Re: [path][rfc] add PR_DETACH prctl command

From: Stas Sergeev
Date: Fri Apr 08 2011 - 17:15:38 EST

09.04.2011 00:52, Bryan Donlan wrote:
Still, you can workaround this by either:
Yes, sure.

a) Load the vendor library via dlopen()
Too much to dlsym(), and by the way, what does this give?
I _have to_ init that lib early at bootup, so I don't see how
dlopen will help, could you clarify?

b) Use a separate launcher executable to handle the fork-and-wait
Yes, that's certainly possible, except that I was trying the
semaphore instead of a signal, as in your example, but its
the same.

Just kill(atoi(getenv("LAUNCHER_PID")), SIGUSR1) to detach. Much
easier than doing some very racy things in the kernel, no? It's
certainly more obvious that this ought to be correct in the face of
races with its parent :)
But what races do you mean? Yes, the workaround is a
workaround, and it works. And is simpler to implement. :)
But what problems do you see with the PR_DETACH approach,
except for the bugs in my patch? :) I mean, the fact that
daemon() silently loses threads, sounds like a limitation,
after all.
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