X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=AppPkg%2FApplications%2FPython%2FPython-2.7.10%2FModules%2Fgcmodule.c;fp=AppPkg%2FApplications%2FPython%2FPython-2.7.10%2FModules%2Fgcmodule.c;h=0000000000000000000000000000000000000000;hp=1746887391022ad33f164bec32bcf871f3315219;hb=964f432b9b0afe103c41c7613fade3e699118afe;hpb=e2d3a25f1a3135221a9c8061e1b8f90245d727eb diff --git a/AppPkg/Applications/Python/Python-2.7.10/Modules/gcmodule.c b/AppPkg/Applications/Python/Python-2.7.10/Modules/gcmodule.c deleted file mode 100644 index 1746887391..0000000000 --- a/AppPkg/Applications/Python/Python-2.7.10/Modules/gcmodule.c +++ /dev/null @@ -1,1570 +0,0 @@ -/* - - Reference Cycle Garbage Collection - ================================== - - Neil Schemenauer - - Based on a post on the python-dev list. Ideas from Guido van Rossum, - Eric Tiedemann, and various others. - - http://www.arctrix.com/nas/python/gc/ - http://www.python.org/pipermail/python-dev/2000-March/003869.html - http://www.python.org/pipermail/python-dev/2000-March/004010.html - http://www.python.org/pipermail/python-dev/2000-March/004022.html - - For a highlevel view of the collection process, read the collect - function. - -*/ - -#include "Python.h" -#include "frameobject.h" /* for PyFrame_ClearFreeList */ - -/* Get an object's GC head */ -#define AS_GC(o) ((PyGC_Head *)(o)-1) - -/* Get the object given the GC head */ -#define FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1)) - -/*** Global GC state ***/ - -struct gc_generation { - PyGC_Head head; - int threshold; /* collection threshold */ - int count; /* count of allocations or collections of younger - generations */ -}; - -#define NUM_GENERATIONS 3 -#define GEN_HEAD(n) (&generations[n].head) - -/* linked lists of container objects */ -static struct gc_generation generations[NUM_GENERATIONS] = { - /* PyGC_Head, threshold, count */ - {{{GEN_HEAD(0), GEN_HEAD(0), 0}}, 700, 0}, - {{{GEN_HEAD(1), GEN_HEAD(1), 0}}, 10, 0}, - {{{GEN_HEAD(2), GEN_HEAD(2), 0}}, 10, 0}, -}; - -PyGC_Head *_PyGC_generation0 = GEN_HEAD(0); - -static int enabled = 1; /* automatic collection enabled? */ - -/* true if we are currently running the collector */ -static int collecting = 0; - -/* list of uncollectable objects */ -static PyObject *garbage = NULL; - -/* Python string to use if unhandled exception occurs */ -static PyObject *gc_str = NULL; - -/* Python string used to look for __del__ attribute. */ -static PyObject *delstr = NULL; - -/* This is the number of objects who survived the last full collection. It - approximates the number of long lived objects tracked by the GC. - - (by "full collection", we mean a collection of the oldest generation). -*/ -static Py_ssize_t long_lived_total = 0; - -/* This is the number of objects who survived all "non-full" collections, - and are awaiting to undergo a full collection for the first time. - -*/ -static Py_ssize_t long_lived_pending = 0; - -/* - NOTE: about the counting of long-lived objects. - - To limit the cost of garbage collection, there are two strategies; - - make each collection faster, e.g. by scanning fewer objects - - do less collections - This heuristic is about the latter strategy. - - In addition to the various configurable thresholds, we only trigger a - full collection if the ratio - long_lived_pending / long_lived_total - is above a given value (hardwired to 25%). - - The reason is that, while "non-full" collections (i.e., collections of - the young and middle generations) will always examine roughly the same - number of objects -- determined by the aforementioned thresholds --, - the cost of a full collection is proportional to the total number of - long-lived objects, which is virtually unbounded. - - Indeed, it has been remarked that doing a full collection every - of object creations entails a dramatic performance - degradation in workloads which consist in creating and storing lots of - long-lived objects (e.g. building a large list of GC-tracked objects would - show quadratic performance, instead of linear as expected: see issue #4074). - - Using the above ratio, instead, yields amortized linear performance in - the total number of objects (the effect of which can be summarized - thusly: "each full garbage collection is more and more costly as the - number of objects grows, but we do fewer and fewer of them"). - - This heuristic was suggested by Martin von Löwis on python-dev in - June 2008. His original analysis and proposal can be found at: - http://mail.python.org/pipermail/python-dev/2008-June/080579.html -*/ - -/* - NOTE: about untracking of mutable objects. - - Certain types of container cannot participate in a reference cycle, and - so do not need to be tracked by the garbage collector. Untracking these - objects reduces the cost of garbage collections. However, determining - which objects may be untracked is not free, and the costs must be - weighed against the benefits for garbage collection. - - There are two possible strategies for when to untrack a container: - - i) When the container is created. - ii) When the container is examined by the garbage collector. - - Tuples containing only immutable objects (integers, strings etc, and - recursively, tuples of immutable objects) do not need to be tracked. - The interpreter creates a large number of tuples, many of which will - not survive until garbage collection. It is therefore not worthwhile - to untrack eligible tuples at creation time. - - Instead, all tuples except the empty tuple are tracked when created. - During garbage collection it is determined whether any surviving tuples - can be untracked. A tuple can be untracked if all of its contents are - already not tracked. Tuples are examined for untracking in all garbage - collection cycles. It may take more than one cycle to untrack a tuple. - - Dictionaries containing only immutable objects also do not need to be - tracked. Dictionaries are untracked when created. If a tracked item is - inserted