Deallocating Memory to MS-DOS (48636)

MORE INFORMATION

To clarify the documentation, the memory allocated by the ALLOCATE instruction is held by the program until the program terminates. The DEALLOCATE instruction frees the memory for use inside the main program. The space is not returned to MS-DOS.

If you must have the memory deallocate back to MS-DOS, you can spawn to a child process where you ALLOCATE and DEALLOCATE. When the child process terminates, the memory that was claimed by the FORTRAN child process will be returned to MS-DOS.

The following code demonstrates this process:

Sample Code

C
C Main file.
C
      interface to integer*2 function spawnlp
     + [C,VARYING] (mode)
      integer*2 mode
      end
C
      integer*2 spawnlp
C
      I=spawnlp(0,loc('child.exe'C),loc('child.exe'C),
     Xint4(0))
      end
C----------------------------------------------------------

C----------------------------------------------------------
C Child process (separate file), called by spawnlp in
C parent.
C
      integer size
      character*1 arr1[allocatable] ()
      parameter (size=20000)
C
      allocate (arr1(size))
      DEALLOCATE (arr1)
      end
C----------------------------------------------------------