bugfix: should not allow to create timer in the exit process phase (openresty#1907)

Since the exit process phase runs after all timers have been processed.

Author: rainingmaster

README.markdown

@@ -1672,6 +1672,8 @@ For example,
  }
 ```
 
+It's not allowed to create a timer (even a 0-delay timer) here since it runs after all timers have been processed.
+
 This directive was first introduced in the `v0.10.18` release.
 
 [Back to TOC](#directives)
@@ -3154,9 +3156,10 @@ The directive is supported when using OpenSSL 1.0.2 or higher and nginx 1.19.4 o
 
 Several `lua_ssl_conf_command` directives can be specified on the same level:
 
-```
-lua_ssl_conf_command Options PrioritizeChaCha;
-lua_ssl_conf_command Ciphersuites TLS_CHACHA20_POLY1305_SHA256;
+```nginx
+
+ lua_ssl_conf_command Options PrioritizeChaCha;
+ lua_ssl_conf_command Ciphersuites TLS_CHACHA20_POLY1305_SHA256;
 ```
 
 Configuration commands are applied after OpenResty own configuration for SSL, so they can be used to override anything set by OpenResty.
@@ -3165,6 +3168,8 @@ Note though that configuring OpenSSL directly with `lua_ssl_conf_command` might
 
 This directive was first introduced in the `v0.10.21` release.
 
+
+
 [Back to TOC](#directives)
 
 lua_http10_buffering
@@ -8405,7 +8410,7 @@ ngx.timer.at
 
 **syntax:** *hdl, err = ngx.timer.at(delay, callback, user_arg1, user_arg2, ...)*
 
-**context:** *init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*, exit_worker_by_lua**
+**context:** *init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua**
 
 Creates an Nginx timer with a user callback function as well as optional user arguments.
 
@@ -8548,7 +8553,7 @@ ngx.timer.every
 
 **syntax:** *hdl, err = ngx.timer.every(delay, callback, user_arg1, user_arg2, ...)*
 
-**context:** *init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*, exit_worker_by_lua**
+**context:** *init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua**
 
 Similar to the [ngx.timer.at](#ngxtimerat) API function, but
 

doc/HttpLuaModule.wiki

@@ -1362,6 +1362,8 @@ For example,
  }
 </geshi>
 
+It's not allowed to create a timer (even a 0-delay timer) here since it runs after all timers have been processed.
+
 This directive was first introduced in the <code>v0.10.18</code> release.
 
 == exit_worker_by_lua_file ==
@@ -7196,7 +7198,7 @@ See also [[#lua_check_client_abort|lua_check_client_abort]].
 
 '''syntax:''' ''hdl, err = ngx.timer.at(delay, callback, user_arg1, user_arg2, ...)''
 
-'''context:''' ''init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*, exit_worker_by_lua*''
+'''context:''' ''init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''
 
 Creates an Nginx timer with a user callback function as well as optional user arguments.
 
@@ -7334,7 +7336,7 @@ This API was first introduced in the <code>v0.8.0</code> release.
 
 '''syntax:''' ''hdl, err = ngx.timer.every(delay, callback, user_arg1, user_arg2, ...)''
 
-'''context:''' ''init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*, exit_worker_by_lua*''
+'''context:''' ''init_worker_by_lua*, 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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''
 
 Similar to the [[#ngx.timer.at|ngx.timer.at]] API function, but
 

src/ngx_http_lua_timer.c

@@ -174,6 +174,15 @@ ngx_http_lua_ngx_timer_helper(lua_State *L, int every)
 
  ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
 
+ /*
+ * Since nginx has been confirmed that all timers have been cleaned up when
+ * exit worker is executed, all timers will no longer be executed in exit
+ * worker phase.
+ * Reference https://github.com/nginx/nginx/blob/f02e2a734ef472f0dcf83ab2
+ * e8ce96d1acead8a5/src/os/unix/ngx_process_cycle.c#L715
+ */
+ ngx_http_lua_check_context(L, ctx, ~NGX_HTTP_LUA_CONTEXT_EXIT_WORKER);
+
  if (ngx_exiting && delay > 0) {
  lua_pushnil(L);
  lua_pushliteral(L, "process exiting");

t/162-exit-worker.t

@@ -5,7 +5,7 @@ use Test::Nginx::Socket::Lua;
 master_on();
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 2 + 2) + 12;
+plan tests => repeat_each() * (blocks() * 2 + 2) + 11;
 
 #log_level("warn");
 no_long_string();
@@ -79,7 +79,7 @@ hello, world
 
 
 
-=== TEST 4: exit_worker_by_lua single process ngx.timer not work
+=== TEST 4: ngx.timer is not allow
 --- http_config
  exit_worker_by_lua_block {
  local function bar()
@@ -101,8 +101,8 @@ hello, world
 GET /t
 --- response_body
 ok
---- no_error_log
-[error]
+--- shutdown_error_log
+API disabled in the context of exit_worker_by_lua*