How to identify Tenured Space

Question

I want to build a MemoryWarningSystem as described in many articles: e.g. as in http://www.javaspecialists.eu/archive/Issue092.html.

Therefore, I want to identify the tenured space like this:

    private MemoryPoolMXBean findTenuredGenPool() {
        for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {

                 if(pool is tenured space)
                    return tenured

        }
    }

I have seen two different ways to identify tenured space

1. Check if pool name equals to "PS Old Gen" and/or "Tenured Gen".
2. Check whether "pool.getType() == MemoryType.HEAP && pool.isUsageThresholdSupported()"

Problem with 1: What about CMS Old Gen? What about other tenured spaces? Should I add all of them to the List of Tenured Names?

Problem with 2: Is this a "safe" way of retrieving the tenured space? Is it reliable?

Thanks!

Answer 1

For HotSpot JVM possible memory pool name for old space

• Tenured Gen
• PS Old Gen
• CMS Old Gen
• G1 Old Gen

For JRockit

• Old Space