ext: Upgrade PyBind11 to version 2.1.1

Change-Id: I16870dec402d661295f9d013dc23e362b2b2c169
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3225
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/ext/pybind11/docs/advanced/misc.rst b/ext/pybind11/docs/advanced/misc.rst
index c13df7bf8..d98466512 100644
--- a/ext/pybind11/docs/advanced/misc.rst
+++ b/ext/pybind11/docs/advanced/misc.rst
@@ -19,6 +19,7 @@ another name and use it in the macro to avoid this problem.
 Global Interpreter Lock (GIL)
 =============================
 
+When calling a C++ function from Python, the GIL is always held.
 The classes :class:`gil_scoped_release` and :class:`gil_scoped_acquire` can be
 used to acquire and release the global interpreter lock in the body of a C++
 function call. In this way, long-running C++ code can be parallelized using
@@ -169,6 +170,20 @@ would be then able to access the data behind the same pointer.
 
 .. [#f6] https://docs.python.org/3/extending/extending.html#using-capsules
 
+Module Destructors
+==================
+
+pybind11 does not provide an explicit mechanism to invoke cleanup code at
+module destruction time. In rare cases where such functionality is required, it
+is possible to emulate it using Python capsules with a destruction callback.
+
+.. code-block:: cpp
+
+    auto cleanup_callback = []() {
+        // perform cleanup here -- this function is called with the GIL held
+    };
+
+    m.add_object("_cleanup", py::capsule(cleanup_callback));
 
 Generating documentation using Sphinx
 =====================================