (!gc_list_is_empty(collectable)) { |
| 729 | PyGC_Head *gc = collectable->gc.gc_next; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 730 | PyObject *op = FROM_GC(gc); |
Tim Peters | 8839617 | 2002-06-30 17:56:40 +0000 | [diff] [blame] | 731 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 732 | assert(IS_TENTATIVELY_UNREACHABLE(op)); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 733 | if (debug & DEBUG_SAVEALL) { |
| 734 | PyList_Append(garbage, op); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 735 | } |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 736 | else { |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 737 | if ((clear = Py_TYPE(op)->tp_clear) != NULL) { |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 738 | Py_INCREF(op); |
Jeremy Hylton | 8a13518 | 2002-06-06 23:23:55 +0000 | [diff] [blame] | 739 | clear(op); |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 740 | Py_DECREF(op); |
| 741 | } |
| 742 | } |
Jeremy Hylton | ce136e9 | 2003-04-04 19:59:06 +0000 | [diff] [blame] | 743 | if (collectable->gc.gc_next == gc) { |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 744 | /* object is still alive, move it, it may die later */ |
Tim Peters | e2d5918 | 2004-11-01 01:39:08 +0000 | [diff] [blame] | 745 | gc_list_move(gc, old); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 746 | gc->gc.gc_refs = GC_REACHABLE; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 747 | } |
| 748 | } |
| 749 | } |
| 750 | |
Christian Heimes | a156e09 | 2008-02-16 07:38:31 +0000 | [diff] [blame] | 751 | /* Clear all free lists |
| 752 | * All free lists are cleared during the collection of the highest generation. |
| 753 | * Allocated items in the free list may keep a pymalloc arena occupied. |
| 754 | * Clearing the free lists may give back memory to the OS earlier. |
| 755 | */ |
| 756 | static void |
| 757 | clear_freelists(void) |
| 758 | { |
| 759 | (void)PyMethod_ClearFreeList(); |
| 760 | (void)PyFrame_ClearFreeList(); |
| 761 | (void)PyCFunction_ClearFreeList(); |
| 762 | (void)PyTuple_ClearFreeList(); |
| 763 | (void)PyUnicode_ClearFreeList(); |
Georg Brandl | 2ee470f | 2008-07-16 12:55:28 +0000 | [diff] [blame] | 764 | (void)PyFloat_ClearFreeList(); |
Christian Heimes | a156e09 | 2008-02-16 07:38:31 +0000 | [diff] [blame] | 765 | } |
| 766 | |
Antoine Pitrou | 621601a | 2008-12-17 23:18:19 +0000 | [diff] [blame] | 767 | static double |
| 768 | get_time(void) |
| 769 | { |
| 770 | double result = 0; |
| 771 | if (tmod != NULL) { |
| 772 | PyObject *f = PyObject_CallMethod(tmod, "time", NULL); |
| 773 | if (f == NULL) { |
| 774 | PyErr_Clear(); |
| 775 | } |
| 776 | else { |
| 777 | if (PyFloat_Check(f)) |
| 778 | result = PyFloat_AsDouble(f); |
| 779 | Py_DECREF(f); |
| 780 | } |
| 781 | } |
| 782 | return result; |
| 783 | } |
| 784 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 785 | /* This is the main function. Read this to understand how the |
| 786 | * collection process works. */ |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 787 | static Py_ssize_t |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 788 | collect(int generation) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 789 | { |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 790 | int i; |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 791 | Py_ssize_t m = 0; /* # objects collected */ |
| 792 | Py_ssize_t n = 0; /* # unreachable objects that couldn't be collected */ |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 793 | PyGC_Head *young; /* the generation we are examining */ |
| 794 | PyGC_Head *old; /* next older generation */ |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 795 | PyGC_Head unreachable; /* non-problematic unreachable trash */ |
| 796 | PyGC_Head finalizers; /* objects with, & reachable from, __del__ */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 797 | PyGC_Head *gc; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 798 | double t1 = 0.0; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 799 | |
Tim Peters | 93ad66d | 2003-04-05 17:15:44 +0000 | [diff] [blame] | 800 | if (delstr == NULL) { |
Martin v. Löwis | 5b22213 | 2007-06-10 09:51:05 +0000 | [diff] [blame] | 801 | delstr = PyUnicode_InternFromString("__del__"); |
Tim Peters | 93ad66d | 2003-04-05 17:15:44 +0000 | [diff] [blame] | 802 | if (delstr == NULL) |
| 803 | Py_FatalError("gc couldn't allocate \"__del__\""); |
| 804 | } |
| 805 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 806 | if (debug & DEBUG_STATS) { |
Antoine Pitrou | 621601a | 2008-12-17 23:18:19 +0000 | [diff] [blame] | 807 | t1 = get_time(); |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 808 | PySys_WriteStderr("gc: collecting generation %d...\n", |
| 809 | generation); |
| 810 | PySys_WriteStderr("gc: objects in each generation:"); |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 811 | for (i = 0; i < NUM_GENERATIONS; i++) |
| 812 | PySys_WriteStderr(" %" PY_FORMAT_SIZE_T "d", |
| 813 | gc_list_size(GEN_HEAD(i))); |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 814 | PySys_WriteStderr("\n"); |
| 815 | } |
| 816 | |
| 817 | /* update collection and allocation counters */ |
| 818 | if (generation+1 < NUM_GENERATIONS) |
| 819 | generations[generation+1].count += 1; |
| 820 | for (i = 0; i <= generation; i++) |
Neil Schemenauer | c905164 | 2002-06-28 19:16:04 +0000 | [diff] [blame] | 821 | generations[i].count = 0; |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 822 | |
| 823 | /* merge younger generations with one we are currently collecting */ |
| 824 | for (i = 0; i < generation; i++) { |
| 825 | gc_list_merge(GEN_HEAD(i), GEN_HEAD(generation)); |
| 826 | } |
| 827 | |
| 828 | /* handy references */ |
