*_trylock return on success?
So what is a coder to do. We need to define the pi_mutex_trylock(). If I understand this thread, it should return 0 on success. Is this correct?
George
Quoted 8 lines · Roger Larsson
Quoted 7 lines · Philipp Rumpf
Quoted 3 lines · Roger Larsson
Quoted 1 line
_trylockfunctions return 0 for success.Not
spin_trylockArgh, I missed the (recent ?) change to make x86 spinlocks use 1 to mean unlocked. You're correct, and obviously this should be fixed.
Have looked more into this now...tasklet_trylock is also wrong (but there are only four of them) Is this 2.4 only, or where there spin locks earlier too?
My suggestion now is a few steps:
1) to release a kernel version that has corrected _trylocks; spin2_trylock and tasklet2_trylock.
[with corresponding updates in as many places as possible:
s/!spin_trylock/spin2_trylock/g s/spin_trylock/!spin2_trylock/g
. . .]
(ready for spin trylock, not done for tasklet yet..., attached,
hope it got included OK - not fully used to kmail)
2) This will in house only drives or compilations that in some strange way uses this calls...
3a) (DANGEROUS) global rename spin2_trylock to spin_trylock
[no logic change this time - only name]
3b) (dangerous) add compatibility interface
#define spin_trylock(L) (!spin2_trylock(L)) Probably not necessary since it can not be linked against. Binary modules will contain their own compatibility code :-) Probably preferred by those who maintain drivers for several releases; 2.2, 2.4, ...
3c) do not do anything more...
Alternative:
1b) do nothing at all - suffer later
/RogerL
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