RFR: JDK-8241883: (zipfs) SeekableByteChannel:close followed by SeekableByteChannel:close will throw an NPE

[mark sheppard]

Hi Lance,
     In the ByteArrayChannel is there any merit in making
the readonly member variable final to exhibit its immutable characteristic
i.e. it appears to be set during construction only,
and the closed member variable volatile to ensure consistency of reads
for concurrent  isOpen and closed method  invocations ?

regards
Mark



________________________________
From: nio-dev <nio-dev-bounces at openjdk.java.net> on behalf of Lance Andersen <lance.andersen at oracle.com>
Sent: Thursday 9 April 2020 18:20
To: Alan Bateman <Alan.Bateman at oracle.com>
Cc: nio-dev <nio-dev at openjdk.java.net>
Subject: Re: RFR: JDK-8241883: (zipfs) SeekableByteChannel:close followed by SeekableByteChannel:close will throw an NPE



On Apr 9, 2020, at 3:03 AM, Alan Bateman <Alan.Bateman at oracle.com<mailto:Alan.Bateman at oracle.com>> wrote:


In the case of the close method above, ByteArrayChannel::toByteArray uses a readLock  ByteArrayChannel::close uses a writeLock

The patch adds a new lock and doesn't appear use the readLock. Would it be possible to generate a webrev with the full patch as it's not possible to see the fully implications of what is proposed here.

Of course, and can be found at: http://cr.openjdk.java.net/~lancea/8241883/webrev.00/index.html

I modified the patch to use the beginWrite() from ByteArrayChannel per Christoph’s suggestion (I had done that originally but talked myself out of that for some reason …)

-Alan

[cid:E1C4E2F0-ECD0-4C9D-ADB4-B16CA7BCB7FC at home]<http://oracle.com/us/design/oracle-email-sig-198324.gif>
<http://oracle.com/us/design/oracle-email-sig-198324.gif><http://oracle.com/us/design/oracle-email-sig-198324.gif>
<http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance Andersen| Principal Member of Technical Staff | +1.781.442.2037
Oracle Java Engineering
1 Network Drive
Burlington, MA 01803
Lance.Andersen at oracle.com<mailto:Lance.Andersen at oracle.com>



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.java.net/pipermail/nio-dev/attachments/20200409/d4928787/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: oracle_sig_logo.gif
Type: image/gif
Size: 658 bytes
Desc: oracle_sig_logo.gif
URL: <https://mail.openjdk.java.net/pipermail/nio-dev/attachments/20200409/d4928787/oracle_sig_logo.gif>