| 829 | young = GEN_HEAD(generation); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 830 | if (generation < NUM_GENERATIONS-1) |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 831 | old = GEN_HEAD(generation+1); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 832 | else |
| 833 | old = young; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 834 | |
| 835 | /* Using ob_refcnt and gc_refs, calculate which objects in the |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 836 | * container set are reachable from outside the set (i.e., have a |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 837 | * refcount greater than 0 when all the references within the |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 838 | * set are taken into account). |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 839 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 840 | update_refs(young); |
| 841 | subtract_refs(young); |
| 842 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 843 | /* Leave everything reachable from outside young in young, and move |
| 844 | * everything else (in young) to unreachable. |
| 845 | * NOTE: This used to move the reachable objects into a reachable |
| 846 | * set instead. But most things usually turn out to be reachable, |
| 847 | * so it's more efficient to move the unreachable things. |
| 848 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 849 | gc_list_init(&unreachable); |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 850 | move_unreachable(young, &unreachable); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 851 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 852 | /* Move reachable objects to next generation. */ |
Antoine Pitrou | 14b78f5 | 2009-01-09 22:27:08 +0000 | [diff] [blame] | 853 | if (young != old) { |
| 854 | if (generation == NUM_GENERATIONS - 2) { |
| 855 | long_lived_pending += gc_list_size(young); |
| 856 | } |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 857 | gc_list_merge(young, old); |
Antoine Pitrou | 14b78f5 | 2009-01-09 22:27:08 +0000 | [diff] [blame] | 858 | } |
| 859 | else { |
| 860 | long_lived_pending = 0; |
| 861 | long_lived_total = gc_list_size(young); |
| 862 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 863 | |
Tim Peters | 19b74c7 | 2002-07-01 03:52:19 +0000 | [diff] [blame] | 864 | /* All objects in unreachable are trash, but objects reachable from |
| 865 | * finalizers can't safely be deleted. Python programmers should take |
| 866 | * care not to create such things. For Python, finalizers means |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 867 | * instance objects with __del__ methods. Weakrefs with callbacks |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 868 | * can also call arbitrary Python code but they will be dealt with by |
| 869 | * handle_weakrefs(). |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 870 | */ |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 871 | gc_list_init(&finalizers); |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 872 | move_finalizers(&unreachable, &finalizers); |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 873 | /* finalizers contains the unreachable objects with a finalizer; |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 874 | * unreachable objects reachable *from* those are also uncollectable, |
| 875 | * and we move those into the finalizers list too. |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 876 | */ |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 877 | move_finalizer_reachable(&finalizers); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 878 | |
| 879 | /* Collect statistics on collectable objects found and print |
Tim Peters | 403a203 | 2003-11-20 21:21:46 +0000 | [diff] [blame] | 880 | * debugging information. |
| 881 | */ |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 882 | for (gc = unreachable.gc.gc_next; gc != &unreachable; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 883 | gc = gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 884 | m++; |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 885 | if (debug & DEBUG_COLLECTABLE) { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 886 | debug_cycle("collectable", FROM_GC(gc)); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 887 | } |
| 888 | } |
Tim Peters | ead8b7a | 2004-10-30 23:09:22 +0000 | [diff] [blame] | 889 | |
| 890 | /* Clear weakrefs and invoke callbacks as necessary. */ |
| 891 | m += handle_weakrefs(&unreachable, old); |
| 892 | |
Tim Peters | fb2ab4d | 2003-04-07 22:41:24 +0000 | [diff] [blame] | 893 | /* Call tp_clear on objects in the unreachable set. This will cause |
| 894 | * the reference cycles to be broken. It may also cause some objects |
| 895 | * in finalizers to be freed. |
| 896 | */ |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 897 | delete_garbage(&unreachable, old); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 898 | |
| 899 | /* Collect statistics on uncollectable objects found and print |
| 900 | * debugging information. */ |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 901 | for (gc = finalizers.gc.gc_next; |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 902 | gc != &finalizers; |
| 903 | gc = gc->gc.gc_next) { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 904 | n++; |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 905 | if (debug & DEBUG_UNCOLLECTABLE) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 906 | debug_cycle("uncollectable", FROM_GC(gc)); |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 907 | } |
Jeremy Hylton | 0625777 | 2000-08-31 15:10:24 +0000 | [diff] [blame] | 908 | if (debug & DEBUG_STATS) { |
Antoine Pitrou | 621601a | 2008-12-17 23:18:19 +0000 | [diff] [blame] | 909 | double t2 = get_time(); |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 910 | if (m == 0 && n == 0) |
