test_smart_ptr.cpp
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1 /*
2  tests/test_smart_ptr.cpp -- binding classes with custom reference counting,
3  implicit conversions between types
4 
5  Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
6 
7  All rights reserved. Use of this source code is governed by a
8  BSD-style license that can be found in the LICENSE file.
9 */
10 
11 #include "object.h"
12 #include "pybind11_tests.h"
13 
14 namespace {
15 
16 // This is just a wrapper around unique_ptr, but with extra fields to deliberately bloat up the
17 // holder size to trigger the non-simple-layout internal instance layout for single inheritance
18 // with large holder type:
19 template <typename T>
20 class huge_unique_ptr {
21  std::unique_ptr<T> ptr;
22  uint64_t padding[10];
23 
24 public:
25  explicit huge_unique_ptr(T *p) : ptr(p) {}
26  T *get() { return ptr.get(); }
27 };
28 
29 // Simple custom holder that works like unique_ptr
30 template <typename T>
31 class custom_unique_ptr {
32  std::unique_ptr<T> impl;
33 
34 public:
35  explicit custom_unique_ptr(T *p) : impl(p) {}
36  T *get() const { return impl.get(); }
37  T *release_ptr() { return impl.release(); }
38 };
39 
40 // Simple custom holder that works like shared_ptr and has operator& overload
41 // To obtain address of an instance of this holder pybind should use std::addressof
42 // Attempt to get address via operator& may leads to segmentation fault
43 template <typename T>
44 class shared_ptr_with_addressof_operator {
45  std::shared_ptr<T> impl;
46 
47 public:
48  shared_ptr_with_addressof_operator() = default;
49  explicit shared_ptr_with_addressof_operator(T *p) : impl(p) {}
50  T *get() const { return impl.get(); }
51  T **operator&() { throw std::logic_error("Call of overloaded operator& is not expected"); }
52 };
53 
54 // Simple custom holder that works like unique_ptr and has operator& overload
55 // To obtain address of an instance of this holder pybind should use std::addressof
56 // Attempt to get address via operator& may leads to segmentation fault
57 template <typename T>
58 class unique_ptr_with_addressof_operator {
59  std::unique_ptr<T> impl;
60 
61 public:
62  unique_ptr_with_addressof_operator() = default;
63  explicit unique_ptr_with_addressof_operator(T *p) : impl(p) {}
64  T *get() const { return impl.get(); }
65  T *release_ptr() { return impl.release(); }
66  T **operator&() { throw std::logic_error("Call of overloaded operator& is not expected"); }
67 };
68 
69 // Custom object with builtin reference counting (see 'object.h' for the implementation)
70 class MyObject1 : public Object {
71 public:
72  explicit MyObject1(int value) : value(value) { print_created(this, toString()); }
73  std::string toString() const override { return "MyObject1[" + std::to_string(value) + "]"; }
74 
75 protected:
76  ~MyObject1() override { print_destroyed(this); }
77 
78 private:
79  int value;
80 };
81 
82 // Object managed by a std::shared_ptr<>
83 class MyObject2 {
84 public:
85  MyObject2(const MyObject2 &) = default;
86  explicit MyObject2(int value) : value(value) { print_created(this, toString()); }
87  std::string toString() const { return "MyObject2[" + std::to_string(value) + "]"; }
88  virtual ~MyObject2() { print_destroyed(this); }
89 
90 private:
91  int value;
92 };
93 
