mirror of https://github.com/python/cpython
GH-126491: GC: Mark objects reachable from roots before doing cycle collection (GH-126502)
* Mark almost all reachable objects before doing collection phase * Add stats for objects marked * Visit new frames before each increment * Remove lazy dict tracking * Update docs * Clearer calculation of work to do.
This commit is contained in:
Mark Shannon
GitHub
parent
a1d9c8aa80
commit
b0fcc2c47a
|
|
@ -99,6 +99,8 @@ typedef struct _gc_stats {
|
|||
uint64_t collections;
|
||||
uint64_t object_visits;
|
||||
uint64_t objects_collected;
|
||||
uint64_t objects_transitively_reachable;
|
||||
uint64_t objects_not_transitively_reachable;
|
||||
} GCStats;
|
||||
|
||||
typedef struct _uop_stats {
|
||||
|
|
|
|||
|
|
@ -43,8 +43,6 @@ extern int _PyDict_Next(
|
|||
|
||||
extern int _PyDict_HasOnlyStringKeys(PyObject *mp);
|
||||
|
||||
extern void _PyDict_MaybeUntrack(PyObject *mp);
|
||||
|
||||
// Export for '_ctypes' shared extension
|
||||
PyAPI_FUNC(Py_ssize_t) _PyDict_SizeOf(PyDictObject *);
|
||||
|
||||
|
|
|
|||
|
|
@ -75,6 +75,7 @@ typedef struct _PyInterpreterFrame {
|
|||
_PyStackRef *stackpointer;
|
||||
uint16_t return_offset; /* Only relevant during a function call */
|
||||
char owner;
|
||||
char visited;
|
||||
/* Locals and stack */
|
||||
_PyStackRef localsplus[1];
|
||||
} _PyInterpreterFrame;
|
||||
|
|
@ -207,6 +208,7 @@ _PyFrame_Initialize(
|
|||
#endif
|
||||
frame->return_offset = 0;
|
||||
frame->owner = FRAME_OWNED_BY_THREAD;
|
||||
frame->visited = 0;
|
||||
|
||||
for (int i = null_locals_from; i < code->co_nlocalsplus; i++) {
|
||||
frame->localsplus[i] = PyStackRef_NULL;
|
||||
|
|
@ -389,6 +391,7 @@ _PyFrame_PushTrampolineUnchecked(PyThreadState *tstate, PyCodeObject *code, int
|
|||
frame->instr_ptr = _PyCode_CODE(code);
|
||||
#endif
|
||||
frame->owner = FRAME_OWNED_BY_THREAD;
|
||||
frame->visited = 0;
|
||||
frame->return_offset = 0;
|
||||
|
||||
#ifdef Py_GIL_DISABLED
|
||||
|
|
|
|||
|
|
@ -10,11 +10,11 @@ extern "C" {
|
|||
|
||||
/* GC information is stored BEFORE the object structure. */
|
||||
typedef struct {
|
||||
// Pointer to next object in the list.
|
||||
// Tagged pointer to next object in the list.
|
||||
// 0 means the object is not tracked
|
||||
uintptr_t _gc_next;
|
||||
|
||||
// Pointer to previous object in the list.
|
||||
// Tagged pointer to previous object in the list.
|
||||
// Lowest two bits are used for flags documented later.
|
||||
uintptr_t _gc_prev;
|
||||
} PyGC_Head;
|
||||
|
|
@ -302,6 +302,11 @@ struct gc_generation_stats {
|
|||
Py_ssize_t uncollectable;
|
||||
};
|
||||
|
||||
enum _GCPhase {
|
||||
GC_PHASE_MARK = 0,
|
||||
GC_PHASE_COLLECT = 1
|
||||
};
|
||||
|
||||
struct _gc_runtime_state {
|
||||
/* List of objects that still need to be cleaned up, singly linked
|
||||
* via their gc headers' gc_prev pointers. */
|
||||
|
|
@ -325,10 +330,12 @@ struct _gc_runtime_state {
|
|||
/* a list of callbacks to be invoked when collection is performed */
|
||||
PyObject *callbacks;
|
||||
|
||||
Py_ssize_t prior_heap_size;
|
||||
Py_ssize_t heap_size;
|
||||
Py_ssize_t work_to_do;
|
||||
/* Which of the old spaces is the visited space */
|
||||
int visited_space;
|
||||
int phase;
|
||||
|
||||
#ifdef Py_GIL_DISABLED
|
||||
/* This is the number of objects that survived the last full
|
||||
|
|
|
|||
|
|
@ -466,8 +466,8 @@ static inline void _PyObject_GC_TRACK(
|
|||
PyGC_Head *last = (PyGC_Head*)(generation0->_gc_prev);
|
||||
_PyGCHead_SET_NEXT(last, gc);
|
||||
_PyGCHead_SET_PREV(gc, last);
|
||||
/* Young objects will be moved into the visited space during GC, so set the bit here */
|
||||
gc->_gc_next = ((uintptr_t)generation0) | (uintptr_t)interp->gc.visited_space;
|
||||
uintptr_t not_visited = 1 ^ interp->gc.visited_space;
|
||||
gc->_gc_next = ((uintptr_t)generation0) | not_visited;
|
||||
generation0->_gc_prev = (uintptr_t)gc;
|
||||
#endif
|
||||
}
|
||||
|
|
|
|||
|
|
@ -134,6 +134,7 @@ extern PyTypeObject _PyExc_MemoryError;
|
|||
{ .threshold = 0, }, \
|
||||
}, \
|
||||
.work_to_do = -5000, \
|
||||
.phase = GC_PHASE_MARK, \
|
||||
}, \
|
||||
.qsbr = { \
|
||||
.wr_seq = QSBR_INITIAL, \
|
||||
|
|
|
|||
|
|
@ -351,6 +351,7 @@ follows these steps in order:
|
|||
the reference counts fall to 0, triggering the destruction of all unreachable
|
||||
objects.
|
||||
|
||||
|
||||
Optimization: incremental collection
|
||||
====================================
|
||||
|
||||
|
|
@ -484,6 +485,46 @@ specifically in a generation by calling `gc.collect(generation=NUM)`.
|
|||
```
|
||||
|
||||
|
||||
Optimization: visiting reachable objects
|
||||
========================================
|
||||
|
||||
An object cannot be garbage if it can be reached.
|
||||
|
||||
To avoid having to identify reference cycles across the whole heap, we can
|
||||
reduce the amount of work done considerably by first moving most reachable objects
|
||||
to the `visited` space. Empirically, most reachable objects can be reached from a
|
||||
small set of global objects and local variables.
|
||||
This step does much less work per object, so reduces the time spent
|
||||
performing garbage collection by at least half.
|
||||
|
||||
> [!NOTE]
|
||||
> Objects that are not determined to be reachable by this pass are not necessarily
|
||||
> unreachable. We still need to perform the main algorithm to determine which objects
|
||||
> are actually unreachable.
|
||||
|
||||
We use the same technique of forming a transitive closure as the incremental
|
||||
collector does to find reachable objects, seeding the list with some global
|
||||
objects and the currently executing frames.
|
||||
|
||||
This phase moves objects to the `visited` space, as follows:
|
||||
|
||||
1. All objects directly referred to by any builtin class, the `sys` module, the `builtins`
|
||||
module and all objects directly referred to from stack frames are added to a working
|
||||
set of reachable objects.
|
||||
2. Until this working set is empty:
|
||||
1. Pop an object from the set and move it to the `visited` space
|
||||
2. For each object directly reachable from that object:
|
||||
* If it is not already in `visited` space and it is a GC object,
|
||||
add it to the working set
|
||||
|
||||
|
||||
Before each increment of collection is performed, the stacks are scanned
|
||||
to check for any new stack frames that have been created since the last
|
||||
increment. All objects directly referred to from those stack frames are
|
||||
added to the working set.
