codekingpro/portable-devtools

1#ifndef Py_CPYTHON_WEAKREFOBJECT_H2#  error "this header file must not be included directly"3#endif4 5/* PyWeakReference is the base struct for the Python ReferenceType, ProxyType,6 * and CallableProxyType.7 */8struct _PyWeakReference {9    PyObject_HEAD10 11    /* The object to which this is a weak reference, or Py_None if none.12     * Note that this is a stealth reference:  wr_object's refcount is13     * not incremented to reflect this pointer.14     */15    PyObject *wr_object;16 17    /* A callable to invoke when wr_object dies, or NULL if none. */18    PyObject *wr_callback;19 20    /* A cache for wr_object's hash code.  As usual for hashes, this is -121     * if the hash code isn't known yet.22     */23    Py_hash_t hash;24 25    /* If wr_object is weakly referenced, wr_object has a doubly-linked NULL-26     * terminated list of weak references to it.  These are the list pointers.27     * If wr_object goes away, wr_object is set to Py_None, and these pointers28     * have no meaning then.29     */30    PyWeakReference *wr_prev;31    PyWeakReference *wr_next;32    vectorcallfunc vectorcall;33 34#ifdef Py_GIL_DISABLED35    /* Pointer to the lock used when clearing in free-threaded builds.36     * Normally this can be derived from wr_object, but in some cases we need37     * to lock after wr_object has been set to Py_None.38     */39    PyMutex *weakrefs_lock;40#endif41};42 43PyAPI_FUNC(void) _PyWeakref_ClearRef(PyWeakReference *self);44 45#define _PyWeakref_CAST(op) \46    (assert(PyWeakref_Check(op)), _Py_CAST(PyWeakReference*, (op)))47 48// Test if a weak reference is dead.49PyAPI_FUNC(int) PyWeakref_IsDead(PyObject *ref);50 51Py_DEPRECATED(3.13) static inline PyObject* PyWeakref_GET_OBJECT(PyObject *ref_obj)52{53    PyWeakReference *ref = _PyWeakref_CAST(ref_obj);54    PyObject *obj = ref->wr_object;55    // Explanation for the Py_REFCNT() check: when a weakref's target is part56    // of a long chain of deallocations which triggers the trashcan mechanism,57    // clearing the weakrefs can be delayed long after the target's refcount58    // has dropped to zero.  In the meantime, code accessing the weakref will59    // be able to "see" the target object even though it is supposed to be60    // unreachable.  See issue gh-60806.61    if (Py_REFCNT(obj) > 0) {62        return obj;63    }64    return Py_None;65}66#define PyWeakref_GET_OBJECT(ref) PyWeakref_GET_OBJECT(_PyObject_CAST(ref))67