Antoine Pitrou | 621601a | 2008-12-17 23:18:19 +0000 | [diff] [blame] | 911 | PySys_WriteStderr("gc: done"); |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 912 | else |
Neal Norwitz | e22373d | 2006-03-06 23:31:56 +0000 | [diff] [blame] | 913 | PySys_WriteStderr( |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 914 | "gc: done, " |
| 915 | "%" PY_FORMAT_SIZE_T "d unreachable, " |
Antoine Pitrou | 621601a | 2008-12-17 23:18:19 +0000 | [diff] [blame] | 916 | "%" PY_FORMAT_SIZE_T "d uncollectable", |
Neal Norwitz | e22373d | 2006-03-06 23:31:56 +0000 | [diff] [blame] | 917 | n+m, n); |
Antoine Pitrou | 621601a | 2008-12-17 23:18:19 +0000 | [diff] [blame] | 918 | if (t1 && t2) { |
| 919 | PySys_WriteStderr(", %.4fs elapsed", t2-t1); |
| 920 | } |
| 921 | PySys_WriteStderr(".\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 922 | } |
| 923 | |
| 924 | /* Append instances in the uncollectable set to a Python |
| 925 | * reachable list of garbage. The programmer has to deal with |
Tim Peters | bf384c2 | 2003-04-06 00:11:39 +0000 | [diff] [blame] | 926 | * this if they insist on creating this type of structure. |
| 927 | */ |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 928 | (void)handle_finalizers(&finalizers, old); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 929 | |
Christian Heimes | a156e09 | 2008-02-16 07:38:31 +0000 | [diff] [blame] | 930 | /* Clear free list only during the collection of the higest |
| 931 | * generation */ |
| 932 | if (generation == NUM_GENERATIONS-1) { |
| 933 | clear_freelists(); |
| 934 | } |
| 935 | |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 936 | if (PyErr_Occurred()) { |
Tim Peters | f6b8045 | 2003-04-07 19:21:15 +0000 | [diff] [blame] | 937 | if (gc_str == NULL) |
Neal Norwitz | 53cbdaa | 2007-08-23 21:42:55 +0000 | [diff] [blame] | 938 | gc_str = PyUnicode_FromString("garbage collection"); |
Jeremy Hylton | b709df3 | 2000-09-01 02:47:25 +0000 | [diff] [blame] | 939 | PyErr_WriteUnraisable(gc_str); |
| 940 | Py_FatalError("unexpected exception during garbage collection"); |
| 941 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 942 | return n+m; |
| 943 | } |
| 944 | |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 945 | static Py_ssize_t |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 946 | collect_generations(void) |
| 947 | { |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 948 | int i; |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 949 | Py_ssize_t n = 0; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 950 | |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 951 | /* Find the oldest generation (higest numbered) where the count |
| 952 | * exceeds the threshold. Objects in the that generation and |
| 953 | * generations younger than it will be collected. */ |
| 954 | for (i = NUM_GENERATIONS-1; i >= 0; i--) { |
| 955 | if (generations[i].count > generations[i].threshold) { |
Antoine Pitrou | 14b78f5 | 2009-01-09 22:27:08 +0000 | [diff] [blame] | 956 | /* Avoid quadratic performance degradation in number |
| 957 | of tracked objects. See comments at the beginning |
| 958 | of this file, and issue #4074. |
| 959 | */ |
| 960 | if (i == NUM_GENERATIONS - 1 |
| 961 | && long_lived_pending < long_lived_total / 4) |
| 962 | continue; |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 963 | n = collect(i); |
| 964 | break; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 965 | } |
| 966 | } |
| 967 | return n; |
| 968 | } |
| 969 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 970 | PyDoc_STRVAR(gc_enable__doc__, |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 971 | "enable() -> None\n" |
| 972 | "\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 973 | "Enable automatic garbage collection.\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 974 | |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 975 | static PyObject * |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 976 | gc_enable(PyObject *self, PyObject *noargs) |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 977 | { |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 978 | enabled = 1; |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 979 | Py_INCREF(Py_None); |
| 980 | return Py_None; |
| 981 | } |
| 982 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 983 | PyDoc_STRVAR(gc_disable__doc__, |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 984 | "disable() -> None\n" |
| 985 | "\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 986 | "Disable automatic garbage collection.\n"); |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 987 | |
| 988 | static PyObject * |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 989 | gc_disable(PyObject *self, PyObject *noargs) |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 990 | { |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 991 | enabled = 0; |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 992 | Py_INCREF(Py_None); |
| 993 | return Py_None; |
| 994 | } |
| 995 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 996 | PyDoc_STRVAR(gc_isenabled__doc__, |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 997 | "isenabled() -> status\n" |
| 998 | "\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 999 | "Returns true if automatic garbage collection is enabled.\n"); |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1000 | |
| 1001 | static PyObject * |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1002 | gc_isenabled(PyObject *self, PyObject *noargs) |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1003 | { |
Raymond Hettinger | 674d56b | 2004-01-04 04:00:13 +0000 | [diff] [blame] | 1004 | return PyBool_FromLong((long)enabled); |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1005 | } |
