cross_module_gil_utils.cpp revision 14299:2fbea9df56d2 
1/*
2    tests/cross_module_gil_utils.cpp -- tools for acquiring GIL from a different module
3
4    Copyright (c) 2019 Google LLC
5
6    All rights reserved. Use of this source code is governed by a
7    BSD-style license that can be found in the LICENSE file.
8*/
9#include <pybind11/pybind11.h>
10#include <cstdint>
11
12// This file mimics a DSO that makes pybind11 calls but does not define a
13// PYBIND11_MODULE. The purpose is to test that such a DSO can create a
14// py::gil_scoped_acquire when the running thread is in a GIL-released state.
15//
16// Note that we define a Python module here for convenience, but in general
17// this need not be the case. The typical scenario would be a DSO that implements
18// shared logic used internally by multiple pybind11 modules.
19
20namespace {
21
22namespace py = pybind11;
23void gil_acquire() { py::gil_scoped_acquire gil; }
24
25constexpr char kModuleName[] = "cross_module_gil_utils";
26
27#if PY_MAJOR_VERSION >= 3
28struct PyModuleDef moduledef = {
29    PyModuleDef_HEAD_INIT,
30    kModuleName,
31    NULL,
32    0,
33    NULL,
34    NULL,
35    NULL,
36    NULL,
37    NULL
38};
39#else
40PyMethodDef module_methods[] = {
41    {NULL, NULL, 0, NULL}
42};
43#endif
44
45}  // namespace
46
47extern "C" PYBIND11_EXPORT
48#if PY_MAJOR_VERSION >= 3
49PyObject* PyInit_cross_module_gil_utils()
50#else
51void initcross_module_gil_utils()
52#endif
53{
54
55    PyObject* m =
56#if PY_MAJOR_VERSION >= 3
57        PyModule_Create(&moduledef);
58#else
59        Py_InitModule(kModuleName, module_methods);
60#endif
61
62    if (m != NULL) {
63        static_assert(
64            sizeof(&gil_acquire) == sizeof(void*),
65            "Function pointer must have the same size as void*");
66        PyModule_AddObject(m, "gil_acquire_funcaddr",
67                           PyLong_FromVoidPtr(reinterpret_cast<void*>(&gil_acquire)));
68    }
69
70#if PY_MAJOR_VERSION >= 3
71    return m;
72#endif
73}
74