|
||||
Then the above algorithm is repeated, starting from step 2.
|
||||
|
||||
|
||||
Optimization: reusing fields to save memory
|
||||
===========================================
|
||||
|
||||
|
|
@ -532,8 +573,8 @@ of `PyGC_Head` discussed in the `Memory layout and object structure`_ section:
|
|||
currently in. Instead, when that's needed, ad hoc tricks (like the
|
||||
`NEXT_MASK_UNREACHABLE` flag) are employed.
|
||||
|
||||
Optimization: delay tracking containers
|
||||
=======================================
|
||||
Optimization: delayed untracking of containers
|
||||
==============================================
|
||||
|
||||
Certain types of containers cannot participate in a reference cycle, and so do
|
||||
not need to be tracked by the garbage collector. Untracking these objects
|
||||
|
|
@ -548,8 +589,8 @@ a container:
|
|||
As a general rule, instances of atomic types aren't tracked and instances of
|
||||
non-atomic types (containers, user-defined objects...) are. However, some
|
||||
type-specific optimizations can be present in order to suppress the garbage
|
||||
collector footprint of simple instances. Some examples of native types that
|
||||
benefit from delayed tracking:
|
||||
collector footprint of simple instances. Historically, both dictionaries and
|
||||
tuples were untracked during garbage collection. Now it is only tuples:
|
||||
|
||||
- Tuples containing only immutable objects (integers, strings etc,
|
||||
and recursively, tuples of immutable objects) do not need to be tracked. The
|
||||
|
|
@ -558,14 +599,8 @@ benefit from delayed tracking:
|
|||
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.
|
||||
already not tracked. Tuples are examined for untracking when moved from the
|
||||
young to the old generation.
|
||||
|
||||
The garbage collector module provides the Python function `is_tracked(obj)`, which returns
|
||||
the current tracking status of the object. Subsequent garbage collections may change the
|
||||
|
|
@ -578,11 +613,9 @@ tracking status of the object.
|
|||
False
|
||||
>>> gc.is_tracked([])
|
||||
True
|
||||
>>> gc.is_tracked({})
|
||||
>>> gc.is_tracked(("a", 1))
|
||||
False
|
||||
>>> gc.is_tracked({"a": 1})
|
||||
False
|
||||
>>> gc.is_tracked({"a": []})
|
||||
True
|
||||
```
|
||||
|
||||
|
|
|
|||
|
|
@ -880,115 +880,6 @@ class DictTest(unittest.TestCase):
|
|||
gc.collect()
|
||||
self.assertIs(ref(), None, "Cycle was not collected")
|
||||
|
||||
def _not_tracked(self, t):
|
||||
# Nested containers can take several collections to untrack
|
||||
gc.collect()
|
||||
gc.collect()
|
||||
self.assertFalse(gc.is_tracked(t), t)
|
||||
|
||||
def _tracked(self, t):
|
||||
self.assertTrue(gc.is_tracked(t), t)
|
||||
gc.collect()
|
||||
gc.collect()
|
||||
self.assertTrue(gc.is_tracked(t), t)
|
||||
|
||||
def test_string_keys_can_track_values(self):
|
||||
# Test that this doesn't leak.
|
||||
for i in range(10):
|
||||
d = {}
|
||||
for j in range(10):
|
||||
d[str(j)] = j
|
||||
d["foo"] = d
|
||||
|
||||
@support.cpython_only
|
||||
def test_track_literals(self):
|
||||
# Test GC-optimization of dict literals
|
||||
x, y, z, w = 1.5, "a", (1, None), []
|
||||
|
||||
self._not_tracked({})
|
||||
self._not_tracked({x:(), y:x, z:1})
|
||||
self._not_tracked({1: "a", "b": 2})
|
||||
self._not_tracked({1: 2, (None, True, False, ()): int})
|
||||
self._not_tracked({1: object()})
|
||||
|
||||
# Dicts with mutable elements are always tracked, even if those
|
||||
# elements are not tracked right now.
|
||||
self._tracked({1: []})
|
||||
self._tracked({1: ([],)})
|
||||
self._tracked({1: {}})
|
||||
self._tracked({1: set()})
|
||||
|
||||
@support.cpython_only
|
||||
def test_track_dynamic(self):
|
||||
# Test GC-optimization of dynamically-created dicts
|
||||
class MyObject(object):
|
||||
pass
|
||||
x, y, z, w, o = 1.5, "a", (1, object()), [], MyObject()
|
||||
|
||||
d = dict()
|
||||
self._not_tracked(d)
|
||||
d[1] = "a"
|
||||
self._not_tracked(d)
|
||||
d[y] = 2
|
||||
self._not_tracked(d)
|
||||
d[z] = 3
|
||||
self._not_tracked(d)
|
||||
self._not_tracked(d.copy())
|
||||
d[4] = w
|
||||
self._tracked(d)
|
||||
self._tracked(d.copy())
|
||||
d[4] = None
|
||||
self._not_tracked(d)
|
||||
self._not_tracked(d.copy())
|
||||
|
||||
# dd isn't tracked right now, but it may mutate and therefore d
|
||||
# which contains it must be tracked.
|
||||
d = dict()
|
||||
dd = dict()
|
||||
d[1] = dd
|
||||
self._not_tracked(dd)
|
||||
self._tracked(d)
|
||||
dd[1] = d
|
||||
self._tracked(dd)
|
||||
|
||||
d = dict.fromkeys([x, y, z])
|
||||
self._not_tracked(d)
|
||||
dd = dict()
|
||||
dd.update(d)
|
||||
self._not_tracked(dd)
|
||||
d = dict.fromkeys([x, y, z, o])
|
||||
self._tracked(d)
|
||||
dd = dict()
|
||||
dd.update(d)
|
||||
self._tracked(dd)
|
||||
|
||||
d = dict(x=x, y=y, z=z)
|
||||
self._not_tracked(d)
|
||||
d = dict(x=x, y=y, z=z, w=w)
|
||||
self._tracked(d)
|
||||
d = dict()
|
||||
d.update(x=x, y=y, z=z)
|
||||
self._not_tracked(d)
|
||||
d.update(w=w)
|
||||
self._tracked(d)
|
||||
|
||||
d = dict([(x, y), (z, 1)])
|
||||
self._not_tracked(d)
|
||||
d = dict([(x, y), (z, w)])
|
||||
self._tracked(d)
|
||||
d = dict()
|
||||
d.update([(x, y), (z, 1)])
|
||||
self._not_tracked(d)
|
||||
d.update([(x, y), (z, w)])
|
||||
self._tracked(d)
|
||||
|
||||
@support.cpython_only
|
||||
def test_track_subtypes(self):
|
||||
# Dict subtypes are always tracked
|
||||
class MyDict(dict):
|
||||
pass
|
||||
self._tracked(MyDict())
|
||||
|
||||
def make_shared_key_dict(self, n):
|
||||
class C:
|
||||
pass
|
||||
|
|
|
|||
|
|
@ -31,6 +31,11 @@ except ImportError:
|
|||
return C
|
||||
ContainerNoGC = None
|
||||
|
||||
try:
|
||||
import _testinternalcapi
|
||||
except ImportError:
|
||||
_testinternalcapi = None
|
||||
|
||||
### Support code
|
||||
###############################################################################
|
||||
|
||||
|
|
@ -1130,6 +1135,7 @@ class IncrementalGCTests(unittest.TestCase):
|
|||
def tearDown(self):
|
||||
gc.disable()
|
||||
|
||||
@unittest.skipIf(_testinternalcapi is None, "requires _testinternalcapi")
|
||||
@requires_gil_enabled("Free threading does not support incremental GC")
|
||||
# Use small increments to emulate longer running process in a shorter time
|
||||
@gc_threshold(200, 10)
|
||||
|
|
@ -1155,32 +1161,18 @@ class IncrementalGCTests(unittest.TestCase):
|
|||
return head
|
||||
|
||||
head = make_ll(1000)