| 1006 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1007 | PyDoc_STRVAR(gc_collect__doc__, |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1008 | "collect([generation]) -> n\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1009 | "\n" |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1010 | "With no arguments, run a full collection. The optional argument\n" |
| 1011 | "may be an integer specifying which generation to collect. A ValueError\n" |
| 1012 | "is raised if the generation number is invalid.\n\n" |
| 1013 | "The number of unreachable objects is returned.\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1014 | |
| 1015 | static PyObject * |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1016 | gc_collect(PyObject *self, PyObject *args, PyObject *kws) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1017 | { |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1018 | static char *keywords[] = {"generation", NULL}; |
| 1019 | int genarg = NUM_GENERATIONS - 1; |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 1020 | Py_ssize_t n; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1021 | |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1022 | if (!PyArg_ParseTupleAndKeywords(args, kws, "|i", keywords, &genarg)) |
| 1023 | return NULL; |
| 1024 | |
| 1025 | else if (genarg < 0 || genarg >= NUM_GENERATIONS) { |
| 1026 | PyErr_SetString(PyExc_ValueError, "invalid generation"); |
| 1027 | return NULL; |
| 1028 | } |
| 1029 | |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1030 | if (collecting) |
Neil Schemenauer | e8c40cb | 2001-10-31 23:09:35 +0000 | [diff] [blame] | 1031 | n = 0; /* already collecting, don't do anything */ |
Neil Schemenauer | e8c40cb | 2001-10-31 23:09:35 +0000 | [diff] [blame] | 1032 | else { |
| 1033 | collecting = 1; |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1034 | n = collect(genarg); |
Neil Schemenauer | e8c40cb | 2001-10-31 23:09:35 +0000 | [diff] [blame] | 1035 | collecting = 0; |
| 1036 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1037 | |
Christian Heimes | 217cfd1 | 2007-12-02 14:31:20 +0000 | [diff] [blame] | 1038 | return PyLong_FromSsize_t(n); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1039 | } |
| 1040 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1041 | PyDoc_STRVAR(gc_set_debug__doc__, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1042 | "set_debug(flags) -> None\n" |
| 1043 | "\n" |
| 1044 | "Set the garbage collection debugging flags. Debugging information is\n" |
| 1045 | "written to sys.stderr.\n" |
| 1046 | "\n" |
| 1047 | "flags is an integer and can have the following bits turned on:\n" |
| 1048 | "\n" |
| 1049 | " DEBUG_STATS - Print statistics during collection.\n" |
| 1050 | " DEBUG_COLLECTABLE - Print collectable objects found.\n" |
| 1051 | " DEBUG_UNCOLLECTABLE - Print unreachable but uncollectable objects found.\n" |
Neil Schemenauer | 544de1e | 2000-09-22 15:22:38 +0000 | [diff] [blame] | 1052 | " DEBUG_SAVEALL - Save objects to gc.garbage rather than freeing them.\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1053 | " DEBUG_LEAK - Debug leaking programs (everything but STATS).\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1054 | |
| 1055 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1056 | gc_set_debug(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1057 | { |
Neil Schemenauer | 7760cff | 2000-09-22 22:35:36 +0000 | [diff] [blame] | 1058 | if (!PyArg_ParseTuple(args, "i:set_debug", &debug)) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1059 | return NULL; |
| 1060 | |
| 1061 | Py_INCREF(Py_None); |
| 1062 | return Py_None; |
| 1063 | } |
| 1064 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1065 | PyDoc_STRVAR(gc_get_debug__doc__, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1066 | "get_debug() -> flags\n" |
| 1067 | "\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1068 | "Get the garbage collection debugging flags.\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1069 | |
| 1070 | static PyObject * |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1071 | gc_get_debug(PyObject *self, PyObject *noargs) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1072 | { |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1073 | return Py_BuildValue("i", debug); |
| 1074 | } |
| 1075 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1076 | PyDoc_STRVAR(gc_set_thresh__doc__, |
Neal Norwitz | 2a47c0f | 2002-01-29 00:53:41 +0000 | [diff] [blame] | 1077 | "set_threshold(threshold0, [threshold1, threshold2]) -> None\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1078 | "\n" |
| 1079 | "Sets the collection thresholds. Setting threshold0 to zero disables\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1080 | "collection.\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1081 | |
| 1082 | static PyObject * |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1083 | gc_set_thresh(PyObject *self, PyObject *args) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1084 | { |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1085 | int i; |
| 1086 | if (!PyArg_ParseTuple(args, "i|ii:set_threshold", |
| 1087 | &generations[0].threshold, |
| 1088 | &generations[1].threshold, |
| 1089 | &generations[2].threshold)) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1090 | return NULL; |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1091 | for (i = 2; i < NUM_GENERATIONS; i++) { |
| 1092 | /* generations higher than 2 get the same threshold */ |
| 1093 | generations[i].threshold = generations[2].threshold; |
| 1094 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1095 | |
| 1096 | Py_INCREF(Py_None); |
| 1097 | return Py_None; |
| 1098 | } |
| 1099 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1100 | PyDoc_STRVAR(gc_get_thresh__doc__, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1101 | "get_threshold() -> (threshold0, threshold1, threshold2)\n" |
