casa-mp-base

From d04a9b1d9e6a0aa3601972f1291d181377759d14 Mon Sep 17 00:00:00 2001

From: Borja Zarco <bzarco@google.com>

Date: Fri, 8 Dec 2017 17:35:59 -0500

Subject: [PATCH] Use `PyGILState_GetThisThreadState` when using

 gil_scoped_acquire.

​

This avoids GIL deadlocking when pybind11 tries to acquire the GIL in a thread that already acquired it using standard Python API (e.g. when running from a Python thread).

---

 include/pybind11/pybind11.h |  9 +++++

 tests/CMakeLists.txt        |  1 +

 tests/test_gil_scoped.cpp   | 43 ++++++++++++++++++++

 tests/test_gil_scoped.py    | 80 +++++++++++++++++++++++++++++++++++++

 4 files changed, 133 insertions(+)

 create mode 100644 tests/test_gil_scoped.cpp

 create mode 100644 tests/test_gil_scoped.py

​

diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h

index e986d007a..5f5f5c82a 100644

--- include/pybind11/pybind11.h

+++ include/pybind11/pybind11.h

@@ -1749,6 +1749,15 @@ class gil_scoped_acquire {

         auto const &internals = detail::get_internals();

         tstate = (PyThreadState *) PYBIND11_TLS_GET_VALUE(internals.tstate);

+        if (!tstate) {

+            /* Check if the GIL was acquired using the PyGILState_* API instead (e.g. if

+               calling from a Python thread). Since we use a different key, this ensures

+               we don't create a new thread state and deadlock in PyEval_AcquireThread

+               below. Note we don't save this state with internals.tstate, since we don't

+               create it we would fail to clear it (its reference count should be > 0). */

+            tstate = PyGILState_GetThisThreadState();

+        }

+

         if (!tstate) {

             tstate = PyThreadState_New(internals.istate);

             #if !defined(NDEBUG)

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt

index b5e0b526e..a31d5b8b7 100644

--- tests/CMakeLists.txt

+++ tests/CMakeLists.txt

@@ -40,6 +40,7 @@ set(PYBIND11_TEST_FILES

   test_eval.cpp

   test_exceptions.cpp

   test_factory_constructors.cpp

+  test_gil_scoped.cpp

   test_iostream.cpp

   test_kwargs_and_defaults.cpp

   test_local_bindings.cpp

diff --git a/tests/test_gil_scoped.cpp b/tests/test_gil_scoped.cpp

new file mode 100644

index 000000000..a94b7a2e2

--- /dev/null

+++ tests/test_gil_scoped.cpp

@@ -0,0 +1,43 @@

+/*

+    tests/test_gil_scoped.cpp -- acquire and release gil

+

+    Copyright (c) 2017 Borja Zarco (Google LLC) <bzarco@google.com>

+

+    All rights reserved. Use of this source code is governed by a

+    BSD-style license that can be found in the LICENSE file.

+*/

+

+#include "pybind11_tests.h"

+#include <pybind11/functional.h>

+

+

+class VirtClass  {

+public:

+    virtual void virtual_func() {}

+    virtual void pure_virtual_func() = 0;

+};

+

+class PyVirtClass : public VirtClass {

+    void virtual_func() override {

+        PYBIND11_OVERLOAD(void, VirtClass, virtual_func,);

+    }

+    void pure_virtual_func() override {

+        PYBIND11_OVERLOAD_PURE(void, VirtClass, pure_virtual_func,);

+    }

+};

+

+TEST_SUBMODULE(gil_scoped, m) {

+  py::class_<VirtClass, PyVirtClass>(m, "VirtClass")

+      .def(py::init<>())

+      .def("virtual_func", &VirtClass::virtual_func)

+      .def("pure_virtual_func", &VirtClass::pure_virtual_func);

+

+    m.def("test_callback_py_obj",

+          [](py::object func) { func(); });

+    m.def("test_callback_std_func",