Add reference counting to AcediaCore types

sources/Memory/MemoryAPI.uc

@@ -209,6 +209,10 @@ public final function Free(Object objectToDeallocate)
         if (!objectAsAcediaObject.IsAllocated()) {
             return;
         }
+        objectAsAcediaObject._deref();
+        if (objectAsAcediaObject._getRefCount() > 0) {
+            return;
+        }
         relevantPool = objectAsAcediaObject._getPool();
         objectAsAcediaObject._finalizer();
     }
@@ -217,6 +221,10 @@ public final function Free(Object objectToDeallocate)
         if (!objectAsAcediaActor.IsAllocated()) {
             return;
         }
+        objectAsAcediaActor._deref();
+        if (objectAsAcediaActor._getRefCount() > 0) {
+            return;
+        }
         objectAsAcediaActor._finalizer();
     }
     //  Try to store freed object in a pool

sources/Memory/Tests/TEST_Memory.uc

@@ -27,6 +27,7 @@ protected static function TESTS()
     Test_ActorConstructorsFinalizers();
     Test_ObjectPoolUsage();
     Test_LifeVersionIsUnique();
+    Test_RefCounting();
 }
 
 protected static function Test_LifeVersionIsUnique()
@@ -164,6 +165,116 @@ protected static function Test_ObjectPoolUsage()
     TEST_ExpectTrue(obj1 != obj2);
 }
 
+protected static function Test_RefCounting()
+{
+    Context("Testing usage of reference counting.");
+    SubTest_RefCountingObjectFreeSelf();
+    SubTest_RefCountingObjectFree();
+    SubTest_RefCountingActorFreeSelf();
+    SubTest_RefCountingActorFree();
+}
+
+protected static function SubTest_RefCountingObjectFreeSelf()
+{
+    local MockObject temp;
+    Issue("Reference counting for `AcediaObject`s does not work correctly"
+        @ "with `FreeSelf()`");
+    temp = MockObject(__().memory.Allocate(class'MockObject'));
+    temp.NewRef().NewRef().NewRef();
+    TEST_ExpectTrue(temp._getRefCount() == 4);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(temp._getRefCount() == 3);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(temp._getRefCount() == 2);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(temp._getRefCount() == 1);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(temp._getRefCount() == 0);
+    TEST_ExpectFalse(temp.IsAllocated());
+}
+
+protected static function SubTest_RefCountingObjectFree()
+{
+    local MockObject temp;
+    Issue("Reference counting for `AcediaObject`s does not work correctly"
+        @ "with `__().memory.Free()`");
+    temp = MockObject(__().memory.Allocate(class'MockObject'));
+    temp.NewRef().NewRef().NewRef();
+    TEST_ExpectTrue(temp._getRefCount() == 4);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(temp._getRefCount() == 3);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(temp._getRefCount() == 2);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(temp._getRefCount() == 1);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(temp._getRefCount() == 0);
+    TEST_ExpectFalse(temp.IsAllocated());
+}
+
+protected static function SubTest_RefCountingActorFreeSelf()
+{
+    local MockActor temp;
+    class'MockActor'.default.actorCount = 0;
+    Issue("Reference counting for `AcediaActor`s does not work correctly"
+        @ "with `FreeSelf()`");
+    temp = MockActor(__().memory.Allocate(class'MockActor'));
+    temp.NewRef().NewRef().NewRef();
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 4);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 3);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 2);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 1);
+    TEST_ExpectTrue(temp.IsAllocated());
+    temp.FreeSelf();
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 0);
+}
+
+protected static function SubTest_RefCountingActorFree()
+{
+    local MockActor temp;
+    class'MockActor'.default.actorCount = 0;
+    Issue("Reference counting for `AcediaActor`s does not work correctly"
+        @ "with `Free()`");
+    temp = MockActor(__().memory.Allocate(class'MockActor'));
+    temp.NewRef().NewRef().NewRef();
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 4);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 3);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 2);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 1);
+    TEST_ExpectTrue(temp._getRefCount() == 1);
+    TEST_ExpectTrue(temp.IsAllocated());
+    __().memory.Free(temp);
+    TEST_ExpectTrue(class'MockActor'.default.actorCount == 0);
+}
+
+
 defaultproperties
 {
     caseGroup = "Memory"

sources/Types/AcediaActor.uc

@@ -26,6 +26,12 @@ class AcediaActor extends Actor
 //  Reference to Acedia's APIs for simple access.
 var protected Global _;
 