| 1102 | "\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1103 | "Return the current collection thresholds\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1104 | |
| 1105 | static PyObject * |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1106 | gc_get_thresh(PyObject *self, PyObject *noargs) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1107 | { |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1108 | return Py_BuildValue("(iii)", |
| 1109 | generations[0].threshold, |
| 1110 | generations[1].threshold, |
| 1111 | generations[2].threshold); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1112 | } |
| 1113 | |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1114 | PyDoc_STRVAR(gc_get_count__doc__, |
| 1115 | "get_count() -> (count0, count1, count2)\n" |
| 1116 | "\n" |
| 1117 | "Return the current collection counts\n"); |
| 1118 | |
| 1119 | static PyObject * |
| 1120 | gc_get_count(PyObject *self, PyObject *noargs) |
| 1121 | { |
| 1122 | return Py_BuildValue("(iii)", |
| 1123 | generations[0].count, |
| 1124 | generations[1].count, |
| 1125 | generations[2].count); |
| 1126 | } |
| 1127 | |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1128 | static int |
Martin v. Löwis | 560da62 | 2001-11-24 09:24:51 +0000 | [diff] [blame] | 1129 | referrersvisit(PyObject* obj, PyObject *objs) |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1130 | { |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1131 | Py_ssize_t i; |
Martin v. Löwis | c8fe77b | 2001-11-29 18:08:31 +0000 | [diff] [blame] | 1132 | for (i = 0; i < PyTuple_GET_SIZE(objs); i++) |
| 1133 | if (PyTuple_GET_ITEM(objs, i) == obj) |
| 1134 | return 1; |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1135 | return 0; |
| 1136 | } |
| 1137 | |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 1138 | static int |
Martin v. Löwis | 560da62 | 2001-11-24 09:24:51 +0000 | [diff] [blame] | 1139 | gc_referrers_for(PyObject *objs, PyGC_Head *list, PyObject *resultlist) |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1140 | { |
| 1141 | PyGC_Head *gc; |
| 1142 | PyObject *obj; |
| 1143 | traverseproc traverse; |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 1144 | 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] | 1145 | obj = FROM_GC(gc); |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 1146 | traverse = Py_TYPE(obj)->tp_traverse; |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1147 | if (obj == objs || obj == resultlist) |
| 1148 | continue; |
Martin v. Löwis | 560da62 | 2001-11-24 09:24:51 +0000 | [diff] [blame] | 1149 | if (traverse(obj, (visitproc)referrersvisit, objs)) { |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 1150 | if (PyList_Append(resultlist, obj) < 0) |
| 1151 | return 0; /* error */ |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1152 | } |
| 1153 | } |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 1154 | return 1; /* no error */ |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1155 | } |
| 1156 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1157 | PyDoc_STRVAR(gc_get_referrers__doc__, |
Martin v. Löwis | 560da62 | 2001-11-24 09:24:51 +0000 | [diff] [blame] | 1158 | "get_referrers(*objs) -> list\n\ |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1159 | Return the list of objects that directly refer to any of objs."); |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1160 | |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 1161 | static PyObject * |
Martin v. Löwis | 560da62 | 2001-11-24 09:24:51 +0000 | [diff] [blame] | 1162 | gc_get_referrers(PyObject *self, PyObject *args) |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1163 | { |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1164 | int i; |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1165 | PyObject *result = PyList_New(0); |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1166 | if (!result) return NULL; |
| 1167 | |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1168 | for (i = 0; i < NUM_GENERATIONS; i++) { |
| 1169 | if (!(gc_referrers_for(args, GEN_HEAD(i), result))) { |
| 1170 | Py_DECREF(result); |
| 1171 | return NULL; |
| 1172 | } |
Neil Schemenauer | 17e7be6 | 2001-08-10 14:46:47 +0000 | [diff] [blame] | 1173 | } |
Neil Schemenauer | 48c7034 | 2001-08-09 15:38:31 +0000 | [diff] [blame] | 1174 | return result; |
| 1175 | } |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1176 | |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1177 | /* Append obj to list; return true if error (out of memory), false if OK. */ |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1178 | static int |
Tim Peters | 730f553 | 2003-04-08 17:17:17 +0000 | [diff] [blame] | 1179 | referentsvisit(PyObject *obj, PyObject *list) |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1180 | { |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1181 | return PyList_Append(list, obj) < 0; |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1182 | } |
| 1183 | |
Tim Peters | 730f553 | 2003-04-08 17:17:17 +0000 | [diff] [blame] | 1184 | PyDoc_STRVAR(gc_get_referents__doc__, |
| 1185 | "get_referents(*objs) -> list\n\ |
Jeremy Hylton | 059b094 | 2003-04-03 16:29:13 +0000 | [diff] [blame] | 1186 | Return the list of objects that are directly referred to by objs."); |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1187 | |
| 1188 | static PyObject * |
Tim Peters | 730f553 | 2003-04-08 17:17:17 +0000 | [diff] [blame] | 1189 | gc_get_referents(PyObject *self, PyObject *args) |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1190 | { |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1191 | Py_ssize_t i; |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1192 | PyObject *result = PyList_New(0); |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1193 | |
| 1194 | if (result == NULL) |
| 1195 | return NULL; |
