{ *************************************************************************** }
MODULE mod_handle_shared_area ;
{  Created  25-MAR-1991 MICHIGAN STATE UNIVERSITY, TRIGGER CONTROL SOFTWARE   }
{ *************************************************************************** }
INCLUDE
  mod_handle_tracing,
  $MUTEX ;                            {from ELN$:RTLOBJECT.OLB                }
{ *************************************************************************** }
EXPORT
  find_area_lock ; {PROCEDURE create & initialize or connect to existing area }
{ *************************************************************************** }
IMPORT

  handle_trc_sys,                     {from module MOD_HANDLE_TRACING         }
  handle_trc_err,                     {from module MOD_HANDLE_TRACING         }
  handle_trc_sta,                     {from module MOD_HANDLE_TRACING         }

  AREA_LOCK_VARIABLE,                 {from module $MUTEX                     }
  ELN$INITIALIZE_AREA_LOCK ;          {from module $MUTEX                     }
{ *************************************************************************** }
PROCEDURE find_area_lock ( caller : VARYING_STRING(16) := '' ;
                        area_name : VARYING_STRING(20) ;
                  VAR area_object : AREA ;
                 VAR area_pointer :^ANYTYPE ;
                        area_size : INTEGER ;
                       VAR status : INTEGER ) ;
TYPE 

  generic_shared_area =
  PACKED RECORD
    lock : AREA_LOCK_VARIABLE ;
    body : STRING( area_size - 2 ) ; {SIZE(AREA_LOCK_VARIABLE) = 2}
  END ;

VAR

  dummy :^generic_shared_area ;

BEGIN

  CREATE_AREA ( area_object, dummy, area_name, STATUS := status ) ;
  area_pointer := dummy ;

  IF ( ( status MOD 8 ) <> 1 )
  THEN BEGIN { failure creating area }

    handle_trc_sta ( TAG := 'CRE/SHA%', STATUS := status ) ;
    handle_trc_err ( TAG := 'CRE/SHA% ' + caller, 
                 MESSAGE := ' Failed Creating Area ' + area_name ) ;
  END

  ELSE BEGIN { success creating area }

    IF ( status = 1 ) 
    THEN BEGIN { this is a new area }

      ELN$INITIALIZE_AREA_LOCK ( area_object, dummy^.lock, status ) ; 

      IF ( status <> 1 ) 
      THEN BEGIN
        handle_trc_sta ( TAG := 'INI/LCK%', STATUS := status ) ;
        handle_trc_err ( TAG := 'INI/LCK% ' + caller, 
                     MESSAGE := ' Failed Initializing Area ' + area_name ) ;
      END ;

    END 

    ELSE BEGIN { the area was already created, no initialize }

      status := 1 ; 
      handle_trc_sys ( TAG := 'CON/SHA% ' + caller,
                   MESSAGE := ' Connected to Existing Area ' + area_name ) ;
    END ;

  END ;

END ;
{ *************************************************************************** }
{ *************************************************************************** }
END.