into a dictionary (either as a key or value), the dictionary - becomes tracked. During a full garbage collection (all generations), - the collector will untrack any dictionaries whose contents are not - tracked. - - The module provides the python function is_tracked(obj), which returns - the CURRENT tracking status of the object. Subsequent garbage - collections may change the tracking status of the object. - - Untracking of certain containers was introduced in issue #4688, and - the algorithm was refined in response to issue #14775. -*/ - -/* set for debugging information */ -#define DEBUG_STATS (1<<0) /* print collection statistics */ -#define DEBUG_COLLECTABLE (1<<1) /* print collectable objects */ -#define DEBUG_UNCOLLECTABLE (1<<2) /* print uncollectable objects */ -#define DEBUG_INSTANCES (1<<3) /* print instances */ -#define DEBUG_OBJECTS (1<<4) /* print other objects */ -#define DEBUG_SAVEALL (1<<5) /* save all garbage in gc.garbage */ -#define DEBUG_LEAK DEBUG_COLLECTABLE | \ - DEBUG_UNCOLLECTABLE | \ - DEBUG_INSTANCES | \ - DEBUG_OBJECTS | \ - DEBUG_SAVEALL -static int debug; -static PyObject *tmod = NULL; - -/*-------------------------------------------------------------------------- -gc_refs values. - -Between collections, every gc'ed object has one of two gc_refs values: - -GC_UNTRACKED - The initial state; objects returned by PyObject_GC_Malloc are in this - state. The object doesn't live in any generation list, and its - tp_traverse slot must not be called. - -GC_REACHABLE - The object lives in some generation list, and its tp_traverse is safe to - call. An object transitions to GC_REACHABLE when PyObject_GC_Track - is called. - -During a collection, gc_refs can temporarily take on other states: - ->= 0 - At the start of a collection, update_refs() copies the true refcount - to gc_refs, for each object in the generation being collected. - subtract_refs() then adjusts gc_refs so that it equals the number of - times an object is referenced directly from outside the generation - being collected. - gc_refs remains >= 0 throughout these steps. - -GC_TENTATIVELY_UNREACHABLE - move_unreachable() then moves objects not reachable (whether directly or - indirectly) from outside the generation into an "unreachable" set. - Objects that are found to be reachable have gc_refs set to GC_REACHABLE - again. Objects that are found to be unreachable have gc_refs set to - GC_TENTATIVELY_UNREACHABLE. It's "tentatively" because the pass doing - this can't be sure until it ends, and GC_TENTATIVELY_UNREACHABLE may - transition back to GC_REACHABLE. - - Only objects with GC_TENTATIVELY_UNREACHABLE still set are candidates - for collection. If it's decided not to collect such an object (e.g., - it has a __del__ method), its gc_refs is restored to GC_REACHABLE again. ----------------------------------------------------------------------------- -*/ -#define GC_UNTRACKED _PyGC_REFS_UNTRACKED -#define GC_REACHABLE _PyGC_REFS_REACHABLE -#define GC_TENTATIVELY_UNREACHABLE _PyGC_REFS_TENTATIVELY_UNREACHABLE - -#define IS_TRACKED(o) ((AS_GC(o))->gc.gc_refs != GC_UNTRACKED) -#define IS_REACHABLE(o) ((AS_GC(o))->gc.gc_refs == GC_REACHABLE) -#define IS_TENTATIVELY_UNREACHABLE(o) ( \ - (AS_GC(o))->gc.gc_refs == GC_TENTATIVELY_UNREACHABLE) - -/*** list functions ***/ - -static void -gc_list_init(PyGC_Head *list) -{ - list->gc.gc_prev = list; - list->gc.gc_next = list; -} - -static int -gc_list_is_empty(PyGC_Head *list) -{ - return (list->gc.gc_next == list); -} - -#if 0 -/* This became unused after gc_list_move() was introduced. */ -/* Append `node` to `list`. */ -static void -gc_list_append(PyGC_Head *node, PyGC_Head *list) -{ - node->gc.gc_next = list; - node->gc.gc_prev = list->gc.gc_prev; - node->gc.gc_prev->gc.gc_next = node; - list->gc.gc_prev = node; -} -#endif - -/* Remove `node` from the gc list it's currently in. */ -static void -gc_list_remove(PyGC_Head *node) -{ - node->gc.gc_prev->gc.gc_next = node->gc.gc_next; - node->gc.gc_next->gc.gc_prev = node->gc.gc_prev; - node->gc.gc_next = NULL; /* object is not currently tracked */ -} - -/* Move `node` from the gc list it's currently in (which is not explicitly - * named here) to the end of `list`. This is semantically the same as - * gc_list_remove(node) followed by gc_list_append(node, list). - */ -static void -gc_list_move(PyGC_Head *node, PyGC_Head *list) -{ - PyGC_Head *new_prev; - PyGC_Head *current_prev = node->gc.gc_prev; - PyGC_Head *current_next = node->gc.gc_next; - /* Unlink from current list. */ - current_prev->gc.gc_next = current_next; - current_next->gc.gc_prev = current_prev; - /* Relink at end of new list. */ - new_prev = node->gc.gc_prev = list->gc.gc_prev; - new_prev->gc.gc_next = list->gc.gc_prev = node; - node->gc.gc_next = list; -} - -/* append list `from` onto list `to`; `from` becomes an empty list */ -static void -gc_list_merge(PyGC_Head *from, PyGC_Head *to) -{ - PyGC_Head *tail; - assert(from != to); - if (!gc_list_is_empty(from)) { - tail = to->gc.gc_prev; - tail->gc.gc_next = from->gc.gc_next; - tail->gc.gc_next->gc.gc_prev = tail; - to->gc.gc_prev = from->gc.gc_prev; - to->gc.gc_prev->gc.gc_next = to; - } - gc_list_init(from); -} - -static Py_ssize_t -gc_list_size(PyGC_Head *list) -{ - PyGC_Head *gc; - Py_ssize_t n = 0; - for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) { - n++; - } - return n; -} - -/* Append objects in a GC list to a Python list. - * Return 0 if all OK, < 0 if error (out of memory for list). - */ -static int -append_objects(PyObject *py_list, PyGC_Head *gc_list) -{ - PyGC_Head *gc; - for (gc = gc_list->gc.gc_next; gc != gc_list; gc = gc->gc.gc_next) { - PyObject *op = FROM_GC(gc); - if (op != py_list) { - if (PyList_Append(py_list, op)) { - return -1; /* exception */ - } - } - } - return 0; -} - -/*** end of list stuff ***/ - - -/* Set all gc_refs = ob_refcnt. After this, gc_refs is > 0 for all objects - * in containers, and is GC_REACHABLE for all tracked gc objects not in - * containers. - */ -static void -update_refs(PyGC_Head *containers) -{ - PyGC_Head *gc = containers->gc.gc_next; - for (; gc != containers; gc = gc->gc.gc_next) { - assert(gc->gc.gc_refs == GC_REACHABLE); - gc->gc.gc_refs = Py_REFCNT(FROM_GC(gc)); - /* Python's cyclic gc should never see an incoming refcount - * of 0: if something decref'ed to 0, it should have been - * deallocated immediately at that time. - * Possible cause (if the assert triggers): a tp_dealloc - * routine left a gc-aware object tracked during its teardown - * phase, and did something-- or allowed something to happen -- - * that called back into Python. gc can trigger then, and may - * see the still-tracked dying object. Before this assert - * was added, such mistakes went on to allow gc to try to - * delete the object again. In a debug build, that caused - * a mysterious segfault, when _Py_ForgetReference tried - * to remove the object from the doubly-linked list of all - * objects a second time. In a release build, an actual - * double deallocation occurred, which leads to corruption - * of the allocator's internal bookkeeping pointers. That's - * so serious that maybe this should be a release-build - * check instead of an assert? - */ - assert(gc->gc.gc_refs != 0); - } -} - -/* A traversal callback for subtract_refs. */ -static int -visit_decref(PyObject *op, void *data) -{ - assert(op != NULL); - if (PyObject_IS_GC(op)) { - PyGC_Head *gc = AS_GC(op); - /* We're only interested in gc_refs for objects in the - * generation being collected, which can be recognized - * because only they have positive gc_refs. - */ - assert(gc->gc.gc_refs != 0); /* else refcount was too small */ - if (gc->gc.gc_refs > 0) - gc->gc.gc_refs--; - } - return 0; -} - -/* Subtract internal references from gc_refs. After this, gc_refs is >= 0 - * for all objects in containers, and is GC_REACHABLE for all tracked gc - * objects not in containers. The ones with gc_refs > 0 are directly - * reachable from outside containers, and so can't be collected. - */ -static void -subtract_refs(PyGC_Head *containers) -{ - traverseproc traverse; - PyGC_Head *gc = containers->gc.gc_next; - for (; gc != containers; gc=gc->gc.gc_next) { - traverse = Py_TYPE(FROM_GC(gc))->tp_traverse; - (void) traverse(FROM_GC(gc), - (visitproc)visit_decref, - NULL); - } -} - -/* A traversal callback for move_unreachable. */ -static int -visit_reachable(PyObject *op, PyGC_Head *reachable) -{ - if (PyObject_IS_GC(op)) { - PyGC_Head *gc = AS_GC(op); - const Py_ssize_t gc_refs = gc->gc.gc_refs; - - if (gc_refs == 0) { - /* This is in move_unreachable's 'young' list, but - * the traversal hasn't yet gotten to it. All - * we need to do is tell move_unreachable that it's - * reachable. - */ - gc->gc.gc_refs = 1; - } - else if (gc_refs == GC_TENTATIVELY_UNREACHABLE) { - /* This had gc_refs = 0 when move_unreachable got - * to it, but turns out it's reachable after all. - * Move it back to move_unreachable's 'young' list, - * and move_unreachable will eventually get to it - * again. - */ - gc_list_move(gc, reachable); - gc->gc.gc_refs = 1; - } - /* Else there's nothing to do. - * If gc_refs > 0, it must be in move_unreachable's 'young' - * list, and move_unreachable will eventually get to it. - * If gc_refs == GC_REACHABLE, it's either in some other - * generation so we don't care about it, or move_unreachable - * already dealt with it. - * If gc_refs == GC_UNTRACKED, it must be ignored. - */ - else { - assert(gc_refs > 0 - || gc_refs == GC_REACHABLE - || gc_refs == GC_UNTRACKED); - } - } - return 0; -} - -/* Move the unreachable objects from young to unreachable. After this, - * all objects in young have gc_refs = GC_REACHABLE, and all objects in - * unreachable have gc_refs = GC_TENTATIVELY_UNREACHABLE. All tracked - * gc objects not in young or unreachable still have gc_refs = GC_REACHABLE. - * All objects in young after this are directly or indirectly reachable - * from outside the original young; and all objects in unreachable are - * not. - */ -static void -move_unreachable(PyGC_Head *young, PyGC_Head *unreachable) -{ - PyGC_Head *gc = young->gc.gc_next; - - /* Invariants: all objects "to the left" of us in young have gc_refs - * = GC_REACHABLE, and are indeed reachable (directly or indirectly) - * from outside the young list as it was at entry. All other objects - * from the original young "to the left" of us are in unreachable now, - * and have gc_refs = GC_TENTATIVELY_UNREACHABLE. All objects to the - * left of us in 'young' now have been scanned, and no objects here - * or to the right have been scanned yet. - */ - - while (gc != young) { - PyGC_Head *next; - - if (gc->gc.gc_refs) { - /* gc is definitely reachable from outside the - * original 'young'. Mark it as such, and traverse - * its pointers to find any other objects that may - * be directly reachable from it. Note that the - * call to tp_traverse may append objects to young, - * so we have to wait until it returns to determine - * the next object to visit. - */ - PyObject *op = FROM_GC(gc); - traverseproc traverse = Py_TYPE(op)->tp_traverse; - assert(gc->gc.gc_refs > 0); - gc->gc.gc_refs = GC_REACHABLE; - (void) traverse(op, - (visitproc)visit_reachable, - (void *)young); - next = gc->gc.gc_next; - if (PyTuple_CheckExact(op)) { - _PyTuple_MaybeUntrack(op); - } - } - else { - /* This *may* be unreachable. To make progress, - * assume it is. gc isn't directly reachable from - * any object we've already traversed, but may be - * reachable from an object we haven't gotten to yet. - * visit_reachable will eventually move gc back into - * young if that's so, and we'll see it again. - */ - next = gc->gc.gc_next; - gc_list_move(gc, unreachable); - gc->gc.gc_refs = GC_TENTATIVELY_UNREACHABLE; - } - gc = next; - } -} - -/* Return true if object has a finalization method. - * CAUTION: An instance of an old-style class has to be checked for a - *__del__ method, and earlier versions of this used to call PyObject_HasAttr, - * which