Documentation
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Overview ¶
Package brc ports cpython/Python/brc.c. v0.3 ships only the field layout and no-op operations; the GIL build does not need biased reference counting. The free-threading build wires the queues in a later phase (see roadmap v0.14).
CPython: Python/brc.c file overview
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func DrainQueue ¶
func DrainQueue(_ *ThreadState)
DrainQueue runs the owner-side drain step. v0.3 has nothing to drain; the loop body lands in v0.14.
CPython: Python/brc.c:L131 _Py_brc_merge_refcounts
func QueueRemote ¶
func QueueRemote(_ *ThreadState, _ *QueuedObject)
QueueRemote enqueues obj on the owner's remote queue. In the GIL build this is a no-op because every thread shares one refcount. In the free-threading build (v0.14) this walks the lock-free push path from CPython.
CPython: Python/brc.c:L66 _Py_brc_queue_object
Types ¶
type QueuedObject ¶
type QueuedObject struct {
Next *QueuedObject
}
QueuedObject is the link entry that a remote thread pushes onto an owner's biased-refcount queue when it decrements an object that the owner allocated. The owner drains its own queue without atomics.
CPython: Include/internal/pycore_brc.h:L29 _PyObjectQueue
type ThreadState ¶
type ThreadState struct {
LocalQueue *QueuedObject
RemoteQueue atomic.Pointer[QueuedObject]
QueueMutex uint32
TID uint64
}
ThreadState is the per-thread biased-refcount slot. Each Python thread embeds one of these in its state.Thread (wired up in v0.14). The owner pushes "merged" decrements into LocalQueue; remote threads push into RemoteQueue, which the owner drains under QueueMutex.
CPython: Include/internal/pycore_brc.h:L57 _Py_brc_per_thread_state
Source Files