From 7a9dfd47d3b2c850ad2abf33a25687557508e160 Mon Sep 17 00:00:00 2001
From: Sky Johnson <skylearj@gmail.com>
Date: Thu, 22 May 2025 10:31:00 -0500
Subject: [PATCH] ensure funcs get unique pointer

---
 functions.go | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/functions.go b/functions.go
index f5d336b..0d396a8 100644
--- a/functions.go
+++ b/functions.go
@@ -40,31 +40,30 @@ var (
 func goFunctionWrapper(L *C.lua_State) C.int {
 	state := &State{L: L}
 
-	// Get function pointer from the first upvalue
 	ptr := C.lua_touserdata(L, C.get_upvalue_index(1))
 	if ptr == nil {
 		state.PushString("error: function pointer not found")
 		return -1
 	}
 
-	// Use read-lock for better concurrency
 	functionRegistry.RLock()
 	fn, ok := functionRegistry.funcs[ptr]
 	functionRegistry.RUnlock()
 
 	if !ok {
+		// Debug logging
+		fmt.Printf("Function not found for pointer %p\n", ptr)
 		state.PushString("error: function not found in registry")
 		return -1
 	}
 
-	// Call the Go function
 	return C.int(fn(state))
 }
 
 // PushGoFunction wraps a Go function and pushes it onto the Lua stack
 func (s *State) PushGoFunction(fn GoFunction) error {
-	// Allocate a pointer to use as the function key
-	ptr := C.malloc(1)
+	// Allocate unique memory for each function
+	ptr := C.malloc(C.size_t(unsafe.Sizeof(uintptr(0))))
 	if ptr == nil {
 		return fmt.Errorf("failed to allocate memory for function pointer")
 	}
@@ -74,10 +73,8 @@ func (s *State) PushGoFunction(fn GoFunction) error {
 	functionRegistry.funcs[ptr] = fn
 	functionRegistry.Unlock()
 
-	// Push the pointer as lightuserdata (first upvalue)
+	// Push the pointer as lightuserdata
 	C.lua_pushlightuserdata(s.L, ptr)
-
-	// Create closure with the C wrapper and the upvalue
 	C.lua_pushcclosure(s.L, (*[0]byte)(C.goFunctionWrapper), 1)
 
 	return nil