bpo-36710: Add runtime variable to Py_InitializeEx() (GH-12939)

Py_InitializeEx() now uses a runtime variable passed to subfunctions,
rather than working directly on the global variable _PyRuntime.

Add 'runtime' parameter to _PyCoreConfig_Write(), _PySys_Create(),
_PySys_InitMain(), _PyGILState_Init(),
emit_stderr_warning_for_legacy_locale() and other subfunctions.

Author: vstinner

Include/internal/pycore_coreconfig.h

@@ -8,6 +8,8 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#include "pycore_pystate.h"   /* _PyRuntimeState */
+
 
 /* --- _PyWstrList ------------------------------------------------ */
 
@@ -108,7 +110,8 @@ PyAPI_FUNC(_PyInitError) _PyCoreConfig_SetPathConfig(
     const _PyCoreConfig *config);
 PyAPI_FUNC(_PyInitError) _PyCoreConfig_Read(_PyCoreConfig *config,
     const _PyArgv *args);
-PyAPI_FUNC(void) _PyCoreConfig_Write(const _PyCoreConfig *config);
+PyAPI_FUNC(void) _PyCoreConfig_Write(const _PyCoreConfig *config,
+    _PyRuntimeState *runtime);
 
 
 /* --- Function used for testing ---------------------------------- */

Include/internal/pycore_pylifecycle.h

@@ -34,10 +34,13 @@ extern _PyInitError _PyFaulthandler_Init(int enable);
 extern int _PyTraceMalloc_Init(int enable);
 extern PyObject * _PyBuiltin_Init(void);
 extern _PyInitError _PySys_Create(
+    _PyRuntimeState *runtime,
     PyInterpreterState *interp,
     PyObject **sysmod_p);
 extern _PyInitError _PySys_SetPreliminaryStderr(PyObject *sysdict);
-extern int _PySys_InitMain(PyInterpreterState *interp);
+extern int _PySys_InitMain(
+    _PyRuntimeState *runtime,
+    PyInterpreterState *interp);
 extern _PyInitError _PyImport_Init(PyInterpreterState *interp);
 extern _PyInitError _PyExc_Init(void);
 extern _PyInitError _PyBuiltins_AddExceptions(PyObject * bltinmod);
@@ -74,7 +77,10 @@ extern void _PyFaulthandler_Fini(void);
 extern void _PyHash_Fini(void);
 extern int _PyTraceMalloc_Fini(void);
 
-extern void _PyGILState_Init(PyInterpreterState *, PyThreadState *);
+extern void _PyGILState_Init(
+    _PyRuntimeState *runtime,
+    PyInterpreterState *interp,
+    PyThreadState *tstate);
 extern void _PyGILState_Fini(_PyRuntimeState *runtime);
 
 PyAPI_FUNC(void) _PyGC_DumpShutdownStats(void);

Python/coreconfig.c

@@ -1605,13 +1605,13 @@ config_init_stdio(const _PyCoreConfig *config)
    - set Py_xxx global configuration variables
    - initialize C standard streams (stdin, stdout, stderr) */
 void
-_PyCoreConfig_Write(const _PyCoreConfig *config)
+_PyCoreConfig_Write(const _PyCoreConfig *config, _PyRuntimeState *runtime)
 {
     _PyCoreConfig_SetGlobalConfig(config);
     config_init_stdio(config);
 
     /* Write the new pre-configuration into _PyRuntime */
-    _PyPreConfig *preconfig = &_PyRuntime.preconfig;
+    _PyPreConfig *preconfig = &runtime->preconfig;
     preconfig->isolated = config->isolated;
     preconfig->use_environment = config->use_environment;
     preconfig->dev_mode = config->dev_mode;