mmap.control(threshold=-1)
.Machine$integer.max
.
threshold
is negative (the default),
returns the current threshold. Otherwise, returns the previous
value of the threshold.
threshold
to be memory-mapped.
Memory-mapping is a technique that can sometimes make more memory available within your S-PLUS session. It can be particularly effective if you need to access only small parts of large objects; with memory-mapped objects, Spotfire S+ can read the pieces it needs directly from the file. However, TIBCO's experience with memory-mapping indicates it is not always useful, and can cause difficulties, so we have set the threshold to prevent automatic memory-mapping.
There are a limited number of files that can be memory-mapped per process,
the limit depending upon the operating system. Regardless of the value
of
mmap.control
, S-PLUS uses memory-mapped files
for loading the standard S-PLUS libraries in the search list, 2 per library.
There should be no problems accessing S objects associated with a memory-mapped file, and these files are very efficient for read-only purposes. Problems may arise, however, if your S-PLUS functions or scripts try to modify objects which are memory-mapped.
Memory-mapping of binary S-PLUS objects is experimental and subject to change in future versions of S-PLUS.
# Set memory-mapping threshold to 50000 mmap.control(50000)