94 // Object managed by a std::shared_ptr<>, additionally derives from std::enable_shared_from_this<>
95 class MyObject3 : public std::enable_shared_from_this<MyObject3> {
96 public:
97  MyObject3(const MyObject3 &) = default;
98  explicit MyObject3(int value) : value(value) { print_created(this, toString()); }
99  std::string toString() const { return "MyObject3[" + std::to_string(value) + "]"; }
100  virtual ~MyObject3() { print_destroyed(this); }
101 
102 private:
103  int value;
104 };
105 
106 // test_unique_nodelete
107 // Object with a private destructor
108 class MyObject4;
109 std::unordered_set<MyObject4 *> myobject4_instances;
110 class MyObject4 {
111 public:
112  explicit MyObject4(int value) : value{value} {
113  print_created(this);
114  myobject4_instances.insert(this);
115  }
116  int value;
117 
118  static void cleanupAllInstances() {
119  auto tmp = std::move(myobject4_instances);
120  myobject4_instances.clear();
121  for (auto *o : tmp) {
122  delete o;
123  }
124  }
125 
126 private:
127  ~MyObject4() {
128  myobject4_instances.erase(this);
129  print_destroyed(this);
130  }
131 };
132 
133 // test_unique_deleter
134 // Object with std::unique_ptr<T, D> where D is not matching the base class
135 // Object with a protected destructor
136 class MyObject4a;
137 std::unordered_set<MyObject4a *> myobject4a_instances;
138 class MyObject4a {
139 public:
140  explicit MyObject4a(int i) : value{i} {
141  print_created(this);
142  myobject4a_instances.insert(this);
143  };
144  int value;
145 
146  static void cleanupAllInstances() {
147  auto tmp = std::move(myobject4a_instances);
148  myobject4a_instances.clear();
149  for (auto *o : tmp) {
150  delete o;
151  }
152  }
153 
154 protected:
155  virtual ~MyObject4a() {
156  myobject4a_instances.erase(this);
157  print_destroyed(this);
158  }
159 };
160 
161 // Object derived but with public destructor and no Deleter in default holder
162 class MyObject4b : public MyObject4a {
163 public:
164  explicit MyObject4b(int i) : MyObject4a(i) { print_created(this); }
165  ~MyObject4b() override { print_destroyed(this); }
166 };
167 
168 // test_large_holder
169 class MyObject5 { // managed by huge_unique_ptr
170 public:
171  explicit MyObject5(int value) : value{value} { print_created(this); }
172  ~MyObject5() { print_destroyed(this); }
173  int value;
174 };
175 
176 // test_shared_ptr_and_references
177 struct SharedPtrRef {
178  struct A {
179  A() { print_created(this); }
180  A(const A &) { print_copy_created(this); }
181  A(A &&) noexcept { print_move_created(this); }
182  ~A() { print_destroyed(this); }
183  };
184 
185  A value = {};
186  std::shared_ptr<A> shared = std::make_shared<A>();
187 };
188 
189 // test_shared_ptr_from_this_and_references
190 struct SharedFromThisRef {
191  struct B : std::enable_shared_from_this<B> {
192  B() { print_created(this); }
193  // NOLINTNEXTLINE(bugprone-copy-constructor-init)
194  B(const B &) : std::enable_shared_from_this<B>() { print_copy_created(this); }
195  B(B &&) noexcept : std::enable_shared_from_this<B>() { print_move_created(this); }
196  ~B() { print_destroyed(this); }
197  };
198 
199  B value = {};
200  std::shared_ptr<B> shared = std::make_shared<B>();
201 };
202 
203 // Issue #865: shared_from_this doesn't work with virtual inheritance
204 struct SharedFromThisVBase : std::enable_shared_from_this<SharedFromThisVBase> {
