Issue #14428, #14397: Implement the PEP 418
* Rename time.steady() to time.monotonic()
* On Windows, time.monotonic() uses GetTickCount/GetTickCount64() instead of
QueryPerformanceCounter()
* time.monotonic() uses CLOCK_HIGHRES if available
* Add time.get_clock_info(), time.perf_counter() and time.process_time()
functions
diff --git a/Doc/library/time.rst b/Doc/library/time.rst
index 70ef114..56ca865 100644
--- a/Doc/library/time.rst
+++ b/Doc/library/time.rst
@@ -155,6 +155,30 @@
.. versionadded:: 3.3
+.. class:: clock_info
+
+ Clock information object created by :func:`get_clock_info`.
+
+ .. attribute:: implementation
+
+ name of the underlying C function used to get the clock value
+
+ .. attribute:: is_monotonic
+
+ ``True`` if the clock cannot go backward, ``False`` otherwise
+
+ .. attribute:: is_adjusted
+
+ ``True`` if the clock can be adjusted (e.g. by a NTP daemon),
+ ``False`` otherwise
+
+ .. attribute:: resolution
+
+ Resolution of the clock in seconds (:class:`float`)
+
+ .. versionadded:: 3.3
+
+
.. function:: clock_settime(clk_id, time)
Set the time of the specified clock *clk_id*.
@@ -236,6 +260,22 @@
Nonzero if a DST timezone is defined.
+.. function:: get_clock_info(name)
+
+ Get information on the specified clock as a :class:`clock_info` object.
+
+ Supported clock names:
+
+
+ * ``'clock'``: :func:`time.clock`
+ * ``'monotonic'``: :func:`time.monotonic`
+ * ``'perf_counter'``: :func:`time.perf_counter`
+ * ``'process_time'``: :func:`time.process_time`
+ * ``'time'``: :func:`time.time`
+
+ .. versionadded:: 3.3
+
+
.. function:: gmtime([secs])
Convert a time expressed in seconds since the epoch to a :class:`struct_time` in
@@ -265,20 +305,43 @@
The earliest date for which it can generate a time is platform-dependent.
-.. function:: steady(strict=False)
+.. function:: monotonic()
- .. index::
- single: benchmarking
+ Monotonic clock, i.e. cannot go backward. It is not affected by system
+ clock updates. The reference point of the returned value is undefined, so
+ that only the difference between the results of consecutive calls is valid
+ and is a number of seconds.
- Return the current time as a floating point number expressed in seconds.
- This clock advances at a steady rate relative to real time and it may not be
- adjusted. The reference point of the returned value is undefined so only the
- difference of consecutive calls is valid.
+ On Windows versions older than Vista, :func:`monotonic` detects
+ :c:func:`GetTickCount` integer overflow (32 bits, roll-over after 49.7
+ days). It increases an internal epoch (reference time by) 2\ :sup:`32` each
+ time that an overflow is detected. The epoch is stored in the process-local
+ state and so the value of :func:`monotonic` may be different in two Python
+ processes running for more than 49 days. On more recent versions of Windows
+ and on other operating systems, :func:`monotonic` is system-wide.
- If available, a monotonic clock is used. By default,
- the function falls back to another clock if the monotonic clock failed or is
- not available. If *strict* is True, raise an :exc:`OSError` on error or
- :exc:`NotImplementedError` if no monotonic clock is available.
+ Availability: Windows, Mac OS X, Linux, FreeBSD, OpenBSD, Solaris.
+
+ .. versionadded:: 3.3
+
+
+.. function:: perf_counter()
+
+ Performance counter with the highest available resolution to measure a short
+ duration. It does include time elapsed during sleep and is system-wide.
+ The reference point of the returned value is undefined, so that only the
+ difference between the results of consecutive calls is valid and is a number
+ of seconds.
+
+ .. versionadded:: 3.3
+
+
+.. function:: process_time()
+
+ Sum of the system and user CPU time of the current process. It does not
+ include time elapsed during sleep. It is process-wide by definition. The
+ reference point of the returned value is undefined, so that only the
+ difference between the results of consecutive calls is valid.
.. versionadded:: 3.3