bpo-31784: Implement PEP 564: add time.time_ns() (#3989)

Add new time functions:

* time.clock_gettime_ns()
* time.clock_settime_ns()
* time.monotonic_ns()
* time.perf_counter_ns()
* time.process_time_ns()
* time.time_ns()

Add new _PyTime functions:

* _PyTime_FromTimespec()
* _PyTime_FromNanosecondsObject()
* _PyTime_FromTimeval()

Other changes:

* Add also os.times() tests to test_os.
* pytime_fromtimeval() and pytime_fromtimeval() now return
  _PyTime_MAX or _PyTime_MIN on overflow, rather than undefined
  behaviour
* _PyTime_FromNanoseconds() parameter type changes from long long to
  _PyTime_t

1 files changed, 19 insertions, 1 deletions

diff --git a/Include/pytime.h b/Include/pytime.h
index 9f48918..4870a9d 100644
--- a/Include/pytime.h
+++ b/Include/pytime.h
@@ -85,7 +85,11 @@ PyAPI_FUNC(_PyTime_t) _PyTime_FromSeconds(int seconds);
             ((_PyTime_t)(seconds) * (1000 * 1000 * 1000))
 
 /* Create a timestamp from a number of nanoseconds. */
-PyAPI_FUNC(_PyTime_t) _PyTime_FromNanoseconds(long long ns);
+PyAPI_FUNC(_PyTime_t) _PyTime_FromNanoseconds(_PyTime_t ns);
+
+/* Create a timestamp from nanoseconds (Python int). */
+PyAPI_FUNC(int) _PyTime_FromNanosecondsObject(_PyTime_t *t,
+    PyObject *obj);
 
 /* Convert a number of seconds (Python float or int) to a timetamp.
    Raise an exception and return -1 on error, return 0 on success. */
@@ -114,6 +118,10 @@ PyAPI_FUNC(_PyTime_t) _PyTime_AsMicroseconds(_PyTime_t t,
    object. */
 PyAPI_FUNC(PyObject *) _PyTime_AsNanosecondsObject(_PyTime_t t);
 
+/* Create a timestamp from a timeval structure.
+   Raise an exception and return -1 on overflow, return 0 on success. */
+PyAPI_FUNC(int) _PyTime_FromTimeval(_PyTime_t *tp, struct timeval *tv);
+
 /* Convert a timestamp to a timeval structure (microsecond resolution).
    tv_usec is always positive.
    Raise an exception and return -1 if the conversion overflowed,
@@ -140,12 +148,22 @@ PyAPI_FUNC(int) _PyTime_AsTimevalTime_t(
     _PyTime_round_t round);
 
 #if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_KQUEUE)
+/* Create a timestamp from a timespec structure.
+   Raise an exception and return -1 on overflow, return 0 on success. */
+PyAPI_FUNC(int) _PyTime_FromTimespec(_PyTime_t *tp, struct timespec *ts);
+
 /* Convert a timestamp to a timespec structure (nanosecond resolution).
    tv_nsec is always positive.
    Raise an exception and return -1 on error, return 0 on success. */
 PyAPI_FUNC(int) _PyTime_AsTimespec(_PyTime_t t, struct timespec *ts);
 #endif
 
+/* Compute ticks * mul / div.
+   The caller must ensure that ((div - 1) * mul) cannot overflow. */
+PyAPI_FUNC(_PyTime_t) _PyTime_MulDiv(_PyTime_t ticks,
+    _PyTime_t mul,
+    _PyTime_t div);
+
 /* Get the current time from the system clock.
 
    The function cannot fail. _PyTime_Init() ensures that the system clock