Proposed KiwiEnvironment enhancements

[sleberknight]

Some proposed methods:

• currentThread()
• interruptCurrentThread()
• currentProcess()

Considerations:

• Will Sonar understand interruptCurrentThread in a catch InterruptedException block, or complain about not re-interrupting the current thread?
• Same question if you were to use: kiwiEnv.currentThread().interrupt()
• What about other tools like Error Prone? Do we care? (since we're not actively using them right now, and only use Sonar and IntelliJ's native built-in analysis)

[sleberknight]

Added currentProcessHandle in #919

[sleberknight]

Another possible method is to get a ProcessHandle for a specific pid. ProcessHandle contains:

public static Optional<ProcessHandle> of(long pid)

We could add a similar method to KiwiEnvironment, e.g.

Optional<ProcessHandle> procesHandleOfPid(long pid)

[sleberknight]

I created a bit of sample code to see whether the Sonar warning about InterruptedException (rule java:S2142) would go away using either of the proposed methods related to current threads. Here is the sample code:

package org.kiwiproject.util;

import org.kiwiproject.base.KiwiEnvironment;

public class CurrentThreadSample {

    private KiwiEnvironment env;

    public CurrentThreadSample(KiwiEnvironment env) {
        this.env = env;
    }

    void callsMethodThatMightBeInterrupted() {
        try {
            methodThatMightBeInterrupted();
        } catch (InterruptedException e) {
            env.interruptCurrentThread();  // the Sonar warning still occurs if use only this method

            env.currentThread().interrupt();  // the Sonar warning goes away if use this method
        }
    }

    void methodThatMightBeInterrupted()  throws InterruptedException {
        Thread.sleep(42);
    }
}

Since the Sonar warning still occurs if you use interruptCurrentThread, we should not add it to KiwiEnvironment.

But, since the Sonar warning disappears when using env.currentThread() and then calling interrupt(), we can go ahead and add currentThread() to KiwiEnvironment. Then, we can easily provide a mock KiwiEnvironment to test code and verify the correct handling of InterruptedException.

[sleberknight]

I had been using VSCode to check whether the Sonar warning goes away. I just now checked while using IntelliJ (2022.3.3) with SonarLint (8.1.65508), and unfortunately the warning does not go away.

[sleberknight]

Added the following issues:

• Add currentThread method to KiwiEnvironment #942
• Add processHandleOfPid to KiwiEnvironment #943

Note that interruptCurrentThread() will not be added because the Sonar still warns about InterruptedException, as described in the comments above.

Along with the previous completion of #919 (currentProcessHandle), this discussion is now effectively closed.