To be technically correct this is a "static initialized lock" using
something like PTHREAD_MUTEX_INIT. We must version every function that
could have had a statically initialized lock, and at the start of said
function, check the lock words and reset as appropriate. This involves
a) Detect parisc-lt {1,1,1,1} and convert that to {0,0,0,0} b) If the
last word in the lock[4] is zero then do nothing. Note that with
parisc-nptl only the first word is used for locking and it doesn't
have to be more than int aligned.
IMHO, there is no need for versioning. Moreover it wouldn't be sufficient.
Imagine function in a shared library foo which takes as argument
pthread_mutex_t and does usual:
pthread_mutex_lock()
do some work
pthread_mutex_unlock()
And a program bar, which uses foo. Inside bar is a static initialized
lock. The foo might be (re)compiled against NPTL, while bar would be
still compiled against LT. Therefore check_and_reset() should be called as
long as any installed (debian) package have not been recompiled against
NPTL. The overhead of check_and_reset() looks very small, it should be no
problem at all. The harder part is to determine each place, where
check_and_reset() should be called. It have to be in all places,
where static initialized lock might be passed for the 1st time,
i.e. it should be in pthread_mutex_lock(), but not in
pthread_mutex_unlock().
Petr
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