(svn r15330) -Fix [FS#2597]: leaking of Squirrel when using circular references (by enabling the GC).

src/ai/ai_core.cpp

@@ -3,6 +3,7 @@
 /** @file ai_core.cpp Implementation of AI. */
 
 #include "../stdafx.h"
+#include "../core/bitmath_func.hpp"
 #include "../company_base.h"
 #include "../company_func.h"
 #include "../debug.h"
@@ -68,6 +69,13 @@
 		}
 	}
 
+	/* Occasionally collect garbage; every 255 ticks do one company.
+	 * Effectively collecting garbage once every two months per AI. */
+	if ((AI::frame_counter & 255) == 0) {
+		CompanyID cid = (CompanyID)GB(AI::frame_counter, 8, 4);
+		if (IsValidCompanyID(cid) && !IsHumanCompany(cid)) GetCompany(cid)->ai_instance->CollectGarbage();
+	}
+
 	_current_company = OWNER_NONE;
 }
 

src/ai/ai_instance.cpp

@@ -296,6 +296,11 @@ void AIInstance::GameLoop()
 	}
 }
 
+void AIInstance::CollectGarbage()
+{
+	if (this->is_started && !this->is_dead) this->engine->CollectGarbage();
+}
+
 /* static */ void AIInstance::DoCommandReturn(AIInstance *instance)
 {
 	instance->engine->InsertResult(AIObject::GetLastCommandRes());

src/ai/ai_instance.hpp

@@ -44,6 +44,11 @@ public:
 	 */
 	void GameLoop();
 
+	/**
+	 * Let the VM collect any garbage.
+	 */
+	void CollectGarbage();
+
 	/**
 	 * Get the storage of this AI.
 	 */