in turn could call the class's __getattr__ hook (if any). That - * could invoke arbitrary Python code, mutating the object graph in arbitrary - * ways, and that was the source of some excruciatingly subtle bugs. - */ -static int -has_finalizer(PyObject *op) -{ - if (PyInstance_Check(op)) { - assert(delstr != NULL); - return _PyInstance_Lookup(op, delstr) != NULL; - } - else if (PyType_HasFeature(op->ob_type, Py_TPFLAGS_HEAPTYPE)) - return op->ob_type->tp_del != NULL; - else if (PyGen_CheckExact(op)) - return PyGen_NeedsFinalizing((PyGenObject *)op); - else - return 0; -} - -/* Try to untrack all currently tracked dictionaries */ -static void -untrack_dicts(PyGC_Head *head) -{ - PyGC_Head *next, *gc = head->gc.gc_next; - while (gc != head) { - PyObject *op = FROM_GC(gc); - next = gc->gc.gc_next; - if (PyDict_CheckExact(op)) - _PyDict_MaybeUntrack(op); - gc = next; - } -} - -/* Move the objects in unreachable with __del__ methods into `finalizers`. - * Objects moved into `finalizers` have gc_refs set to GC_REACHABLE; the - * objects remaining in unreachable are left at GC_TENTATIVELY_UNREACHABLE. - */ -static void -move_finalizers(PyGC_Head *unreachable, PyGC_Head *finalizers) -{ - PyGC_Head *gc; - PyGC_Head *next; - - /* March over unreachable. Move objects with finalizers into - * `finalizers`. - */ - for (gc = unreachable->gc.gc_next; gc != unreachable; gc = next) { - PyObject *op = FROM_GC(gc); - - assert(IS_TENTATIVELY_UNREACHABLE(op)); - next = gc->gc.gc_next; - - if (has_finalizer(op)) { - gc_list_move(gc, finalizers); - gc->gc.gc_refs = GC_REACHABLE; - } - } -} - -/* A traversal callback for move_finalizer_reachable. */ -static int -visit_move(PyObject *op, PyGC_Head *tolist) -{ - if (PyObject_IS_GC(op)) { - if (IS_TENTATIVELY_UNREACHABLE(op)) { - PyGC_Head *gc = AS_GC(op); - gc_list_move(gc, tolist); - gc->gc.gc_refs = GC_REACHABLE; - } - } - return 0; -} - -/* Move objects that are reachable from finalizers, from the unreachable set - * into finalizers set. - */ -static void -move_finalizer_reachable(PyGC_Head *finalizers) -{ - traverseproc traverse; - PyGC_Head *gc = finalizers->gc.gc_next; - for (; gc != finalizers; gc = gc->gc.gc_next) { - /* Note that the finalizers list may grow during this. */ - traverse = Py_TYPE(FROM_GC(gc))->tp_traverse; - (void) traverse(FROM_GC(gc), - (visitproc)visit_move, - (void *)finalizers); - } -} - -/* Clear all weakrefs to unreachable objects, and if such a weakref has a - * callback, invoke it if necessary. Note that it's possible for such - * weakrefs to be outside the unreachable set -- indeed, those are precisely - * the weakrefs whose callbacks must be invoked. See gc_weakref.txt for - * overview & some details. Some weakrefs with callbacks may be reclaimed - * directly by this routine; the number reclaimed is the return value. Other - * weakrefs with callbacks may be moved into the `old` generation. Objects - * moved into `old` have gc_refs set to GC_REACHABLE; the objects remaining in - * unreachable are left at GC_TENTATIVELY_UNREACHABLE. When this returns, - * no object in `unreachable` is weakly referenced anymore. - */ -static int -handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old) -{ - PyGC_Head *gc; - PyObject *op; /* generally FROM_GC(gc) */ - PyWeakReference *wr; /* generally a cast of op */ - PyGC_Head wrcb_to_call; /* weakrefs with callbacks to call */ - PyGC_Head *next; - int num_freed = 0; - - gc_list_init(&wrcb_to_call); - - /* Clear all weakrefs to the objects in unreachable. If such a weakref - * also has a callback, move it into `wrcb_to_call` if the callback - * needs to be invoked. Note that we cannot invoke any callbacks until - * all weakrefs to unreachable objects are cleared, lest the callback - * resurrect an unreachable object via a still-active weakref. We - * make another pass over wrcb_to_call, invoking callbacks, after this - * pass completes. - */ - for (gc = unreachable->gc.gc_next; gc != unreachable; gc = next) { - PyWeakReference **wrlist; - - op = FROM_GC(gc); - assert(IS_TENTATIVELY_UNREACHABLE(op)); - next = gc->gc.gc_next; - - if (! PyType_SUPPORTS_WEAKREFS(Py_TYPE(op))) - continue; - - /* It supports weakrefs. Does it have any? */ - wrlist = (PyWeakReference **) - PyObject_GET_WEAKREFS_LISTPTR(op); - - /* `op` may have some weakrefs. March over the list, clear - * all the weakrefs, and move the weakrefs with callbacks - * that must be called into wrcb_to_call. - */ - for (wr = *wrlist; wr != NULL; wr = *wrlist) { - PyGC_Head *wrasgc; /* AS_GC(wr) */ - - /* _PyWeakref_ClearRef clears the weakref but leaves - * the callback pointer intact. Obscure: it also - * changes *wrlist. - */ - assert(wr->wr_object == op); - _PyWeakref_ClearRef(wr); - assert(wr->wr_object == Py_None); - if (wr->wr_callback == NULL) - continue; /* no callback */ - - /* Headache time. `op` is going away, and is weakly referenced by - * `wr`, which has a callback. Should the callback be invoked? If wr - * is also trash, no: - * - * 1. There's no need to call it. The object and the weakref are - * both going away, so it's legitimate to pretend the weakref is - * going away first. The user has to ensure a weakref outlives its - * referent if they want a guarantee that the wr callback will get - * invoked. - * - * 2. It may be catastrophic to call it. If the callback is also in - * cyclic trash (CT), then although the CT is unreachable from - * outside the current generation, CT may be reachable from the - * callback. Then the callback could resurrect insane objects. - * - * Since the callback is never needed and may be unsafe in this case, - * wr is simply left in the unreachable set. Note that because we - * already called _PyWeakref_ClearRef(wr), its callback will never - * trigger. - * - * OTOH, if wr isn't part of CT, we should invoke the callback: the - * weakref outlived the trash. Note that since wr isn't CT in this - * case, its callback can't be CT either -- wr acted as an external - * root to