Added warning about logging use from asynchronous signal handlers.
diff --git a/Doc/library/logging.rst b/Doc/library/logging.rst
index 8226661..2a21d28 100644
--- a/Doc/library/logging.rst
+++ b/Doc/library/logging.rst
@@ -2351,6 +2351,9 @@
locks; there is one lock to serialize access to the module's shared data, and
each handler also creates a lock to serialize access to its underlying I/O.
+Note that in Linux/Unix environments, threading APIs may not be usable in
+asynchronous signal handlers. This may mean that you cannot use logging from
+within asynchronous signal handlers; please check your OS documentation.
Configuration
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