Subj : lock preemption
To   : comp.unix.aix,comp.programming.threads
From : Kamal R. Prasad
Date : Tue Jun 14 2005 10:22 am

Hello,

 I am dealing with a strange beast called complex locks inside AIX
kernel extensions. The documentation indicates that a higher priority
thread can premept a lower priority thread holding a complex lock. I
believe the funda behind this is generic -meaning pthread_rwlock() is
implemented about the same way. How does lock premption actually happen
in such a situation? If one thread is holding a read lock, can a higher
priority thrread premept it  and acqurie the write lock, finish its
activity, release the lock and have the other thread resume execution?
If so, is it possible for the thread to premept another thread holding
a write lock?

thanks
-kamal

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