bugfix: Lua VM might run out of memory when lua_code_cache is off; now we always enforce a full Lua GC cycle right after unloading most of the loaded Lua modules when the Lua code cache is turned off.

Author: agentzh

src/ngx_http_lua_cache.c

@@ -406,6 +406,9 @@ ngx_http_lua_clear_package_loaded(lua_State *L)
     /* package loaded */
     lua_pop(L, 2);
 
+    /* force a full GC cycle */
+    lua_gc(L, LUA_GCCOLLECT, 0);
+
 #if 0
     lua_newtable(L);
     lua_setglobal(L, "_G");