Ports-wise, from a Nov 2019 build on i386, these used it:
$ grep -Rl pthread_spin_unlock wrkscan
wrkscan/devel/libivykis
wrkscan/x11/gnustep/base wrkscan/x11/e17/eina
wrkscan/misc/posixtestsuite
wrkscan/net/libunbound
wrkscan/net/libshout
wrkscan/net/icecast
wrkscan/net/bird/1,-doc
wrkscan/net/bird/1,-main,v6
wrkscan/net/bird/2
wrkscan/net/strongswan wrkscan/mail/mailest
wrkscan/geo/gdal,-main
--
Sent from a phone, apologies for poor formatting.
On 3 October 2020 10:45:05 Martijn van Duren
<[email protected]> wrote:
Back in 2012 kurt@ added an abort call for the undefined behaviour cases
on pthread_mutex_unlock. This helped me a great deal in examining the
cause of some weird behaviour in icinga (or in the case of openbsd, just
plain crash).
For shits and giggles I deceided to look into pthread_spin_unlock and
saw that we return EPERM here, while POSIX states that this behaviour
is unconditionally undefined.[0] Is there a reason why we shouldn't
abort here as well?
I don't have a particular usecase for this, but the mutex case helped me
and it only seems like the right thing to do from a semetrical point of
view. The only cases of pthread_spin_unlock in base I found were in
libunbound (which with my testing with unwind didn't caused any issues)
and gnu/llvm/compiler-rt/lib/tsan, which I don't know where to test.
I have no idea which ports use it.
martijn@
[0]
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_unlock.html
Index: librthread/rthread_spin_lock.c
===================================================================
RCS file: /cvs/src/lib/librthread/rthread_spin_lock.c,v
retrieving revision 1.5
diff -u -p -r1.5 rthread_spin_lock.c
--- librthread/rthread_spin_lock.c 6 Apr 2020 00:01:08 -0000 1.5
+++ librthread/rthread_spin_lock.c 3 Oct 2020 09:42:21 -0000
@@ -102,12 +102,12 @@ pthread_spin_unlock(pthread_spinlock_t *
pthread_spinlock_t l;
if (lock == NULL || *lock == NULL)
- return (EINVAL);
+ abort();
l = *lock;
if (l->owner != self)
- return (EPERM);
+ abort();
l->owner = NULL;
_spinunlock(&l->lock);
Index: libpthread/man/pthread_spin_unlock.3
===================================================================
RCS file: /cvs/src/lib/libpthread/man/pthread_spin_unlock.3,v
retrieving revision 1.3
diff -u -p -r1.3 pthread_spin_unlock.3
--- libpthread/man/pthread_spin_unlock.3 6 Apr 2020 00:01:08 -0000
1.3
+++ libpthread/man/pthread_spin_unlock.3 3 Oct 2020 09:42:21 -0000
@@ -38,17 +38,14 @@ functions.
.Sh RETURN VALUES
If successful,
.Fn pthread_spin_unlock
-returns zero; otherwise an error number is returned to indicate the error.
+returns zero.
.Sh ERRORS
.Fn pthread_spin_unlock
-will fail if:
-.Bl -tag -width Er
-.It Bq Er EINVAL
-The value specified by
+will call
+.Xr abort 3
+if the value specified by
.Fa lock
-is invalid.
-.It Bq Er EPERM
-The lock is not owned by the calling thread.
+is invalid or if the lock is not owned by the calling thread.
.El
.Sh SEE ALSO
.Xr pthread_spin_init 3 ,
