bpo-30860: Consolidate stateful runtime globals. (#3397)

* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals

Other globals are excluded (see globals.txt and check-c-globals.py).

Python/pylifecycle.c

@@ -4,6 +4,7 @@
 
 #include "Python-ast.h"
 #undef Yield /* undefine macro conflicting with winbase.h */
+#include "internal/pystate.h"
 #include "grammar.h"
 #include "node.h"
 #include "token.h"
@@ -75,6 +76,36 @@ extern void _Py_ReadyTypes(void);
 extern void _PyGILState_Init(PyInterpreterState *, PyThreadState *);
 extern void _PyGILState_Fini(void);
 
+_PyRuntimeState _PyRuntime = {0, 0};
+
+void
+_PyRuntime_Initialize(void)
+{
+    /* XXX We only initialize once in the process, which aligns with
+       the static initialization of the former globals now found in
+       _PyRuntime.  However, _PyRuntime *should* be initialized with
+       every Py_Initialize() call, but doing so breaks the runtime.
+       This is because the runtime state is not properly finalized
+       currently. */
+    static int initialized = 0;
+    if (initialized)
+        return;
+    initialized = 1;
+    _PyRuntimeState_Init(&_PyRuntime);
+}
+
+void
+_PyRuntime_Finalize(void)
+{
+    _PyRuntimeState_Fini(&_PyRuntime);
+}
+
+int
+_Py_IsFinalizing(void)
+{
+    return _PyRuntime.finalizing != NULL;
+}
+
 /* Global configuration variable declarations are in pydebug.h */
 /* XXX (ncoghlan): move those declarations to pylifecycle.h? */
 int Py_DebugFlag; /* Needed by parser.c */
@@ -98,8 +129,6 @@ int Py_LegacyWindowsFSEncodingFlag = 0; /* Uses mbcs instead of utf-8 */
 int Py_LegacyWindowsStdioFlag = 0; /* Uses FileIO instead of WindowsConsoleIO */
 #endif
 
-PyThreadState *_Py_Finalizing = NULL;
-
 /* Hack to force loading of object files */
 int (*_PyOS_mystrnicmp_hack)(const char *, const char *, Py_ssize_t) = \
     PyOS_mystrnicmp; /* Python/pystrcmp.o */
@@ -117,19 +146,17 @@ PyModule_GetWarningsModule(void)
  *
  * Can be called prior to Py_Initialize.
  */
-int _Py_CoreInitialized = 0;
-int _Py_Initialized = 0;
 
 int
 _Py_IsCoreInitialized(void)
 {
-    return _Py_CoreInitialized;
+    return _PyRuntime.core_initialized;
 }
 
 int
 Py_IsInitialized(void)
 {
-    return _Py_Initialized;
+    return _PyRuntime.initialized;
 }
 
 /* Helper to allow an embedding application to override the normal
@@ -542,14 +569,16 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
     _PyCoreConfig core_config = _PyCoreConfig_INIT;
     _PyMainInterpreterConfig preinit_config = _PyMainInterpreterConfig_INIT;
 
+    _PyRuntime_Initialize();
+
     if (config != NULL) {
         core_config = *config;
     }
 
-    if (_Py_Initialized) {
+    if (_PyRuntime.initialized) {
         Py_FatalError("Py_InitializeCore: main interpreter already initialized");
     }
-    if (_Py_CoreInitialized) {
+    if (_PyRuntime.core_initialized) {
         Py_FatalError("Py_InitializeCore: runtime core already initialized");
     }
 
@@ -562,7 +591,14 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
      * threads still hanging around from a previous Py_Initialize/Finalize
      * pair :(
      */
-    _Py_Finalizing = NULL;
+    _PyRuntime.finalizing = NULL;
+
+    if (_PyMem_SetupAllocators(core_config.allocator) < 0) {
+        fprintf(stderr,
+            "Error in PYTHONMALLOC: unknown allocator \"%s\"!\n",
+            core_config.allocator);
+        exit(1);
+    }
 
 #ifdef __ANDROID__
     /* Passing "" to setlocale() on Android requests the C locale rather
@@ -604,7 +640,7 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
         Py_HashRandomizationFlag = 1;
     }
 
-    _PyInterpreterState_Init();
+    _PyInterpreterState_Enable(&_PyRuntime);
     interp = PyInterpreterState_New();
     if (interp == NULL)
         Py_FatalError("Py_InitializeCore: can't make main interpreter");
@@ -694,7 +730,7 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
     }
 