205  SharedFromThisVBase() = default;
206  SharedFromThisVBase(const SharedFromThisVBase &) = default;
207  virtual ~SharedFromThisVBase() = default;
208 };
209 struct SharedFromThisVirt : virtual SharedFromThisVBase {};
210 
211 // test_move_only_holder
212 struct C {
213  C() { print_created(this); }
214  ~C() { print_destroyed(this); }
215 };
216 
217 // test_holder_with_addressof_operator
218 struct TypeForHolderWithAddressOf {
219  TypeForHolderWithAddressOf() { print_created(this); }
220  TypeForHolderWithAddressOf(const TypeForHolderWithAddressOf &) { print_copy_created(this); }
221  TypeForHolderWithAddressOf(TypeForHolderWithAddressOf &&) noexcept {
222  print_move_created(this);
223  }
224  ~TypeForHolderWithAddressOf() { print_destroyed(this); }
225  std::string toString() const {
226  return "TypeForHolderWithAddressOf[" + std::to_string(value) + "]";
227  }
228  int value = 42;
229 };
230 
231 // test_move_only_holder_with_addressof_operator
232 struct TypeForMoveOnlyHolderWithAddressOf {
233  explicit TypeForMoveOnlyHolderWithAddressOf(int value) : value{value} { print_created(this); }
234  ~TypeForMoveOnlyHolderWithAddressOf() { print_destroyed(this); }
235  std::string toString() const {
236  return "MoveOnlyHolderWithAddressOf[" + std::to_string(value) + "]";
237  }
238  int value;
239 };
240 
241 // test_smart_ptr_from_default
242 struct HeldByDefaultHolder {};
243 
244 // test_shared_ptr_gc
245 // #187: issue involving std::shared_ptr<> return value policy & garbage collection
246 struct ElementBase {
247  virtual ~ElementBase() = default; /* Force creation of virtual table */
248  ElementBase() = default;
249  ElementBase(const ElementBase &) = delete;
250 };
251 
252 struct ElementA : ElementBase {
253  explicit ElementA(int v) : v(v) {}
254  int value() const { return v; }
255  int v;
256 };
257 
258 struct ElementList {
259  void add(const std::shared_ptr<ElementBase> &e) { l.push_back(e); }
260  std::vector<std::shared_ptr<ElementBase>> l;
261 };
262 
263 } // namespace
264 
265 // ref<T> is a wrapper for 'Object' which uses intrusive reference counting
266 // It is always possible to construct a ref<T> from an Object* pointer without
267 // possible inconsistencies, hence the 'true' argument at the end.
268 // Make pybind11 aware of the non-standard getter member function
269 namespace pybind11 {
270 namespace detail {
271 template <typename T>
272 struct holder_helper<ref<T>> {
273  static const T *get(const ref<T> &p) { return p.get_ptr(); }
274 };
275 } // namespace detail
276 } // namespace pybind11
277 
278 // Make pybind aware of the ref-counted wrapper type (s):
280 // The following is not required anymore for std::shared_ptr, but it should compile without error:
281 PYBIND11_DECLARE_HOLDER_TYPE(T, std::shared_ptr<T>);
282 PYBIND11_DECLARE_HOLDER_TYPE(T, huge_unique_ptr<T>);
283 PYBIND11_DECLARE_HOLDER_TYPE(T, custom_unique_ptr<T>);
284 PYBIND11_DECLARE_HOLDER_TYPE(T, shared_ptr_with_addressof_operator<T>);
285 PYBIND11_DECLARE_HOLDER_TYPE(T, unique_ptr_with_addressof_operator<T>);
286 
287 TEST_SUBMODULE(smart_ptr, m) {
288  // Please do not interleave `struct` and `class` definitions with bindings code,
289  // but implement `struct`s and `class`es in the anonymous namespace above.
290  // This helps keeping the smart_holder branch in sync with master.
