1 #ifndef Py_INTERNAL_BRC_H 2 #define Py_INTERNAL_BRC_H 3 4 #include <stdint.h> 5 #include "pycore_llist.h" // struct llist_node 6 #include "pycore_lock.h" // PyMutex 7 #include "pycore_object_stack.h" // _PyObjectStack 8 9 #ifdef __cplusplus 10 extern "C" { 11 #endif 12 13 #ifndef Py_BUILD_CORE 14 # error "this header requires Py_BUILD_CORE define" 15 #endif 16 17 #ifdef Py_GIL_DISABLED 18 19 // Prime number to avoid correlations with memory addresses. 20 #define _Py_BRC_NUM_BUCKETS 257 21 22 // Hash table bucket 23 struct _brc_bucket { 24 // Mutex protects both the bucket and thread state queues in this bucket. 25 PyMutex mutex; 26 27 // Linked list of _PyThreadStateImpl objects hashed to this bucket. 28 struct llist_node root; 29 }; 30 31 // Per-interpreter biased reference counting state 32 struct _brc_state { 33 // Hash table of thread states by thread-id. Thread states within a bucket 34 // are chained using a doubly-linked list. 35 struct _brc_bucket table[_Py_BRC_NUM_BUCKETS]; 36 }; 37 38 // Per-thread biased reference counting state 39 struct _brc_thread_state { 40 // Linked-list of thread states per hash bucket 41 struct llist_node bucket_node; 42 43 // Thread-id as determined by _PyThread_Id() 44 uintptr_t tid; 45 46 // Objects with refcounts to be merged (protected by bucket mutex) 47 _PyObjectStack objects_to_merge; 48 49 // Local stack of objects to be merged (not accessed by other threads) 50 _PyObjectStack local_objects_to_merge; 51 }; 52 53 // Initialize/finalize the per-thread biased reference counting state 54 void _Py_brc_init_thread(PyThreadState *tstate); 55 void _Py_brc_remove_thread(PyThreadState *tstate); 56 57 // Initialize per-interpreter state 58 void _Py_brc_init_state(PyInterpreterState *interp); 59 60 void _Py_brc_after_fork(PyInterpreterState *interp); 61 62 // Enqueues an object to be merged by it's owning thread (tid). This 63 // steals a reference to the object. 64 void _Py_brc_queue_object(PyObject *ob); 65 66 // Merge the refcounts of queued objects for the current thread. 67 void _Py_brc_merge_refcounts(PyThreadState *tstate); 68 69 #endif /* Py_GIL_DISABLED */ 70 71 #ifdef __cplusplus 72 } 73 #endif 74 #endif /* !Py_INTERNAL_BRC_H */ 75