|
||||
count = 1000
|
||||
|
||||
# There will be some objects we aren't counting,
|
||||
# e.g. the gc stats dicts. This test checks
|
||||
# that the counts don't grow, so we try to
|
||||
# correct for the uncounted objects
|
||||
# This is just an estimate.
|
||||
CORRECTION = 20
|
||||
|
||||
enabled = gc.isenabled()
|
||||
gc.enable()
|
||||
olds = []
|
||||
initial_heap_size = _testinternalcapi.get_heap_size()
|
||||
for i in range(20_000):
|
||||
newhead = make_ll(20)
|
||||
count += 20
|
||||
newhead.surprise = head
|
||||
olds.append(newhead)
|
||||
if len(olds) == 20:
|
||||
stats = gc.get_stats()
|
||||
young = stats[0]
|
||||
incremental = stats[1]
|
||||
old = stats[2]
|
||||
collected = young['collected'] + incremental['collected'] + old['collected']
|
||||
count += CORRECTION
|
||||
live = count - collected
|
||||
self.assertLess(live, 25000)
|
||||
new_objects = _testinternalcapi.get_heap_size() - initial_heap_size
|
||||
self.assertLess(new_objects, 25_000)
|
||||
del olds[:]
|
||||
if not enabled:
|
||||
gc.disable()
|
||||
|
|
@ -1322,7 +1314,8 @@ class GCCallbackTests(unittest.TestCase):
|
|||
from test.support import gc_collect, SuppressCrashReport
|
||||
|
||||
a = [1, 2, 3]
|
||||
b = [a]
|
||||
b = [a, a]
|
||||
a.append(b)
|
||||
|
||||
# Avoid coredump when Py_FatalError() calls abort()
|
||||
SuppressCrashReport().__enter__()
|
||||
|
|
@ -1332,6 +1325,8 @@ class GCCallbackTests(unittest.TestCase):
|
|||
# (to avoid deallocating it):
|
||||
import ctypes
|
||||
ctypes.pythonapi.Py_DecRef(ctypes.py_object(a))
|
||||
del a
|
||||
del b
|
||||
|
||||
# The garbage collector should now have a fatal error
|
||||
# when it reaches the broken object
|
||||
|
|
@ -1360,7 +1355,7 @@ class GCCallbackTests(unittest.TestCase):
|
|||
self.assertRegex(stderr,
|
||||
br'object type name: list')
|
||||
self.assertRegex(stderr,
|
||||
br'object repr : \[1, 2, 3\]')
|
||||
br'object repr : \[1, 2, 3, \[\[...\], \[...\]\]\]')
|
||||
|
||||
|
||||
class GCTogglingTests(unittest.TestCase):
|
||||
|
|
|
|||
|
|
@ -0,0 +1,4 @@
|
|||
Add a marking phase to the GC. All objects that can be transitively
|
||||
reached from builtin modules or the stacks are marked as reachable
|
||||
before cycle detection. This reduces the amount of work done by the
|
||||
GC by approximately half.
|
||||
|
|
@ -2077,6 +2077,12 @@ has_deferred_refcount(PyObject *self, PyObject *op)
|
|||
}
|
||||
|
||||
|
||||
static PyObject *
|
||||
get_heap_size(PyObject *self, PyObject *Py_UNUSED(ignored))
|
||||
{
|
||||
return PyLong_FromInt64(PyInterpreterState_Get()->gc.heap_size);
|
||||
}
|
||||
|
||||
static PyMethodDef module_functions[] = {
|
||||
{"get_configs", get_configs, METH_NOARGS},
|
||||
{"get_recursion_depth", get_recursion_depth, METH_NOARGS},
|
||||
|
|
@ -2174,6 +2180,7 @@ static PyMethodDef module_functions[] = {
|
|||
{"get_static_builtin_types", get_static_builtin_types, METH_NOARGS},
|
||||
{"identify_type_slot_wrappers", identify_type_slot_wrappers, METH_NOARGS},
|
||||
{"has_deferred_refcount", has_deferred_refcount, METH_O},
|
||||
{"get_heap_size", get_heap_size, METH_NOARGS},
|
||||
{NULL, NULL} /* sentinel */
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -883,6 +883,7 @@ new_dict(PyInterpreterState *interp,
|
|||
mp->ma_used = used;
|
||||
mp->_ma_watcher_tag = 0;
|
||||
ASSERT_CONSISTENT(mp);
|
||||
_PyObject_GC_TRACK(mp);
|
||||
return (PyObject *)mp;
|
||||
}
|
||||
|
||||
|
|
@ -1578,64 +1579,6 @@ _PyDict_HasOnlyStringKeys(PyObject *dict)
|
|||
return 1;
|
||||
}
|
||||
|
||||
#define MAINTAIN_TRACKING(mp, key, value) \
|
||||
do { \
|
||||
if (!_PyObject_GC_IS_TRACKED(mp)) { \
|
||||
if (_PyObject_GC_MAY_BE_TRACKED(key) || \
|
||||
_PyObject_GC_MAY_BE_TRACKED(value)) { \
|
||||
_PyObject_GC_TRACK(mp); \
|
||||
} \
|
||||
} \
|
||||
} while(0)
|
||||
|
||||
void
|
||||
_PyDict_MaybeUntrack(PyObject *op)
|
||||
{
|
||||
PyDictObject *mp;
|
||||
PyObject *value;
|
||||
Py_ssize_t i, numentries;
|
||||
|
||||
ASSERT_WORLD_STOPPED_OR_DICT_LOCKED(op);
|
||||
|
||||
if (!PyDict_CheckExact(op) || !_PyObject_GC_IS_TRACKED(op))
|
||||
return;
|
||||
|
||||
mp = (PyDictObject *) op;
|
||||
ASSERT_CONSISTENT(mp);
|
||||
numentries = mp->ma_keys->dk_nentries;
|
||||
if (_PyDict_HasSplitTable(mp)) {
|
||||
for (i = 0; i < numentries; i++) {
|
||||
if ((value = mp->ma_values->values[i]) == NULL)
|
||||
continue;
|
||||
if (_PyObject_GC_MAY_BE_TRACKED(value)) {
|
||||
return;
|
||||
}
|
||||
}
|
||||
}
|
||||
else {
|
