Make default handles ref-counted as well

include/podio/utilities/MaybeSharedPtr.h

@@ -81,8 +81,10 @@ class MaybeSharedPtr {
 
   /// Get a raw pointer to the managed pointer and assume ownership.
   T* release() {
-    // From now on we only need to keep track of the control block
-    m_ctrlBlock->owned = false;
+    if (m_ctrlBlock) {
+      // From now on we only need to keep track of the control block
+      m_ctrlBlock->owned = false;
+    }
     return m_ptr;
   }
 

python/templates/Collection.cc.jinja2

@@ -165,7 +165,7 @@ void {{ collection_type }}::push_back({{ class.bare_type }} object) {
     // This path is only possible if we arrive here from an untracked Mutable object
     throw std::invalid_argument("Object needs to be tracked by another collection in order for it to be storable in a subset collection");
   }
-  m_storage.entries.push_back(obj);
+  m_storage.entries.push_back(obj.release());
 }
 
 podio::CollectionWriteBuffers {{ collection_type }}::getBuffers() {

python/templates/MutableObject.cc.jinja2

@@ -34,7 +34,7 @@
 
 {{ full_type }}::{{ full_type }}(podio::utils::MaybeSharedPtr<{{ class.bare_type }}Obj> obj) : m_obj(obj) {}
 
-{{ full_type }}::operator {{ class.bare_type }}() const { return {{ class.bare_type }}(m_obj.get()); }
+{{ full_type }}::operator {{ class.bare_type }}() const { return {{ class.bare_type }}(m_obj); }
 
 {% endwith %}
 

python/templates/Object.cc.jinja2

@@ -1,3 +1,4 @@
+#include "podio/utilities/MaybeSharedPtr.h"
 {% import "macros/utils.jinja2" as utils %}
 {% import "macros/implementations.jinja2" as macros %}
 // AUTOMATICALLY GENERATED FILE - DO NOT EDIT
@@ -18,7 +19,9 @@
 
 {{ macros.common_constructors_destructors(class.bare_type, Members) }}
 
-{{ class.bare_type }}::{{ class.bare_type }}({{ class.bare_type }}Obj* obj) : m_obj(obj) {}
+{{ class.bare_type }}::{{ class.bare_type }}(podio::utils::MaybeSharedPtr<{{ class.bare_type }}Obj> obj) : m_obj(obj) {}
+
+{{ class.bare_type }}::{{ class.bare_type }}({{ class.bare_type }}Obj* obj) : m_obj(podio::utils::MaybeSharedPtr<{{ class.bare_type }}Obj>(obj)) {}
 
 {{ class.bare_type }} {{ class.bare_type }}::makeEmpty() {
   return {nullptr};

python/templates/Object.h.jinja2

@@ -11,6 +11,8 @@
 {{ include }}
 {% endfor %}
 
+#include "podio/utilities/MaybeSharedPtr.h"
+
 #include <ostream>
 #include <cstddef>
 
@@ -49,14 +51,15 @@ public:
 {{ utils.if_present(ExtraCode, "declaration") }}
 {{ macros.common_object_funcs(class.bare_type) }}
 
-  /// disconnect from the {{ class.bare_type }}Obj
-  void unlink() { m_obj = nullptr; }
+  /// disconnect from {{ class.bare_type }}Obj instance
+  void unlink() { m_obj = podio::utils::MaybeSharedPtr<{{ class.bare_type }}Obj>{nullptr}; }
 
 private:
   /// constructor from existing {{ class.bare_type }}Obj
+  explicit {{ class.bare_type}}(podio::utils::MaybeSharedPtr<{{ class.bare_type }}Obj> obj);
   {{ class.bare_type}}({{ class.bare_type }}Obj* obj);
 
