bpo-46417: _testembed.c avoids Py_SetProgramName() (GH-30732)

* _testembed_Py_Initialize() now uses the PyConfig API, rather than
  deprecated Py_SetProgramName().
* Reduce INIT_LOOPS from 16 to 4: test_embed now takes 8.7 seconds
  rather than 14.7 seconds.

Author: vstinner

Lib/test/test_embed.py

@@ -32,7 +32,7 @@
 # _PyCoreConfig_InitIsolatedConfig()
 API_ISOLATED = 3
 
-INIT_LOOPS = 16
+INIT_LOOPS = 4
 MAX_HASH_SEED = 4294967295
 
 

Programs/_testembed.c

@@ -30,7 +30,7 @@ char **main_argv;
 /* Use path starting with "./" avoids a search along the PATH */
 #define PROGRAM_NAME L"./_testembed"
 
-#define INIT_LOOPS 16
+#define INIT_LOOPS 4
 
 // Ignore Py_DEPRECATED() compiler warnings: deprecated functions are
 // tested on purpose here.
@@ -45,10 +45,39 @@ static void error(const char *msg)
 }
 
 
+static void config_set_string(PyConfig *config, wchar_t **config_str, const wchar_t *str)
+{
+    PyStatus status = PyConfig_SetString(config, config_str, str);
+    if (PyStatus_Exception(status)) {
+        PyConfig_Clear(config);
+        Py_ExitStatusException(status);
+    }
+}
+
+
+static void config_set_program_name(PyConfig *config)
+{
+    const wchar_t *program_name = PROGRAM_NAME;
+    config_set_string(config, &config->program_name, program_name);
+}
+
+
+static void init_from_config_clear(PyConfig *config)
+{
+    PyStatus status = Py_InitializeFromConfig(config);
+    PyConfig_Clear(config);
+    if (PyStatus_Exception(status)) {
+        Py_ExitStatusException(status);
+    }
+}
+
+
 static void _testembed_Py_Initialize(void)
 {
-    Py_SetProgramName(PROGRAM_NAME);
-    Py_Initialize();
+    PyConfig config;
+    _PyConfig_InitCompatConfig(&config);
+    config_set_program_name(&config);
+    init_from_config_clear(&config);
 }
 
 
@@ -391,16 +420,6 @@ static int test_init_initialize_config(void)
 }
 
 
-static void config_set_string(PyConfig *config, wchar_t **config_str, const wchar_t *str)
-{
-    PyStatus status = PyConfig_SetString(config, config_str, str);
-    if (PyStatus_Exception(status)) {
-        PyConfig_Clear(config);
-        Py_ExitStatusException(status);
-    }
-}
-
-
 static void config_set_argv(PyConfig *config, Py_ssize_t argc, wchar_t * const *argv)
 {
     PyStatus status = PyConfig_SetArgv(config, argc, argv);
@@ -423,23 +442,6 @@ config_set_wide_string_list(PyConfig *config, PyWideStringList *list,
 }
 
 
-static void config_set_program_name(PyConfig *config)
-{
-    const wchar_t *program_name = PROGRAM_NAME;
-    config_set_string(config, &config->program_name, program_name);
-}
-
-
-static void init_from_config_clear(PyConfig *config)
-{
-    PyStatus status = Py_InitializeFromConfig(config);
-    PyConfig_Clear(config);
-    if (PyStatus_Exception(status)) {
-        Py_ExitStatusException(status);
-    }
-}
-
-
 static int check_init_compat_config(int preinit)
 {
     PyStatus status;