On Mon, Jul 24, 2017 at 01:12:59PM -0400, John Ferlan wrote: > > > On 07/19/2017 10:31 AM, Michal Privoznik wrote: > > We already have virRWLockInit. But this uses pthread defaults > > which prefer reader to initialize the RW lock. This may lead to > > writer starvation. Therefore we need to have the counterpart that > > prefers writers. Now, according to the > > pthread_rwlockattr_setkind_np() man page setting > > PTHREAD_RWLOCK_PREFER_WRITER_NP attribute is no-op. Therefore we > > need to use PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP > > attribute. So much for good enum value names. > > > > Signed-off-by: Michal Privoznik <mpriv...@redhat.com> > > --- > > src/libvirt_private.syms | 1 + > > src/util/virthread.c | 35 +++++++++++++++++++++++++++++++++++ > > src/util/virthread.h | 1 + > > 3 files changed, 37 insertions(+) > > > > This has broken the CI build, freebsd is not happy: > > ../../src/util/virthread.c:133:42: error: use of undeclared identifier > 'PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP' > pthread_rwlockattr_setkind_np(&attr, > PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP); > ^ > 1 error generated.
It is not just FreeBSD, it also breaks OS-X and Win32. The suffix '_np' / '_NP' is shorthand for nNon portable" - these are glibc inventions. IMHO we should not really use this in our code as if we're going to make assumptions that writers are not starved as a result, because writers will be starved on any non-Linux platform. IOW, I think we need to just revert this. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