-  {{ class.bare_type }}Obj* m_obj{nullptr};
+  podio::utils::MaybeSharedPtr<{{ class.bare_type }}Obj> m_obj{nullptr};
 };
 
 std::ostream& operator<<(std::ostream& o, const {{ class.bare_type }}& value);

python/templates/macros/iterator.jinja2

@@ -1,6 +1,6 @@
 {% macro iterator_declaration(class, prefix='') %}
 {% with iterator_type = class.bare_type + prefix + 'CollectionIterator' %}
-{% set ptr_init = 'podio::utils::MaybeSharedPtr<' + class.bare_type +'Obj>{nullptr}' if prefix else 'nullptr' %}
+{% set ptr_init = 'podio::utils::MaybeSharedPtr<' + class.bare_type +'Obj>{nullptr}' %}
 class {{ iterator_type }} {
 public:
   {{ iterator_type }}(size_t index, const {{ class.bare_type }}ObjPointerContainer* collection) : m_index(index), m_object({{ ptr_init }}), m_collection(collection) {}
@@ -31,7 +31,7 @@ private:
 
 {% macro iterator_definitions(class, prefix='') %}
 {% with iterator_type = class.bare_type + prefix + 'CollectionIterator' %}
-{% set ptr_type = 'podio::utils::MaybeSharedPtr<' + class.bare_type +'Obj>' if prefix else '' %}
+{% set ptr_type = 'podio::utils::MaybeSharedPtr<' + class.bare_type +'Obj>' %}
 {{ prefix }}{{ class.bare_type }} {{ iterator_type }}::operator*() {
   m_object.m_obj = {{ ptr_type }}((*m_collection)[m_index]);
   return m_object;

tests/unittests/unittest.cpp

@@ -149,14 +149,24 @@ TEST_CASE("Component", "[basics]") {
   REQUIRE(3 == info.component().data.x);
 }
 
+TEST_CASE("makeEmpty", "[basics]") {
+  auto hit = ExampleHit::makeEmpty();
+  // Any access to such a handle is a crash
+  REQUIRE_FALSE(hit.isAvailable());
+
+  hit = MutableExampleHit{};
+  REQUIRE(hit.isAvailable());
+  REQUIRE(hit.energy() == 0);
+}
+
 TEST_CASE("Cyclic", "[basics][relations][memory-management]") {
-  auto start = MutableExampleForCyclicDependency1();
-  auto isAvailable = start.ref().isAvailable();
-  REQUIRE_FALSE(isAvailable);
-  auto end = MutableExampleForCyclicDependency2();
+  auto coll1 = ExampleForCyclicDependency1Collection();
+  auto start = coll1.create();
+  REQUIRE_FALSE(start.ref().isAvailable());
+  auto coll2 = ExampleForCyclicDependency2Collection();
+  auto end = coll2.create();
   start.ref(end);
-  isAvailable = start.ref().isAvailable();
-  REQUIRE(isAvailable);
+  REQUIRE(start.ref().isAvailable());
   end.ref(start);
   REQUIRE(start == end.ref());
   auto end_eq = start.ref();
@@ -165,6 +175,31 @@ TEST_CASE("Cyclic", "[basics][relations][memory-management]") {
   REQUIRE(start == start.ref().ref());
 }
 
+TEST_CASE("Cyclic w/o collection", "[LEAK-FAIL][basics][relations][memory-management]") {
+  auto start = MutableExampleForCyclicDependency1{};
+  REQUIRE_FALSE(start.ref().isAvailable());
+  auto end = MutableExampleForCyclicDependency2{};
+  start.ref(end);
+  REQUIRE(start.ref().isAvailable());
+  end.ref(start);
+  REQUIRE(start == end.ref());
+  auto end_eq = start.ref();
+  auto start_eq = end_eq.ref();
+  REQUIRE(start == start_eq);
+  REQUIRE(start == start.ref().ref());
+}
+
+TEST_CASE("Container lifetime", "[basics][memory-management]") {
+  std::vector<ExampleHit> hits;
+  {
+    MutableExampleHit hit;
+    hit.energy(3.14f);
+    hits.push_back(hit);
+  }
+  auto hit = hits[0];
+  REQUIRE(hit.energy() == 3.14f);
+}
+
 TEST_CASE("Invalid_refs", "[basics][relations]") {
   auto store = podio::EventStore();
   auto& hits = store.create<ExampleHitCollection>("hits");