||||
if (DK_IS_UNICODE(mp->ma_keys)) {
|
||||
PyDictUnicodeEntry *ep0 = DK_UNICODE_ENTRIES(mp->ma_keys);
|
||||
for (i = 0; i < numentries; i++) {
|
||||
if ((value = ep0[i].me_value) == NULL)
|
||||
continue;
|
||||
if (_PyObject_GC_MAY_BE_TRACKED(value))
|
||||
return;
|
||||
}
|
||||
}
|
||||
else {
|
||||
PyDictKeyEntry *ep0 = DK_ENTRIES(mp->ma_keys);
|
||||
for (i = 0; i < numentries; i++) {
|
||||
if ((value = ep0[i].me_value) == NULL)
|
||||
continue;
|
||||
if (_PyObject_GC_MAY_BE_TRACKED(value) ||
|
||||
_PyObject_GC_MAY_BE_TRACKED(ep0[i].me_key))
|
||||
return;
|
||||
}
|
||||
}
|
||||
}
|
||||
_PyObject_GC_UNTRACK(op);
|
||||
}
|
||||
|
||||
void
|
||||
_PyDict_EnablePerThreadRefcounting(PyObject *op)
|
||||
{
|
||||
|
|
@ -1761,7 +1704,6 @@ insert_split_value(PyInterpreterState *interp, PyDictObject *mp, PyObject *key,
|
|||
{
|
||||
assert(PyUnicode_CheckExact(key));
|
||||
ASSERT_DICT_LOCKED(mp);
|
||||
MAINTAIN_TRACKING(mp, key, value);
|
||||
PyObject *old_value = mp->ma_values->values[ix];
|
||||
if (old_value == NULL) {
|
||||
_PyDict_NotifyEvent(interp, PyDict_EVENT_ADDED, mp, key, value);
|
||||
|
|
@ -1818,8 +1760,6 @@ insertdict(PyInterpreterState *interp, PyDictObject *mp,
|
|||
if (ix == DKIX_ERROR)
|
||||
goto Fail;
|
||||
|
||||
MAINTAIN_TRACKING(mp, key, value);
|
||||
|
||||
if (ix == DKIX_EMPTY) {
|
||||
assert(!_PyDict_HasSplitTable(mp));
|
||||
/* Insert into new slot. */
|
||||
|
|
@ -1878,8 +1818,6 @@ insert_to_emptydict(PyInterpreterState *interp, PyDictObject *mp,
|
|||
/* We don't decref Py_EMPTY_KEYS here because it is immortal. */
|
||||
assert(mp->ma_values == NULL);
|
||||
|
||||
MAINTAIN_TRACKING(mp, key, value);
|
||||
|
||||
size_t hashpos = (size_t)hash & (PyDict_MINSIZE-1);
|
||||
dictkeys_set_index(newkeys, hashpos, 0);
|
||||
if (unicode) {
|
||||
|
|
@ -3770,11 +3708,6 @@ dict_dict_merge(PyInterpreterState *interp, PyDictObject *mp, PyDictObject *othe
|
|||
STORE_USED(mp, other->ma_used);
|
||||
ASSERT_CONSISTENT(mp);
|
||||
|
||||
if (_PyObject_GC_IS_TRACKED(other) && !_PyObject_GC_IS_TRACKED(mp)) {
|
||||
/* Maintain tracking. */
|
||||
_PyObject_GC_TRACK(mp);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
|
@ -4024,8 +3957,7 @@ copy_lock_held(PyObject *o)
|
|||
split_copy->ma_used = mp->ma_used;
|
||||
split_copy->_ma_watcher_tag = 0;
|
||||
dictkeys_incref(mp->ma_keys);
|
||||
if (_PyObject_GC_IS_TRACKED(mp))
|
||||
_PyObject_GC_TRACK(split_copy);
|
||||
_PyObject_GC_TRACK(split_copy);
|
||||
return (PyObject *)split_copy;
|
||||
}
|
||||
|
||||
|
|
@ -4060,10 +3992,6 @@ copy_lock_held(PyObject *o)
|
|||
|
||||
new->ma_used = mp->ma_used;
|
||||
ASSERT_CONSISTENT(new);
|
||||
if (_PyObject_GC_IS_TRACKED(mp)) {
|
||||
/* Maintain tracking. */
|
||||
_PyObject_GC_TRACK(new);
|
||||
}
|
||||
|
||||
return (PyObject *)new;
|
||||
}
|
||||
|
|
@ -4350,8 +4278,6 @@ dict_setdefault_ref_lock_held(PyObject *d, PyObject *key, PyObject *default_valu
|
|||
*result = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
MAINTAIN_TRACKING(mp, key, value);
|
||||
STORE_USED(mp, mp->ma_used + 1);
|
||||
assert(mp->ma_keys->dk_usable >= 0);
|
||||
ASSERT_CONSISTENT(mp);
|
||||
|
|
@ -4801,15 +4727,8 @@ dict_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
|
|||
d->ma_values = NULL;
|
||||
ASSERT_CONSISTENT(d);
|
||||
|
||||
if (type != &PyDict_Type) {
|
||||
// Don't track if a subclass tp_alloc is PyType_GenericAlloc()
|
||||
if (!_PyObject_GC_IS_TRACKED(d)) {
|
||||
_PyObject_GC_TRACK(d);
|
||||
}
|
||||
}
|
||||
else {
|
||||
// _PyType_AllocNoTrack() does not track the created object
|
||||
assert(!_PyObject_GC_IS_TRACKED(d));
|
||||
if (!_PyObject_GC_IS_TRACKED(d)) {
|
||||
_PyObject_GC_TRACK(d);
|
||||
}
|
||||
return self;
|
||||
}
|
||||
|
|
@ -6746,19 +6665,14 @@ make_dict_from_instance_attributes(PyInterpreterState *interp,
|
|||
{
|
||||
dictkeys_incref(keys);
|
||||
Py_ssize_t used = 0;
|
||||
Py_ssize_t track = 0;
|
||||
size_t size = shared_keys_usable_size(keys);
|
||||
for (size_t i = 0; i < size; i++) {
|
||||
PyObject *val = values->values[i];
|
||||
if (val != NULL) {
|
||||
used += 1;
|
||||
track += _PyObject_GC_MAY_BE_TRACKED(val);
|
||||
}
|
||||
}
|
||||
PyDictObject *res = (PyDictObject *)new_dict(interp, keys, values, used, 0);
|
||||
if (track && res) {
|
||||
_PyObject_GC_TRACK(res);
|
||||
}
|
||||
return res;
|
||||
}
|
||||
|
||||
|
|
@ -7204,6 +7118,7 @@ _PyObject_SetManagedDict(PyObject *obj, PyObject *new_dict)
|
|||
// since we locked it.
