mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-14 18:59:46 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

gh-124218: Use per-thread refcounts for code objects (#125216)

Browse source 
Use per-thread refcounting for the reference from function objects to
their corresponding code object. This can be a source of contention when
frequently creating nested functions. Deferred refcounting alone isn't a
great fit here because these references are on the heap and may be
modified by other libraries.
This commit is contained in:
Sam Gross 2024-10-15 15:06:41 -04:00 • committed by GitHub
parent 206de4155b
commit 3ea488aac4
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
11 changed files with 126 additions and 83 deletions
Download patch file Download diff file Expand all files Collapse all files

67
Python/uniqueid.c
View file

@ -98,36 +98,60 @@ _PyObject_AssignUniqueId(PyObject *obj)
return unique_id;
}
void
_PyObject_ReleaseUniqueId(Py_ssize_t unique_id)
static void
release_unique_id(Py_ssize_t unique_id)
{
PyInterpreterState *interp = _PyInterpreterState_GET();
struct _Py_unique_id_pool *pool = &interp->unique_ids;
if (unique_id < 0) {
// The id is not assigned
return;
}
LOCK_POOL(pool);
assert(unique_id >= 0 && unique_id < pool->size);
_Py_unique_id_entry *entry = &pool->table[unique_id];
entry->next = pool->freelist;
pool->freelist = entry;
UNLOCK_POOL(pool);
}
static Py_ssize_t
clear_unique_id(PyObject *obj)
{
Py_ssize_t id = -1;
if (PyType_Check(obj)) {
if (PyType_HasFeature((PyTypeObject *)obj, Py_TPFLAGS_HEAPTYPE)) {
PyHeapTypeObject *ht = (PyHeapTypeObject *)obj;
id = ht->unique_id;
ht->unique_id = -1;
}
}
else if (PyCode_Check(obj)) {
PyCodeObject *co = (PyCodeObject *)obj;
id = co->_co_unique_id;
co->_co_unique_id = -1;
}
return id;
}
void
_PyType_IncrefSlow(PyHeapTypeObject *type)
_PyObject_DisablePerThreadRefcounting(PyObject *obj)
{
Py_ssize_t id = clear_unique_id(obj);
if (id >= 0) {
release_unique_id(id);
}
}
void
_PyObject_ThreadIncrefSlow(PyObject *obj, Py_ssize_t unique_id)
{
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
if (type->unique_id < 0 || resize_local_refcounts(tstate) < 0) {
// just incref the type directly.
Py_INCREF(type);
if (unique_id < 0 || resize_local_refcounts(tstate) < 0) {
// just incref the object directly.
Py_INCREF(obj);
return;
}
assert(type->unique_id < tstate->refcounts.size);
tstate->refcounts.values[type->unique_id]++;
assert(unique_id < tstate->refcounts.size);
tstate->refcounts.values[unique_id]++;
#ifdef Py_REF_DEBUG
_Py_IncRefTotal((PyThreadState *)tstate);
#endif
@ -179,20 +203,15 @@ _PyObject_FinalizeUniqueIdPool(PyInterpreterState *interp)
pool->freelist = next;
}
// Now everything non-NULL is a type. Set the type's id to -1 in case it
// outlives the interpreter.
// Now everything non-NULL is a object. Clear their unique ids as the
// object outlives the interpreter.
for (Py_ssize_t i = 0; i < pool->size; i++) {
PyObject *obj = pool->table[i].obj;
pool->table[i].obj = NULL;
if (obj == NULL) {
continue;
}
if (PyType_Check(obj)) {
assert(PyType_HasFeature((PyTypeObject *)obj, Py_TPFLAGS_HEAPTYPE));
((PyHeapTypeObject *)obj)->unique_id = -1;
}
else {
Py_UNREACHABLE();
if (obj != NULL) {
Py_ssize_t id = clear_unique_id(obj);
(void)id;
assert(id == i);
}
}
PyMem_Free(pool->table);