Suggested fix for JDK-4724038 (Add unmap method to MappedByteBuffer)

Andrew Haley aph at
Thu Sep 10 14:22:04 UTC 2015

On 09/10/2015 03:13 PM, Vitaly Davidovich wrote:

> So what happens after safepoint is done and thread accesses the
> mapping (it would need protection NONE, not just write)? JVM is then
> going to trap the signal and convert to an exception?

One of us is missing something, and I don't think it's me.  :-)

There is a protection page (just one page) associated with every
mapping.  Every access to a mapping is guarded by that protection
page.  The protection page is mapped for as long as the
MappedByteBuffer is alive.


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