pybind11/tests/test_call_policies.cpp
Dean Moldovan 1ac19036d6 Add a scope guard call policy
```c++
m.def("foo", foo, py::call_guard<T>());
```

is equivalent to:

```c++
m.def("foo", [](args...) {
    T scope_guard;
    return foo(args...); // forwarded arguments
});
```
2017-04-03 00:52:47 +02:00

92 lines
3.0 KiB
C++

/*
tests/test_call_policies.cpp -- keep_alive and call_guard
Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
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"
class Child {
public:
Child() { py::print("Allocating child."); }
~Child() { py::print("Releasing child."); }
};
class Parent {
public:
Parent() { py::print("Allocating parent."); }
~Parent() { py::print("Releasing parent."); }
void addChild(Child *) { }
Child *returnChild() { return new Child(); }
Child *returnNullChild() { return nullptr; }
};
test_initializer keep_alive([](py::module &m) {
py::class_<Parent>(m, "Parent")
.def(py::init<>())
.def("addChild", &Parent::addChild)
.def("addChildKeepAlive", &Parent::addChild, py::keep_alive<1, 2>())
.def("returnChild", &Parent::returnChild)
.def("returnChildKeepAlive", &Parent::returnChild, py::keep_alive<1, 0>())
.def("returnNullChildKeepAliveChild", &Parent::returnNullChild, py::keep_alive<1, 0>())
.def("returnNullChildKeepAliveParent", &Parent::returnNullChild, py::keep_alive<0, 1>());
py::class_<Child>(m, "Child")
.def(py::init<>());
});
struct CustomGuard {
static bool enabled;
CustomGuard() { enabled = true; }
~CustomGuard() { enabled = false; }
static const char *report_status() { return enabled ? "guarded" : "unguarded"; }
};
bool CustomGuard::enabled = false;
struct DependentGuard {
static bool enabled;
DependentGuard() { enabled = CustomGuard::enabled; }
~DependentGuard() { enabled = false; }
static const char *report_status() { return enabled ? "guarded" : "unguarded"; }
};
bool DependentGuard::enabled = false;
test_initializer call_guard([](py::module &pm) {
auto m = pm.def_submodule("call_policies");
m.def("unguarded_call", &CustomGuard::report_status);
m.def("guarded_call", &CustomGuard::report_status, py::call_guard<CustomGuard>());
m.def("multiple_guards_correct_order", []() {
return CustomGuard::report_status() + std::string(" & ") + DependentGuard::report_status();
}, py::call_guard<CustomGuard, DependentGuard>());
m.def("multiple_guards_wrong_order", []() {
return DependentGuard::report_status() + std::string(" & ") + CustomGuard::report_status();
}, py::call_guard<DependentGuard, CustomGuard>());
#if defined(WITH_THREAD) && !defined(PYPY_VERSION)
// `py::call_guard<py::gil_scoped_release>()` should work in PyPy as well,
// but it's unclear how to test it without `PyGILState_GetThisThreadState`.
auto report_gil_status = []() {
auto is_gil_held = false;
if (auto tstate = py::detail::get_thread_state_unchecked())
is_gil_held = (tstate == PyGILState_GetThisThreadState());
return is_gil_held ? "GIL held" : "GIL released";
};
m.def("with_gil", report_gil_status);
m.def("without_gil", report_gil_status, py::call_guard<py::gil_scoped_release>());
#endif
});