|
||||
dict = _PyObject_ManagedDictPointer(obj)->dict;
|
||||
err = _PyDict_DetachFromObject(dict, obj);
|
||||
assert(err == 0 || new_dict == NULL);
|
||||
if (err == 0) {
|
||||
FT_ATOMIC_STORE_PTR(_PyObject_ManagedDictPointer(obj)->dict,
|
||||
(PyDictObject *)Py_XNewRef(new_dict));
|
||||
|
|
@ -7236,7 +7151,21 @@ void
|
|||
PyObject_ClearManagedDict(PyObject *obj)
|
||||
{
|
||||
if (_PyObject_SetManagedDict(obj, NULL) < 0) {
|
||||
/* Must be out of memory */
|
||||
assert(PyErr_Occurred() == PyExc_MemoryError);
|
||||
PyErr_WriteUnraisable(NULL);
|
||||
/* Clear the dict */
|
||||
PyDictObject *dict = _PyObject_GetManagedDict(obj);
|
||||
Py_BEGIN_CRITICAL_SECTION2(dict, obj);
|
||||
dict = _PyObject_ManagedDictPointer(obj)->dict;
|
||||
PyInterpreterState *interp = _PyInterpreterState_GET();
|
||||
PyDictKeysObject *oldkeys = dict->ma_keys;
|
||||
set_keys(dict, Py_EMPTY_KEYS);
|
||||
dict->ma_values = NULL;
|
||||
dictkeys_decref(interp, oldkeys, IS_DICT_SHARED(dict));
|
||||
STORE_USED(dict, 0);
|
||||
set_dict_inline_values(obj, NULL);
|
||||
Py_END_CRITICAL_SECTION2();
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -7261,12 +7190,6 @@ _PyDict_DetachFromObject(PyDictObject *mp, PyObject *obj)
|
|||
PyDictValues *values = copy_values(mp->ma_values);
|
||||
|
||||
if (values == NULL) {
|
||||
/* Out of memory. Clear the dict */
|
||||
PyInterpreterState *interp = _PyInterpreterState_GET();
|
||||
PyDictKeysObject *oldkeys = mp->ma_keys;
|
||||
set_keys(mp, Py_EMPTY_KEYS);
|
||||
dictkeys_decref(interp, oldkeys, IS_DICT_SHARED(mp));
|
||||
STORE_USED(mp, 0);
|
||||
PyErr_NoMemory();
|
||||
return -1;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -107,8 +107,6 @@ static void
|
|||
track_module(PyModuleObject *m)
|
||||
{
|
||||
_PyDict_EnablePerThreadRefcounting(m->md_dict);
|
||||
PyObject_GC_Track(m->md_dict);
|
||||
|
||||
_PyObject_SetDeferredRefcount((PyObject *)m);
|
||||
PyObject_GC_Track(m);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -2340,10 +2340,6 @@ dummy_func(
|
|||
DEOPT_IF(ep->me_key != name);
|
||||
PyObject *old_value = ep->me_value;
|
||||
DEOPT_IF(old_value == NULL);
|
||||
/* Ensure dict is GC tracked if it needs to be */
|
||||
if (!_PyObject_GC_IS_TRACKED(dict) && _PyObject_GC_MAY_BE_TRACKED(PyStackRef_AsPyObjectBorrow(value))) {
|
||||
_PyObject_GC_TRACK(dict);
|
||||
}
|
||||
_PyDict_NotifyEvent(tstate->interp, PyDict_EVENT_MODIFIED, dict, name, PyStackRef_AsPyObjectBorrow(value));
|
||||
ep->me_value = PyStackRef_AsPyObjectSteal(value);
|
||||
// old_value should be DECREFed after GC track checking is done, if not, it could raise a segmentation fault,
|
||||
|
|
|
|||
|
|
@ -821,6 +821,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
|
|||
entry_frame.instr_ptr = (_Py_CODEUNIT *)_Py_INTERPRETER_TRAMPOLINE_INSTRUCTIONS + 1;
|
||||
entry_frame.stackpointer = entry_frame.localsplus;
|
||||
entry_frame.owner = FRAME_OWNED_BY_CSTACK;
|
||||
entry_frame.visited = 0;
|
||||
entry_frame.return_offset = 0;
|
||||
/* Push frame */
|
||||
entry_frame.previous = tstate->current_frame;
|
||||
|
|
|
|||
|
|
@ -2914,10 +2914,6 @@
|
|||
UOP_STAT_INC(uopcode, miss);
|
||||
JUMP_TO_JUMP_TARGET();
|
||||
}
|
||||
/* Ensure dict is GC tracked if it needs to be */
|
||||
if (!_PyObject_GC_IS_TRACKED(dict) && _PyObject_GC_MAY_BE_TRACKED(PyStackRef_AsPyObjectBorrow(value))) {
|
||||
_PyObject_GC_TRACK(dict);
|
||||
}
|
||||
_PyFrame_SetStackPointer(frame, stack_pointer);
|
||||
_PyDict_NotifyEvent(tstate->interp, PyDict_EVENT_MODIFIED, dict, name, PyStackRef_AsPyObjectBorrow(value));
|
||||
stack_pointer = _PyFrame_GetStackPointer(frame);
|
||||
|
|
|
|||
277
Python/gc.c
277
Python/gc.c
|
|
@ -5,7 +5,7 @@
|
|||
#include "Python.h"
|
||||
#include "pycore_ceval.h" // _Py_set_eval_breaker_bit()
|
||||
#include "pycore_context.h"
|
||||
#include "pycore_dict.h" // _PyDict_MaybeUntrack()
|
||||
#include "pycore_dict.h" // _PyInlineValuesSize()
|
||||
#include "pycore_initconfig.h"
|
||||
#include "pycore_interp.h" // PyInterpreterState.gc
|
||||
#include "pycore_object.h"
|
||||
|
|
@ -185,6 +185,7 @@ _PyGC_Init(PyInterpreterState *interp)
|
|||
if (gcstate->callbacks == NULL) {
|
||||
return _PyStatus_NO_MEMORY();
|
||||
}
|
||||
gcstate->prior_heap_size = 0;
|
||||
gcstate->heap_size = 0;
|
||||
|
||||
return _PyStatus_OK();
|
||||
|
|
@ -747,21 +748,6 @@ untrack_tuples(PyGC_Head *head)
|
|||
}
|
||||
}
|
||||
|
||||
/* Try to untrack all currently tracked dictionaries */
|
||||
static void
|
||||
untrack_dicts(PyGC_Head *head)
|
||||
{
|
||||
PyGC_Head *next, *gc = GC_NEXT(head);
|
||||
while (gc != head) {
|
||||
PyObject *op = FROM_GC(gc);
|
||||
next = GC_NEXT(gc);
|
||||
if (PyDict_CheckExact(op)) {
|
||||
_PyDict_MaybeUntrack(op);
|
||||
}
|
||||
gc = next;
|
||||
}
|
||||
}
|
||||
|
||||
/* Return true if object has a pre-PEP 442 finalization method. */
|
||||
static int
|
||||
has_legacy_finalizer(PyObject *op)
|
||||
|
|
@ -1258,15 +1244,10 @@ handle_resurrected_objects(PyGC_Head *unreachable, PyGC_Head* still_unreachable,
|
|||
gc_list_merge(resurrected, old_generation);
|
||||
}
|
||||
|
||||
|
||||
#define UNTRACK_TUPLES 1
|
||||
#define UNTRACK_DICTS 2
|
||||
|
||||
static void
|
||||
gc_collect_region(PyThreadState *tstate,
|
||||
PyGC_Head *from,
|
||||
PyGC_Head *to,
|
||||
int untrack,
|
||||
struct gc_collection_stats *stats);
|
||||
|
||||
static inline Py_ssize_t
|
||||
|
|
@ -1315,6 +1296,7 @@ gc_collect_young(PyThreadState *tstate,
|
|||
GCState *gcstate = &tstate->interp->gc;
|
||||
PyGC_Head *young = &gcstate->young.head;
|
||||
PyGC_Head *visited = &gcstate->old[gcstate->visited_space].head;
|
||||
untrack_tuples(&gcstate->young.head);
|
||||
GC_STAT_ADD(0, collections, 1);
|
||||
#ifdef Py_STATS
|
||||
{
|
||||
|
|
@ -1328,7 +1310,8 @@ gc_collect_young(PyThreadState *tstate,
|
|||
|
||||
PyGC_Head survivors;
|
||||
gc_list_init(&survivors);
|
||||
gc_collect_region(tstate, young, &survivors, UNTRACK_TUPLES, stats);
|
||||
gc_list_set_space(young, gcstate->visited_space);
|
||||
gc_collect_region(tstate, young, &survivors, stats);
|
||||
Py_ssize_t survivor_count = 0;
|
||||
