libthr: Robust tryjoin test

[aokblast]

Summary

We cannot actually rely on a status (finish) before thr_exit. The
thread needs the kernel signal status=1 to userspace. Before that,
any tryjoin fails. The previous one works as we sleep 1 and should be
enough for normal case.

[kib]

You could query the kernel to see the state of the thread using kinfo_proc().

Somewhat curiously, I thought about adding an API to query the list of the threads for the current process.

[kib]

In D60832#1395064, @kib wrote:

Somewhat curiously, I thought about adding an API to query the list of the threads for the current process.

D60838

[aokblast]

In D60832#1395064, @kib wrote:

You could query the kernel to see the state of the thread using kinfo_proc().

Somewhat curiously, I thought about adding an API to query the list of the threads for the current process.

Yes, but it is a test for pthread_tryjoin_np so :).

[kib]

In D60832#1395514, @aokblast wrote:

In D60832#1395064, @kib wrote:

You could query the kernel to see the state of the thread using kinfo_proc().

Somewhat curiously, I thought about adding an API to query the list of the threads for the current process.

Yes, but it is a test for pthread_tryjoin_np so :).

I do not understand what do you intended to say by this sentence.