bpo-30860: Consolidate stateful runtime globals. (#2594)

* 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).

1 files changed, 91 insertions, 99 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 436e5cad25..9741c15b89 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -36,7 +36,8 @@ extern int _PyObject_GetMethod(PyObject *, PyObject *, PyObject **);
 typedef PyObject *(*callproc)(PyObject *, PyObject *, PyObject *);
 
 /* Forward declarations */
-Py_LOCAL_INLINE(PyObject *) call_function(PyObject ***, Py_ssize_t, PyObject *);
+Py_LOCAL_INLINE(PyObject *) call_function(PyObject ***, Py_ssize_t,
+                                          PyObject *);
 static PyObject * do_call_core(PyObject *, PyObject *, PyObject *);
 
 #ifdef LLTRACE
@@ -52,13 +53,15 @@ static int call_trace_protected(Py_tracefunc, PyObject *,
 static void call_exc_trace(Py_tracefunc, PyObject *,
                            PyThreadState *, PyFrameObject *);
 static int maybe_call_line_trace(Py_tracefunc, PyObject *,
-                                 PyThreadState *, PyFrameObject *, int *, int *, int *);
+                                 PyThreadState *, PyFrameObject *,
+                                 int *, int *, int *);
 static void maybe_dtrace_line(PyFrameObject *, int *, int *, int *);
 static void dtrace_function_entry(PyFrameObject *);
 static void dtrace_function_return(PyFrameObject *);
 
 static PyObject * cmp_outcome(int, PyObject *, PyObject *);
-static PyObject * import_name(PyFrameObject *, PyObject *, PyObject *, PyObject *);
+static PyObject * import_name(PyFrameObject *, PyObject *, PyObject *,
+                              PyObject *);
 static PyObject * import_from(PyObject *, PyObject *);
 static int import_all_from(PyObject *, PyObject *);
 static void format_exc_check_arg(PyObject *, const char *, PyObject *);
@@ -88,7 +91,7 @@ static long dxp[256];
 #endif
 
 #ifdef WITH_THREAD
-#define GIL_REQUEST _Py_atomic_load_relaxed(&gil_drop_request)
+#define GIL_REQUEST _Py_atomic_load_relaxed(&_PyRuntime.ceval.gil_drop_request)
 #else
 #define GIL_REQUEST 0
 #endif
@@ -98,22 +101,22 @@ static long dxp[256];
    the GIL eventually anyway. */
 #define COMPUTE_EVAL_BREAKER() \
     _Py_atomic_store_relaxed( \
-        &eval_breaker, \
+        &_PyRuntime.ceval.eval_breaker, \
         GIL_REQUEST | \
-        _Py_atomic_load_relaxed(&pendingcalls_to_do) | \
-        pending_async_exc)
+        _Py_atomic_load_relaxed(&_PyRuntime.ceval.pending.calls_to_do) | \
+        _PyRuntime.ceval.pending.async_exc)
 
 #ifdef WITH_THREAD
 
 #define SET_GIL_DROP_REQUEST() \
     do { \
-        _Py_atomic_store_relaxed(&gil_drop_request, 1); \
-        _Py_atomic_store_relaxed(&eval_breaker, 1); \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.gil_drop_request, 1); \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
     } while (0)
 
 #define RESET_GIL_DROP_REQUEST() \
     do { \
-        _Py_atomic_store_relaxed(&gil_drop_request, 0); \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.gil_drop_request, 0); \
         COMPUTE_EVAL_BREAKER(); \
     } while (0)
 
@@ -122,34 +125,28 @@ static long dxp[256];
 /* Pending calls are only modified under pending_lock */
 #define SIGNAL_PENDING_CALLS() \
     do { \
-        _Py_atomic_store_relaxed(&pendingcalls_to_do, 1); \
-        _Py_atomic_store_relaxed(&eval_breaker, 1); \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.pending.calls_to_do, 1); \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
     } while (0)
 
 #define UNSIGNAL_PENDING_CALLS() \
     do { \
-        _Py_atomic_store_relaxed(&pendingcalls_to_do, 0); \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.pending.calls_to_do, 0); \
         COMPUTE_EVAL_BREAKER(); \
     } while (0)
 
 #define SIGNAL_ASYNC_EXC() \
     do { \
-        pending_async_exc = 1; \
-        _Py_atomic_store_relaxed(&eval_breaker, 1); \
+        _PyRuntime.ceval.pending.async_exc = 1; \
+        _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
     } while (0)
 
