Issue #14428: Use the new time.perf_counter() and time.process_time() functions

vstinner · vstinner · commit fe98e2fc8391 · 2012-04-29T03:01:20.000+02:00
* Replace "time.clock on windows, or time.time" with time.perf_counter()
 * profile module: only use time.process_time() instead of trying different
   functions providing the process time
 * timeit module: use time.perf_counter() by default, time.time() and
   time.clock() can still be used using --time and --clock options
 * pybench program: use time.perf_counter() by default, add support for
   the new time.process_time() and time.perf_counter() functions, but stay
   backward compatible. Use also time.get_clock_info() to display information
   of the timer.
diff --git a/Doc/includes/mp_benchmarks.py b/Doc/includes/mp_benchmarks.py
@@ -6,16 +6,12 @@
 #
 
 import time
-import sys
 import multiprocessing
 import threading
 import queue
 import gc
 
-if sys.platform == 'win32':
-    _timer = time.clock
-else:
-    _timer = time.time
+_timer = time.perf_counter
 
 delta = 1
 
diff --git a/Lib/idlelib/ColorDelegator.py b/Lib/idlelib/ColorDelegator.py
@@ -149,9 +149,9 @@ def recolorize(self):
             self.stop_colorizing = False
             self.colorizing = True
             if DEBUG: print("colorizing...")
-            t0 = time.clock()
+            t0 = time.perf_counter()
             self.recolorize_main()
-            t1 = time.clock()
+            t1 = time.perf_counter()
             if DEBUG: print("%.3f seconds" % (t1-t0))
         finally:
             self.colorizing = False
diff --git a/Lib/profile.py b/Lib/profile.py
@@ -83,26 +83,6 @@ def runctx(statement, globals, locals, filename=None, sort=-1):
     else:
         return prof.print_stats(sort)
 
-if hasattr(os, "times"):
-    def _get_time_times(timer=os.times):
-        t = timer()
-        return t[0] + t[1]
-
-# Using getrusage(3) is better than clock(3) if available:
-# on some systems (e.g. FreeBSD), getrusage has a higher resolution
-# Furthermore, on a POSIX system, returns microseconds, which
-# wrap around after 36min.
-_has_res = 0
-try:
-    import resource
-    resgetrusage = lambda: resource.getrusage(resource.RUSAGE_SELF)
-    def _get_time_resource(timer=resgetrusage):
-        t = timer()
-        return t[0] + t[1]
-    _has_res = 1
-except ImportError:
-    pass
-
 class Profile:
     """Profiler class.
 
@@ -155,20 +135,8 @@ def __init__(self, timer=None, bias=None):
         self.bias = bias     # Materialize in local dict for lookup speed.
 
         if not timer:
-            if _has_res:
-                self.timer = resgetrusage
-                self.dispatcher = self.trace_dispatch
-                self.get_time = _get_time_resource
-            elif hasattr(time, 'clock'):
-                self.timer = self.get_time = time.clock
-                self.dispatcher = self.trace_dispatch_i
-            elif hasattr(os, 'times'):
-                self.timer = os.times
-                self.dispatcher = self.trace_dispatch
-                self.get_time = _get_time_times
-            else:
-                self.timer = self.get_time = time.time
-                self.dispatcher = self.trace_dispatch_i
+            self.timer = self.get_time = time.process_time
+            self.dispatcher = self.trace_dispatch_i
         else:
             self.timer = timer
             t = self.timer() # test out timer function
diff --git a/Lib/test/reperf.py b/Lib/test/reperf.py
@@ -9,13 +9,13 @@ def main():
     timefunc(10, p.findall, s)
 
 def timefunc(n, func, *args, **kw):
-    t0 = time.clock()
+    t0 = time.perf_counter()
     try:
         for i in range(n):
             result = func(*args, **kw)
         return result
     finally:
-        t1 = time.clock()
+        t1 = time.perf_counter()
         if n > 1:
             print(n, "times", end=' ')
         print(func.__name__, "%.3f" % (t1-t0), "CPU seconds")
diff --git a/Lib/test/sortperf.py b/Lib/test/sortperf.py
@@ -57,9 +57,9 @@ def flush():
     sys.stdout.flush()
 
 def doit(L):
-    t0 = time.clock()
+    t0 = time.perf_counter()
     L.sort()
-    t1 = time.clock()
+    t1 = time.perf_counter()
     print("%6.2f" % (t1-t0), end=' ')
     flush()
 
diff --git a/Lib/timeit.py b/Lib/timeit.py
@@ -15,8 +15,8 @@
   -n/--number N: how many times to execute 'statement' (default: see below)
   -r/--repeat N: how many times to repeat the timer (default 3)
   -s/--setup S: statement to be executed once initially (default 'pass')
-  -t/--time: use time.time() (default on Unix)
-  -c/--clock: use time.clock() (default on Windows)
+  -t/--time: use time.time()
+  -c/--clock: use time.clock()
   -v/--verbose: print raw timing results; repeat for more digits precision
   -h/--help: print this usage message and exit
   --: separate options from statement, use when statement starts with -
@@ -66,13 +66,7 @@
 dummy_src_name = "<timeit-src>"
 default_number = 1000000
 default_repeat = 3
-
-if sys.platform == "win32":
-    # On Windows, the best timer is time.clock()
-    default_timer = time.clock
-else:
-    # On most other platforms the best timer is time.time()
-    default_timer = time.time
+default_timer = time.perf_counter
 
 # Don't change the indentation of the template; the reindent() calls
 # in Timer.__init__() depend on setup being indented 4 spaces and stmt
diff --git a/Tools/pybench/pybench.py b/Tools/pybench/pybench.py
@@ -73,11 +73,15 @@
 
 # Timer types
 TIMER_TIME_TIME = 'time.time'
+TIMER_TIME_PROCESS_TIME = 'time.process_time'
+TIMER_TIME_PERF_COUNTER = 'time.perf_counter'
 TIMER_TIME_CLOCK = 'time.clock'
 TIMER_SYSTIMES_PROCESSTIME = 'systimes.processtime'
 
 # Choose platform default timer
-if sys.platform[:3] == 'win':
+if hasattr(time, 'perf_counter'):
+    TIMER_PLATFORM_DEFAULT = TIMER_TIME_PERF_COUNTER
+elif sys.platform[:3] == 'win':
     # On WinXP this has 2.5ms resolution
     TIMER_PLATFORM_DEFAULT = TIMER_TIME_CLOCK
 else:
@@ -93,6 +97,10 @@ def get_timer(timertype):
 
     if timertype == TIMER_TIME_TIME:
         return time.time
+    elif timertype == TIMER_TIME_PROCESS_TIME:
+        return time.process_time
+    elif timertype == TIMER_TIME_PERF_COUNTER:
+        return time.perf_counter
     elif timertype == TIMER_TIME_CLOCK:
         return time.clock
     elif timertype == TIMER_SYSTIMES_PROCESSTIME:
@@ -866,7 +874,18 @@ def main(self):
             print('* using timer: systimes.processtime (%s)' % \
                   systimes.SYSTIMES_IMPLEMENTATION)
         else:
+            # Check that the clock function does exist
+            try:
+                get_timer(timer)
+            except TypeError:
+                print("* Error: Unknown timer: %s" % timer)
+                return
+
             print('* using timer: %s' % timer)
+            if hasattr(time, 'get_clock_info'):
+                info = time.get_clock_info(timer[5:])
+                print('* timer: resolution=%s, implementation=%s'
+                      % (info.resolution, info.implementation))
 
         print()
 
