php man page for mysql_thread_id

MYSQL_THREAD_ID(3)							 1							MYSQL_THREAD_ID(3)

mysql_thread_id - Return the current thread ID

SYNOPSIS
       Warning

	      This  extension  is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should
	      be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:

		     omysqli_thread_id(3)

       int mysql_thread_id ([resource  $link_identifier = NULL])

DESCRIPTION
	Retrieves the current thread ID. If the connection is lost, and a reconnect with mysql_ping(3) is executed, the  thread  ID  will  change.
       This means only retrieve the thread ID when needed.

	      o $
		link_identifier  -The  MySQL  connection.  If  the  link  identifier is not specified, the last link opened by mysql_connect(3) is
		assumed. If no such link is found, it will try to create one as if mysql_connect(3) was called with no arguments. If no connection
		is found or established, an E_WARNING level error is generated.

	The thread ID on success or FALSE on failure.

       Example #1

	      mysql_thread_id(3) example

	      <?php
	      $link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
	      $thread_id = mysql_thread_id($link);
	      if ($thread_id){
		  printf("current thread id is %d
", $thread_id);
	      }
	      ?>

	      The above example will output something similar to:

	      current thread id is 73

       mysql_ping(3), mysql_list_processes(3).

PHP Documentation Group 													MYSQL_THREAD_ID(3)