gh-112567: Add _Py_GetTicksPerSecond() function (#112587)

* Move _PyRuntimeState.time to _posixstate.ticks_per_second and
  time_module_state.ticks_per_second.
* Add time_module_state.clocks_per_second.
* Rename _PyTime_GetClockWithInfo() to py_clock().
* Rename _PyTime_GetProcessTimeWithInfo() to py_process_time().
* Add process_time_times() helper function, called by
  py_process_time().
* os.times() is now always built: no longer rely on HAVE_TIMES.

Author: vstinner

Include/internal/pycore_fileutils.h

@@ -320,6 +320,10 @@ PyAPI_FUNC(char*) _Py_UniversalNewlineFgetsWithSize(char *, int, FILE*, PyObject
 
 extern int _PyFile_Flush(PyObject *);
 
+#ifndef MS_WINDOWS
+extern int _Py_GetTicksPerSecond(long *ticks_per_second);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

Include/internal/pycore_pylifecycle.h

@@ -40,7 +40,6 @@ extern void _PySys_FiniTypes(PyInterpreterState *interp);
 extern int _PyBuiltins_AddExceptions(PyObject * bltinmod);
 extern PyStatus _Py_HashRandomization_Init(const PyConfig *);
 
-extern PyStatus _PyTime_Init(void);
 extern PyStatus _PyGC_Init(PyInterpreterState *interp);
 extern PyStatus _PyAtExit_Init(PyInterpreterState *interp);
 extern int _Py_Deepfreeze_Init(void);

Include/internal/pycore_runtime.h

@@ -21,7 +21,6 @@ extern "C" {
 #include "pycore_pymem.h"           // struct _pymem_allocators
 #include "pycore_pythread.h"        // struct _pythread_runtime_state
 #include "pycore_signal.h"          // struct _signals_runtime_state
-#include "pycore_time.h"            // struct _time_runtime_state
 #include "pycore_tracemalloc.h"     // struct _tracemalloc_runtime_state
 #include "pycore_typeobject.h"      // struct _types_runtime_state
 #include "pycore_unicodeobject.h"   // struct _Py_unicode_runtime_state
@@ -205,7 +204,6 @@ typedef struct pyruntimestate {
     struct _pymem_allocators allocators;
     struct _obmalloc_global_state obmalloc;
     struct pyhash_runtime_state pyhash_state;
-    struct _time_runtime_state time;
     struct _pythread_runtime_state threads;
     struct _signals_runtime_state signals;
 

Include/internal/pycore_time.h

@@ -52,16 +52,6 @@ extern "C" {
 #endif
 
 
-struct _time_runtime_state {
-#ifdef HAVE_TIMES
-    int ticks_per_second_initialized;
-    long ticks_per_second;
-#else
-    int _not_used;
-#endif
-};
-
-
 #ifdef __clang__
 struct timeval;
 #endif

Modules/clinic/posixmodule.c.h

@@ -1030,6 +1030,10 @@ typedef struct {
     PyObject *struct_rusage;
 #endif
     PyObject *st_mode;
+#ifndef MS_WINDOWS
+    // times() clock frequency in hertz; used by os.times()
+    long ticks_per_second;
+#endif
 } _posixstate;
 
 
@@ -9986,8 +9990,6 @@ os_symlink_impl(PyObject *module, path_t *src, path_t *dst,
 #endif /* HAVE_SYMLINK */
 
 
-
-
 static PyStructSequence_Field times_result_fields[] = {
     {"user",    "user time"},
     {"system",   "system time"},
@@ -10013,12 +10015,6 @@ static PyStructSequence_Desc times_result_desc = {
     5
 };
 
-#ifdef MS_WINDOWS
-#define HAVE_TIMES  /* mandatory, for the method table */
-#endif
-
-#ifdef HAVE_TIMES
-
 static PyObject *
 build_times_result(PyObject *module, double user, double system,
     double children_user, double children_system,
@@ -10064,8 +10060,8 @@ All fields are floating point numbers.
 static PyObject *
 os_times_impl(PyObject *module)
 /*[clinic end generated code: output=35f640503557d32a input=2bf9df3d6ab2e48b]*/
-#ifdef MS_WINDOWS
 {
+#ifdef MS_WINDOWS
     FILETIME create, exit, kernel, user;
     HANDLE hProc;
     hProc = GetCurrentProcess();
@@ -10083,28 +10079,26 @@ os_times_impl(PyObject *module)
         (double)0,
         (double)0,
         (double)0);
-}
 #else /* MS_WINDOWS */
-{
-    struct tms t;
-    clock_t c;
+    _posixstate *state = get_posix_state(module);
+    long ticks_per_second = state->ticks_per_second;
+
+    struct tms process;
+    clock_t elapsed;
     errno = 0;
-    c = times(&t);
-    if (c == (clock_t) -1) {
+    elapsed = times(&process);
+    if (elapsed == (clock_t) -1) {
         return posix_error();
     }
-    assert(_PyRuntime.time.ticks_per_second_initialized);
-#define ticks_per_second _PyRuntime.time.ticks_per_second
+
     return build_times_result(module,
-                         (double)t.tms_utime / ticks_per_second,
-                         (double)t.tms_stime / ticks_per_second,
-                         (double)t.tms_cutime / ticks_per_second,
-                         (double)t.tms_cstime / ticks_per_second,
-                         (double)c / ticks_per_second);
-#undef ticks_per_second
-}
+        (double)process.tms_utime / ticks_per_second,
+        (double)process.tms_stime / ticks_per_second,
+        (double)process.tms_cutime / ticks_per_second,
+        (double)process.tms_cstime / ticks_per_second,
+        (double)elapsed / ticks_per_second);
 #endif /* MS_WINDOWS */
-#endif /* HAVE_TIMES */
+}
 
 
 #if defined(HAVE_TIMERFD_CREATE)
@@ -17279,6 +17273,15 @@ posixmodule_exec(PyObject *m)
         Py_DECREF(unicode);
     }
 
+#ifndef MS_WINDOWS
+    if (_Py_GetTicksPerSecond(&state->ticks_per_second) < 0) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "cannot read ticks_per_second");
+        return -1;
+    }
+    assert(state->ticks_per_second >= 1);
+#endif
+
     return PyModule_Add(m, "_have_functions", list);
 }