if (gcstate->visited_space) {
|
||||
/* objects in visited space have bit set, so we set it here */
|
||||
|
|
@ -1343,16 +1326,11 @@ gc_collect_young(PyThreadState *tstate,
|
|||
survivor_count++;
|
||||
}
|
||||
}
|
||||
(void)survivor_count; // Silence compiler warning
|
||||
gc_list_merge(&survivors, visited);
|
||||
validate_old(gcstate);
|
||||
gcstate->young.count = 0;
|
||||
gcstate->old[gcstate->visited_space].count++;
|
||||
Py_ssize_t scale_factor = gcstate->old[0].threshold;
|
||||
if (scale_factor < 1) {
|
||||
scale_factor = 1;
|
||||
}
|
||||
gcstate->work_to_do += gcstate->heap_size / SCAN_RATE_DIVISOR / scale_factor;
|
||||
gcstate->work_to_do += survivor_count * 4;
|
||||
add_stats(gcstate, 0, stats);
|
||||
}
|
||||
|
||||
|
|
@ -1368,15 +1346,15 @@ IS_IN_VISITED(PyGC_Head *gc, int visited_space)
|
|||
struct container_and_flag {
|
||||
PyGC_Head *container;
|
||||
int visited_space;
|
||||
uintptr_t size;
|
||||
Py_ssize_t size;
|
||||
};
|
||||
|
||||
/* A traversal callback for adding to container) */
|
||||
static int
|
||||
visit_add_to_container(PyObject *op, void *arg)
|
||||
{
|
||||
OBJECT_STAT_INC(object_visits);
|
||||
struct container_and_flag *cf = (struct container_and_flag *)arg;
|
||||
OBJECT_STAT_INC(object_visits);
|
||||
int visited = cf->visited_space;
|
||||
assert(visited == get_gc_state()->visited_space);
|
||||
if (!_Py_IsImmortal(op) && _PyObject_IS_GC(op)) {
|
||||
|
|
@ -1391,10 +1369,9 @@ visit_add_to_container(PyObject *op, void *arg)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static uintptr_t
|
||||
static Py_ssize_t
|
||||
expand_region_transitively_reachable(PyGC_Head *container, PyGC_Head *gc, GCState *gcstate)
|
||||
{
|
||||
validate_list(container, collecting_clear_unreachable_clear);
|
||||
struct container_and_flag arg = {
|
||||
.container = container,
|
||||
.visited_space = gcstate->visited_space,
|
||||
|
|
@ -1406,6 +1383,7 @@ expand_region_transitively_reachable(PyGC_Head *container, PyGC_Head *gc, GCStat
|
|||
* have been marked as visited */
|
||||
assert(IS_IN_VISITED(gc, gcstate->visited_space));
|
||||
PyObject *op = FROM_GC(gc);
|
||||
assert(_PyObject_GC_IS_TRACKED(op));
|
||||
if (_Py_IsImmortal(op)) {
|
||||
PyGC_Head *next = GC_NEXT(gc);
|
||||
gc_list_move(gc, &get_gc_state()->permanent_generation.head);
|
||||
|
|
@ -1425,20 +1403,187 @@ expand_region_transitively_reachable(PyGC_Head *container, PyGC_Head *gc, GCStat
|
|||
static void
|
||||
completed_cycle(GCState *gcstate)
|
||||
{
|
||||
#ifdef Py_DEBUG
|
||||
PyGC_Head *not_visited = &gcstate->old[gcstate->visited_space^1].head;
|
||||
assert(gc_list_is_empty(not_visited));
|
||||
#endif
|
||||
gcstate->visited_space = flip_old_space(gcstate->visited_space);
|
||||
assert(gc_list_is_empty(&gcstate->old[gcstate->visited_space^1].head));
|
||||
int not_visited = gcstate->visited_space;
|
||||
gcstate->visited_space = flip_old_space(not_visited);
|
||||
/* Make sure all young objects have old space bit set correctly */
|
||||
PyGC_Head *young = &gcstate->young.head;
|
||||
PyGC_Head *gc = GC_NEXT(young);
|
||||
while (gc != young) {
|
||||
PyGC_Head *next = GC_NEXT(gc);
|
||||
gc_set_old_space(gc, gcstate->visited_space);
|
||||
gc_set_old_space(gc, not_visited);
|
||||
gc = next;
|
||||
}
|
||||
gcstate->work_to_do = 0;
|
||||
gcstate->phase = GC_PHASE_MARK;
|
||||
}
|
||||
|
||||
static Py_ssize_t
|
||||
move_to_reachable(PyObject *op, PyGC_Head *reachable, int visited_space)
|
||||
{
|
||||
if (op != NULL && !_Py_IsImmortal(op) && _PyObject_IS_GC(op)) {
|
||||
PyGC_Head *gc = AS_GC(op);
|
||||
if (_PyObject_GC_IS_TRACKED(op) &&
|
||||
gc_old_space(gc) != visited_space) {
|
||||
gc_flip_old_space(gc);
|
||||
gc_list_move(gc, reachable);
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static Py_ssize_t
|
||||
mark_all_reachable(PyGC_Head *reachable, PyGC_Head *visited, int visited_space)
|
||||
{
|
||||
// Transitively traverse all objects from reachable, until empty
|
||||
struct container_and_flag arg = {
|
||||
.container = reachable,
|
||||
.visited_space = visited_space,
|
||||
.size = 0
|
||||
};
|
||||
while (!gc_list_is_empty(reachable)) {
|
||||
PyGC_Head *gc = _PyGCHead_NEXT(reachable);
|
||||
assert(gc_old_space(gc) == visited_space);
|
||||
gc_list_move(gc, visited);
|
||||
PyObject *op = FROM_GC(gc);
|
||||
traverseproc traverse = Py_TYPE(op)->tp_traverse;
|
||||
(void) traverse(op,
|
||||
visit_add_to_container,
|
||||
&arg);
|
||||
}
|
||||
gc_list_validate_space(visited, visited_space);
|
||||
return arg.size;
|
||||
}
|
||||
|
||||
static Py_ssize_t
|
||||
mark_global_roots(PyInterpreterState *interp, PyGC_Head *visited, int visited_space)
|
||||
{
|
||||
PyGC_Head reachable;
|
||||
gc_list_init(&reachable);
|
||||
Py_ssize_t objects_marked = 0;
|
||||
objects_marked += move_to_reachable(interp->sysdict, &reachable, visited_space);
|
||||
objects_marked += move_to_reachable(interp->builtins, &reachable, visited_space);
|
||||
objects_marked += move_to_reachable(interp->dict, &reachable, visited_space);
|
||||
struct types_state *types = &interp->types;
|
||||
for (int i = 0; i < _Py_MAX_MANAGED_STATIC_BUILTIN_TYPES; i++) {
|
||||
objects_marked += move_to_reachable(types->builtins.initialized[i].tp_dict, &reachable, visited_space);
|
||||
objects_marked += move_to_reachable(types->builtins.initialized[i].tp_subclasses, &reachable, visited_space);
|
||||
}
|
||||
for (int i = 0; i < _Py_MAX_MANAGED_STATIC_EXT_TYPES; i++) {
|
||||
objects_marked += move_to_reachable(types->for_extensions.initialized[i].tp_dict, &reachable, visited_space);
|
||||
objects_marked += move_to_reachable(types->for_extensions.initialized[i].tp_subclasses, &reachable, visited_space);
|
||||
}
|
||||
objects_marked += mark_all_reachable(&reachable, visited, visited_space);
|
||||
assert(gc_list_is_empty(&reachable));
|
||||
return objects_marked;
|
||||
}
|
||||
|
||||
static Py_ssize_t
|
||||
mark_stacks(PyInterpreterState *interp, PyGC_Head *visited, int visited_space, bool start)
|
||||
{
|
||||
PyGC_Head reachable;
|
||||
gc_list_init(&reachable);
|
||||
Py_ssize_t objects_marked = 0;
|
||||
