From ea94c070110e8de2cb55fed633b51b9f9cf3594d Mon Sep 17 00:00:00 2001
From: howsohazard <143410553+howsohazard@users.noreply.github.com>
Date: Wed, 29 May 2024 14:26:04 -0400
Subject: [PATCH] 20412: Reduces memory allocations for assign and accum
 opcodes (#141)

---
 src/Amalgam/interpreter/InterpreterOpcodesBase.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/Amalgam/interpreter/InterpreterOpcodesBase.cpp b/src/Amalgam/interpreter/InterpreterOpcodesBase.cpp
index bd1beeec..2c9c572b 100644
--- a/src/Amalgam/interpreter/InterpreterOpcodesBase.cpp
+++ b/src/Amalgam/interpreter/InterpreterOpcodesBase.cpp
@@ -1006,9 +1006,12 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_ASSIGN_and_ACCUM(Evaluable
 		if(value_destination == nullptr)
 			value_destination = GetOrCreateCallStackSymbolLocation(variable_sid, destination_call_stack_index);
 
-		//need to make a copy so that modifications can be dropped in directly
-		// this is essential as some values may be shared by other areas of memory, threads, or entities
-		EvaluableNode *value_replacement = evaluableNodeManager->DeepAllocCopy(*value_destination);
+		EvaluableNode *value_replacement = *value_destination;
+	#ifdef MULTITHREAD_SUPPORT
+		//if editing a shared variable, then need to make a copy before editing in place to prevent another thread from reading the data structure mid-edit
+		if(accum && destination_call_stack_index < callStackUniqueAccessStartingDepth)
+			value_replacement = evaluableNodeManager->DeepAllocCopy(value_replacement);
+	#endif
 
 		for(size_t index = 0; index < num_replacements; index++)
 		{