     /* Only when we get here is the runtime core fully initialized */
-    _Py_CoreInitialized = 1;
+    _PyRuntime.core_initialized = 1;
 }
 
 /* Read configuration settings from standard locations
@@ -735,10 +771,10 @@ int _Py_InitializeMainInterpreter(const _PyMainInterpreterConfig *config)
     PyInterpreterState *interp;
     PyThreadState *tstate;
 
-    if (!_Py_CoreInitialized) {
+    if (!_PyRuntime.core_initialized) {
         Py_FatalError("Py_InitializeMainInterpreter: runtime core not initialized");
     }
-    if (_Py_Initialized) {
+    if (_PyRuntime.initialized) {
         Py_FatalError("Py_InitializeMainInterpreter: main interpreter already initialized");
     }
 
@@ -759,7 +795,7 @@ int _Py_InitializeMainInterpreter(const _PyMainInterpreterConfig *config)
          * This means anything which needs support from extension modules
          * or pure Python code in the standard library won't work.
          */
-        _Py_Initialized = 1;
+        _PyRuntime.initialized = 1;
         return 0;
     }
     /* TODO: Report exceptions rather than fatal errors below here */
@@ -804,7 +840,7 @@ int _Py_InitializeMainInterpreter(const _PyMainInterpreterConfig *config)
         Py_XDECREF(warnings_module);
     }
 
-    _Py_Initialized = 1;
+    _PyRuntime.initialized = 1;
 
     if (!Py_NoSiteFlag)
         initsite(); /* Module site */
@@ -920,7 +956,7 @@ Py_FinalizeEx(void)
     PyThreadState *tstate;
     int status = 0;
 
-    if (!_Py_Initialized)
+    if (!_PyRuntime.initialized)
         return status;
 
     wait_for_thread_shutdown();
@@ -942,9 +978,9 @@ Py_FinalizeEx(void)
 
     /* Remaining threads (e.g. daemon threads) will automatically exit
        after taking the GIL (in PyEval_RestoreThread()). */
-    _Py_Finalizing = tstate;
-    _Py_Initialized = 0;
-    _Py_CoreInitialized = 0;
+    _PyRuntime.finalizing = tstate;
+    _PyRuntime.initialized = 0;
+    _PyRuntime.core_initialized = 0;
 
     /* Flush sys.stdout and sys.stderr */
     if (flush_std_files() < 0) {
@@ -1104,6 +1140,7 @@ Py_FinalizeEx(void)
 #endif
 
     call_ll_exitfuncs();
+    _PyRuntime_Finalize();
     return status;
 }
 
@@ -1133,7 +1170,7 @@ Py_NewInterpreter(void)
     PyThreadState *tstate, *save_tstate;
     PyObject *bimod, *sysmod;
 
-    if (!_Py_Initialized)
+    if (!_PyRuntime.initialized)
         Py_FatalError("Py_NewInterpreter: call Py_Initialize first");
 
     /* Issue #10915, #15751: The GIL API doesn't work with multiple
@@ -1844,20 +1881,19 @@ exit:
 
 #  include "pythread.h"
 
-static void (*pyexitfunc)(void) = NULL;
 /* For the atexit module. */
 void _Py_PyAtExit(void (*func)(void))
 {
-    pyexitfunc = func;
+    _PyRuntime.pyexitfunc = func;
 }
 
 static void
 call_py_exitfuncs(void)
 {
-    if (pyexitfunc == NULL)
+    if (_PyRuntime.pyexitfunc == NULL)
         return;
 
-    (*pyexitfunc)();
+    (*_PyRuntime.pyexitfunc)();
     PyErr_Clear();
 }
 
@@ -1888,22 +1924,19 @@ wait_for_thread_shutdown(void)
 }
 
 #define NEXITFUNCS 32
-static void (*exitfuncs[NEXITFUNCS])(void);
-static int nexitfuncs = 0;
-
 int Py_AtExit(void (*func)(void))
 {
-    if (nexitfuncs >= NEXITFUNCS)
+    if (_PyRuntime.nexitfuncs >= NEXITFUNCS)
         return -1;
-    exitfuncs[nexitfuncs++] = func;
+    _PyRuntime.exitfuncs[_PyRuntime.nexitfuncs++] = func;
     return 0;
 }
 
 static void
 call_ll_exitfuncs(void)
 {
-    while (nexitfuncs > 0)
-        (*exitfuncs[--nexitfuncs])();
+    while (_PyRuntime.nexitfuncs > 0)
+        (*_PyRuntime.exitfuncs[--_PyRuntime.nexitfuncs])();
 
     fflush(stdout);
     fflush(stderr);