python · markshannon · Aug 1, 2025 · Jul 7, 2025 · Jul 7, 2025 · Jul 7, 2025
@@ -198,6 +198,9 @@ struct _ts {

    PyObject *current_executor;

+    /* Internal to the JIT */
+    struct _PyExitData *jit_exit;
+
    uint64_t dict_global_version;

    /* Used to store/retrieve `threading.local` keys/values for this thread */

diff --git a/Include/internal/pycore_interp_structs.h b/Include/internal/pycore_interp_structs.h
@@ -943,6 +943,7 @@ struct _is {
    bool jit;
    struct _PyExecutorObject *executor_list_head;
    struct _PyExecutorObject *executor_deletion_list_head;
+    struct _PyExecutorObject *cold_executor;
    int executor_deletion_list_remaining_capacity;
    size_t trace_run_counter;
    _rare_events rare_events;

diff --git a/Include/internal/pycore_optimizer.h b/Include/internal/pycore_optimizer.h
@@ -67,8 +67,9 @@ typedef struct {
 #endif
 } _PyUOpInstruction;

-typedef struct {
+typedef struct _PyExitData {
    uint32_t target;
+    uint16_t index;
    _Py_BackoffCounter temperature;
    struct _PyExecutorObject *executor;
 } _PyExitData;
@@ -354,6 +355,16 @@ PyAPI_FUNC(PyObject *) _Py_uop_symbols_test(PyObject *self, PyObject *ignored);

 PyAPI_FUNC(int) _PyOptimizer_Optimize(_PyInterpreterFrame *frame, _Py_CODEUNIT *start, _PyExecutorObject **exec_ptr, int chain_depth);

+static inline _PyExecutorObject *_PyExecutor_FromExit(_PyExitData *exit)
+{
+    _PyExitData *exit0 = exit - exit->index;
+    return (_PyExecutorObject *)(((char *)exit0) - offsetof(_PyExecutorObject, exits));
+}
+
+extern _PyExecutorObject *_PyExecutor_GetColdExecutor(void);
+
+PyAPI_FUNC(void) _PyExecutor_ClearExit(_PyExitData *exit);
+
 static inline int is_terminator(const _PyUOpInstruction *uop)
 {
    int opcode = uop->opcode;
@@ -363,6 +374,8 @@ static inline int is_terminator(const _PyUOpInstruction *uop)
    );
 }

+extern void _PyExecutor_Free(_PyExecutorObject *self);
+
 PyAPI_FUNC(int) _PyDumpExecutors(FILE *out);
 #ifdef _Py_TIER2
 extern void _Py_ClearExecutorDeletionList(PyInterpreterState *interp);