 #define UNSIGNAL_ASYNC_EXC() \
-    do { pending_async_exc = 0; COMPUTE_EVAL_BREAKER(); } while (0)
-
+    do { \
+        _PyRuntime.ceval.pending.async_exc = 0; \
+        COMPUTE_EVAL_BREAKER(); \
+    } while (0)
 
-/* This single variable consolidates all requests to break out of the fast path
-   in the eval loop. */
-static _Py_atomic_int eval_breaker = {0};
-/* Request for running pending calls. */
-static _Py_atomic_int pendingcalls_to_do = {0};
-/* Request for looking at the `async_exc` field of the current thread state.
-   Guarded by the GIL. */
-static int pending_async_exc = 0;
 
 #ifdef WITH_THREAD
 
@@ -157,12 +154,6 @@ static int pending_async_exc = 0;
 #include <errno.h>
 #endif
 #include "pythread.h"
-
-static PyThread_type_lock pending_lock = 0; /* for pending calls */
-static unsigned long main_thread = 0;
-/* Request for dropping the GIL */
-static _Py_atomic_int gil_drop_request = {0};
-
 #include "ceval_gil.h"
 
 int
@@ -178,9 +169,9 @@ PyEval_InitThreads(void)
         return;
     create_gil();
     take_gil(PyThreadState_GET());
-    main_thread = PyThread_get_thread_ident();
-    if (!pending_lock)
-        pending_lock = PyThread_allocate_lock();
+    _PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident();
+    if (!_PyRuntime.ceval.pending.lock)
+        _PyRuntime.ceval.pending.lock = PyThread_allocate_lock();
 }
 
 void
@@ -248,9 +239,9 @@ PyEval_ReInitThreads(void)
     if (!gil_created())
         return;
     recreate_gil();
-    pending_lock = PyThread_allocate_lock();
+    _PyRuntime.ceval.pending.lock = PyThread_allocate_lock();
     take_gil(current_tstate);
-    main_thread = PyThread_get_thread_ident();
+    _PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident();
 
     /* Destroy all threads except the current one */
     _PyThreadState_DeleteExcept(current_tstate);
@@ -294,7 +285,7 @@ PyEval_RestoreThread(PyThreadState *tstate)
         int err = errno;
         take_gil(tstate);
         /* _Py_Finalizing is protected by the GIL */
-        if (_Py_Finalizing && tstate != _Py_Finalizing) {
+        if (_Py_IS_FINALIZING() && !_Py_CURRENTLY_FINALIZING(tstate)) {
             drop_gil(tstate);
             PyThread_exit_thread();
             assert(0);  /* unreachable */
@@ -346,19 +337,11 @@ _PyEval_SignalReceived(void)
    callback.
  */
 
-#define NPENDINGCALLS 32
-static struct {
-    int (*func)(void *);
-    void *arg;
-} pendingcalls[NPENDINGCALLS];
-static int pendingfirst = 0;
-static int pendinglast = 0;
-
 int
 Py_AddPendingCall(int (*func)(void *), void *arg)
 {
     int i, j, result=0;
-    PyThread_type_lock lock = pending_lock;
+    PyThread_type_lock lock = _PyRuntime.ceval.pending.lock;
 
     /* try a few times for the lock.  Since this mechanism is used
      * for signal handling (on the main thread), there is a (slim)
@@ -380,14 +363,14 @@ Py_AddPendingCall(int (*func)(void *), void *arg)
             return -1;
     }
 
-    i = pendinglast;
+    i = _PyRuntime.ceval.pending.last;
     j = (i + 1) % NPENDINGCALLS;
-    if (j == pendingfirst) {
+    if (j == _PyRuntime.ceval.pending.first) {
         result = -1; /* Queue full */
     } else {
-        pendingcalls[i].func = func;
-        pendingcalls[i].arg = arg;
-        pendinglast = j;
+        _PyRuntime.ceval.pending.calls[i].func = func;
+        _PyRuntime.ceval.pending.calls[i].arg = arg;
+        _PyRuntime.ceval.pending.last = j;
     }
     /* signal main loop */
     SIGNAL_PENDING_CALLS();
@@ -405,16 +388,19 @@ Py_MakePendingCalls(void)
 
     assert(PyGILState_Check());
 
-    if (!pending_lock) {
+    if (!_PyRuntime.ceval.pending.lock) {
         /* initial allocation of the lock */
-        pending_lock = PyThread_allocate_lock();
-        if (pending_lock == NULL)
+        _PyRuntime.ceval.pending.lock = PyThread_allocate_lock();
+        if (_PyRuntime.ceval.pending.lock == NULL)
             return -1;
     }
 
