pythongh-108388: test_concurrent_futures requires cpu

The test_concurrent_futures and test_multiprocessing_spawn tests now
require the 'cpu' resource. Skip these tests unless the 'cpu'
resource is enabled (it is disabled by default).

test_concurrent_futures is no longer skipped if Python is built with
ASAN or MSAN sanitizer.

Lib/test/test_concurrent_futures.py

@@ -33,10 +33,8 @@
 import multiprocessing as mp
 
 
-if support.check_sanitizer(address=True, memory=True):
-    # gh-90791: Skip the test because it is too slow when Python is built
-    # with ASAN/MSAN: between 5 and 20 minutes on GitHub Actions.
-    raise unittest.SkipTest("test too slow on ASAN/MSAN build")
+# This test spawns many threads and processes and is slow
+support.requires('cpu')
 
 
 def create_future(state=PENDING, exception=None, result=None):

Lib/test/test_multiprocessing_spawn.py

@@ -3,6 +3,9 @@
 
 from test import support
 
+# This test spawns many processes and is slow
+support.requires('cpu')
+
 if support.PGO:
     raise unittest.SkipTest("test is not helpful for PGO")
 

Misc/NEWS.d/next/Tests/2023-08-24-01-08-04.gh-issue-108388.fhO42m.rst

@@ -0,0 +1,6 @@
+The slowest tests are now skipped by default, unless the "cpu" resource is
+enabled: test_concurrent_futures, test_multiprocessing_spawn,
+test_peg_generator and test_tools.test_freeze. Run the test suite with ``-u
+cpu`` or ``-u all`` to run these tests. Moreover, these tests are no longer
+skipped on Python built with ASAN or MSAN sanitizer. Patch by Victor
+Stinner.