test_call_policies.cpp revision 14299:2fbea9df56d2 
1/*
2    tests/test_call_policies.cpp -- keep_alive and call_guard
3
4    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
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
10#include "pybind11_tests.h"
11
12struct CustomGuard {
13    static bool enabled;
14
15    CustomGuard() { enabled = true; }
16    ~CustomGuard() { enabled = false; }
17
18    static const char *report_status() { return enabled ? "guarded" : "unguarded"; }
19};
20bool CustomGuard::enabled = false;
21
22struct DependentGuard {
23    static bool enabled;
24
25    DependentGuard() { enabled = CustomGuard::enabled; }
26    ~DependentGuard() { enabled = false; }
27
28    static const char *report_status() { return enabled ? "guarded" : "unguarded"; }
29};
30bool DependentGuard::enabled = false;
31
32TEST_SUBMODULE(call_policies, m) {
33    // Parent/Child are used in:
34    // test_keep_alive_argument, test_keep_alive_return_value, test_alive_gc_derived,
35    // test_alive_gc_multi_derived, test_return_none, test_keep_alive_constructor
36    class Child {
37    public:
38        Child() { py::print("Allocating child."); }
39        Child(const Child &) = default;
40        Child(Child &&) = default;
41        ~Child() { py::print("Releasing child."); }
42    };
43    py::class_<Child>(m, "Child")
44        .def(py::init<>());
45
46    class Parent {
47    public:
48        Parent() { py::print("Allocating parent."); }
49        ~Parent() { py::print("Releasing parent."); }
50        void addChild(Child *) { }
51        Child *returnChild() { return new Child(); }
52        Child *returnNullChild() { return nullptr; }
53    };
54    py::class_<Parent>(m, "Parent")
55        .def(py::init<>())
56        .def(py::init([](Child *) { return new Parent(); }), py::keep_alive<1, 2>())
57        .def("addChild", &Parent::addChild)
58        .def("addChildKeepAlive", &Parent::addChild, py::keep_alive<1, 2>())
59        .def("returnChild", &Parent::returnChild)
60        .def("returnChildKeepAlive", &Parent::returnChild, py::keep_alive<1, 0>())
61        .def("returnNullChildKeepAliveChild", &Parent::returnNullChild, py::keep_alive<1, 0>())
62        .def("returnNullChildKeepAliveParent", &Parent::returnNullChild, py::keep_alive<0, 1>());
63
64#if !defined(PYPY_VERSION)
65    // test_alive_gc
66    class ParentGC : public Parent {
67    public:
68        using Parent::Parent;
69    };
70    py::class_<ParentGC, Parent>(m, "ParentGC", py::dynamic_attr())
71        .def(py::init<>());
72#endif
73
74    // test_call_guard
75    m.def("unguarded_call", &CustomGuard::report_status);
76    m.def("guarded_call", &CustomGuard::report_status, py::call_guard<CustomGuard>());
77
78    m.def("multiple_guards_correct_order", []() {
79        return CustomGuard::report_status() + std::string(" & ") + DependentGuard::report_status();
80    }, py::call_guard<CustomGuard, DependentGuard>());
81
82    m.def("multiple_guards_wrong_order", []() {
83        return DependentGuard::report_status() + std::string(" & ") + CustomGuard::report_status();
84    }, py::call_guard<DependentGuard, CustomGuard>());
85
86#if defined(WITH_THREAD) && !defined(PYPY_VERSION)
87    // `py::call_guard<py::gil_scoped_release>()` should work in PyPy as well,
88    // but it's unclear how to test it without `PyGILState_GetThisThreadState`.
89    auto report_gil_status = []() {
90        auto is_gil_held = false;
91        if (auto tstate = py::detail::get_thread_state_unchecked())
92            is_gil_held = (tstate == PyGILState_GetThisThreadState());
93
94        return is_gil_held ? "GIL held" : "GIL released";
95    };
96
97    m.def("with_gil", report_gil_status);
98    m.def("without_gil", report_gil_status, py::call_guard<py::gil_scoped_release>());
99#endif
100}
101