1 files changed, 43 insertions, 0 deletions
diff --git a/lib/ansible/utils/lock.py b/lib/ansible/utils/lock.py
new file mode 100644
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+++ b/lib/ansible/utils/lock.py
@@ -0,0 +1,43 @@
+# Copyright (c) 2020 Matt Martz <matt@sivel.net>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from functools import wraps
+
+
+def lock_decorator(attr='missing_lock_attr', lock=None):
+    '''This decorator is a generic implementation that allows you
+    to either use a pre-defined instance attribute as the location
+    of the lock, or to explicitly pass a lock object.
+
+    This code was implemented with ``threading.Lock`` in mind, but
+    may work with other locks, assuming that they function as
+    context managers.
+
+    When using ``attr``, the assumption is the first argument to
+    the wrapped method, is ``self`` or ``cls``.
+
+    Examples:
+
+        @lock_decorator(attr='_callback_lock')
+        def send_callback(...):
+
+        @lock_decorator(lock=threading.Lock())
+        def some_method(...):
+    '''
+    def outer(func):
+        @wraps(func)
+        def inner(*args, **kwargs):
+            # Python2 doesn't have ``nonlocal``
+            # assign the actual lock to ``_lock``
+            if lock is None:
+                _lock = getattr(args[0], attr)
+            else:
+                _lock = lock
+            with _lock:
+                return func(*args, **kwargs)
+        return inner
+    return outer