| 1196 | |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1197 | for (i = 0; i < PyTuple_GET_SIZE(args); i++) { |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1198 | traverseproc traverse; |
Tim Peters | 93ad66d | 2003-04-05 17:15:44 +0000 | [diff] [blame] | 1199 | PyObject *obj = PyTuple_GET_ITEM(args, i); |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1200 | |
| 1201 | if (! PyObject_IS_GC(obj)) |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1202 | continue; |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 1203 | traverse = Py_TYPE(obj)->tp_traverse; |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1204 | if (! traverse) |
| 1205 | continue; |
Tim Peters | 730f553 | 2003-04-08 17:17:17 +0000 | [diff] [blame] | 1206 | if (traverse(obj, (visitproc)referentsvisit, result)) { |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1207 | Py_DECREF(result); |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1208 | return NULL; |
Tim Peters | 0f81ab6 | 2003-04-08 16:39:48 +0000 | [diff] [blame] | 1209 | } |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1210 | } |
| 1211 | return result; |
| 1212 | } |
| 1213 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1214 | PyDoc_STRVAR(gc_get_objects__doc__, |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1215 | "get_objects() -> [...]\n" |
| 1216 | "\n" |
| 1217 | "Return a list of objects tracked by the collector (excluding the list\n" |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1218 | "returned).\n"); |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1219 | |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1220 | static PyObject * |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1221 | gc_get_objects(PyObject *self, PyObject *noargs) |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1222 | { |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1223 | int i; |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1224 | PyObject* result; |
| 1225 | |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1226 | result = PyList_New(0); |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1227 | if (result == NULL) |
Martin v. Löwis | f8a6f24 | 2001-12-02 18:31:02 +0000 | [diff] [blame] | 1228 | return NULL; |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1229 | for (i = 0; i < NUM_GENERATIONS; i++) { |
| 1230 | if (append_objects(result, GEN_HEAD(i))) { |
| 1231 | Py_DECREF(result); |
| 1232 | return NULL; |
| 1233 | } |
Martin v. Löwis | 155aad1 | 2001-12-02 12:21:34 +0000 | [diff] [blame] | 1234 | } |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1235 | return result; |
| 1236 | } |
| 1237 | |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 1238 | PyDoc_STRVAR(gc_is_tracked__doc__, |
| 1239 | "is_tracked(obj) -> bool\n" |
| 1240 | "\n" |
| 1241 | "Returns true if the object is tracked by the garbage collector.\n" |
| 1242 | "Simple atomic objects will return false.\n" |
| 1243 | ); |
| 1244 | |
| 1245 | static PyObject * |
| 1246 | gc_is_tracked(PyObject *self, PyObject *obj) |
| 1247 | { |
| 1248 | PyObject *result; |
| 1249 | |
| 1250 | if (PyObject_IS_GC(obj) && IS_TRACKED(obj)) |
| 1251 | result = Py_True; |
| 1252 | else |
| 1253 | result = Py_False; |
| 1254 | Py_INCREF(result); |
| 1255 | return result; |
| 1256 | } |
| 1257 | |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1258 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 1259 | PyDoc_STRVAR(gc__doc__, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1260 | "This module provides access to the garbage collector for reference cycles.\n" |
| 1261 | "\n" |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1262 | "enable() -- Enable automatic garbage collection.\n" |
| 1263 | "disable() -- Disable automatic garbage collection.\n" |
| 1264 | "isenabled() -- Returns true if automatic collection is enabled.\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1265 | "collect() -- Do a full collection right now.\n" |
Thomas Wouters | 89f507f | 2006-12-13 04:49:30 +0000 | [diff] [blame] | 1266 | "get_count() -- Return the current collection counts.\n" |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1267 | "set_debug() -- Set debugging flags.\n" |
| 1268 | "get_debug() -- Get debugging flags.\n" |
| 1269 | "set_threshold() -- Set the collection thresholds.\n" |
| 1270 | "get_threshold() -- Return the current the collection thresholds.\n" |
Neil Schemenauer | c7c8d8e | 2001-08-09 15:58:59 +0000 | [diff] [blame] | 1271 | "get_objects() -- Return a list of all objects tracked by the collector.\n" |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 1272 | "is_tracked() -- Returns true if a given object is tracked.\n" |
Jeremy Hylton | 5bd378b | 2003-04-03 16:28:38 +0000 | [diff] [blame] | 1273 | "get_referrers() -- Return the list of objects that refer to an object.\n" |
Tim Peters | 730f553 | 2003-04-08 17:17:17 +0000 | [diff] [blame] | 1274 | "get_referents() -- Return the list of objects that an object refers to.\n"); |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1275 | |
| 1276 | static PyMethodDef GcMethods[] = { |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1277 | {"enable", gc_enable, METH_NOARGS, gc_enable__doc__}, |
| 1278 | {"disable", gc_disable, METH_NOARGS, gc_disable__doc__}, |
| 1279 | {"isenabled", gc_isenabled, METH_NOARGS, gc_isenabled__doc__}, |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1280 | {"set_debug", gc_set_debug, METH_VARARGS, gc_set_debug__doc__}, |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1281 | {"get_debug", gc_get_debug, METH_NOARGS, gc_get_debug__doc__}, |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1282 | {"get_count", gc_get_count, METH_NOARGS, gc_get_count__doc__}, |
Vladimir Marangozov | f9d20c3 | 2000-08-06 22:45:31 +0000 | [diff] [blame] | 1283 | {"set_threshold", gc_set_thresh, METH_VARARGS, gc_set_thresh__doc__}, |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1284 | {"get_threshold", gc_get_thresh, METH_NOARGS, gc_get_thresh__doc__}, |
