Session.auto_start Configuration Analysis of PHP source code analysis

  Zhanhailiang Date: 2014-10-20

Application analysis

In daily development, the php.ini configuration session.auto_start=0 closes the session by default if you want to open the session to call Session_Start:

<?php Session_Start (); //...

Kernel analysis

By checking the source code, we know that session_start is defined as follows:

1881  /* {{{proto bool Session_Start (void) 1882 Begin session-reinitializes freezed variables, registers browsers etc */ 1883  static  php_function ( session_ Start)   1884  {   1885  /* skipping check for Non-zero Args for performance reasons here? */ 1886  Php_session_start(Tsrmls_c);1887 1888         if (PS(Session_status) !=php_session_active) {1889Return_false;1890         }1891return_true;1892 }

You can see that the Session_Start essence is to open the session by calling Php_session_start.

If you modify the php.ini in Session.auto_start=1 by default when the session is opened by the source, the Rinit (that is, request initialization) automatically calls Php_session_start to open the conversation:

2129 Staticphp_rinit_function(Session) /* {{{ */2130 {2131php_rinit_session_globals(Tsrmls_c);2132 2133 +-----  8Lines: if (PS(MoD) ==NULL) {----------------------------------------------------------------------------------------------------------- ---------------------2141                 2142 +-----  8Lines: if (PS(Serializer) ==NULL) {---------------------------------------------------------------------------------------------------------- ---------------2150                 2151 +-----  5Lines: if (PS(MoD) ==NULL||PS(Serializer) ==NULL) {------------------------------------------------------------------------------------------------------2156                         2157         if (PS(Auto_start)) {2158                 Php_session_start(Tsrmls_c);2159         }2160 2161         returnSUCCESS;2162 }2163 /* }}} */

Session.auto_start Configuration Analysis of PHP source code analysis