Messages in this thread | | | Date | Tue, 08 Oct 2002 13:24:48 +0200 | From | Francesc Oller <> | Subject | futex API docs? |
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Hi all!
I've been trying to understand how futexes work looking at the last dev. kernel. I've not found any docs. Are there any?
Basically:
P (fast P sem op):
if (atomic_decrement(sem)<0) sys_futex(..,FUTEX_WAIT,....);
V (fast V sem op):
if (atomic_increment(sem)<=0) sys_futex(..,FUTEX_WAKE,....);
Futexes need be counting semaphores since there could be WAKEs in the middle of atomic_decrements and WAITs (not atomic) but I do not see this in the code. I can't find the kernel counter in the sources
Can anybody help me?
Many thanks in advance
Please CC to my e-mail since I'm not subscribed.
Cheers
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