Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH] Futex Asynchronous Interface | Date | Thu, 13 Jun 2002 12:57:51 +1000 |
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In message <Pine.LNX.4.44.0206120946100.22189-100000@home.transmeta.com> you wr ite: > > > > On Wed, 12 Jun 2002, Peter W=E4chtler wrote: > > > > For the uncontended case: their is no blocked process... > > Wrong. > > The process that holds the lock can die _before_ it gets contended. > > When another thread comes in, it now is contended, but the kernel doesn't > know about anything.
Note also: this is a feature.
I have a little helper program which can grab or release a futex in a (mmapped) file. It's great for shell scripts to grab locks. In this case the helper exits with the lock held, and a later invocation releases a lock it never held.
*AND* the lock is persistent across reboots, since it's in a file. How cool is that!
This is the *third* major thread on this subject, BTW. Rusty. -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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