RFR [9] 8153181: Examine sun.misc.VMSupport

Alan Bateman Alan.Bateman at oracle.com
Sat Apr 2 09:53:02 UTC 2016

(cc'ing serviceability-dev as this is where this code is maintained).

On 02/04/2016 00:32, Mandy Chung wrote:
> Hi Chris,
> Would jdk.internal.vm be appropriate for this VMSupoprt class?
I agree.

> VMSupport::getAgentProperties simply calls JVM_InitAgentProperties.  java.management could call JVM_InitAgentProperties directly.
> src/jdk.jdwp.agent/share/native/libjdwp/util.c
>     JDWP calls it and needs to be updated.
If I recall correctly then this is so that the debugger transport 
details can be advertised. There is a process AttachingConnector that 
depends on that so I agree this needs to be updated.

> VMSupport.getVMTemporaryDirectory() is for jdk.jvmstat to use and I suggest to move this method to jdk.internal.perf.Perf.
It could although I assume this means that introducing a new shared library.


> Mandy
>> On Mar 31, 2016, at 9:02 AM, Chris Hegarty <chris.hegarty at oracle.com> wrote:
>> As part of JEP 260, all non-Critical APIs in sun.misc are being examined.
>> sun.misc.VMSupport is a utility class supporting two functions:
>>   1) the initialization of management Agent properties, and
>>   2) the retrieval of the VM temporary directory used by the attach and perf data files.
>> The initialization of Agent properties is used statically by the java.managment module,
>> or can be provoked by a serviceability tool on a VM that has had an agent loaded in it.
>> The location of VM temporary files is a low-level interface between the libraries and VM.
>> For these reasons, VMSupport should remain in the base module, but be moved to an
>> internal package.
>> http://cr.openjdk.java.net/~chegar/8153181/00/
>> https://bugs.openjdk.java.net/browse/JDK-8153181
>> -Chris.

More information about the core-libs-dev mailing list