Barry Warsaw | d3c38ff | 2006-03-07 09:46:03 +0000 | [diff] [blame] | 1285 | {"collect", (PyCFunction)gc_collect, |
| 1286 | METH_VARARGS | METH_KEYWORDS, gc_collect__doc__}, |
Tim Peters | 50c61d5 | 2003-04-06 01:50:50 +0000 | [diff] [blame] | 1287 | {"get_objects", gc_get_objects,METH_NOARGS, gc_get_objects__doc__}, |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 1288 | {"is_tracked", gc_is_tracked, METH_O, gc_is_tracked__doc__}, |
Martin v. Löwis | 560da62 | 2001-11-24 09:24:51 +0000 | [diff] [blame] | 1289 | {"get_referrers", gc_get_referrers, METH_VARARGS, |
| 1290 | gc_get_referrers__doc__}, |
Tim Peters | 730f553 | 2003-04-08 17:17:17 +0000 | [diff] [blame] | 1291 | {"get_referents", gc_get_referents, METH_VARARGS, |
| 1292 | gc_get_referents__doc__}, |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1293 | {NULL, NULL} /* Sentinel */ |
| 1294 | }; |
| 1295 | |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1296 | static struct PyModuleDef gcmodule = { |
| 1297 | PyModuleDef_HEAD_INIT, |
| 1298 | "gc", |
| 1299 | gc__doc__, |
| 1300 | -1, |
| 1301 | GcMethods, |
| 1302 | NULL, |
| 1303 | NULL, |
| 1304 | NULL, |
| 1305 | NULL |
| 1306 | }; |
| 1307 | |
| 1308 | |
Jason Tishler | 6bc06ec | 2003-09-04 11:59:50 +0000 | [diff] [blame] | 1309 | PyMODINIT_FUNC |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1310 | PyInit_gc(void) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1311 | { |
| 1312 | PyObject *m; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1313 | |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1314 | m = PyModule_Create(&gcmodule); |
| 1315 | |
Neal Norwitz | 1ac754f | 2006-01-19 06:09:39 +0000 | [diff] [blame] | 1316 | if (m == NULL) |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1317 | return NULL; |
Tim Peters | 1155887 | 2003-04-06 23:30:52 +0000 | [diff] [blame] | 1318 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1319 | if (garbage == NULL) { |
| 1320 | garbage = PyList_New(0); |
Tim Peters | 1155887 | 2003-04-06 23:30:52 +0000 | [diff] [blame] | 1321 | if (garbage == NULL) |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1322 | return NULL; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1323 | } |
Neil Schemenauer | 3b1cbf9 | 2005-06-18 17:37:06 +0000 | [diff] [blame] | 1324 | Py_INCREF(garbage); |
Tim Peters | 1155887 | 2003-04-06 23:30:52 +0000 | [diff] [blame] | 1325 | if (PyModule_AddObject(m, "garbage", garbage) < 0) |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1326 | return NULL; |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 1327 | |
| 1328 | /* Importing can't be done in collect() because collect() |
| 1329 | * can be called via PyGC_Collect() in Py_Finalize(). |
| 1330 | * This wouldn't be a problem, except that <initialized> is |
| 1331 | * reset to 0 before calling collect which trips up |
| 1332 | * the import and triggers an assertion. |
| 1333 | */ |
| 1334 | if (tmod == NULL) { |
Christian Heimes | 072c0f1 | 2008-01-03 23:01:04 +0000 | [diff] [blame] | 1335 | tmod = PyImport_ImportModuleNoBlock("time"); |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 1336 | if (tmod == NULL) |
| 1337 | PyErr_Clear(); |
| 1338 | } |
| 1339 | |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1340 | #define ADD_INT(NAME) if (PyModule_AddIntConstant(m, #NAME, NAME) < 0) return NULL |
Tim Peters | 1155887 | 2003-04-06 23:30:52 +0000 | [diff] [blame] | 1341 | ADD_INT(DEBUG_STATS); |
| 1342 | ADD_INT(DEBUG_COLLECTABLE); |
| 1343 | ADD_INT(DEBUG_UNCOLLECTABLE); |
Tim Peters | 1155887 | 2003-04-06 23:30:52 +0000 | [diff] [blame] | 1344 | ADD_INT(DEBUG_SAVEALL); |
| 1345 | ADD_INT(DEBUG_LEAK); |
| 1346 | #undef ADD_INT |
Martin v. Löwis | 1a21451 | 2008-06-11 05:26:20 +0000 | [diff] [blame] | 1347 | return m; |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 1348 | } |
| 1349 | |
Guido van Rossum | e13ddc9 | 2003-04-17 17:29:22 +0000 | [diff] [blame] | 1350 | /* API to invoke gc.collect() from C */ |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 1351 | Py_ssize_t |
Guido van Rossum | e13ddc9 | 2003-04-17 17:29:22 +0000 | [diff] [blame] | 1352 | PyGC_Collect(void) |
| 1353 | { |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 1354 | Py_ssize_t n; |
Guido van Rossum | e13ddc9 | 2003-04-17 17:29:22 +0000 | [diff] [blame] | 1355 | |
| 1356 | if (collecting) |
| 1357 | n = 0; /* already collecting, don't do anything */ |
| 1358 | else { |
| 1359 | collecting = 1; |
| 1360 | n = collect(NUM_GENERATIONS - 1); |
| 1361 | collecting = 0; |
| 1362 | } |
| 1363 | |
| 1364 | return n; |
| 1365 | } |
| 1366 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1367 | /* for debugging */ |
Guido van Rossum | e13ddc9 | 2003-04-17 17:29:22 +0000 | [diff] [blame] | 1368 | void |
| 1369 | _PyGC_Dump(PyGC_Head *g) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1370 | { |
| 1371 | _PyObject_Dump(FROM_GC(g)); |
| 1372 | } |
| 1373 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1374 | /* extension modules might be compiled with GC support so these |
| 1375 | functions must always be available */ |
| 1376 | |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1377 | #undef PyObject_GC_Track |
| 1378 | #undef PyObject_GC_UnTrack |
| 1379 | #undef PyObject_GC_Del |
| 1380 | #undef _PyObject_GC_Malloc |
| 1381 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1382 | void |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1383 | PyObject_GC_Track(void *op) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1384 | { |
| 1385 | _PyObject_GC_TRACK(op); |
| 1386 | } |
| 1387 | |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1388 | /* for binary compatibility with 2.2 */ |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1389 | void |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1390 | _PyObject_GC_Track(PyObject *op) |
