python 2.7 -> python 3.14

extern/include/python/internal/pycore_brc.h

@@ -0,0 +1,73 @@
+#ifndef Py_INTERNAL_BRC_H
+#define Py_INTERNAL_BRC_H
+
+#include <stdint.h>
+#include "pycore_llist.h"           // struct llist_node
+#include "pycore_object_stack.h"    // _PyObjectStack
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+#ifdef Py_GIL_DISABLED
+
+// Prime number to avoid correlations with memory addresses.
+#define _Py_BRC_NUM_BUCKETS 257
+
+// Hash table bucket
+struct _brc_bucket {
+    // Mutex protects both the bucket and thread state queues in this bucket.
+    PyMutex mutex;
+
+    // Linked list of _PyThreadStateImpl objects hashed to this bucket.
+    struct llist_node root;
+};
+
+// Per-interpreter biased reference counting state
+struct _brc_state {
+    // Hash table of thread states by thread-id. Thread states within a bucket
+    // are chained using a doubly-linked list.
+    struct _brc_bucket table[_Py_BRC_NUM_BUCKETS];
+};
+
+// Per-thread biased reference counting state
+struct _brc_thread_state {
+    // Linked-list of thread states per hash bucket
+    struct llist_node bucket_node;
+
+    // Thread-id as determined by _PyThread_Id()
+    uintptr_t tid;
+
+    // Objects with refcounts to be merged (protected by bucket mutex)
+    _PyObjectStack objects_to_merge;
+
+    // Local stack of objects to be merged (not accessed by other threads)
+    _PyObjectStack local_objects_to_merge;
+};
+
+// Initialize/finalize the per-thread biased reference counting state
+void _Py_brc_init_thread(PyThreadState *tstate);
+void _Py_brc_remove_thread(PyThreadState *tstate);
+
+// Initialize per-interpreter state
+void _Py_brc_init_state(PyInterpreterState *interp);
+
+void _Py_brc_after_fork(PyInterpreterState *interp);
+
+// Enqueues an object to be merged by it's owning thread (tid). This
+// steals a reference to the object.
+void _Py_brc_queue_object(PyObject *ob);
+
+// Merge the refcounts of queued objects for the current thread.
+void _Py_brc_merge_refcounts(PyThreadState *tstate);
+
+#endif /* Py_GIL_DISABLED */
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_INTERNAL_BRC_H */