     /* only service pending calls on main thread */
-    if (main_thread && PyThread_get_thread_ident() != main_thread)
+    if (_PyRuntime.ceval.pending.main_thread &&
+        PyThread_get_thread_ident() != _PyRuntime.ceval.pending.main_thread)
+    {
         return 0;
+    }
     /* don't perform recursive pending calls */
     if (busy)
         return 0;
@@ -436,16 +422,16 @@ Py_MakePendingCalls(void)
         void *arg = NULL;
 
         /* pop one item off the queue while holding the lock */
-        PyThread_acquire_lock(pending_lock, WAIT_LOCK);
-        j = pendingfirst;
-        if (j == pendinglast) {
+        PyThread_acquire_lock(_PyRuntime.ceval.pending.lock, WAIT_LOCK);
+        j = _PyRuntime.ceval.pending.first;
+        if (j == _PyRuntime.ceval.pending.last) {
             func = NULL; /* Queue empty */
         } else {
-            func = pendingcalls[j].func;
-            arg = pendingcalls[j].arg;
-            pendingfirst = (j + 1) % NPENDINGCALLS;
+            func = _PyRuntime.ceval.pending.calls[j].func;
+            arg = _PyRuntime.ceval.pending.calls[j].arg;
+            _PyRuntime.ceval.pending.first = (j + 1) % NPENDINGCALLS;
         }
-        PyThread_release_lock(pending_lock);
+        PyThread_release_lock(_PyRuntime.ceval.pending.lock);
         /* having released the lock, perform the callback */
         if (func == NULL)
             break;
@@ -489,14 +475,6 @@ error:
    The two threads could theoretically wiggle around the "busy" variable.
 */
 
-#define NPENDINGCALLS 32
-static struct {
-    int (*func)(void *);
-    void *arg;
-} pendingcalls[NPENDINGCALLS];
-static volatile int pendingfirst = 0;
-static volatile int pendinglast = 0;
-
 int
 Py_AddPendingCall(int (*func)(void *), void *arg)
 {
@@ -506,15 +484,15 @@ Py_AddPendingCall(int (*func)(void *), void *arg)
     if (busy)
         return -1;
     busy = 1;
-    i = pendinglast;
+    i = _PyRuntime.ceval.pending.last;
     j = (i + 1) % NPENDINGCALLS;
-    if (j == pendingfirst) {
+    if (j == _PyRuntime.ceval.pending.first) {
         busy = 0;
         return -1; /* Queue full */
     }
-    pendingcalls[i].func = func;
-    pendingcalls[i].arg = arg;
-    pendinglast = j;
+    _PyRuntime.ceval.pending.calls[i].func = func;
+    _PyRuntime.ceval.pending.calls[i].arg = arg;
+    _PyRuntime.ceval.pending.last = j;
 
     SIGNAL_PENDING_CALLS();
     busy = 0;
@@ -543,12 +521,12 @@ Py_MakePendingCalls(void)
         int i;
         int (*func)(void *);
         void *arg;
-        i = pendingfirst;
-        if (i == pendinglast)
+        i = _PyRuntime.ceval.pending.first;
+        if (i == _PyRuntime.ceval.pending.last)
             break; /* Queue empty */
-        func = pendingcalls[i].func;
-        arg = pendingcalls[i].arg;
-        pendingfirst = (i + 1) % NPENDINGCALLS;
+        func = _PyRuntime.ceval.pending.calls[i].func;
+        arg = _PyRuntime.ceval.pending.calls[i].arg;
+        _PyRuntime.ceval.pending.first = (i + 1) % NPENDINGCALLS;
         if (func(arg) < 0) {
             goto error;
         }
@@ -570,20 +548,32 @@ error:
 #ifndef Py_DEFAULT_RECURSION_LIMIT
 #define Py_DEFAULT_RECURSION_LIMIT 1000
 #endif
-static int recursion_limit = Py_DEFAULT_RECURSION_LIMIT;
-int _Py_CheckRecursionLimit = Py_DEFAULT_RECURSION_LIMIT;
+
+void
+_PyEval_Initialize(struct _ceval_runtime_state *state)
+{
+    state->recursion_limit = Py_DEFAULT_RECURSION_LIMIT;
+    state->check_recursion_limit = Py_DEFAULT_RECURSION_LIMIT;
+    _gil_initialize(&state->gil);
+}
+
+int
+_PyEval_CheckRecursionLimit(void)
+{
+    return _PyRuntime.ceval.check_recursion_limit;
+}
 
 int
 Py_GetRecursionLimit(void)
 {
-    return recursion_limit;
+    return _PyRuntime.ceval.recursion_limit;
 }
 
 void
 Py_SetRecursionLimit(int new_limit)
 {
-    recursion_limit = new_limit;
-    _Py_CheckRecursionLimit = recursion_limit;
+    _PyRuntime.ceval.recursion_limit = new_limit;
+    _PyRuntime.ceval.check_recursion_limit = _PyRuntime.ceval.recursion_limit;
 }
 
