Name: rlT66838 Date: 05/04/2000


java version "1.3.0rc3"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0rc3-Z)
Java HotSpot(TM) Client VM (build 1.3.0rc3-Z, mixed mode)

Since the amount of total memory
(as reported by java.lang.Runtime.totalMemory())
can change, it would be good if the Runtime also
returned the maximum amount of memory.

An appropriate algorithm might look like:

Assume we have a function long absMaxMem() which returns the absolute maximum
size of the VM (for instance, from the -Xm flag, or from system memory if the
VM can grow without limit). Also assume there is a function long freeSysMem(),
which returns the currently free amount of system memory.

long Runtime.maxMemory()
{
   long maxMem = absMaxMem();
   long freeMem = freeSysMem();

   return ((maxMem > freeMem) ? freeMem : maxMem);
}

There just isn't any reasonable way to know if you can read in a large file
unless you know how big the VM can get. Of course, if you could catch
OutOfMemoryError that wouln't be as big a deal, 'cause you could clean up after
the file if it didn't completely read in.
(Review ID: 104479)
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