pwait: Test the new -r option

[des]

Summary

Test that pwait without -r reports a process as soon as it terminates,
while pwait with -r does not report it until it has been reaped.

MFC after: 1 week
Sponsored by: Klara, Inc.
Sponsored by: NetApp, Inc.

[des]

new behavior is now optional, test both variants

[des]

rename test

[kib]

bin/pwait/tests/pwait_reap.c

126

Why not using posix_spawn() there?

136

You are not waiting for the termination there, wait_zero(false) only checks for termination and asserts if not. As the consequence, the test is racy, since nothing guarantees that the target has exited when waitpid() is called.

[des]

bin/pwait/tests/pwait_reap.c

126

What would be the advantage?

136

I think you're confusing WNOWAIT with WNOHANG.

[kib]

bin/pwait/tests/pwait_reap.c

126

That the used API is specifically designed for the task at hand.

136

No, I do not. Re-read what I wrote: wait_zero(false) may assert falsely.

[des]

bin/pwait/tests/pwait_reap.c

136

No. It will block until the target terminates. It will fail if interrupted, but I don't consider that a problem.

[des]

tolerate EINTR

[markj]

bin/pwait/tests/pwait_reap.c

169

Shouldn't this be pwait_reap_test(false)?

[des]

bin/pwait/tests/pwait_reap.c

169

You're right, will fix.