this generation, and therefore its callback did too. So - * nothing in CT is reachable from the callback either, so it's hard - * to imagine how calling it later could create a problem for us. wr - * is moved to wrcb_to_call in this case. - */ - if (IS_TENTATIVELY_UNREACHABLE(wr)) - continue; - assert(IS_REACHABLE(wr)); - - /* Create a new reference so that wr can't go away - * before we can process it again. - */ - Py_INCREF(wr); - - /* Move wr to wrcb_to_call, for the next pass. */ - wrasgc = AS_GC(wr); - assert(wrasgc != next); /* wrasgc is reachable, but - next isn't, so they can't - be the same */ - gc_list_move(wrasgc, &wrcb_to_call); - } - } - - /* Invoke the callbacks we decided to honor. It's safe to invoke them - * because they can't reference unreachable objects. - */ - while (! gc_list_is_empty(&wrcb_to_call)) { - PyObject *temp; - PyObject *callback; - - gc = wrcb_to_call.gc.gc_next; - op = FROM_GC(gc); - assert(IS_REACHABLE(op)); - assert(PyWeakref_Check(op)); - wr = (PyWeakReference *)op; - callback = wr->wr_callback; - assert(callback != NULL); - - /* copy-paste of weakrefobject.c's handle_callback() */ - temp = PyObject_CallFunctionObjArgs(callback, wr, NULL); - if (temp == NULL) - PyErr_WriteUnraisable(callback); - else - Py_DECREF(temp); - - /* Give up the reference we created in the first pass. When - * op's refcount hits 0 (which it may or may not do right now), - * op's tp_dealloc will decref op->wr_callback too. Note - * that the refcount probably will hit 0 now, and because this - * weakref was reachable to begin with, gc didn't already - * add it to its count of freed objects. Example: a reachable - * weak value dict maps some key to this reachable weakref. - * The callback removes this key->weakref mapping from the - * dict, leaving no other references to the weakref (excepting - * ours). - */ - Py_DECREF(op); - if (wrcb_to_call.gc.gc_next == gc) { - /* object is still alive -- move it */ - gc_list_move(gc, old); - } - else - ++num_freed; - } - - return num_freed; -} - -static void -debug_instance(char *msg, PyInstanceObject *inst) -{ - char *cname; - /* simple version of instance_repr */ - PyObject *classname = inst->in_class->cl_name; - if (classname != NULL && PyString_Check(classname)) - cname = PyString_AsString(classname); - else - cname = "?"; - PySys_WriteStderr("gc: %.100s <%.100s instance at %p>\n", - msg, cname, inst); -} - -static void -debug_cycle(char *msg, PyObject *op) -{ - if ((debug & DEBUG_INSTANCES) && PyInstance_Check(op)) { - debug_instance(msg, (PyInstanceObject *)op); - } - else if (debug & DEBUG_OBJECTS) { - PySys_WriteStderr("gc: %.100s <%.100s %p>\n", - msg, Py_TYPE(op)->tp_name, op); - } -} - -/* Handle uncollectable garbage (cycles with finalizers, and stuff reachable - * only from such cycles). - * If DEBUG_SAVEALL, all objects in finalizers are appended to the module - * garbage list (a Python list), else only the objects in finalizers with - * __del__ methods are appended to garbage. All objects in finalizers are - * merged into the old list regardless. - * Returns 0 if all OK, <0 on error (out of memory to grow the garbage list). - * The finalizers list is made empty on a successful return. - */ -static int -handle_finalizers(PyGC_Head *finalizers, PyGC_Head *old) -{ - PyGC_Head *gc = finalizers->gc.gc_next; - - if (garbage == NULL) { - garbage = PyList_New(0); - if (garbage == NULL) - Py_FatalError("gc couldn't create gc.garbage list"); - } - for (; gc != finalizers; gc = gc->gc.gc_next) { - PyObject *op = FROM_GC(gc); - - if ((debug & DEBUG_SAVEALL) || has_finalizer(op)) { - if (PyList_Append(garbage, op) < 0) - return -1; - } - } - - gc_list_merge(finalizers, old); - return 0; -} - -/* Break reference cycles by clearing the containers involved. This is - * tricky business as the lists can be changing and we don't know which - * objects may be freed. It is possible I screwed something up here. - */ -static void -delete_garbage(PyGC_Head *collectable, PyGC_Head *old) -{ - inquiry clear; - - while (!gc_list_is_empty(collectable)) { - PyGC_Head *gc = collectable->gc.gc_next; - PyObject *op = FROM_GC(gc); - - assert(IS_TENTATIVELY_UNREACHABLE(op)); - if (debug & DEBUG_SAVEALL) { - PyList_Append(garbage, op); - } - else { - if ((clear = Py_TYPE(op)->tp_clear) != NULL) { - Py_INCREF(op); - clear(op); - Py_DECREF(op); - } - } - if (collectable->gc.gc_next == gc) { - /* object is still alive, move it, it may die later */ - gc_list_move(gc, old); - gc->gc.gc_refs = GC_REACHABLE; - } - } -} - -/* Clear all free lists - * All free lists are cleared during the collection of the highest generation. - * Allocated items in the free list may keep a pymalloc arena occupied. - * Clearing the free lists may give back memory to the OS earlier. - */ -static void -clear_freelists(void) -{ - (void)PyMethod_ClearFreeList(); - (void)PyFrame_ClearFreeList(); - (void)PyCFunction_ClearFreeList(); - (void)PyTuple_ClearFreeList(); -#ifdef Py_USING_UNICODE - (void)PyUnicode_ClearFreeList(); -#endif - (void)PyInt_ClearFreeList(); - (void)PyFloat_ClearFreeList(); -} - -static double -get_time(void) -{ - double result = 0; - if (tmod != NULL) { - PyObject *f = PyObject_CallMethod(tmod, "time", NULL); - if (f == NULL) { - PyErr_Clear(); - } - else { - if (PyFloat_Check(f)) - result = PyFloat_AsDouble(f); - Py_DECREF(f); - } - } - return result; -} - -/* This is the main function. Read this to understand how the - * collection process works. */ -static Py_ssize_t -collect(int generation) -{ - int i; - Py_ssize_t m = 0; /* # objects collected */ - Py_ssize_t n = 0; /* # unreachable objects that couldn't be collected */ - PyGC_Head *young; /* the generation we are examining */ - PyGC_Head *old; /* next older generation */ - PyGC_Head unreachable; /* non-problematic unreachable trash */ - PyGC_Head finalizers; /* objects with, & reachable from, __del__ */ - PyGC_Head *gc; - double t1 = 0.0; - - if (delstr == NULL) { - delstr = PyString_InternFromString("__del__"); - if (delstr == NULL) - Py_FatalError("gc couldn't allocate \"__del__\""); - } - - if (debug & DEBUG_STATS) { - PySys_WriteStderr("gc: collecting generation %d...