optimize: now we make use of the new lua_getexdata2 and lua_setexdata2 to attach coctx to the Lua thread objects directly which save the lookup overhead which can become the bottleneck when there are many Lua light threads around in a single request handler.

Author: agentzh

src/ngx_http_lua_accessby.c

@@ -287,6 +287,8 @@ ngx_http_lua_access_by_chunk(lua_State *L, ngx_http_request_t *r)
     ctx->cur_co_ctx->co_top = 1;
 #endif
 
+    ngx_http_lua_attach_co_ctx_to_L(co, ctx->cur_co_ctx);
+
     /*  }}} */
 
     /*  {{{ register request cleanup hooks */

src/ngx_http_lua_contentby.c

@@ -79,6 +79,8 @@ ngx_http_lua_content_by_chunk(lua_State *L, ngx_http_request_t *r)
     ctx->cur_co_ctx->co_top = 1;
 #endif
 
+    ngx_http_lua_attach_co_ctx_to_L(co, ctx->cur_co_ctx);
+
     /*  {{{ register request cleanup hooks */
     if (ctx->cleanup == NULL) {
         cln = ngx_http_cleanup_add(r, 0);

src/ngx_http_lua_coroutine.c

@@ -148,6 +148,7 @@ ngx_http_lua_coroutine_create_helper(lua_State *L, ngx_http_request_t *r,
 
 #ifdef OPENRESTY_LUAJIT
     ngx_http_lua_set_req(co, r);
+    ngx_http_lua_attach_co_ctx_to_L(co, coctx);
 #else
     /* make new coroutine share globals of the parent coroutine.
      * NOTE: globals don't have to be separated! */

src/ngx_http_lua_module.c

@@ -800,13 +800,23 @@ ngx_http_lua_init(ngx_conf_t *cf)
                           "the OpenResty releases from https://openresty.org/"
                           "en/download.html)");
         }
-#elif !defined(HAVE_LUA_RESETTHREAD)
+#else
+#   if !defined(HAVE_LUA_RESETTHREAD)
         ngx_log_error(NGX_LOG_ALERT, cf->log, 0,
                       "detected an old version of OpenResty's LuaJIT missing "
                       "the lua_resetthread API and thus the "
                       "performance will be compromised; please upgrade to the "
                       "latest version of OpenResty's LuaJIT: "
                       "https://github.com/openresty/luajit2");
+#   endif
+#   if !defined(HAVE_LUA_EXDATA2)
+        ngx_log_error(NGX_LOG_ALERT, cf->log, 0,
+                      "detected an old version of OpenResty's LuaJIT missing "
+                      "the exdata2 API and thus the "
+                      "performance will be compromised; please upgrade to the "
+                      "latest version of OpenResty's LuaJIT: "
+                      "https://github.com/openresty/luajit2");
+#   endif
 #endif
 
         ngx_http_lua_content_length_hash =

src/ngx_http_lua_rewriteby.c

@@ -287,6 +287,8 @@ ngx_http_lua_rewrite_by_chunk(lua_State *L, ngx_http_request_t *r)
     ctx->cur_co_ctx->co_top = 1;
 #endif
 
+    ngx_http_lua_attach_co_ctx_to_L(co, ctx->cur_co_ctx);
+
     /*  }}} */
 
     /*  {{{ register request cleanup hooks */

src/ngx_http_lua_ssl_certby.c

@@ -491,6 +491,8 @@ ngx_http_lua_ssl_cert_by_chunk(lua_State *L, ngx_http_request_t *r)
     ctx->cur_co_ctx->co_top = 1;
 #endif
 
+    ngx_http_lua_attach_co_ctx_to_L(co, ctx->cur_co_ctx);
+
     /* register request cleanup hooks */
     if (ctx->cleanup == NULL) {
         cln = ngx_http_cleanup_add(r, 0);

src/ngx_http_lua_ssl_session_fetchby.c

@@ -513,6 +513,8 @@ ngx_http_lua_ssl_sess_fetch_by_chunk(lua_State *L, ngx_http_request_t *r)
     ctx->cur_co_ctx->co_top = 1;
 #endif
 
+    ngx_http_lua_attach_co_ctx_to_L(co, ctx->cur_co_ctx);
+
     /* register request cleanup hooks */
     if (ctx->cleanup == NULL) {
         cln = ngx_http_cleanup_add(r, 0);

src/ngx_http_lua_timer.c

@@ -621,6 +621,8 @@ ngx_http_lua_timer_handler(ngx_event_t *ev)
     /*  save the request in coroutine globals table */
     ngx_http_lua_set_req(tctx.co, r);
 
+    ngx_http_lua_attach_co_ctx_to_L(tctx.co, ctx->cur_co_ctx);
+
     lmcf->running_timers++;
 
     lua_pushboolean(tctx.co, tctx.premature);

src/ngx_http_lua_util.c

@@ -3168,6 +3168,9 @@ ngx_http_lua_param_set(lua_State *L)
 ngx_http_lua_co_ctx_t *
 ngx_http_lua_get_co_ctx(lua_State *L, ngx_http_lua_ctx_t *ctx)
 {
+#ifdef HAVE_LUA_EXDATA2
+    return (ngx_http_lua_co_ctx_t *) lua_getexdata2(L);
+#else
     ngx_uint_t                   i;
     ngx_list_part_t             *part;
     ngx_http_lua_co_ctx_t       *coctx;
@@ -3203,6 +3206,7 @@ ngx_http_lua_get_co_ctx(lua_State *L, ngx_http_lua_ctx_t *ctx)
     }
 
     return NULL;
+#endif
 }
 
 

src/ngx_http_lua_util.h

@@ -398,6 +398,15 @@ ngx_http_lua_set_req(lua_State *L, ngx_http_request_t *r)
 }
 
 
+static ngx_inline void
+ngx_http_lua_attach_co_ctx_to_L(lua_State *L, ngx_http_lua_co_ctx_t *coctx)
+{
+#ifdef HAVE_LUA_EXDATA2
+    lua_setexdata2(L, (void *) coctx);
+#endif
+}
+
+
 #ifndef OPENRESTY_LUAJIT
 static ngx_inline void
 ngx_http_lua_get_globals_table(lua_State *L)