RFR: 8234060: Potential memory reordering problem in JfrBuffer flush mechanism

[Markus Gronlund]

Hi,

Denghui raised the issue with memory ordering in relation to the JfrBuffer flush mechanism.

I have taken a pass over some of the core parts and I suggest to extend his changeset as follows:

Webrev: http://cr.openjdk.java.net/~mgronlun/8234060/webrev01/ 

Thanks
Markus

-----Original Message-----
From: Markus Gronlund 
Sent: den 13 november 2019 12:17
To: Denghui Dong <denghui.ddh at alibaba-inc.com>; hotspot-jfr-dev at openjdk.java.net
Subject: RE: RFR: 8234060: Potential memory reordering problem in JfrBuffer flush mechanism

Hi Denghui,

 

Looks good. You also remembered to update the Java side as well – very good.

 

Can you please move the #include “runtime/orderAccess.hpp” from jfrBuffer.cpp to jfrBuffer.hpp? No need for another webrev for that.

 

I can sponsor this change for you if needed.

 

Thanks again

Markus

 

From: Denghui Dong <denghui.ddh at alibaba-inc.com> 
Sent: den 13 november 2019 09:06
To: hotspot-jfr-dev at openjdk.java.net; markus.gronlund <markus.gronlund at oracle.com>
Subject: RFR: 8234060: Potential memory reordering problem in JfrBuffer flush mechanism

 

Hi,

Please help me to review this patch.

Bug: https://bugs.openjdk.java.net/browse/JDK-8234060

Webrev: http://cr.openjdk.java.net/~ddong/8234060/

 

Thanks,

Denghui Dong