// Move all objects on stacks to reachable
|
||||
_PyRuntimeState *runtime = &_PyRuntime;
|
||||
HEAD_LOCK(runtime);
|
||||
PyThreadState* ts = PyInterpreterState_ThreadHead(interp);
|
||||
HEAD_UNLOCK(runtime);
|
||||
while (ts) {
|
||||
_PyInterpreterFrame *frame = ts->current_frame;
|
||||
while (frame) {
|
||||
if (frame->owner == FRAME_OWNED_BY_CSTACK) {
|
||||
frame = frame->previous;
|
||||
continue;
|
||||
}
|
||||
_PyStackRef *locals = frame->localsplus;
|
||||
_PyStackRef *sp = frame->stackpointer;
|
||||
objects_marked += move_to_reachable(frame->f_locals, &reachable, visited_space);
|
||||
PyObject *func = PyStackRef_AsPyObjectBorrow(frame->f_funcobj);
|
||||
objects_marked += move_to_reachable(func, &reachable, visited_space);
|
||||
while (sp > locals) {
|
||||
sp--;
|
||||
if (PyStackRef_IsNull(*sp)) {
|
||||
continue;
|
||||
}
|
||||
PyObject *op = PyStackRef_AsPyObjectBorrow(*sp);
|
||||
if (!_Py_IsImmortal(op) && _PyObject_IS_GC(op)) {
|
||||
PyGC_Head *gc = AS_GC(op);
|
||||
if (_PyObject_GC_IS_TRACKED(op) &&
|
||||
gc_old_space(gc) != visited_space) {
|
||||
gc_flip_old_space(gc);
|
||||
objects_marked++;
|
||||
gc_list_move(gc, &reachable);
|
||||
}
|
||||
}
|
||||
}
|
||||
if (!start && frame->visited) {
|
||||
// If this frame has already been visited, then the lower frames
|
||||
// will have already been visited and will not have changed
|
||||
break;
|
||||
}
|
||||
frame->visited = 1;
|
||||
frame = frame->previous;
|
||||
}
|
||||
HEAD_LOCK(runtime);
|
||||
ts = PyThreadState_Next(ts);
|
||||
HEAD_UNLOCK(runtime);
|
||||
}
|
||||
objects_marked += mark_all_reachable(&reachable, visited, visited_space);
|
||||
assert(gc_list_is_empty(&reachable));
|
||||
return objects_marked;
|
||||
}
|
||||
|
||||
static Py_ssize_t
|
||||
mark_at_start(PyThreadState *tstate)
|
||||
{
|
||||
// TO DO -- Make this incremental
|
||||
GCState *gcstate = &tstate->interp->gc;
|
||||
validate_old(gcstate);
|
||||
PyGC_Head *visited = &gcstate->old[gcstate->visited_space].head;
|
||||
Py_ssize_t objects_marked = mark_global_roots(tstate->interp, visited, gcstate->visited_space);
|
||||
objects_marked += mark_stacks(tstate->interp, visited, gcstate->visited_space, true);
|
||||
gcstate->work_to_do -= objects_marked;
|
||||
gcstate->phase = GC_PHASE_COLLECT;
|
||||
return objects_marked;
|
||||
}
|
||||
|
||||
static Py_ssize_t
|
||||
assess_work_to_do(GCState *gcstate)
|
||||
{
|
||||
/* The amount of work we want to do depends on three things.
|
||||
* 1. The number of new objects created
|
||||
* 2. The growth in heap size since the last collection
|
||||
* 3. The heap size (up to the number of new objects, to avoid quadratic effects)
|
||||
*
|
||||
* For a steady state heap, the amount of work to do is three times the number
|
||||
* of new objects added to the heap. This ensures that we stay ahead in the
|
||||
* worst case of all new objects being garbage.
|
||||
*
|
||||
* This could be improved by tracking survival rates, but it is still a
|
||||
* large improvement on the non-marking approach.
|
||||
*/
|
||||
Py_ssize_t scale_factor = gcstate->old[0].threshold;
|
||||
if (scale_factor < 2) {
|
||||
scale_factor = 2;
|
||||
}
|
||||
Py_ssize_t new_objects = gcstate->young.count;
|
||||
Py_ssize_t growth = gcstate->heap_size - gcstate->prior_heap_size;
|
||||
if (growth < 0) {
|
||||
growth = 0;
|
||||
}
|
||||
if (gcstate->heap_size < new_objects * scale_factor) {
|
||||
// Small heap: ignore growth
|
||||
growth = 0;
|
||||
}
|
||||
Py_ssize_t heap_fraction = gcstate->heap_size / SCAN_RATE_DIVISOR / scale_factor;
|
||||
if (heap_fraction > new_objects) {
|
||||
heap_fraction = new_objects;
|
||||
}
|
||||
gcstate->young.count = 0;
|
||||
gcstate->prior_heap_size = gcstate->heap_size;
|
||||
return new_objects*3/2 + growth*2 + heap_fraction*3/2;
|
||||
}
|
||||
|
||||
static void
|
||||
|
|
@ -1446,16 +1591,24 @@ gc_collect_increment(PyThreadState *tstate, struct gc_collection_stats *stats)
|
|||
{
|
||||
GC_STAT_ADD(1, collections, 1);
|
||||
GCState *gcstate = &tstate->interp->gc;
|
||||
|
||||
gcstate->work_to_do += assess_work_to_do(gcstate);
|
||||
untrack_tuples(&gcstate->young.head);
|
||||
if (gcstate->phase == GC_PHASE_MARK) {
|
||||
Py_ssize_t objects_marked = mark_at_start(tstate);
|
||||
GC_STAT_ADD(1, objects_transitively_reachable, objects_marked);
|
||||
gcstate->work_to_do -= objects_marked;
|
||||
return;
|
||||
}
|
||||
PyGC_Head *not_visited = &gcstate->old[gcstate->visited_space^1].head;
|
||||
PyGC_Head *visited = &gcstate->old[gcstate->visited_space].head;
|
||||
PyGC_Head increment;
|
||||
gc_list_init(&increment);
|
||||
Py_ssize_t scale_factor = gcstate->old[0].threshold;
|
||||
if (scale_factor < 1) {
|
||||
scale_factor = 1;
|
||||
}
|
||||
Py_ssize_t objects_marked = mark_stacks(tstate->interp, visited, gcstate->visited_space, false);
|
||||
GC_STAT_ADD(1, objects_transitively_reachable, objects_marked);
|
||||
gcstate->work_to_do -= objects_marked;
|
||||
gc_list_set_space(&gcstate->young.head, gcstate->visited_space);
|
||||
gc_list_merge(&gcstate->young.head, &increment);
|
||||
gcstate->young.count = 0;
|
||||
gc_list_validate_space(&increment, gcstate->visited_space);
|
||||
Py_ssize_t increment_size = 0;
|
||||
while (increment_size < gcstate->work_to_do) {
|
||||
|
|
@ -1465,17 +1618,18 @@ gc_collect_increment(PyThreadState *tstate, struct gc_collection_stats *stats)
|
|||
PyGC_Head *gc = _PyGCHead_NEXT(not_visited);
|
||||
gc_list_move(gc, &increment);
|
||||
increment_size++;
|
||||
assert(!_Py_IsImmortal(FROM_GC(gc)));
|
||||
gc_set_old_space(gc, gcstate->visited_space);
|
||||
increment_size += expand_region_transitively_reachable(&increment, gc, gcstate);
|
||||
}
|
||||
GC_STAT_ADD(1, objects_not_transitively_reachable, increment_size);
|
||||
gc_list_validate_space(&increment, gcstate->visited_space);
|
||||
PyGC_Head survivors;
|
||||
gc_list_init(&survivors);
|
||||
gc_collect_region(tstate, &increment, &survivors, UNTRACK_TUPLES, stats);
|
||||
gc_collect_region(tstate, &increment, &survivors, stats);
|
||||
gc_list_validate_space(&survivors, gcstate->visited_space);
|
||||
gc_list_merge(&survivors, visited);
