Fixed objects which store Lua callback functions to avoid attempting to use dead coroutines when deleting the reference to the callback function. Should fix crashes when coroutines are mixed with those objects.

Also improved the performance of World:rayCast and World:queryBoundingBox.

src/common/Reference.cpp

@@ -26,13 +26,13 @@ namespace love
 const char REFERENCE_TABLE_NAME[] = "love-references";
 
 Reference::Reference()
-	: L(nullptr)
+	: pinnedL(nullptr)
 	, idx(LUA_REFNIL)
 {
 }
 
 Reference::Reference(lua_State *L)
-	: L(L)
+	: pinnedL(nullptr)
 	, idx(LUA_REFNIL)
 {
 	ref(L);
@@ -46,7 +46,7 @@ Reference::~Reference()
 void Reference::ref(lua_State *L)
 {
 	unref(); // Just to be safe.
-	this->L = L;
+	pinnedL = luax_getpinnedthread(L);
 	luax_insist(L, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
 	lua_insert(L, -2); // Move reference table behind value.
 	idx = luaL_ref(L, -2);
@@ -57,38 +57,26 @@ void Reference::unref()
 {
 	if (idx != LUA_REFNIL)
 	{
-		luax_insist(L, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
-		luaL_unref(L, -1, idx);
-		lua_pop(L, 1);
+		// We use a pinned thread/coroutine for the Lua state because we know it
+		// hasn't been garbage collected and is valid, as long as the whole lua
+		// state is still open.
+		luax_insist(pinnedL, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
+		luaL_unref(pinnedL, -1, idx);
+		lua_pop(pinnedL, 1);
 		idx = LUA_REFNIL;
 	}
 }
 
-void Reference::push(lua_State *newL)
+void Reference::push(lua_State *L)
 {
 	if (idx != LUA_REFNIL)
 	{
-		luax_insist(newL, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
-		lua_rawgeti(newL, -1, idx);
-		lua_remove(newL, -2);
+		luax_insist(L, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
+		lua_rawgeti(L, -1, idx);
+		lua_remove(L, -2);
 	}
 	else
-		lua_pushnil(newL);
-}
-
-void Reference::push()
-{
-	push(L);
-}
-
-lua_State *Reference::getL() const
-{
-	return L;
-}
-
-void Reference::setL(lua_State *newL)
-{
-	L = newL;
+		lua_pushnil(L);
 }
 
 } // love