Re: OutOfMemoryError
"Dlugi" <dluugi@gmail.com> wrote in message
news:f6ecnr$8tu$1@news.task.gda.pl...
Is possible to set memory limit which reached throws
java.lang.OutOfMemoryError exception.
I don't express myself exactly, I would like:
for example when 80% of max memory is used JVM throws exception and then
I have 20% of memory available to run algorithm which release memory
AFAIK, this is not possible. What Eclipse does is at the beginning of
the program, it allocates a large chunk of memory (perhaps using a big
array), perhaps around 20MB. Then, it tries to catch the OOME, and upon
doing so, releases that chunk of memory (i.e. it releases the array), then
runs it's memory recovering algorithm, and presumably re-allocates the
array.
If you want to emulate the having the JVM throw the exception at 20%,
you could create a thread which continuously monitors memory usage and
throws it's own OOME when it detects memory dropping below a certain
point, but it seems to me that the exception would be thrown in the
"wrong" thread, and your other threads might not pause, waiting for your
memory-releasing algorithm to complete, unless you specifically code them
to check some sort of flag or other signal to know when they should pause,
and when they should proceed. In other words, it sounds like your
OOME-recovery code will be spread out all over your project, instead of
encapsulated at one point.
- Oliver