|
||||
assert(gc_list_is_empty(&increment));
|
||||
gcstate->work_to_do += gcstate->heap_size / SCAN_RATE_DIVISOR / scale_factor;
|
||||
gcstate->work_to_do -= increment_size;
|
||||
|
||||
validate_old(gcstate);
|
||||
|
|
@ -1496,20 +1650,25 @@ gc_collect_full(PyThreadState *tstate,
|
|||
PyGC_Head *young = &gcstate->young.head;
|
||||
PyGC_Head *pending = &gcstate->old[gcstate->visited_space^1].head;
|
||||
PyGC_Head *visited = &gcstate->old[gcstate->visited_space].head;
|
||||
/* merge all generations into visited */
|
||||
gc_list_validate_space(young, gcstate->visited_space);
|
||||
gc_list_set_space(pending, gcstate->visited_space);
|
||||
untrack_tuples(&gcstate->young.head);
|
||||
/* merge all generations into pending */
|
||||
gc_list_validate_space(young, 1-gcstate->visited_space);
|
||||
gc_list_merge(young, pending);
|
||||
gc_list_set_space(visited, 1-gcstate->visited_space);
|
||||
gc_list_merge(visited, pending);
|
||||
/* Mark reachable */
|
||||
Py_ssize_t reachable = mark_global_roots(tstate->interp, visited, gcstate->visited_space);
|
||||
reachable += mark_stacks(tstate->interp, visited, gcstate->visited_space, true);
|
||||
(void)reachable;
|
||||
GC_STAT_ADD(2, objects_transitively_reachable, reachable);
|
||||
GC_STAT_ADD(2, objects_not_transitively_reachable, gc_list_size(pending));
|
||||
gcstate->young.count = 0;
|
||||
gc_list_merge(pending, visited);
|
||||
|
||||
gc_collect_region(tstate, visited, visited,
|
||||
UNTRACK_TUPLES | UNTRACK_DICTS,
|
||||
stats);
|
||||
gc_list_set_space(pending, gcstate->visited_space);
|
||||
gc_collect_region(tstate, pending, visited, stats);
|
||||
gcstate->young.count = 0;
|
||||
gcstate->old[0].count = 0;
|
||||
gcstate->old[1].count = 0;
|
||||
|
||||
completed_cycle(gcstate);
|
||||
gcstate->work_to_do = - gcstate->young.threshold * 2;
|
||||
_PyGC_ClearAllFreeLists(tstate->interp);
|
||||
validate_old(gcstate);
|
||||
|
|
@ -1522,7 +1681,6 @@ static void
|
|||
gc_collect_region(PyThreadState *tstate,
|
||||
PyGC_Head *from,
|
||||
PyGC_Head *to,
|
||||
int untrack,
|
||||
struct gc_collection_stats *stats)
|
||||
{
|
||||
PyGC_Head unreachable; /* non-problematic unreachable trash */
|
||||
|
|
@ -1536,12 +1694,6 @@ gc_collect_region(PyThreadState *tstate,
|
|||
gc_list_init(&unreachable);
|
||||
deduce_unreachable(from, &unreachable);
|
||||
validate_consistent_old_space(from);
|
||||
if (untrack & UNTRACK_TUPLES) {
|
||||
untrack_tuples(from);
|
||||
}
|
||||
if (untrack & UNTRACK_DICTS) {
|
||||
untrack_dicts(from);
|
||||
}
|
||||
validate_consistent_old_space(to);
|
||||
if (from != to) {
|
||||
gc_list_merge(from, to);
|
||||
|
|
@ -1761,9 +1913,10 @@ _PyGC_Freeze(PyInterpreterState *interp)
|
|||
{
|
||||
GCState *gcstate = &interp->gc;
|
||||
/* The permanent_generation has its old space bit set to zero */
|
||||
if (gcstate->visited_space) {
|
||||
if (!gcstate->visited_space) {
|
||||
gc_list_set_space(&gcstate->young.head, 0);
|
||||
}
|
||||
gc_list_validate_space(&gcstate->young.head, 0);
|
||||
gc_list_merge(&gcstate->young.head, &gcstate->permanent_generation.head);
|
||||
gcstate->young.count = 0;
|
||||
PyGC_Head*old0 = &gcstate->old[0].head;
|
||||
|
|
|
|||
|
|
@ -3,7 +3,7 @@
|
|||
#include "pycore_brc.h" // struct _brc_thread_state
|
||||
#include "pycore_ceval.h" // _Py_set_eval_breaker_bit()
|
||||
#include "pycore_context.h"
|
||||
#include "pycore_dict.h" // _PyDict_MaybeUntrack()
|
||||
#include "pycore_dict.h" // _PyInlineValuesSize()
|
||||
#include "pycore_freelist.h" // _PyObject_ClearFreeLists()
|
||||
#include "pycore_initconfig.h"
|
||||
#include "pycore_interp.h" // PyInterpreterState.gc
|
||||
|
|
@ -493,13 +493,6 @@ update_refs(const mi_heap_t *heap, const mi_heap_area_t *area,
|
|||
return true;
|
||||
}
|
||||
}
|
||||
else if (PyDict_CheckExact(op)) {
|
||||
_PyDict_MaybeUntrack(op);
|
||||
if (!_PyObject_GC_IS_TRACKED(op)) {
|
||||
gc_restore_refs(op);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// We repurpose ob_tid to compute "gc_refs", the number of external
|
||||
|
|
|
|||
|
|
@ -7432,10 +7432,6 @@
|
|||
DEOPT_IF(ep->me_key != name, STORE_ATTR);
|
||||
PyObject *old_value = ep->me_value;
|
||||
DEOPT_IF(old_value == NULL, STORE_ATTR);
|
||||
/* Ensure dict is GC tracked if it needs to be */
|
||||
if (!_PyObject_GC_IS_TRACKED(dict) && _PyObject_GC_MAY_BE_TRACKED(PyStackRef_AsPyObjectBorrow(value))) {
|
||||
_PyObject_GC_TRACK(dict);
|
||||
}
|
||||
_PyFrame_SetStackPointer(frame, stack_pointer);
|
||||
_PyDict_NotifyEvent(tstate->interp, PyDict_EVENT_MODIFIED, dict, name, PyStackRef_AsPyObjectBorrow(value));
|
||||
stack_pointer = _PyFrame_GetStackPointer(frame);
|
||||
|
|
|
|||
|
|
@ -230,6 +230,8 @@ print_gc_stats(FILE *out, GCStats *stats)
|
|||
for (int i = 0; i < NUM_GENERATIONS; i++) {
|
||||
fprintf(out, "GC[%d] collections: %" PRIu64 "\n", i, stats[i].collections);
|
||||
fprintf(out, "GC[%d] object visits: %" PRIu64 "\n", i, stats[i].object_visits);
|
||||
fprintf(out, "GC[%d] objects reachable from roots: %" PRIu64 "\n", i, stats[i].objects_transitively_reachable);
|
||||
fprintf(out, "GC[%d] objects not reachable from roots: %" PRIu64 "\n", i, stats[i].objects_not_transitively_reachable);
|
||||
fprintf(out, "GC[%d] objects collected: %" PRIu64 "\n", i, stats[i].objects_collected);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1118,6 +1118,8 @@ def gc_stats_section() -> Section:
|
|||
Count(gen["collections"]),
|
||||
Count(gen["objects collected"]),
|
||||
Count(gen["object visits"]),
|
||||
Count(gen["objects reachable from roots"]),
|
||||
Count(gen["objects not reachable from roots"]),
|
||||
)
|
||||
for (i, gen) in enumerate(gc_stats)
|
||||
]
|
||||
|
|
@ -1127,7 +1129,8 @@ def gc_stats_section() -> Section:
|
|||
"GC collections and effectiveness",
|
||||
[
|
||||
Table(
|
||||
("Generation:", "Collections:", "Objects collected:", "Object visits:"),
|
||||
("Generation:", "Collections:", "Objects collected:", "Object visits:",
|
||||
"Reachable from roots:", "Not reachable from roots:"),
|
||||
calc_gc_stats,
|
||||
)
|
||||
],
|
||||
|
|
|
|||
Loading…
Reference in New Issue