bpo-37878: Remove PyThreadState_DeleteCurrent() function (GH-15315)

* Rename PyThreadState_DeleteCurrent()
  to _PyThreadState_DeleteCurrent()
* Move it to the internal C API

Co-Authored-By: Carol Willing <carolcode@willingconsulting.com>

Doc/whatsnew/3.9.rst

@@ -219,6 +219,9 @@ Removed
   standard :class:`bytes` objects are always used.
   (Contributed by Jon Janzen in :issue:`36409`.)
 
+* ``PyThreadState_DeleteCurrent()`` has been removed. It was not documented.
+  (Contributed by Joannah Nanjekye in :issue:`37878`.)
+
 
 Porting to Python 3.9
 =====================

Include/internal/pycore_pylifecycle.h

@@ -110,6 +110,8 @@ PyAPI_FUNC(void) _PyErr_Print(PyThreadState *tstate);
 PyAPI_FUNC(void) _PyErr_Display(PyObject *file, PyObject *exception,
                                 PyObject *value, PyObject *tb);
 
+PyAPI_FUNC(void) _PyThreadState_DeleteCurrent(_PyRuntimeState *runtime);
+
 #ifdef __cplusplus
 }
 #endif

Include/pystate.h

@@ -50,7 +50,6 @@ PyAPI_FUNC(PyObject*) PyState_FindModule(struct PyModuleDef*);
 PyAPI_FUNC(PyThreadState *) PyThreadState_New(PyInterpreterState *);
 PyAPI_FUNC(void) PyThreadState_Clear(PyThreadState *);
 PyAPI_FUNC(void) PyThreadState_Delete(PyThreadState *);
-PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void);
 
 /* Get the current thread state.
 

Misc/NEWS.d/next/Documentation/2019-08-16-20-01-10.bpo-37878.MvA6rZ.rst

@@ -0,0 +1 @@
+Make :c:func:`PyThreadState_DeleteCurrent` Internal.

Modules/_threadmodule.c

@@ -993,6 +993,7 @@ struct bootstate {
     PyObject *args;
     PyObject *keyw;
     PyThreadState *tstate;
+    _PyRuntimeState *runtime;
 };
 
 static void
@@ -1000,11 +1001,13 @@ t_bootstrap(void *boot_raw)
 {
     struct bootstate *boot = (struct bootstate *) boot_raw;
     PyThreadState *tstate;
+    _PyRuntimeState *runtime;
     PyObject *res;
 
+    runtime = boot->runtime;
     tstate = boot->tstate;
     tstate->thread_id = PyThread_get_thread_ident();
-    _PyThreadState_Init(&_PyRuntime, tstate);
+    _PyThreadState_Init(runtime, tstate);
     PyEval_AcquireThread(tstate);
     tstate->interp->num_threads++;
     res = PyObject_Call(boot->func, boot->args, boot->keyw);
@@ -1025,13 +1028,14 @@ t_bootstrap(void *boot_raw)
     PyMem_DEL(boot_raw);
     tstate->interp->num_threads--;
     PyThreadState_Clear(tstate);
-    PyThreadState_DeleteCurrent();
+    _PyThreadState_DeleteCurrent(runtime);
     PyThread_exit_thread();
 }
 
 static PyObject *
 thread_PyThread_start_new_thread(PyObject *self, PyObject *fargs)
 {
+    _PyRuntimeState *runtime = &_PyRuntime;
     PyObject *func, *args, *keyw = NULL;
     struct bootstate *boot;
     unsigned long ident;
@@ -1062,6 +1066,7 @@ thread_PyThread_start_new_thread(PyObject *self, PyObject *fargs)
     boot->args = args;
     boot->keyw = keyw;
     boot->tstate = _PyThreadState_Prealloc(boot->interp);
+    boot->runtime = runtime;
     if (boot->tstate == NULL) {
         PyMem_DEL(boot);
         return PyErr_NoMemory();

Modules/_tracemalloc.c

@@ -34,7 +34,7 @@ static struct {
 #if defined(TRACE_RAW_MALLOC)
 /* This lock is needed because tracemalloc_free() is called without
    the GIL held from PyMem_RawFree(). It cannot acquire the lock because it
-   would introduce a deadlock in PyThreadState_DeleteCurrent(). */
+   would introduce a deadlock in _PyThreadState_DeleteCurrent(). */
 static PyThread_type_lock tables_lock;
 #  define TABLES_LOCK() PyThread_acquire_lock(tables_lock, 1)
 #  define TABLES_UNLOCK() PyThread_release_lock(tables_lock)
@@ -728,7 +728,7 @@ tracemalloc_free(void *ctx, void *ptr)
         return;
 
      /* GIL cannot be locked in PyMem_RawFree() because it would introduce
-        a deadlock in PyThreadState_DeleteCurrent(). */
+        a deadlock in _PyThreadState_DeleteCurrent(). */
 
     alloc->free(alloc->ctx, ptr);
 

Python/pystate.c

@@ -809,7 +809,7 @@ PyThreadState_Clear(PyThreadState *tstate)
 }
 
 
-/* Common code for PyThreadState_Delete() and PyThreadState_DeleteCurrent() */
+/* Common code for PyThreadState_Delete() and _PyThreadState_DeleteCurrent() */
 static void
 tstate_delete_common(_PyRuntimeState *runtime, PyThreadState *tstate)
 {
@@ -858,14 +858,14 @@ PyThreadState_Delete(PyThreadState *tstate)
 }
 
 
-static void
+void
 _PyThreadState_DeleteCurrent(_PyRuntimeState *runtime)
 {
     struct _gilstate_runtime_state *gilstate = &runtime->gilstate;
     PyThreadState *tstate = _PyRuntimeGILState_GetThreadState(gilstate);
     if (tstate == NULL)
         Py_FatalError(
-            "PyThreadState_DeleteCurrent: no current tstate");
+            "_PyThreadState_DeleteCurrent: no current tstate");
     tstate_delete_common(runtime, tstate);
     if (gilstate->autoInterpreterState &&
         PyThread_tss_get(&gilstate->autoTSSkey) == tstate)
@@ -876,12 +876,6 @@ _PyThreadState_DeleteCurrent(_PyRuntimeState *runtime)
     PyEval_ReleaseLock();
 }
 
-void
-PyThreadState_DeleteCurrent()
-{
-    _PyThreadState_DeleteCurrent(&_PyRuntime);
-}
-
 
 /*
  * Delete all thread states except the one passed as argument.