From 14108c4f239c81a2908dea7bcb17896f36d0af67 Mon Sep 17 00:00:00 2001
From: allegroai <>
Date: Fri, 20 Aug 2021 00:33:37 +0300
Subject: [PATCH] Fix PY3.x fails calling SemLock._after_fork with forkserver
 context, forking while lock is acquired
 (https://github.com/allegroai/clearml-agent/issues/73)

---
 clearml/utilities/locks/utils.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/clearml/utilities/locks/utils.py b/clearml/utilities/locks/utils.py
index 20a88f16..6d390380 100644
--- a/clearml/utilities/locks/utils.py
+++ b/clearml/utilities/locks/utils.py
@@ -233,6 +233,18 @@ class RLock(Lock):
 
     def acquire(self, timeout=None, check_interval=None, fail_when_locked=None):
         if self._lock:
+            # cleanup bad python behaviour when forking while lock is acquired
+            # see Issue https://github.com/allegroai/clearml-agent/issues/73
+            # and https://bugs.python.org/issue6721
+            if self._pid != os.getpid():
+                # noinspection PyBroadException
+                try:
+                    if self._lock._semlock._count():  # noqa
+                        # this should never happen unless python forgot calling _after_fork
+                        self._lock._semlock._after_fork()  # noqa
+                except BaseException:
+                    pass
+
             if not self._lock.acquire(block=timeout != 0, timeout=timeout):
                 # We got a timeout... reraising
                 raise exceptions.LockException()