SAP ABAP锁机制程序锁

除了数据库有锁定外，ABAP程序本身也有锁定。

SAP提供了两个函数来解决程序运行时的同步锁定问题：ENQUEUE_ES_PROG和DEQUEUE_ES_PROG。

CALL FUNCTION 'ENQUEUE_ES_PROG'
* EXPORTING
*   MODE_TRDIR           = 'E'
*   NAME                 =
*   X_NAME               = ' '
*   _SCOPE               = '2'
*   _WAIT                = ' '
*   _COLLECT             = ' '
* EXCEPTIONS
*   FOREIGN_LOCK         = 1
*   SYSTEM_FAILURE       = 2
*   OTHERS               = 3
          .
Prevents the parallel execution of a program.可防止程序的并行执行。

Description

This function creates a lock in a program that should not be processed more than once, simultaneously.该加锁函数会在程序里创建一把锁阻止同一时间只有一个运行。

CALL FUNCTION 'ENQUEUE_ES_PROG' 

EXPORTING 

 name = sy-repid.

IF sy-subrc ne 0.

MESSAGE '程序被锁定' TYPE 'E'.

RETURN.

endif.

The lock remains in place until either the DEQUEUE_ES_PROG function module

is called or the transaction is completed (with an implicit DEQUEUE_ALL call).

Parameters该锁会保持直到DEQUEUE_ES_PROG函数调用，或者事务（程序）执行完毕（执行完毕后会隐式调用DEQUEUE_ALL）才会释放

EXPORTING输出参数

NAME Program name to lock需上锁的程序名

_SCOPE Controls how the lock is passed to the update program:锁的传播特性？？

Value Meaning

1 The lock is not passed to the update program. The lock

is removed when the transaction ends.

2 (default) The lock is passed to the update program. The update

program is responsible for removing the lock.

3 The lock is passed to the update program. The lock must

be removed in both the interactive(交互) program and in the

update program.
CALL FUNCTION 'DEQUEUE_ES_PROG'
* EXPORTING
*   MODE_TRDIR       = 'E'
*   NAME             =
*   X_NAME           = ' '
*   _SCOPE           = '3'
*   _SYNCHRON        = ' '
*   _COLLECT         = ' ' .

该函数释放由ENQUEUE_ES_PROG.设置的程序锁

使用时需要注意下列问题：

1、  ENQUEUE_ES_PROG函数只是尝试去锁定，如果锁已经被其他程序获取，并不会阻塞，要在调用后通过sy-subrc来判断是否获取成功。可以在循环里通过  WAIT  UP TO xx SECONDS.  语句来等待锁被获取到

2、  ABAP工作台开发程序时，不能同时编辑同一个程序，第一个打开程序的用户会上程序锁，程序锁可以使用SM12来查看当前的程序锁

SAP-ABAP:SAP的锁机制`ENQUEUE_EZPROGRAM_LOCK`功能的深度扩展解析_abap enqueue-CSDN博客