doc: documented the ngx.worker.exiting() API.

README.markdown

@@ -170,6 +170,7 @@ Table of Contents
     * [ngx.config.prefix](#ngxconfigprefix)
     * [ngx.config.nginx_version](#ngxconfignginx_version)
     * [ngx.config.ngx_lua_version](#ngxconfigngx_lua_version)
+    * [ngx.worker.exiting](#ngxworkerexiting)
     * [ndk.set_var.DIRECTIVE](#ndkset_vardirective)
     * [coroutine.create](#coroutinecreate)
     * [coroutine.resume](#coroutineresume)
@@ -5704,6 +5705,19 @@ This API was first introduced in the `0.9.3` release.
 
 [Back to TOC](#table-of-contents)
 
+ngx.worker.exiting
+------------------
+
+**syntax:** *exiting = ngx.worker.exiting()*
+
+**context:** *set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*, ngx.timer.*, init_by_lua**
+
+This function returns a boolean value indicating whether the current Nginx worker process already starts exiting. Nginx worker process exiting happens on Nginx server quit or configuration reload (aka HUP reload).
+
+This API was first introduced in the `0.9.3` release.
+
+[Back to TOC](#table-of-contents)
+
 ndk.set_var.DIRECTIVE
 ---------------------
 **syntax:** *res = ndk.set_var.DIRECTIVE_NAME*

doc/HttpLuaModule.wiki

@@ -4843,6 +4843,16 @@ This field take an integral value indicating the version number of the current <
 
 This API was first introduced in the <code>0.9.3</code> release.
 
+== ngx.worker.exiting ==
+
+'''syntax:''' ''exiting = ngx.worker.exiting()''
+
+'''context:''' ''set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*, ngx.timer.*, init_by_lua*''
+
+This function returns a boolean value indicating whether the current Nginx worker process already starts exiting. Nginx worker process exiting happens on Nginx server quit or configuration reload (aka HUP reload).
+
+This API was first introduced in the <code>0.9.3</code> release.
+
 == ndk.set_var.DIRECTIVE ==
 '''syntax:''' ''res = ndk.set_var.DIRECTIVE_NAME''