Error initialization of VM, not reserve enough memory

Question

Basically i am trying to create a cgi program which opens a filehandle to capture the output of a java program (which outputs 6 simple strings), these strings are then placed into an array and printed to the browser as below:
open(THIS_J, "/usr/j2se/bin/java Testjprob|");
while (<THIS_J>) {
        unshift(@array,$_);
close(THIS_J);
$length = scalar(@array);
if($length != 0){
    print $q->p("The Search Returned No $array[3]");
}The java works when i execute it on the command line through a perl program, however, it doesnt work when i execute it through a cgi program. So i put a test in the perl program to see what version the java is when running:
system "/usr/j2se/bin/java -version > jprobversion.txt" || die "$!";and i looked in the jprobversion.txt and expected to see version numbers etc... instead this message appeared :
"Error occurred during initialization of VM
Could not reserve enough space for object heap"
I have spoken to a few people about this and they came to the conclusion that it is due to the differences in enviornment between running java under cgi and on the command line. I got a response back from a person who mentioned:
"The error message immediatly follows a mmap for 134217728 bytes.
There is no edquivalent mmap when run from the command line."
What is mmap and has anyone else ever come across a problem like this before? Is it just a case of setting an environment variable?

Answer 1

This could be a problem with virtual memory soft limits in the shell that perl exec's. Try this test. Make a test script that does this:
system("ulimit -Ha > /tmp/ul.out 2>&1");
system("ulimit -Sa >> /tmp/ul.out 2>&1");
For comparison, from your command line run:
ulimit -Ha; ulimit -Sa
Look at the resulting output. The line you're interested in is:
virtual memory (kbytes, -v) <some value here>
If the virtual memory size for -Ha in the script is > the size for -Sa then you should be able to increase your virtual memory limit like so in your script:
# increase stack to 64M, if hard limit is 'unlimited' then you could substitue
# the word 'unlimited' for 64000 or the word 'hard'. Check the various man pages
# for ulimit, bash, sh etc.
system("ulimit -Ss 64000; /usr/j2se/bin/java ....");
bill