A$LIST_LOCKS

The A$LIST_LOCKS routine returns the list of active locks in an Application Server environment.

The list of locks is available only if iscobol.file.lock_manager * is set in the server configuration.

isCOBOL supports two types of lock:

•	LOCK READ: acquired by locking records in a file open in INPUT mode. There can be more than one lock of this type on the same record.

•	LOCK WRITE: acquired by locking records in a file open in I-O or OUTPUT mode. There can be only one lock of this type on the same record.

The routine lists both of them.

It’s possible to filter the information and retrieve all the locks associated to a specific client (see threadID in LISTLOCK-OPEN) or all the locks associated to a specific file (see fileName in LISTLOCK-OPEN).

Syntax:

CALL "A$LIST_LOCKS" USING opCode                            parameters                     GIVING returnCode

Parameters:

opCode	The function to be executed. Valid values, defined in iscobol.def, are:
	LISTLOCK-OPEN	Open the list.
	LISTLOCK-NEXT	Retrieve the next item in the list.
	LISTLOCK-CLOSE	Close a previously open list.
parameters	Parameters depend on the opcode.

Return-Code:

The definition and meaning of the returnCode depend on the opcode.

Examples:

Example - Open the list of locks for an Application Server, loop through all the locks to show them and close the list after that.

working-storage section. copy "iscobol.def". 77  locklist                handle. 77  th-id                   pic 9(5). 77  usr-id                  pic x(3). 77  usr-name                pic x(32). 77  usr-addr                pic x(32). 77  usr-pcname              pic x(32). 77  usr-tid                 pic x(32). 77  usr-prog                pic x(32). 77  usr-count               pic 9(5). 77  lock-count              pic 9(5). 77  lock-filename           pic x(50). 77  lock-tid                pic 9(5). 77  lock-open-mode          pic 9(5). 77  lock-mode               pic 9(5). 77  lock-key-val            pic x(256). 77  lock-key-len            pic 9(3).   get-locks-list.    initialize lock-filename lock-tid    call "a$list-locks" using listlock-open                              null                              lock-filename                              lock-tid                       giving locklist      if locklist < 1       display message                "No Locks Found (verify iscobol.file.lock_manager)"       exit paragraph    end-if    move 0 to lock-count    perform until 1 = 2       call "a$list-locks" using listlock-next                                 locklist                                 lock-filename                                 lock-tid                                 lock-open-mode                                 lock-mode                                 lock-key-val                                 lock-key-len

if return-code = 0          exit perform       end-if       add 1 to lock-count       | to get user information from lock-tid       call "a$get-user" using lock-tid                               usr-id                               usr-name                               usr-addr                               usr-pcname                               usr-prog    end-perform    call "a$list-locks" using listlock-close                              locklist    display message "Number of locks : " lock-count.