 /* the macro Py_EnterRecursiveCall() only calls _Py_CheckRecursiveCall()
@@ -595,6 +585,7 @@ int
 _Py_CheckRecursiveCall(const char *where)
 {
     PyThreadState *tstate = PyThreadState_GET();
+    int recursion_limit = _PyRuntime.ceval.recursion_limit;
 
 #ifdef USE_STACKCHECK
     if (PyOS_CheckStack()) {
@@ -603,7 +594,7 @@ _Py_CheckRecursiveCall(const char *where)
         return -1;
     }
 #endif
-    _Py_CheckRecursionLimit = recursion_limit;
+    _PyRuntime.ceval.check_recursion_limit = recursion_limit;
     if (tstate->recursion_critical)
         /* Somebody asked that we don't check for recursion. */
         return 0;
@@ -642,13 +633,7 @@ static void restore_and_clear_exc_state(PyThreadState *, PyFrameObject *);
 static int do_raise(PyObject *, PyObject *);
 static int unpack_iterable(PyObject *, int, int, PyObject **);
 
-/* Records whether tracing is on for any thread.  Counts the number of
-   threads for which tstate->c_tracefunc is non-NULL, so if the value
-   is 0, we know we don't have to check this thread's c_tracefunc.
-   This speeds up the if statement in PyEval_EvalFrameEx() after
-   fast_next_opcode*/
-static int _Py_TracingPossible = 0;
-
+#define _Py_TracingPossible _PyRuntime.ceval.tracing_possible
 
 
 PyObject *
@@ -779,7 +764,7 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
 
 #define DISPATCH() \
     { \
-        if (!_Py_atomic_load_relaxed(&eval_breaker)) {      \
+        if (!_Py_atomic_load_relaxed(&_PyRuntime.ceval.eval_breaker)) { \
                     FAST_DISPATCH(); \
         } \
         continue; \
@@ -827,7 +812,8 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
 /* Code access macros */
 
 /* The integer overflow is checked by an assertion below. */
-#define INSTR_OFFSET()  (sizeof(_Py_CODEUNIT) * (int)(next_instr - first_instr))
+#define INSTR_OFFSET()  \
+    (sizeof(_Py_CODEUNIT) * (int)(next_instr - first_instr))
 #define NEXTOPARG()  do { \
         _Py_CODEUNIT word = *next_instr; \
         opcode = _Py_OPCODE(word); \
@@ -1080,7 +1066,7 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
            async I/O handler); see Py_AddPendingCall() and
            Py_MakePendingCalls() above. */
 
-        if (_Py_atomic_load_relaxed(&eval_breaker)) {
+        if (_Py_atomic_load_relaxed(&_PyRuntime.ceval.eval_breaker)) {
             if (_Py_OPCODE(*next_instr) == SETUP_FINALLY ||
                 _Py_OPCODE(*next_instr) == YIELD_FROM) {
                 /* Two cases where we skip running signal handlers and other
@@ -1097,12 +1083,16 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
                 */
                 goto fast_next_opcode;
             }
-            if (_Py_atomic_load_relaxed(&pendingcalls_to_do)) {
+            if (_Py_atomic_load_relaxed(
+                        &_PyRuntime.ceval.pending.calls_to_do))
+            {
                 if (Py_MakePendingCalls() < 0)
                     goto error;
             }
 #ifdef WITH_THREAD
-            if (_Py_atomic_load_relaxed(&gil_drop_request)) {
+            if (_Py_atomic_load_relaxed(
+                        &_PyRuntime.ceval.gil_drop_request))
+            {
                 /* Give another thread a chance */
                 if (PyThreadState_Swap(NULL) != tstate)
                     Py_FatalError("ceval: tstate mix-up");
@@ -1113,7 +1103,9 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
                 take_gil(tstate);
 
                 /* Check if we should make a quick exit. */
-                if (_Py_Finalizing && _Py_Finalizing != tstate) {
+                if (_Py_IS_FINALIZING() &&
+                    !_Py_CURRENTLY_FINALIZING(tstate))
+                {
                     drop_gil(tstate);
                     PyThread_exit_thread();
                 }