MySQL 的存儲過程中請求一個鎖對象

mysql>  mysql>?delimiter?$$  mysql>  mysql>?CREATE?PROCEDURE?myProc()  ????->?BEGIN  ????->?????DECLARE?lock_result?INT;  ????->?????IF?get_lock('sp_critical_section_lock',60)?THEN  ????->????????/*?This?block?can?only?be?run?by?one?user?at?a?time*/  ????->????????select?'got?lock';  ????->????????/*?Critical?code?here?*/  ????->???????SET?lock_result=release_lock('sp_critical_section_lock');  ????->?????ELSE  ????->????????SELECT?'failed?to?acquire?lock';  ????->????????/*?Error?handling?here?*/  ????->?????END?IF;  ????->?END$$  Query?OK,?0?rows?affected?(0.00?sec)  ?  mysql>  mysql>?delimiter?;  mysql>?call?myProc();  +----------+  |?got?lock?|  +----------+  |?got?lock?|  +----------+  1?row?in?set?(0.02?sec)  ?  Query?OK,?0?rows?affected?(0.02?sec)  ?  mysql>  mysql>?drop?procedure?myProc;  Query?OK,?0?rows?affected?(0.00?sec)  ?  mysql>  mysql>