RFR Backport 8165808: Add release barriers when allocating objects with concurrent collection

[Yangfei (Felix)]

Hi,

> -----Original Message-----
> From: Andrew Haley [mailto:aph at redhat.com]
> Sent: Tuesday, August 25, 2020 5:18 PM
> To: Yangfei (Felix) <felix.yang at huawei.com>; jdk8u-dev at openjdk.java.net
> Subject: Re: RFR Backport 8165808: Add release barriers when allocating
> objects with concurrent collection
> 
> On 25/08/2020 09:56, Yangfei (Felix) wrote:
> >> Yes, certainly. Thanks.
> > Thanks for quick review.
> > I have add new label jdk8u-fix-request and necessary comment on the
> issue.
> 
> By the way, there are many places where arrays are allocated. Do you know
> why only this particular one needs a release barrier?

Not sure if I understand the question correctly.
I think the common entry points are CollectedHeap::obj_allocate & CollectedHeap::array_allocate.  These functions finally calls CollectedHeap::post_allocation_setup_common.
Many places will call these functions to create objects.  For example,
InstanceKlass::allocate_objArray -> CollectedHeap::array_allocate -> CollectedHeap::post_allocation_setup_array -> CollectedHeap::post_allocation_setup_common
Since we do a release store in CollectedHeap::post_allocation_setup_common, so all the places where objects are created will benefit.
Hope that explains.

Thanks,
Felix