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).

Include/internal/pystate.h

@@ -0,0 +1,92 @@
+#ifndef Py_INTERNAL_PYSTATE_H
+#define Py_INTERNAL_PYSTATE_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "pystate.h"
+#include "pyatomic.h"
+#include "pythread.h"
+
+#include "internal/mem.h"
+#include "internal/ceval.h"
+#include "internal/warnings.h"
+
+
+/* GIL state */
+
+struct _gilstate_runtime_state {
+    int check_enabled;
+    /* Assuming the current thread holds the GIL, this is the
+       PyThreadState for the current thread. */
+    _Py_atomic_address tstate_current;
+    PyThreadFrameGetter getframe;
+    /* The single PyInterpreterState used by this process'
+       GILState implementation
+    */
+    /* TODO: Given interp_main, it may be possible to kill this ref */
+    PyInterpreterState *autoInterpreterState;
+    int autoTLSkey;
+};
+
+/* hook for PyEval_GetFrame(), requested for Psyco */
+#define _PyThreadState_GetFrame _PyRuntime.gilstate.getframe
+
+/* Issue #26558: Flag to disable PyGILState_Check().
+   If set to non-zero, PyGILState_Check() always return 1. */
+#define _PyGILState_check_enabled _PyRuntime.gilstate.check_enabled
+
+
+/* Full Python runtime state */
+
+typedef struct pyruntimestate {
+    int initialized;
+    int core_initialized;
+    PyThreadState *finalizing;
+
+    struct pyinterpreters {
+        PyThread_type_lock mutex;
+        PyInterpreterState *head;
+        PyInterpreterState *main;
+        /* _next_interp_id is an auto-numbered sequence of small
+           integers.  It gets initialized in _PyInterpreterState_Init(),
+           which is called in Py_Initialize(), and used in
+           PyInterpreterState_New().  A negative interpreter ID
+           indicates an error occurred.  The main interpreter will
+           always have an ID of 0.  Overflow results in a RuntimeError.
+           If that becomes a problem later then we can adjust, e.g. by
+           using a Python int. */
+        int64_t next_id;
+    } interpreters;
+
+#define NEXITFUNCS 32
+    void (*exitfuncs[NEXITFUNCS])(void);
+    int nexitfuncs;
+    void (*pyexitfunc)(void);
+
+    struct _pyobj_runtime_state obj;
+    struct _gc_runtime_state gc;
+    struct _pymem_runtime_state mem;
+    struct _warnings_runtime_state warnings;
+    struct _ceval_runtime_state ceval;
+    struct _gilstate_runtime_state gilstate;
+
+    // XXX Consolidate globals found via the check-c-globals script.
+} _PyRuntimeState;
+
+PyAPI_DATA(_PyRuntimeState) _PyRuntime;
+PyAPI_FUNC(void) _PyRuntimeState_Init(_PyRuntimeState *);
+PyAPI_FUNC(void) _PyRuntimeState_Fini(_PyRuntimeState *);
+
+#define _Py_CURRENTLY_FINALIZING(tstate) \
+    (_PyRuntime.finalizing == tstate)
+
+
+/* Other */
+
+PyAPI_FUNC(void) _PyInterpreterState_Enable(_PyRuntimeState *);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_INTERNAL_PYSTATE_H */