# HG changeset patch
# Parent c64dec45d46f7f5096d7d4ab70f630a390b45995
Issue #15599: OS X prior to 10.5 also cannot handle gil_interval == 1.


diff --git a/Lib/test/test_threaded_import.py b/Lib/test/test_threaded_import.py
--- a/Lib/test/test_threaded_import.py
+++ b/Lib/test/test_threaded_import.py
@@ -225,8 +225,22 @@
 @reap_threads
 def test_main():
     old_switchinterval = None
+    new_switchinterval = 0.00000001
     # Issue #15599: FreeBSD/KVM cannot handle gil_interval == 1.
-    new_switchinterval = 0.00001 if 'freebsd' in sys.platform else 0.00000001
+    if 'freebsd' in sys.platform:
+        new_switchinterval = 0.00001
+    #               also OS X versions prior to 10.5.
+    elif sys.platform == 'darwin':
+        import platform
+        version_txt = platform.mac_ver()[0]
+        try:
+            version = tuple(map(int, version_txt.split('.')))
+        except ValueError:
+            pass
+        else:
+            if version < (10, 5):
+                new_switchinterval = 0.00001
+
     try:
         old_switchinterval = sys.getswitchinterval()
         sys.setswitchinterval(new_switchinterval)