\n", - generation); - PySys_WriteStderr("gc: objects in each generation:"); - for (i = 0; i < NUM_GENERATIONS; i++) - PySys_WriteStderr(" %" PY_FORMAT_SIZE_T "d", - gc_list_size(GEN_HEAD(i))); - t1 = get_time(); - PySys_WriteStderr("\n"); - } - - /* update collection and allocation counters */ - if (generation+1 < NUM_GENERATIONS) - generations[generation+1].count += 1; - for (i = 0; i <= generation; i++) - generations[i].count = 0; - - /* merge younger generations with one we are currently collecting */ - for (i = 0; i < generation; i++) { - gc_list_merge(GEN_HEAD(i), GEN_HEAD(generation)); - } - - /* handy references */ - young = GEN_HEAD(generation); - if (generation < NUM_GENERATIONS-1) - old = GEN_HEAD(generation+1); - else - old = young; - - /* Using ob_refcnt and gc_refs, calculate which objects in the - * container set are reachable from outside the set (i.e., have a - * refcount greater than 0 when all the references within the - * set are taken into account). - */ - update_refs(young); - subtract_refs(young); - - /* Leave everything reachable from outside young in young, and move - * everything else (in young) to unreachable. - * NOTE: This used to move the reachable objects into a reachable - * set instead. But most things usually turn out to be reachable, - * so it's more efficient to move the unreachable things. - */ - gc_list_init(&unreachable); - move_unreachable(young, &unreachable); - - /* Move reachable objects to next generation. */ - if (young != old) { - if (generation == NUM_GENERATIONS - 2) { - long_lived_pending += gc_list_size(young); - } - gc_list_merge(young, old); - } - else { - /* We only untrack dicts in full collections, to avoid quadratic - dict build-up. See issue #14775. */ - untrack_dicts(young); - long_lived_pending = 0; - long_lived_total = gc_list_size(young); - } - - /* All objects in unreachable are trash, but objects reachable from - * finalizers can't safely be deleted. Python programmers should take - * care not to create such things. For Python, finalizers means - * instance objects with __del__ methods. Weakrefs with callbacks - * can also call arbitrary Python code but they will be dealt with by - * handle_weakrefs(). - */ - gc_list_init(&finalizers); - move_finalizers(&unreachable, &finalizers); - /* finalizers contains the unreachable objects with a finalizer; - * unreachable objects reachable *from* those are also uncollectable, - * and we move those into the finalizers list too. - */ - move_finalizer_reachable(&finalizers); - - /* Collect statistics on collectable objects found and print - * debugging information. - */ - for (gc = unreachable.gc.gc_next; gc != &unreachable; - gc = gc->gc.gc_next) { - m++; - if (debug & DEBUG_COLLECTABLE) { - debug_cycle("collectable", FROM_GC(gc)); - } - } - - /* Clear weakrefs and invoke callbacks as necessary. */ - m += handle_weakrefs(&unreachable, old); - - /* Call tp_clear on objects in the unreachable set. This will cause - * the reference cycles to be broken. It may also cause some objects - * in finalizers to be freed. - */ - delete_garbage(&unreachable, old); - - /* Collect statistics on uncollectable objects found and print - * debugging information. */ - for (gc = finalizers.gc.gc_next; - gc != &finalizers; - gc = gc->gc.gc_next) { - n++; - if (debug & DEBUG_UNCOLLECTABLE) - debug_cycle("uncollectable", FROM_GC(gc)); - } - if (debug & DEBUG_STATS) { - double t2 = get_time(); - if (m == 0 && n == 0) - PySys_WriteStderr("gc: done"); - else - PySys_WriteStderr( - "gc: done, " - "%" PY_FORMAT_SIZE_T "d unreachable, " - "%" PY_FORMAT_SIZE_T "d uncollectable", - n+m, n); - if (t1 && t2) { - PySys_WriteStderr(", %.4fs elapsed", t2-t1); - } - PySys_WriteStderr(".\n"); - } - - /* Append instances in the uncollectable set to a Python - * reachable list of garbage. The programmer has to deal with - * this if they insist on creating this type of structure. - */ - (void)handle_finalizers(&finalizers, old); - - /* Clear free list only during the collection of the highest - * generation */ - if (generation == NUM_GENERATIONS-1) { - clear_freelists(); - } - - if (PyErr_Occurred()) { - if (gc_str == NULL) - gc_str = PyString_FromString("garbage collection"); - PyErr_WriteUnraisable(gc_str); - Py_FatalError("unexpected exception during garbage collection"); - } - return n+m; -} - -static Py_ssize_t -collect_generations(void) -{ - int i; - Py_ssize_t n = 0; - - /* Find the oldest generation (highest numbered) where the count - * exceeds the threshold. Objects in the that generation and - * generations younger than it will be collected. */ - for (i = NUM_GENERATIONS-1; i >= 0; i--) { - if (generations[i].count > generations[i].threshold) { - /* Avoid quadratic performance degradation in number - of tracked objects. See comments at the beginning - of this file, and issue #4074. - */ - if (i == NUM_GENERATIONS - 1 - && long_lived_pending < long_lived_total / 4) - continue; - n = collect(i); - break; - } - } - return n; -} - -PyDoc_STRVAR(gc_enable__doc__, -"enable() -> None\n" -"\n" -"Enable automatic garbage collection.\n"); - -static PyObject * -gc_enable(PyObject *self, PyObject *noargs) -{ - enabled = 1; - Py_INCREF(Py_None); - return Py_None; -} - -PyDoc_STRVAR(gc_disable__doc__, -"disable() -> None\n" -"\n" -"Disable automatic garbage collection.\n"); - -static PyObject * -gc_disable(PyObject *self, PyObject *noargs) -{ - enabled = 0; - Py_INCREF(Py_None); - return Py_None; -} - -PyDoc_STRVAR(gc_isenabled__doc__, -"isenabled() -> status\n" -"\n" -"Returns true if automatic garbage collection is enabled.\n"); - -static PyObject * -gc_isenabled(PyObject *self, PyObject *noargs) -{ - return PyBool_FromLong((long)enabled); -} - -PyDoc_STRVAR(gc_collect__doc__, -"collect([generation]) -> n\n" -"\n" -"With no arguments, run a full collection. The optional argument\n" -"may be an integer specifying which generation to collect. A ValueError\n" -"is raised if the generation number is invalid.