Display core time and wallclock times when test suite finishes, to be able to easily observe/benchmark test suite speedup optimizations. (#24396)

E.g.


![image](https://github.com/user-attachments/assets/ecc3dd77-ae94-4e95-b455-28d37ca91e32)

I need to see the test times on core, not in wallclock time in order to
be able to optimize test runtimes.

A bit clunky, maybe there is a cleaner way to implement this same
feature.

Author: juj

test/parallel_testsuite.py

@@ -90,6 +90,7 @@ def combine_results(self, result, buffered_results):
     # Sort the results back into alphabetical order. Running the tests in
     # parallel causes mis-orderings, this makes the results more readable.
     results = sorted(buffered_results, key=lambda res: str(res.test))
+    result.core_time = 0
     for r in results:
       r.updateResult(result)
     return result
@@ -102,18 +103,21 @@ class BufferedParallelTestResult:
   """
   def __init__(self):
     self.buffered_result = None
+    self.test_duration = 0
 
   @property
   def test(self):
     return self.buffered_result.test
 
-  def addDuration(self, test, elapsed):
-    pass
+  def calculateDuration(self):
+    self.test_duration = time.perf_counter() - self.start_time
+    return self.test_duration
 
   def updateResult(self, result):
     result.startTest(self.test)
     self.buffered_result.updateResult(result)
     result.stopTest(self.test)
+    result.core_time += self.test_duration
 
   def startTest(self, test):
     self.start_time = time.perf_counter()
@@ -122,21 +126,21 @@ def stopTest(self, test):
     # TODO(sbc): figure out a way to display this duration information again when
     # these results get passed back to the TextTestRunner/TextTestResult.
     if hasattr(time, 'perf_counter'):
-      self.buffered_result.duration = time.perf_counter() - self.start_time
+      self.buffered_result.duration = self.test_duration
 
   def addSuccess(self, test):
     if hasattr(time, 'perf_counter'):
-      print(test, '... ok (%.2fs)' % (time.perf_counter() - self.start_time), file=sys.stderr)
+      print(test, '... ok (%.2fs)' % (self.calculateDuration()), file=sys.stderr)
     self.buffered_result = BufferedTestSuccess(test)
 
   def addExpectedFailure(self, test, err):
     if hasattr(time, 'perf_counter'):
-      print(test, '... expected failure (%.2fs)' % (time.perf_counter() - self.start_time), file=sys.stderr)
+      print(test, '... expected failure (%.2fs)' % (self.calculateDuration()), file=sys.stderr)
     self.buffered_result = BufferedTestExpectedFailure(test, err)
 
   def addUnexpectedSuccess(self, test):
     if hasattr(time, 'perf_counter'):
-      print(test, '... unexpected success (%.2fs)' % (time.perf_counter() - self.start_time), file=sys.stderr)
+      print(test, '... unexpected success (%.2fs)' % (self.calculateDuration()), file=sys.stderr)
     self.buffered_result = BufferedTestUnexpectedSuccess(test)
 
   def addSkip(self, test, reason):

test/runner.py

@@ -29,6 +29,7 @@
 import random
 import sys
 import unittest
+import time
 
 # Setup
 
@@ -348,13 +349,20 @@ def run_tests(options, suites):
   else:
     testRunner = unittest.TextTestRunner(verbosity=2, failfast=options.failfast)
 
+  total_core_time = 0
+  run_start_time = time.perf_counter()
   for mod_name, suite in suites:
     print('Running %s: (%s tests)' % (mod_name, suite.countTestCases()))
     res = testRunner.run(suite)
     msg = ('%s: %s run, %s errors, %s failures, %s skipped' %
            (mod_name, res.testsRun, len(res.errors), len(res.failures), len(res.skipped)))
     num_failures += len(res.errors) + len(res.failures) + len(res.unexpectedSuccesses)
     resultMessages.append(msg)
+    if hasattr(res, 'core_time'):
+      total_core_time += res.core_time
+  total_run_time = time.perf_counter() - run_start_time
+  if total_core_time > 0:
+    print('Total core time: %.3fs. Wallclock time: %.3fs. Parallelization: %.2fx.' % (total_core_time, total_run_time, total_core_time / total_run_time))
 
   if len(resultMessages) > 1:
     print('====================')