Replace _can_use_kqueue() -> _CAN_USE_KQUEUE

Author: giampaolo

Lib/subprocess.py

@@ -749,18 +749,16 @@ def _use_posix_spawn():
     # By default, assume that posix_spawn() does not properly report errors.
     return False
 
-
-@functools.lru_cache
-def _can_use_kqueue():
-    names = (
+_CAN_USE_KQUEUE = all(
+    hasattr(select, x)
+    for x in (
         "kqueue",
         "KQ_EV_ADD",
         "KQ_EV_ONESHOT",
         "KQ_FILTER_PROC",
         "KQ_NOTE_EXIT",
     )
-    return all(hasattr(select, x) for x in names)
-
+)
 
 # These are primarily fail-safe knobs for negatives. A True value does not
 # guarantee the given libc/syscall API will be used.
@@ -2090,7 +2088,7 @@ def _wait_pidfd(self, timeout):
 
         def _wait_kqueue(self, timeout):
             """Wait for PID to terminate using kqueue(). macOS and BSD only."""
-            if not _can_use_kqueue():
+            if not _CAN_USE_KQUEUE:
                 return False
             try:
                 kq = select.kqueue()

Lib/test/test_subprocess.py

@@ -4116,13 +4116,13 @@ def test_wait_pidfd_open_error(self):
         self.assert_fast_waitpid_error("os.pidfd_open")
 
     @unittest.skipIf(
-        not subprocess._can_use_kqueue(), reason="macOS / BSD only"
+        not subprocess._CAN_USE_KQUEUE, reason="macOS / BSD only"
     )
     def test_wait_kqueue_error(self):
         self.assert_fast_waitpid_error("select.kqueue")
 
     @unittest.skipIf(
-        not subprocess._can_use_kqueue(), reason="macOS / BSD only"
+        not subprocess._CAN_USE_KQUEUE, reason="macOS / BSD only"
     )
     def test_kqueue_control_error(self):
         # Emulate a case where kqueue.control() fails. _busy_wait()
@@ -4167,7 +4167,7 @@ def test_pidfd_open_race(self):
         self.assert_wait_race_condition("os.pidfd_open", os.pidfd_open)
 
     @unittest.skipIf(
-        not subprocess._can_use_kqueue(), reason="macOS / BSD only"
+        not subprocess._CAN_USE_KQUEUE, reason="macOS / BSD only"
     )
     def test_kqueue_race(self):
         self.assert_wait_race_condition("select.kqueue", select.kqueue)