RFR: 8297778: Modernize and improve module jdk.sctp [v4]

[Sergey Tsypanov]

On Wed, 30 Nov 2022 09:55:54 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This PR proposes a variety of modernisations to the `jdk.sctp` module.
>> 
>> During the fix of https://bugs.openjdk.org/browse/JDK-8296024, several improvement areas were identified including: 
>> 
>> * Replacing duplicate code segments 
>> * Making certain fields final 
>> * Using enhanced switch 
>> * Using records 
>> * Fixing typos 
>> * Marking fields participating in serialisation with `@Serial` 
>> * Modernizing toString() implementations 
>> * Using pattern matching 
>> * Using diamond operators
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Revert more formatting

src/jdk.sctp/unix/classes/sun/nio/ch/sctp/SctpChannelImpl.java line 82:

> 80: 
> 81:     /* IDs of native threads doing send and receive, for signalling */
> 82:     private volatile long receiverThread = 0;

It's not necessary to explicitly initialize volatiles with default values, see https://bugs.openjdk.org/browse/JDK-8272756

src/jdk.sctp/unix/classes/sun/nio/ch/sctp/SctpChannelImpl.java line 1084:

> 1082:         IOUtil.load();   /* loads nio & net native libraries */
> 1083:         java.security.AccessController.doPrivileged(
> 1084:             new java.security.PrivilegedAction<>() {

Is it possible to use `import java.security.PrivilegedAction;` instead of fully-qualified name?

-------------

PR: https://git.openjdk.org/jdk/pull/11418