Can ProcessBuilder be used to run sendctrlc.exe?

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Currently, sendctrlc.exe is spawned in winp.cpp.
Is it possible to use java.lang.ProcessBuilder to spawn sendctrlc.exe and, thus, simplify code?
If no, it'd be great to write a comment in code explaining decision.

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@oleg-nenashev @stephanreiter Any thoughts? I would appreciate your feedback.

[oleg-nenashev]

Sorry, missed the previous notification.
IIRC there was a discussion about that in the pull request, will try to find it.
Native code is not considered as API, so we can always change it without breaking changes.

[stephanreiter]

Using ProcessBuild is no problem. Good idea! Less native code ...
SendCtrlC ended up in native because it started there with some implementation that didn't use a separate EXE.

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@oleg-nenashev Thanks. I meant something like

  public static boolean sendCtrlC(int pid) {
    Process process = new ProcessBuilder("sendctrlc.exe", pid).start();
    return waitFor(process, 5000) != null;
  }

  @Nullable
  private static Integer waitFor(@NotNull Process process, int timeoutMillis) {
    long stop = System.currentTimeMillis() + timeoutMillis;
    while (System.currentTimeMillis() < stop) {
      try {
        Thread.sleep(100);
        return process.exitValue();
      }
      catch (Exception ignore) {
      }
    }
    return null;
  }

This way, ProcessBuilder is not exposed in winp's API, so it can be changed without breaking changes too.

[stephanreiter]

Will that terminate the sendctrl.exe process after 5secs? That shouldn't be left lingering.

[stephanreiter]

Same should be (made) true for the native code! :)

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Oops, process.destroy() is missing in waitFor. Seems it will terminate sendctrlc.exe.
Wondering, have you encountered any pitfalls in ProcessBuilder's behavior of spawning processes that leads to some problems?
Another question: is it possible that running sendctrlc.exe <pid> will also terminate a parent process of a process with ? AFAIU, a child process inherits console of its parent process, so if ctrl+c event is sent to a console, parent process will receive it too, right?

[stephanreiter]

I don't know much about ProcessBuilder anymore. :)

And sendctrlc.exe will first detach from its console, then attach to the process to avoid what you describe w.r.t. the parent process.

FreeConsole(); if (!AttachConsole(pid)) { return GetLastError(); }

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@stephanreiter Sorry for not being clear. Yes, sendctrlc.exe deattaches from its initial console to be able to attach to a console of the specified process. But what if several processes are already attached to the console, sendctrlc.exe tries to attach to? For example, parent_pid and pid are attached to the same console and sendctrlc.exe pid is spawned. Looks like parent_pid will receive CtrlC event as well. Honestly, I haven't managed to reproduce such case, just wondering if it's possible.

[stephanreiter]

Ah, now I understand. Well, then the Ctrl+C will go to the parent as well. I guess that should be documented to make it obvious.