Improve ObjectsRemovalService to handle newly added objects removing

Source/Engine/Core/ObjectsRemovalService.cpp

@@ -5,7 +5,6 @@
 #include "Collections/Dictionary.h"
 #include "Engine/Engine/Time.h"
 #include "Engine/Engine/EngineService.h"
-#include "Engine/Threading/Threading.h"
 #include "Engine/Profiler/ProfilerCPU.h"
 #include "Engine/Scripting/ScriptingObject.h"
 
@@ -14,16 +13,15 @@ const Char* HertzSizesData[] = { TEXT("Hz"), TEXT("KHz"), TEXT("MHz"), TEXT("GHz
 Span<const Char*> Utilities::Private::BytesSizes(BytesSizesData, ARRAY_COUNT(BytesSizesData));
 Span<const Char*> Utilities::Private::HertzSizes(HertzSizesData, ARRAY_COUNT(HertzSizesData));
 
-namespace ObjectsRemovalServiceImpl
+namespace
 {
     CriticalSection PoolLocker;
     DateTime LastUpdate;
     float LastUpdateGameTime;
     Dictionary<Object*, float> Pool(8192);
+    uint64 PoolCounter = 0;
 }
 
-using namespace ObjectsRemovalServiceImpl;
-
 class ObjectsRemoval : public EngineService
 {
 public:
@@ -64,6 +62,7 @@ void ObjectsRemovalService::Add(Object* obj, float timeToLive, bool useGameTime)
 
     PoolLocker.Lock();
     Pool[obj] = timeToLive;
+    PoolCounter++;
     PoolLocker.Unlock();
 }
 
@@ -72,6 +71,7 @@ void ObjectsRemovalService::Flush(float dt, float gameDelta)
     PROFILE_CPU();
 
     PoolLocker.Lock();
+    PoolCounter = 0;
 
     // Update timeouts and delete objects that timed out
     for (auto i = Pool.Begin(); i.IsNotEnd(); ++i)
@@ -90,6 +90,24 @@ void ObjectsRemovalService::Flush(float dt, float gameDelta)
         }
     }
 
+    // If any object was added to the pool while removing objects (by this thread) then retry removing any nested objects (but without delta time)
+    if (PoolCounter != 0)
+    {
+    RETRY:
+        PoolCounter = 0;
+        for (auto i = Pool.Begin(); i.IsNotEnd(); ++i)
+        {
+            if (i->Value <= 0.0f)
+            {
+                Object* obj = i->Key;
+                Pool.Remove(i);
+                obj->OnDeleteObject();
+            }
+        }
+        if (PoolCounter != 0)
+            goto RETRY;
+    }
+
     PoolLocker.Unlock();
 }
 
@@ -121,7 +139,7 @@ void ObjectsRemoval::Dispose()
 
     // Delete all remaining objects
     {
-        ScopeLock lock(PoolLocker);
+        PoolLocker.Lock();
         for (auto i = Pool.Begin(); i.IsNotEnd(); ++i)
         {
             Object* obj = i->Key;
@@ -129,6 +147,7 @@ void ObjectsRemoval::Dispose()
             obj->OnDeleteObject();
         }
         Pool.Clear();
+        PoolLocker.Unlock();
     }
 }
 

Source/Engine/Scripting/Internal/EngineInternalCalls.cpp

@@ -190,7 +190,6 @@ DEFINE_INTERNAL_CALL(bool) ScriptingInternal_IsTypeFromGameScripts(MTypeObject*
 
 DEFINE_INTERNAL_CALL(void) ScriptingInternal_FlushRemovedObjects()
 {
-    ASSERT(IsInMainThread());
     ObjectsRemovalService::Flush();
 }