291 
292  // test_smart_ptr
293 
294  // Object implementation in `object.h`
295  py::class_<Object, ref<Object>> obj(m, "Object");
296  obj.def("getRefCount", &Object::getRefCount);
297 
298  py::class_<MyObject1, ref<MyObject1>>(m, "MyObject1", obj).def(py::init<int>());
299  py::implicitly_convertible<py::int_, MyObject1>();
300 
301  m.def("make_object_1", []() -> Object * { return new MyObject1(1); });
302  m.def("make_object_2", []() -> ref<Object> { return ref<Object>(new MyObject1(2)); });
303  m.def("make_myobject1_1", []() -> MyObject1 * { return new MyObject1(4); });
304  m.def("make_myobject1_2", []() -> ref<MyObject1> { return ref<MyObject1>(new MyObject1(5)); });
305  m.def("print_object_1", [](const Object *obj) { py::print(obj->toString()); });
306  m.def("print_object_2", [](ref<Object> obj) { py::print(obj->toString()); });
307  m.def("print_object_3", [](const ref<Object> &obj) { py::print(obj->toString()); });
308  m.def("print_object_4", [](const ref<Object> *obj) { py::print((*obj)->toString()); });
309  m.def("print_myobject1_1", [](const MyObject1 *obj) { py::print(obj->toString()); });
310  m.def("print_myobject1_2", [](ref<MyObject1> obj) { py::print(obj->toString()); });
311  m.def("print_myobject1_3", [](const ref<MyObject1> &obj) { py::print(obj->toString()); });
312  m.def("print_myobject1_4", [](const ref<MyObject1> *obj) { py::print((*obj)->toString()); });
313 
314  // Expose constructor stats for the ref type
315  m.def("cstats_ref", &ConstructorStats::get<ref_tag>);
316 
317  py::class_<MyObject2, std::shared_ptr<MyObject2>>(m, "MyObject2").def(py::init<int>());
318  m.def("make_myobject2_1", []() { return new MyObject2(6); });
319  m.def("make_myobject2_2", []() { return std::make_shared<MyObject2>(7); });
320  m.def("print_myobject2_1", [](const MyObject2 *obj) { py::print(obj->toString()); });
321  // NOLINTNEXTLINE(performance-unnecessary-value-param)
322  m.def("print_myobject2_2", [](std::shared_ptr<MyObject2> obj) { py::print(obj->toString()); });
323  m.def("print_myobject2_3",
324  [](const std::shared_ptr<MyObject2> &obj) { py::print(obj->toString()); });
325  m.def("print_myobject2_4",
326  [](const std::shared_ptr<MyObject2> *obj) { py::print((*obj)->toString()); });
327 
328  py::class_<MyObject3, std::shared_ptr<MyObject3>>(m, "MyObject3").def(py::init<int>());
329  m.def("make_myobject3_1", []() { return new MyObject3(8); });
330  m.def("make_myobject3_2", []() { return std::make_shared<MyObject3>(9); });
331  m.def("print_myobject3_1", [](const MyObject3 *obj) { py::print(obj->toString()); });
332  // NOLINTNEXTLINE(performance-unnecessary-value-param)
333  m.def("print_myobject3_2", [](std::shared_ptr<MyObject3> obj) { py::print(obj->toString()); });
334  m.def("print_myobject3_3",
335  [](const std::shared_ptr<MyObject3> &obj) { py::print(obj->toString()); });
336  m.def("print_myobject3_4",
337  [](const std::shared_ptr<MyObject3> *obj) { py::print((*obj)->toString()); });
338 
339  // test_smart_ptr_refcounting
340  m.def("test_object1_refcounting", []() {
341  auto o = ref<MyObject1>(new MyObject1(0));
342  bool good = o->getRefCount() == 1;
343  py::object o2 = py::cast(o, py::return_value_policy::reference);
344  // always request (partial) ownership for objects with intrusive
345  // reference counting even when using the 'reference' RVP
346  good &= o->getRefCount() == 2;
347  return good;
348  });
349 
350  // test_unique_nodelete