\n\n" -"The number of unreachable objects is returned.\n"); - -static PyObject * -gc_collect(PyObject *self, PyObject *args, PyObject *kws) -{ - static char *keywords[] = {"generation", NULL}; - int genarg = NUM_GENERATIONS - 1; - Py_ssize_t n; - - if (!PyArg_ParseTupleAndKeywords(args, kws, "|i", keywords, &genarg)) - return NULL; - - else if (genarg < 0 || genarg >= NUM_GENERATIONS) { - PyErr_SetString(PyExc_ValueError, "invalid generation"); - return NULL; - } - - if (collecting) - n = 0; /* already collecting, don't do anything */ - else { - collecting = 1; - n = collect(genarg); - collecting = 0; - } - - return PyInt_FromSsize_t(n); -} - -PyDoc_STRVAR(gc_set_debug__doc__, -"set_debug(flags) -> None\n" -"\n" -"Set the garbage collection debugging flags. Debugging information is\n" -"written to sys.stderr.\n" -"\n" -"flags is an integer and can have the following bits turned on:\n" -"\n" -" DEBUG_STATS - Print statistics during collection.\n" -" DEBUG_COLLECTABLE - Print collectable objects found.\n" -" DEBUG_UNCOLLECTABLE - Print unreachable but uncollectable objects found.\n" -" DEBUG_INSTANCES - Print instance objects.\n" -" DEBUG_OBJECTS - Print objects other than instances.\n" -" DEBUG_SAVEALL - Save objects to gc.garbage rather than freeing them.\n" -" DEBUG_LEAK - Debug leaking programs (everything but STATS).\n"); - -static PyObject * -gc_set_debug(PyObject *self, PyObject *args) -{ - if (!PyArg_ParseTuple(args, "i:set_debug", &debug)) - return NULL; - - Py_INCREF(Py_None); - return Py_None; -} - -PyDoc_STRVAR(gc_get_debug__doc__, -"get_debug() -> flags\n" -"\n" -"Get the garbage collection debugging flags.\n"); - -static PyObject * -gc_get_debug(PyObject *self, PyObject *noargs) -{ - return Py_BuildValue("i", debug); -} - -PyDoc_STRVAR(gc_set_thresh__doc__, -"set_threshold(threshold0, [threshold1, threshold2]) -> None\n" -"\n" -"Sets the collection thresholds. Setting threshold0 to zero disables\n" -"collection.\n"); - -static PyObject * -gc_set_thresh(PyObject *self, PyObject *args) -{ - int i; - if (!PyArg_ParseTuple(args, "i|ii:set_threshold", - &generations[0].threshold, - &generations[1].threshold, - &generations[2].threshold)) - return NULL; - for (i = 2; i < NUM_GENERATIONS; i++) { - /* generations higher than 2 get the same threshold */ - generations[i].threshold = generations[2].threshold; - } - - Py_INCREF(Py_None); - return Py_None; -} - -PyDoc_STRVAR(gc_get_thresh__doc__, -"get_threshold() -> (threshold0, threshold1, threshold2)\n" -"\n" -"Return the current collection thresholds\n"); - -static PyObject * -gc_get_thresh(PyObject *self, PyObject *noargs) -{ - return Py_BuildValue("(iii)", - generations[0].threshold, - generations[1].threshold, - generations[2].threshold); -} - -PyDoc_STRVAR(gc_get_count__doc__, -"get_count() -> (count0, count1, count2)\n" -"\n" -"Return the current collection counts\n"); - -static PyObject * -gc_get_count(PyObject *self, PyObject *noargs) -{ - return Py_BuildValue("(iii)", - generations[0].count, - generations[1].count, - generations[2].count); -} - -static int -referrersvisit(PyObject* obj, PyObject *objs) -{ - Py_ssize_t i; - for (i = 0; i < PyTuple_GET_SIZE(objs); i++) - if (PyTuple_GET_ITEM(objs, i) == obj) - return 1; - return 0; -} - -static int -gc_referrers_for(PyObject *objs, PyGC_Head *list, PyObject *resultlist) -{ - PyGC_Head *gc; - PyObject *obj; - traverseproc traverse; - for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) { - obj = FROM_GC(gc); - traverse = Py_TYPE(obj)->tp_traverse; - if (obj == objs || obj == resultlist) - continue; - if (traverse(obj, (visitproc)referrersvisit, objs)) { - if (PyList_Append(resultlist, obj) < 0) - return 0; /* error */ - } - } - return 1; /* no error */ -} - -PyDoc_STRVAR(gc_get_referrers__doc__, -"get_referrers(*objs) -> list\n\ -Return the list of objects that directly refer to any of objs."); - -static PyObject * -gc_get_referrers(PyObject *self, PyObject *args) -{ - int i; - PyObject *result = PyList_New(0); - if (!result) return NULL; - - for (i = 0; i < NUM_GENERATIONS; i++) { - if (!(gc_referrers_for(args, GEN_HEAD(i), result))) { - Py_DECREF(result); - return NULL; - } - } - return result; -} - -/* Append obj to list; return true if error (out of memory), false if OK. */ -static int -referentsvisit(PyObject *obj, PyObject *list) -{ - return PyList_Append(list, obj) < 0; -} - -PyDoc_STRVAR(gc_get_referents__doc__, -"get_referents(*objs) -> list\n\ -Return the list of objects that are directly referred to by objs."); - -static PyObject * -gc_get_referents(PyObject *self, PyObject *args) -{ - Py_ssize_t i; - PyObject *result = PyList_New(0); - - if (result == NULL) - return NULL; - - for (i = 0; i < PyTuple_GET_SIZE(args); i++) { - traverseproc traverse; - PyObject *obj = PyTuple_GET_ITEM(args, i); - - if (! PyObject_IS_GC(obj)) - continue; - traverse = Py_TYPE(obj)->tp_traverse; - if (! traverse) - continue; - if (traverse(obj, (visitproc)referentsvisit, result)) { - Py_DECREF(result); - return NULL; - } - } - return result; -} - -PyDoc_STRVAR(gc_get_objects__doc__, -"get_objects() -> [...]\n" -"\n" -"Return a list of objects tracked by the collector (excluding the list\n" -"returned).\n"); - -static PyObject * -gc_get_objects(PyObject *self, PyObject *noargs) -{ - int i; - PyObject* result; - - result = PyList_New(0); - if (result == NULL) - return NULL; - for (i = 0; i < NUM_GENERATIONS; i++) { - if (append_objects(result, GEN_HEAD(i))) { - Py_DECREF(result); - return NULL; - } - } - return result; -} - -PyDoc_STRVAR(gc_is_tracked__doc__, -"is_tracked(obj) -> bool\n" -"\n" -"Returns true if the object is tracked by the garbage collector.\n" -"Simple atomic objects will return false.