[jdk11u-dev] RFR: 8191278: MappedByteBuffer bulk access memory failures are not handled gracefully

[Andrew Haley]

On 7/29/21 1:28 PM, Sergey Nazarkin wrote:

> I'd like to backport this changes to fix crash happens on memory mapped file operations.  The patch applies almost cleanly except stubGenerator_arm.cpp due to miss of JEP 340 (One AArch64 Port, Not Two), and some copyright year conflicts. 
> Need to note that a series of follow up is required to fix some platforms build. Particularly arm32/aarch64 is not buildable without 8226871. I'll create necessary PR soon. 
> Tested with tier1/tier2 and new InternalErrorTest.

Wow. This is a very invasive patch for a P3 enhancement (that mysteriously
got upgraded to a P2 for backports.) We'd need to see evidence of significant
hardship to users in order to justify approval.

As far as I know, this only has any effect if someone modifies a file in
some way while a mapping is open.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671