351  py::class_<MyObject4, std::unique_ptr<MyObject4, py::nodelete>>(m, "MyObject4")
352  .def(py::init<int>())
353  .def_readwrite("value", &MyObject4::value)
354  .def_static("cleanup_all_instances", &MyObject4::cleanupAllInstances);
355 
356  // test_unique_deleter
357  py::class_<MyObject4a, std::unique_ptr<MyObject4a, py::nodelete>>(m, "MyObject4a")
358  .def(py::init<int>())
359  .def_readwrite("value", &MyObject4a::value)
360  .def_static("cleanup_all_instances", &MyObject4a::cleanupAllInstances);
361 
362  py::class_<MyObject4b, MyObject4a, std::unique_ptr<MyObject4b>>(m, "MyObject4b")
363  .def(py::init<int>());
364 
365  // test_large_holder
366  py::class_<MyObject5, huge_unique_ptr<MyObject5>>(m, "MyObject5")
367  .def(py::init<int>())
368  .def_readwrite("value", &MyObject5::value);
369 
370  // test_shared_ptr_and_references
371  using A = SharedPtrRef::A;
372  py::class_<A, std::shared_ptr<A>>(m, "A");
373  py::class_<SharedPtrRef, std::unique_ptr<SharedPtrRef>>(m, "SharedPtrRef")
374  .def(py::init<>())
375  .def_readonly("ref", &SharedPtrRef::value)
376  .def_property_readonly(
377  "copy", [](const SharedPtrRef &s) { return s.value; }, py::return_value_policy::copy)
378  .def_readonly("holder_ref", &SharedPtrRef::shared)
379  .def_property_readonly(
380  "holder_copy",
381  [](const SharedPtrRef &s) { return s.shared; },
383  .def("set_ref", [](SharedPtrRef &, const A &) { return true; })
384  // NOLINTNEXTLINE(performance-unnecessary-value-param)
385  .def("set_holder", [](SharedPtrRef &, std::shared_ptr<A>) { return true; });
386 
387  // test_shared_ptr_from_this_and_references
388  using B = SharedFromThisRef::B;
389  py::class_<B, std::shared_ptr<B>>(m, "B");
390  py::class_<SharedFromThisRef, std::unique_ptr<SharedFromThisRef>>(m, "SharedFromThisRef")
391  .def(py::init<>())
392  .def_readonly("bad_wp", &SharedFromThisRef::value)
393  .def_property_readonly("ref",
394  [](const SharedFromThisRef &s) -> const B & { return *s.shared; })
395  .def_property_readonly(
396  "copy",
397  [](const SharedFromThisRef &s) { return s.value; },
399  .def_readonly("holder_ref", &SharedFromThisRef::shared)
400  .def_property_readonly(
401  "holder_copy",
402  [](const SharedFromThisRef &s) { return s.shared; },
404  .def("set_ref", [](SharedFromThisRef &, const B &) { return true; })
405  // NOLINTNEXTLINE(performance-unnecessary-value-param)
406  .def("set_holder", [](SharedFromThisRef &, std::shared_ptr<B>) { return true; });
407 
408  // Issue #865: shared_from_this doesn't work with virtual inheritance
409  static std::shared_ptr<SharedFromThisVirt> sft(new SharedFromThisVirt());
410  py::class_<SharedFromThisVirt, std::shared_ptr<SharedFromThisVirt>>(m, "SharedFromThisVirt")
411  .def_static("get", []() { return sft.get(); });
412 
413  // test_move_only_holder
414  py::class_<C, custom_unique_ptr<C>>(m, "TypeWithMoveOnlyHolder")
415  .def_static("make", []() { return custom_unique_ptr<C>(new C); })
416  .def_static("make_as_object", []() { return py::cast(custom_unique_ptr<C>(new C)); });
417 
418  // test_holder_with_addressof_operator
419  using HolderWithAddressOf = shared_ptr_with_addressof_operator<TypeForHolderWithAddressOf>;
420  py::class_<TypeForHolderWithAddressOf, HolderWithAddressOf>(m, "TypeForHolderWithAddressOf")
421  .def_static("make", []() { return HolderWithAddressOf(new TypeForHolderWithAddressOf); })
422  .def("get", [](const HolderWithAddressOf &self) { return self.get(); })
423  .def("print_object_1",
