RFR: 8364361: [process] java.lang.Process should implement Closeable [v11]

[Roger Riggs]

On Sun, 28 Sep 2025 13:22:55 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Update close() to use "terminate" consistently.
>
> src/java.base/share/classes/java/lang/Process.java line 186:
> 
>> 184:      * <p>
>> 185:      * Before calling this method the caller should read the streams for any
>> 186:      * data or text and call {@linkplain #waitFor() waitFor} if the exit value is needed.
> 
> Should we add some additional text which clearly highlights that waitFor() needs to be called (before close()) to allow the process to run to completion, even when the exit value or the stream contents aren't used/read by the calling application? I realize that a few lines above we specify:
> 
>> The streams are closed immediately and the process is terminated without waiting.
> 
> But maybe explicitly saying that waitFor() is necessary for allowing the process to run to completion would help reduce confusion? When I first saw the PR, my initial thought was `Process.close()` would wait for the process to run to completion and cleanup the resources that were used and I suspect it might become a common pattern where applications do something like:
> 
> 
> try (Process p = new ProcessBuilder("some process that takes 5 seconds to complete normally").start()) {
> }
> 
> and be surprised that the launched process was abruptly terminated. So maybe some clear text on this method would help?

I think those warnings are already present.
- `process is terminated without waiting`
- `the caller should read the streams for any data or text and call waitFor if the exit value is needed`
- `Calling waitFor before calling close or exiting the try-with-resources block allows the process time to clean up and exit.`
- and the example calls waitFor inside the try-with-resources.

Does this add the emphasis you are asking for:
`Calling waitFor after close() or after the try-with-resources block exits returns the status after destroying the process.`

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PR Review Comment: https://git.openjdk.org/jdk/pull/26649#discussion_r2388230174