1 files changed, 9 insertions, 1 deletions
diff --git a/Lib/multiprocessing/resource_tracker.py b/Lib/multiprocessing/resource_tracker.py
index c9bfa9b82b6..cc42dbdda05 100644
--- a/Lib/multiprocessing/resource_tracker.py
+++ b/Lib/multiprocessing/resource_tracker.py
@@ -37,8 +37,16 @@ if os.name == 'posix':
     import _multiprocessing
     import _posixshmem
 
+    # Use sem_unlink() to clean up named semaphores.
+    #
+    # sem_unlink() may be missing if the Python build process detected the
+    # absence of POSIX named semaphores. In that case, no named semaphores were
+    # ever opened, so no cleanup would be necessary.
+    if hasattr(_multiprocessing, 'sem_unlink'):
+        _CLEANUP_FUNCS.update({
+            'semaphore': _multiprocessing.sem_unlink,
+        })
     _CLEANUP_FUNCS.update({
-        'semaphore': _multiprocessing.sem_unlink,
         'shared_memory': _posixshmem.shm_unlink,
     })