From b8cef175bd96ed25d7748d9f7d288b8bb5ce27d7 Mon Sep 17 00:00:00 2001
From: Thierry Fournier <thierry.fournier@ozon.io>
Date: Sat, 28 Nov 2020 15:37:17 +0100
Subject: [PATCH] MINOR: lua-thread: Split hlua_post_init() function in two
 parts

The goal is to allow execution of one main lua state per thread.

This function will be called for each initialized lua state, so
one per thread. The split transforms the lua state variable from
global to local.
---
 src/hlua.c | 59 +++++++++++++++++++++++++++++-------------------------
 1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/src/hlua.c b/src/hlua.c
index c02683698..34e7403cf 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -8255,7 +8255,7 @@ INITCALL1(STG_REGISTER, cfg_register_keywords, &cfg_kws);
  * We are in the initialisation process of HAProxy, this abort() is
  * tolerated.
  */
-int hlua_post_init()
+int hlua_post_init_state(lua_State *L)
 {
 	struct hlua_init_function *init;
 	const char *msg;
@@ -8273,40 +8273,30 @@ int hlua_post_init()
 		hlua_global_allocator.limit = ~hlua_global_allocator.limit;
 
 	/* Call post initialisation function in safe environment. */
-	if (!SET_SAFE_LJMP(gL.T)) {
-		if (lua_type(gL.T, -1) == LUA_TSTRING)
-			error = lua_tostring(gL.T, -1);
+	if (!SET_SAFE_LJMP(L)) {
+		if (lua_type(L, -1) == LUA_TSTRING)
+			error = lua_tostring(L, -1);
 		else
 			error = "critical error";
 		fprintf(stderr, "Lua post-init: %s.\n", error);
 		exit(1);
 	}
 
-#if USE_OPENSSL
-	/* Initialize SSL server. */
-	if (socket_ssl.xprt->prepare_srv) {
-		int saved_used_backed = global.ssl_used_backend;
-		// don't affect maxconn automatic computation
-		socket_ssl.xprt->prepare_srv(&socket_ssl);
-		global.ssl_used_backend = saved_used_backed;
-	}
-#endif
-
-	hlua_fcn_post_init(gL.T);
+	hlua_fcn_post_init(L);
 
 	list_for_each_entry(init, &hlua_init_functions, l) {
-		lua_rawgeti(gL.T, LUA_REGISTRYINDEX, init->function_ref);
+		lua_rawgeti(L, LUA_REGISTRYINDEX, init->function_ref);
 
 #if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM >= 504
-		ret = lua_resume(gL.T, gL.T, 0, &nres);
+		ret = lua_resume(L, L, 0, &nres);
 #else
-		ret = lua_resume(gL.T, gL.T, 0);
+		ret = lua_resume(L, L, 0);
 #endif
 		kind = NULL;
 		switch (ret) {
 
 		case LUA_OK:
-			lua_pop(gL.T, -1);
+			lua_pop(L, -1);
 			break;
 
 		case LUA_ERRERR:
@@ -8315,10 +8305,10 @@ int hlua_post_init()
 		case LUA_ERRRUN:
 			if (!kind)
 				kind = "runtime error";
-			msg = lua_tostring(gL.T, -1);
-			lua_settop(gL.T, 0); /* Empty the stack. */
-			lua_pop(gL.T, 1);
-			trace = hlua_traceback(gL.T);
+			msg = lua_tostring(L, -1);
+			lua_settop(L, 0); /* Empty the stack. */
+			lua_pop(L, 1);
+			trace = hlua_traceback(L);
 			if (msg)
 				ha_alert("Lua init: %s: '%s' from %s\n", kind, msg, trace);
 			else
@@ -8338,9 +8328,9 @@ int hlua_post_init()
 		case LUA_ERRMEM:
 			if (!kind)
 				kind = "out of memory error";
-			lua_settop(gL.T, 0);
-			lua_pop(gL.T, 1);
-			trace = hlua_traceback(gL.T);
+			lua_settop(L, 0);
+			lua_pop(L, 1);
+			trace = hlua_traceback(L);
 			ha_alert("Lua init: %s: %s\n", kind, trace);
 			return_status = 0;
 			break;
@@ -8348,10 +8338,25 @@ int hlua_post_init()
 		if (!return_status)
 			break;
 	}
-	RESET_SAFE_LJMP(gL.T);
+	RESET_SAFE_LJMP(L);
 	return return_status;
 }
 
+int hlua_post_init()
+{
+#if USE_OPENSSL
+	/* Initialize SSL server. */
+	if (socket_ssl.xprt->prepare_srv) {
+		int saved_used_backed = global.ssl_used_backend;
+		// don't affect maxconn automatic computation
+		socket_ssl.xprt->prepare_srv(&socket_ssl);
+		global.ssl_used_backend = saved_used_backed;
+	}
+#endif
+
+	return hlua_post_init_state(gL.T);
+}
+
 /* The memory allocator used by the Lua stack. <ud> is a pointer to the
  * allocator's context. <ptr> is the pointer to alloc/free/realloc. <osize>
  * is the previously allocated size or the kind of object in case of a new