[Spice_announce] Lahey Fortran Operating Limitations

[Lee Elson]

Users of Lahey FORTRAN under Windows operating systems should be aware that the F95 compiler allocates a small amount of memory, in connection with the process of using file OPEN and INQUIRE statements, that it might not free at the end of the file manipulation process. Since the simple opening of a binary kernel file can involve multiple OPEN and INQUIRE statements, the result of this allocation is that if the user were to open many (e.g. 100 or more) kernel files, an application program could sequester memory that would not be freed as expected. A virtual memory error message, such as "A work area cannot be reserved because of insufficient area", may result from this situation. This can adversely affect the stability of the Windows operating system, even after the user program is terminated.

We believe that this behavior affects all versions of SPICELIB compiled using Lahey FORTRAN, including the soon to be released N59 version. We are working with Lahey to resolve this issue. Note that no other FORTRAN compilers are known to exhibit this behavior.

Lee Elson
Lee.Elson at jpl.nasa.gov