DECLARE

  -- lock

  l_lockname    VARCHAR2(100);

  l_lockhandle  VARCHAR2(200);

  l_lock_output NUMBER;

  l_locked      BOOLEAN := FALSE;

  g_pkg_name    VARCHAR2(240) := '2345';

  g_org_id      NUMBER := 112;

BEGIN

  /* 定义按何种方式并发（此处为同一个OU不能同时执行）

  * lockname类似于定义一个唯一的名字，当并发程序执行时就会去判断是否这个唯一标识已经存在 */

  l_lockname := g_pkg_name || '_' || g_org_id;

  --根据l_lockname获取唯一标识l_lockhandle

  dbms_lock.allocate_unique(lockname   => l_lockname,

                            lockhandle => l_lockhandle);

  /*用l_lockhandle这个唯一标识去给当前请求加锁

  --  Return value:

  --    0 - success

  --    1 - timeout

  --    2 - deadlock

  --    3 - parameter error

  --    4 - already own lock specified by 'id' or 'lockhandle'

  --    5 - illegal lockhandle*/

  l_lock_output := dbms_lock.request(l_lockhandle, 6, 60, FALSE);

  dbms_output.put_line('1  ' || l_lock_output);

  dbms_lock.allocate_unique(lockname   => l_lockname,

                            lockhandle => l_lockhandle);

  l_lock_output := dbms_lock.request(l_lockhandle, 6, 60, FALSE);

  dbms_output.put_line('2  ' || l_lock_output);

  --此处添加请求的业务逻辑

  --dbms_lock.sleep(seconds => 50);  

  /*特别注意的是一定要将lockname释放掉 否则这个并发就永远别想再执行了*/

  l_lock_output := dbms_lock.release(l_lockhandle);

  dbms_output.put_line('3  ' || l_lock_output);

  dbms_lock.allocate_unique(lockname   => l_lockname,

                            lockhandle => l_lockhandle);

  l_lock_output := dbms_lock.request(l_lockhandle, 6, 60, FALSE);

  dbms_output.put_line('4  ' || l_lock_output);

  l_lock_output := dbms_lock.release(l_lockhandle);

  dbms_output.put_line('5  ' || l_lock_output);

EXCEPTION

  WHEN apps.fnd_api.g_exc_error THEN

    IF l_lock_output = 0 THEN

      l_lock_output := dbms_lock.release(l_lockhandle);

    END IF;

  WHEN OTHERS THEN

    IF l_lock_output = 0 THEN

      l_lock_output := dbms_lock.release(l_lockhandle);

    END IF;

END;