bugfix: tcpsock:setkeepalive: worker processes might take too long to…

… gracefully shut down when the keep alive connections take a long max idle time.

Now we avoid putting any new connections into the pool when nginx is already
shutting down.

Signed-off-by: Yichun Zhang (agentzh) <yichun@openresty.com>

src/ngx_http_lua_socket_tcp.c

@@ -4690,6 +4690,14 @@ ngx_http_lua_socket_tcp_setkeepalive(lua_State *L)
         return 2;
     }
 
+    if (ngx_terminate || ngx_exiting) {
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                       "lua tcp socket set keepalive while process exiting, "
+                       "closing connection %p", c);
+
+        goto finalize;
+    }
+
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                    "lua tcp socket set keepalive: saving connection %p", c);
 
@@ -4854,6 +4862,8 @@ ngx_http_lua_socket_tcp_setkeepalive(lua_State *L)
         }
     }
 
+finalize:
+
 #if 1
     ngx_http_lua_socket_tcp_finalize(r, u);
 #endif

t/157-socket-keepalive-hup.t

@@ -0,0 +1,91 @@
+# vim:set ft= ts=4 sw=4 et fdm=marker:
+
+our $SkipReason;
+
+BEGIN {
+    if ($ENV{TEST_NGINX_CHECK_LEAK}) {
+        $SkipReason = "unavailable for the hup tests";
+
+    } else {
+        $ENV{TEST_NGINX_USE_HUP} = 1;
+        undef $ENV{TEST_NGINX_USE_STAP};
+    }
+}
+
+use Test::Nginx::Socket::Lua $SkipReason ? (skip_all => $SkipReason) : ();
+
+repeat_each(2);
+
+plan tests => repeat_each() * (blocks() * 8);
+
+#no_diff();
+no_long_string();
+
+worker_connections(1024);
+run_tests();
+
+__DATA__
+
+=== TEST 1: exiting
+--- config
+    location /t {
+        set $port $TEST_NGINX_SERVER_PORT;
+
+        content_by_lua_block {
+            local f, err = io.open("t/servroot/logs/nginx.pid", "r")
+            if not f then
+                ngx.say("failed to open nginx.pid: ", err)
+                return
+            end
+
+            local pid = f:read()
+            -- ngx.say("master pid: [", pid, "]")
+
+            f:close()
+
+            local i = 0
+            local port = ngx.var.port
+
+            local function f(premature)
+                print("timer prematurely expired: ", premature)
+
+                local sock = ngx.socket.tcp()
+
+                local ok, err = sock:connect("127.0.0.1", port)
+                if not ok then
+                    print("failed to connect: ", err)
+                    return
+                end
+
+                local ok, err = sock:setkeepalive()
+                if not ok then
+                    print("failed to setkeepalive: ", err)
+                    return
+                end
+
+                print("setkeepalive successfully")
+            end
+            local ok, err = ngx.timer.at(3, f)
+            if not ok then
+                ngx.say("failed to set timer: ", err)
+                return
+            end
+            ngx.say("registered timer")
+            os.execute("kill -HUP " .. pid)
+        }
+    }
+--- request
+GET /t
+
+--- response_body
+registered timer
+
+--- wait: 0.3
+--- no_error_log
+[error]
+[alert]
+[crit]
+--- error_log
+timer prematurely expired: true
+setkeepalive successfully
+lua tcp socket set keepalive while process exiting, closing connection