| 1391 | { |
| 1392 | PyObject_GC_Track(op); |
| 1393 | } |
| 1394 | |
| 1395 | void |
| 1396 | PyObject_GC_UnTrack(void *op) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1397 | { |
Tim Peters | 803526b | 2002-07-07 05:13:56 +0000 | [diff] [blame] | 1398 | /* Obscure: the Py_TRASHCAN mechanism requires that we be able to |
| 1399 | * call PyObject_GC_UnTrack twice on an object. |
| 1400 | */ |
Neil Schemenauer | a2b11ec | 2002-05-21 15:53:24 +0000 | [diff] [blame] | 1401 | if (IS_TRACKED(op)) |
Guido van Rossum | ff413af | 2002-03-28 20:34:59 +0000 | [diff] [blame] | 1402 | _PyObject_GC_UNTRACK(op); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1403 | } |
| 1404 | |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1405 | /* for binary compatibility with 2.2 */ |
| 1406 | void |
| 1407 | _PyObject_GC_UnTrack(PyObject *op) |
| 1408 | { |
| 1409 | PyObject_GC_UnTrack(op); |
| 1410 | } |
| 1411 | |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1412 | PyObject * |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1413 | _PyObject_GC_Malloc(size_t basicsize) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1414 | { |
| 1415 | PyObject *op; |
Neal Norwitz | 3ce5d92 | 2008-08-24 07:08:55 +0000 | [diff] [blame] | 1416 | PyGC_Head *g; |
| 1417 | if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head)) |
| 1418 | return PyErr_NoMemory(); |
| 1419 | g = (PyGC_Head *)PyObject_MALLOC( |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1420 | sizeof(PyGC_Head) + basicsize); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1421 | if (g == NULL) |
Jeremy Hylton | 8a13518 | 2002-06-06 23:23:55 +0000 | [diff] [blame] | 1422 | return PyErr_NoMemory(); |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 1423 | g->gc.gc_refs = GC_UNTRACKED; |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1424 | generations[0].count++; /* number of allocated GC objects */ |
| 1425 | if (generations[0].count > generations[0].threshold && |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1426 | enabled && |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1427 | generations[0].threshold && |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1428 | !collecting && |
| 1429 | !PyErr_Occurred()) { |
| 1430 | collecting = 1; |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1431 | collect_generations(); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1432 | collecting = 0; |
| 1433 | } |
| 1434 | op = FROM_GC(g); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1435 | return op; |
| 1436 | } |
| 1437 | |
| 1438 | PyObject * |
| 1439 | _PyObject_GC_New(PyTypeObject *tp) |
| 1440 | { |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1441 | PyObject *op = _PyObject_GC_Malloc(_PyObject_SIZE(tp)); |
Tim Peters | fa8efab | 2002-04-28 01:57:25 +0000 | [diff] [blame] | 1442 | if (op != NULL) |
| 1443 | op = PyObject_INIT(op, tp); |
| 1444 | return op; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1445 | } |
| 1446 | |
| 1447 | PyVarObject * |
Martin v. Löwis | 18e1655 | 2006-02-15 17:27:45 +0000 | [diff] [blame] | 1448 | _PyObject_GC_NewVar(PyTypeObject *tp, Py_ssize_t nitems) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1449 | { |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1450 | const size_t size = _PyObject_VAR_SIZE(tp, nitems); |
| 1451 | PyVarObject *op = (PyVarObject *) _PyObject_GC_Malloc(size); |
Tim Peters | fa8efab | 2002-04-28 01:57:25 +0000 | [diff] [blame] | 1452 | if (op != NULL) |
| 1453 | op = PyObject_INIT_VAR(op, tp, nitems); |
| 1454 | return op; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1455 | } |
| 1456 | |
| 1457 | PyVarObject * |
Martin v. Löwis | 4129068 | 2006-02-16 14:56:14 +0000 | [diff] [blame] | 1458 | _PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1459 | { |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 1460 | const size_t basicsize = _PyObject_VAR_SIZE(Py_TYPE(op), nitems); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1461 | PyGC_Head *g = AS_GC(op); |
Neal Norwitz | 3ce5d92 | 2008-08-24 07:08:55 +0000 | [diff] [blame] | 1462 | if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head)) |
| 1463 | return (PyVarObject *)PyErr_NoMemory(); |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1464 | g = (PyGC_Head *)PyObject_REALLOC(g, sizeof(PyGC_Head) + basicsize); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1465 | if (g == NULL) |
| 1466 | return (PyVarObject *)PyErr_NoMemory(); |
| 1467 | op = (PyVarObject *) FROM_GC(g); |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 1468 | Py_SIZE(op) = nitems; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1469 | return op; |
| 1470 | } |
| 1471 | |
| 1472 | void |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1473 | PyObject_GC_Del(void *op) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1474 | { |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1475 | PyGC_Head *g = AS_GC(op); |
Neil Schemenauer | a2b11ec | 2002-05-21 15:53:24 +0000 | [diff] [blame] | 1476 | if (IS_TRACKED(op)) |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1477 | gc_list_remove(g); |
Neil Schemenauer | 2880ae5 | 2002-05-04 05:35:20 +0000 | [diff] [blame] | 1478 | if (generations[0].count > 0) { |
| 1479 | generations[0].count--; |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1480 | } |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1481 | PyObject_FREE(g); |
Neil Schemenauer | 43411b5 | 2001-08-30 00:05:51 +0000 | [diff] [blame] | 1482 | } |
| 1483 | |
Neil Schemenauer | fec4eb1 | 2002-04-12 02:41:03 +0000 | [diff] [blame] | 1484 | /* for binary compatibility with 2.2 */ |
| 1485 | #undef _PyObject_GC_Del |
| 1486 | void |
| 1487 | _PyObject_GC_Del(PyObject *op) |
| 1488 | { |
| 1489 | PyObject_GC_Del(op); |
| 1490 | } |