\n" -); - -static PyObject * -gc_is_tracked(PyObject *self, PyObject *obj) -{ - PyObject *result; - - if (PyObject_IS_GC(obj) && IS_TRACKED(obj)) - result = Py_True; - else - result = Py_False; - Py_INCREF(result); - return result; -} - - -PyDoc_STRVAR(gc__doc__, -"This module provides access to the garbage collector for reference cycles.\n" -"\n" -"enable() -- Enable automatic garbage collection.\n" -"disable() -- Disable automatic garbage collection.\n" -"isenabled() -- Returns true if automatic collection is enabled.\n" -"collect() -- Do a full collection right now.\n" -"get_count() -- Return the current collection counts.\n" -"set_debug() -- Set debugging flags.\n" -"get_debug() -- Get debugging flags.\n" -"set_threshold() -- Set the collection thresholds.\n" -"get_threshold() -- Return the current the collection thresholds.\n" -"get_objects() -- Return a list of all objects tracked by the collector.\n" -"is_tracked() -- Returns true if a given object is tracked.\n" -"get_referrers() -- Return the list of objects that refer to an object.\n" -"get_referents() -- Return the list of objects that an object refers to.\n"); - -static PyMethodDef GcMethods[] = { - {"enable", gc_enable, METH_NOARGS, gc_enable__doc__}, - {"disable", gc_disable, METH_NOARGS, gc_disable__doc__}, - {"isenabled", gc_isenabled, METH_NOARGS, gc_isenabled__doc__}, - {"set_debug", gc_set_debug, METH_VARARGS, gc_set_debug__doc__}, - {"get_debug", gc_get_debug, METH_NOARGS, gc_get_debug__doc__}, - {"get_count", gc_get_count, METH_NOARGS, gc_get_count__doc__}, - {"set_threshold", gc_set_thresh, METH_VARARGS, gc_set_thresh__doc__}, - {"get_threshold", gc_get_thresh, METH_NOARGS, gc_get_thresh__doc__}, - {"collect", (PyCFunction)gc_collect, - METH_VARARGS | METH_KEYWORDS, gc_collect__doc__}, - {"get_objects", gc_get_objects,METH_NOARGS, gc_get_objects__doc__}, - {"is_tracked", gc_is_tracked, METH_O, gc_is_tracked__doc__}, - {"get_referrers", gc_get_referrers, METH_VARARGS, - gc_get_referrers__doc__}, - {"get_referents", gc_get_referents, METH_VARARGS, - gc_get_referents__doc__}, - {NULL, NULL} /* Sentinel */ -}; - -PyMODINIT_FUNC -initgc(void) -{ - PyObject *m; - - m = Py_InitModule4("gc", - GcMethods, - gc__doc__, - NULL, - PYTHON_API_VERSION); - if (m == NULL) - return; - - if (garbage == NULL) { - garbage = PyList_New(0); - if (garbage == NULL) - return; - } - Py_INCREF(garbage); - if (PyModule_AddObject(m, "garbage", garbage) < 0) - return; - - /* Importing can't be done in collect() because collect() - * can be called via PyGC_Collect() in Py_Finalize(). - * This wouldn't be a problem, except that is - * reset to 0 before calling collect which trips up - * the import and triggers an assertion. - */ - if (tmod == NULL) { - tmod = PyImport_ImportModuleNoBlock("time"); - if (tmod == NULL) - PyErr_Clear(); - } - -#define ADD_INT(NAME) if (PyModule_AddIntConstant(m, #NAME, NAME) < 0) return - ADD_INT(DEBUG_STATS); - ADD_INT(DEBUG_COLLECTABLE); - ADD_INT(DEBUG_UNCOLLECTABLE); - ADD_INT(DEBUG_INSTANCES); - ADD_INT(DEBUG_OBJECTS); - ADD_INT(DEBUG_SAVEALL); - ADD_INT(DEBUG_LEAK); -#undef ADD_INT -} - -/* API to invoke gc.collect() from C */ -Py_ssize_t -PyGC_Collect(void) -{ - Py_ssize_t n; - - if (collecting) - n = 0; /* already collecting, don't do anything */ - else { - collecting = 1; - n = collect(NUM_GENERATIONS - 1); - collecting = 0; - } - - return n; -} - -/* for debugging */ -void -_PyGC_Dump(PyGC_Head *g) -{ - _PyObject_Dump(FROM_GC(g)); -} - -/* extension modules might be compiled with GC support so these - functions must always be available */ - -#undef PyObject_GC_Track -#undef PyObject_GC_UnTrack -#undef PyObject_GC_Del -#undef _PyObject_GC_Malloc - -void -PyObject_GC_Track(void *op) -{ - _PyObject_GC_TRACK(op); -} - -/* for binary compatibility with 2.2 */ -void -_PyObject_GC_Track(PyObject *op) -{ - PyObject_GC_Track(op); -} - -void -PyObject_GC_UnTrack(void *op) -{ - /* Obscure: the Py_TRASHCAN mechanism requires that we be able to - * call PyObject_GC_UnTrack twice on an object. - */ - if (IS_TRACKED(op)) - _PyObject_GC_UNTRACK(op); -} - -/* for binary compatibility with 2.2 */ -void -_PyObject_GC_UnTrack(PyObject *op) -{ - PyObject_GC_UnTrack(op); -} - -PyObject * -_PyObject_GC_Malloc(size_t basicsize) -{ - PyObject *op; - PyGC_Head *g; - if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head)) - return PyErr_NoMemory(); - g = (PyGC_Head *)PyObject_MALLOC( - sizeof(PyGC_Head) + basicsize); - if (g == NULL) - return PyErr_NoMemory(); - g->gc.gc_refs = GC_UNTRACKED; - generations[0].count++; /* number of allocated GC objects */ - if (generations[0].count > generations[0].threshold && - enabled && - generations[0].threshold && - !collecting && - !PyErr_Occurred()) { - collecting = 1; - collect_generations(); - collecting = 0; - } - op = FROM_GC(g); - return op; -} - -PyObject * -_PyObject_GC_New(PyTypeObject *tp) -{ - PyObject *op = _PyObject_GC_Malloc(_PyObject_SIZE(tp)); - if (op != NULL) - op = PyObject_INIT(op, tp); - return op; -} - -PyVarObject * -_PyObject_GC_NewVar(PyTypeObject *tp, Py_ssize_t nitems) -{ - const size_t size = _PyObject_VAR_SIZE(tp, nitems); - PyVarObject *op = (PyVarObject *) _PyObject_GC_Malloc(size); - if (op != NULL) - op = PyObject_INIT_VAR(op, tp, nitems); - return op; -} - -PyVarObject * -_PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems) -{ - const size_t basicsize = _PyObject_VAR_SIZE(Py_TYPE(op), nitems); - PyGC_Head *g = AS_GC(op); - if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head)) - return (PyVarObject *)PyErr_NoMemory(); - g = (PyGC_Head *)PyObject_REALLOC(g, sizeof(PyGC_Head) + basicsize); - if (g == NULL) - return (PyVarObject *)PyErr_NoMemory(); - op = (PyVarObject *) FROM_GC(g); - Py_SIZE(op) = nitems; - return op; -} - -void -PyObject_GC_Del(void *op) -{ - PyGC_Head *g = AS_GC(op); - if (IS_TRACKED(op)) - gc_list_remove(g); - if (generations[0].count > 0) { - generations[0].count--; - } - PyObject_FREE(g); -} - -/* for binary compatibility with 2.2 */ -#undef _PyObject_GC_Del -void -_PyObject_GC_Del(PyObject *op) -{ - PyObject_GC_Del(op); -}