424  [](const TypeForHolderWithAddressOf *obj) { py::print(obj->toString()); })
425  // NOLINTNEXTLINE(performance-unnecessary-value-param)
426  .def("print_object_2", [](HolderWithAddressOf obj) { py::print(obj.get()->toString()); })
427  .def("print_object_3",
428  [](const HolderWithAddressOf &obj) { py::print(obj.get()->toString()); })
429  .def("print_object_4",
430  [](const HolderWithAddressOf *obj) { py::print((*obj).get()->toString()); });
431 
432  // test_move_only_holder_with_addressof_operator
433  using MoveOnlyHolderWithAddressOf
434  = unique_ptr_with_addressof_operator<TypeForMoveOnlyHolderWithAddressOf>;
435  py::class_<TypeForMoveOnlyHolderWithAddressOf, MoveOnlyHolderWithAddressOf>(
436  m, "TypeForMoveOnlyHolderWithAddressOf")
437  .def_static("make",
438  []() {
439  return MoveOnlyHolderWithAddressOf(
440  new TypeForMoveOnlyHolderWithAddressOf(0));
441  })
442  .def_readwrite("value", &TypeForMoveOnlyHolderWithAddressOf::value)
443  .def("print_object",
444  [](const TypeForMoveOnlyHolderWithAddressOf *obj) { py::print(obj->toString()); });
445 
446  // test_smart_ptr_from_default
447  py::class_<HeldByDefaultHolder, std::unique_ptr<HeldByDefaultHolder>>(m, "HeldByDefaultHolder")
448  .def(py::init<>())
449  // NOLINTNEXTLINE(performance-unnecessary-value-param)
450  .def_static("load_shared_ptr", [](std::shared_ptr<HeldByDefaultHolder>) {});
451 
452  // test_shared_ptr_gc
453  // #187: issue involving std::shared_ptr<> return value policy & garbage collection
454  py::class_<ElementBase, std::shared_ptr<ElementBase>>(m, "ElementBase");
455 
456  py::class_<ElementA, ElementBase, std::shared_ptr<ElementA>>(m, "ElementA")
457  .def(py::init<int>())
458  .def("value", &ElementA::value);
459 
460  py::class_<ElementList, std::shared_ptr<ElementList>>(m, "ElementList")
461  .def(py::init<>())
462  .def("add", &ElementList::add)
463  .def("get", [](ElementList &el) {
464  py::list list;
465  for (auto &e : el.l) {
466  list.append(py::cast(e));
467  }
468  return list;
469  });
470 }
Matrix< SCALARB, Dynamic, Dynamic, opt_B > B
Definition: bench_gemm.cpp:49
Reference counted object base class.
Definition: object.h:9
Matrix3f m
TEST_SUBMODULE(smart_ptr, m)
void print_destroyed(T *inst, Values &&...values)
Definition: BFloat16.h:88
DiscreteKeys operator &(const DiscreteKey &key1, const DiscreteKey &key2)
Create a list from two keys.
Definition: DiscreteKey.cpp:45
EIGEN_STRONG_INLINE Packet4f print(const Packet4f &a)
void print_copy_created(T *inst, Values &&...values)
Matrix< SCALARA, Dynamic, Dynamic, opt_A > A
Definition: bench_gemm.cpp:48
int getRefCount() const
Return the current reference count.
Definition: object.h:18
static const Line3 l(Rot3(), 1, 1)
Array< int, Dynamic, 1 > v
unsigned __int64 uint64_t
Definition: ms_stdint.h:95
EIGEN_DEVICE_FUNC NewType cast(const OldType &x)
Array< double, 1, 3 > e(1./3., 0.5, 2.)
RealScalar s
Reference counting helper.
Definition: object.h:67
Matrix< Scalar, Dynamic, Dynamic > C
Definition: bench_gemm.cpp:50
virtual std::string toString() const =0
void print_created(T *inst, Values &&...values)
float * p
graph add(PriorFactor< Pose2 >(1, priorMean, priorNoise))
int EIGEN_BLAS_FUNC() copy(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy)
Definition: level1_impl.h:29
void print_move_created(T *inst, Values &&...values)
PYBIND11_DECLARE_HOLDER_TYPE(T, ref< T >, true)


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autogenerated on Tue Jul 4 2023 02:37:46