TMELD - Table Manager Read Lock Block

    CONTROL BLOCK NAME = DFHTMELD
    NAME OF MATCHING PLS CONTROL BLOCK = LBSEG,LBLOCK SLOT (in DFHTMPPS)
    DESCRIPTIVE NAME = CICS TS - Table Management Read Lock Block.
    FUNCTION =
     The table management read lock block consists of a set of read
     locks and a count of locks assigned, on primary directory entries.
     Each time a task uses a locate function, a read lock on the
     primary directory entry, corresponding to the table entry found,
     is created by the locate function. A directory entry which has a
     read lock(s) can not be modified until the lock(s) is(are)
     released. Read locks are released at task termination or on
     specific request.
    LIFETIME =
     The initial read lock block is allocated at AP domain transaction
     initialization, and release in AP domain transaction termination
     and so a lock block is part of the AP transaction environemnt.
     TMP will acquire storage for a lock block when a task issues
     a function that requires a lock on a primary table entry (eg. a
     locate function). Note, when all locks within a lock block are
     released, the storage for the lock block is not released but
     re-initialised, thus making it reusable. If a task should require
     re-starting, then storage for any lock blocks which are not being
     used is released. Otherwise, storage for all read lock blocks is
     released at task termination.
    STORAGE CLASS = CICS storage (CSATCA31/24) above/below the 16M line.
    LOCATION =
     In the TCA, TCARLB is the address of the first read lock block.
     Further read lock blocks are chained by TMELPTR, which is in the
     read lock block itself.
    INNER CONTROL BLOCKS = None.
    NOTES :
       DEPENDENCIES = S/370
       RESTRICTIONS = None.
       MODULE TYPE = Control block definition
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    EXTERNAL REFERENCES = None.
        DATA AREAS = None.
        CONTROL BLOCKS = None.
        GLOBAL VARIABLES (Macro pass) = None.