+//  To make logic simpler and increase efficiency, we allow storing a reference
+//  to any actors in many different places. To know when we can actually
+//  deallocate an actor, we keep this reference counter and only move actor
+//  to the actor pool once nothing refers to it anymore.
+var private int _refCounter;
+
 //  Store allocation status to prevent possible issues
 //  with freeing the same object several times without reallocating it
 //  (such as preventing finalizers or constructors being called several times)
@@ -66,6 +72,7 @@ public function _constructor()
 {
     if (_isAllocated) return;
     _isAllocated = true;
+    _refCounter = 1;
     _ = class'Global'.static.GetInstance();
     if (!default._staticConstructorWasCalled)
     {
@@ -89,6 +96,7 @@ public function _finalizer()
 {
     if (!_isAllocated) return;
     _isAllocated = false;
+    _refCounter = 0;
     Finalizer();
     _ = none;
 }
@@ -179,7 +187,53 @@ private final static function CreateTextCache(optional bool forceCreation)
 }
 
 /**
- *  Acedia actors cannot be deallocated into an object pool, but they still
+ *  This function is called each time this object is freed, to decrease it
+ *  internal reference counter and know when it can be actually deallocated.
+ *
+ *  AVOID MANUALLY CALLING IT.
+ */
+public final function _deref()
+{
+    if (!_isAllocated) {
+        return;
+    }
+    _refCounter = Max(0, _refCounter - 1);
+}
+
+/**
+ *  This function returns current reference counter for the caller actor.
+ *  It is an amount of times it can be freed before being deallocated.
+ *  This should correspond to the amount of places that reference it.
+ *
+ *  AVOID MANUALLY CALLING IT.
+ */
+public final function int _getRefCount()
+{
+    if (!_isAllocated) {
+        return 0;
+    }
+    return _refCounter;
+}
+
+/**
+ *  Method that creates new reference to the given actor.
+ *  Call this if you do not have ownership over the actor, but want to store
+ *  somewhere - this way it should not get deallocated until you free your
+ *  own reference.
+ *
+ *  @return Caller actor, to allow for easier use.
+ */
+public final function AcediaActor NewRef()
+{
+    if (!_isAllocated) {
+        return none;
+    }
+    _refCounter = Max(0, _refCounter + 1);
+    return self;
+}
+
+/**
+ *  Acedia actors cannot be deallocated into an actor pool, but they still
  *  support constructors and destructors and, therefore, track their own
  *  allocation status (`AcediaActor` is considered allocated between constructor
  *  and finalizer calls).

sources/Types/AcediaObject.uc

@@ -35,6 +35,12 @@ var public const bool           usesObjectPool;
 //      This value can be changes through Acedia's system settings.
 var public const int            defaultMaxPoolSize;
 
+//  To make logic simpler and increase efficiency, we allow storing a reference
+//  to any objects in many different places. To know when we can actually
+//  deallocate an object, we keep this reference counter and only move object
+//  to the object pool once nothing refers to it anymore.
+var private int _refCounter;
+
 //      Same object can be reallocated for different purposes and, as far as
 //  users are concerned, - it should be considered a different object after each
 //  reallocation.
@@ -106,9 +112,12 @@ public final static function AcediaObjectPool _getPool()
  */
 public final function _constructor()
 {
-    if (_isAllocated) return;
+    if (_isAllocated) {
+        return;
+    }
     _isAllocated = true;
     _lifeVersion += 1;
+    _refCounter = 1;
     _ = class'Global'.static.GetInstance();
     if (!default._staticConstructorWasCalled)
     {
@@ -131,6 +140,7 @@ public final function _finalizer()
 {
     if (!_isAllocated) return;
     _isAllocated = false;
+    _refCounter = 0;
     Finalizer();
     _ = none;
 }
@@ -220,6 +230,52 @@ private final static function CreateTextCache(optional bool forceCreation)
     }
 }
 
+/**
+ *  This function is called each time this object is freed, to decrease it
+ *  internal reference counter and know when it can be actually deallocated.
+ *
+ *  AVOID MANUALLY CALLING IT.
+ */
+public final function _deref()
+{
+    if (!_isAllocated) {
+        return;
+    }
+    _refCounter = Max(0, _refCounter - 1);
+}
+
+/**
+ *  This function returns current reference counter for the caller object.
+ *  It is an amount of times it can be freed before being deallocated.
+ *  This should correspond to the amount of places that reference it.
+ *
+ *  AVOID MANUALLY CALLING IT.
+ */
+public final function int _getRefCount()
+{
+    if (!_isAllocated) {
+        return 0;
+    }
+    return _refCounter;
+}
+
+/**
+ *  Method that creates new reference to the given object.
+ *  Call this if you do not have ownership over the object, but want to store
+ *  somewhere - this way it should not get deallocated until you free your
+ *  own reference.
+ *
+ *  @return Caller object, to allow for easier use.
+ */
+public final function AcediaObject NewRef()
+{
+    if (!_isAllocated) {
+        return none;
+    }
+    _refCounter = Max(0, _refCounter + 1);
+    return self;
+}
+
 /**
  *  Acedia objects can be deallocated into an object pool to be reused later and
  *  such instances should not be used while in the pool.