From e37eb3cba0cd92aae7c51d74e650c9629239a0d7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BA=91=E9=A3=8E?= <cloudwu@gmail.com>
Date: Tue, 12 Apr 2022 11:11:08 +0800
Subject: [PATCH] Callback (#1571)

* Use independent thread for callback

* bugfix: use new cb_ctx when changing callback
---
 lualib-src/lua-skynet.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/lualib-src/lua-skynet.c b/lualib-src/lua-skynet.c
index 6b686b56..dc3765bb 100644
--- a/lualib-src/lua-skynet.c
+++ b/lualib-src/lua-skynet.c
@@ -46,18 +46,16 @@ traceback (lua_State *L) {
 	return 1;
 }
 
+struct callback_context {
+	lua_State *L;
+};
+
 static int
 _cb(struct skynet_context * context, void * ud, int type, int session, uint32_t source, const void * msg, size_t sz) {
-	lua_State *L = ud;
+	struct callback_context *cb_ctx = (struct callback_context *)ud;
+	lua_State *L = cb_ctx->L;
 	int trace = 1;
 	int r;
-	int top = lua_gettop(L);
-	if (top == 0) {
-		lua_pushcfunction(L, traceback);
-		lua_rawgetp(L, LUA_REGISTRYINDEX, _cb);
-	} else {
-		assert(top == 2);
-	}
 	lua_pushvalue(L,2);
 
 	lua_pushinteger(L, type);
@@ -102,17 +100,17 @@ lcallback(lua_State *L) {
 	int forward = lua_toboolean(L, 2);
 	luaL_checktype(L,1,LUA_TFUNCTION);
 	lua_settop(L,1);
-	lua_rawsetp(L, LUA_REGISTRYINDEX, _cb);
-
-	lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_MAINTHREAD);
-	lua_State *gL = lua_tothread(L,-1);
-	// reload callback function, See _cb()
-	lua_settop(gL, 0);
+	struct callback_context *cb_ctx = (struct callback_context *)lua_newuserdata(L, sizeof(*cb_ctx));
+	cb_ctx->L = lua_newthread(L);
+	lua_pushcfunction(cb_ctx->L, traceback);
+	lua_setuservalue(L, -2);
+	lua_setfield(L, LUA_REGISTRYINDEX, "callback_context");
+	lua_xmove(L, cb_ctx->L, 1);
 
 	if (forward) {
-		skynet_callback(context, gL, forward_cb);
+		skynet_callback(context, cb_ctx, forward_cb);
 	} else {
-		skynet_callback(context, gL, _cb);
+		skynet_callback(context, cb_ctx, _cb);
 	}
 
 	return 0;