hurd: Add __pthread_spin_wait and use it

900778283a ("htl: make pthread_spin_lock really spin") made
pthread_spin_lock really spin and not block, but the current users of
__pthread_spin_lock were assuming that it blocks, i.e. they use it as a
lightweight mutex fitting in just one int.

__pthread_spin_wait provides that support back.

sysdeps/htl/pt-barrier-wait.c

@@ -24,7 +24,7 @@
 int
 pthread_barrier_wait (pthread_barrier_t *barrier)
 {
-  __pthread_spin_lock (&barrier->__lock);
+  __pthread_spin_wait (&barrier->__lock);
   if (--barrier->__pending == 0)
     {
       barrier->__pending = barrier->__count;

sysdeps/htl/pt-cond-brdcast.c

@@ -26,7 +26,7 @@ __pthread_cond_broadcast (pthread_cond_t *cond)
 {
   struct __pthread *wakeup;
 
-  __pthread_spin_lock (&cond->__lock);
+  __pthread_spin_wait (&cond->__lock);
   while ((wakeup = cond->__queue))
     {
       __pthread_dequeue (wakeup);
@@ -34,7 +34,7 @@ __pthread_cond_broadcast (pthread_cond_t *cond)
       /* Wake it up without spin held, so it may have a chance to really
          preempt us */
       __pthread_wakeup (wakeup);
-      __pthread_spin_lock (&cond->__lock);
+      __pthread_spin_wait (&cond->__lock);
     }
   __pthread_spin_unlock (&cond->__lock);
 

sysdeps/htl/pt-cond-destroy.c

@@ -24,7 +24,7 @@ __pthread_cond_destroy (pthread_cond_t *cond)
 {
   int ret = 0;
 
-  __pthread_spin_lock (&cond->__lock);
+  __pthread_spin_wait (&cond->__lock);
   if (cond->__queue)
     ret = EBUSY;
   __pthread_spin_unlock (&cond->__lock);

sysdeps/htl/pt-cond-signal.c

@@ -27,7 +27,7 @@ __pthread_cond_signal (pthread_cond_t *cond)
 {
   struct __pthread *wakeup;
 
-  __pthread_spin_lock (&cond->__lock);
+  __pthread_spin_wait (&cond->__lock);
   wakeup = cond->__queue;
   if (wakeup != NULL)
     __pthread_dequeue (wakeup);

sysdeps/htl/pt-cond-timedwait.c

@@ -50,7 +50,7 @@ cancel_hook (void *arg)
   pthread_cond_t *cond = ctx->cond;
   int unblock;
 
-  __pthread_spin_lock (&cond->__lock);
+  __pthread_spin_wait (&cond->__lock);
   /* The thread only needs to be awaken if it's blocking or about to block.
      If it was already unblocked, it's not queued any more.  */
   unblock = wakeup->prevp != NULL;
@@ -112,7 +112,7 @@ __pthread_cond_timedwait_internal (pthread_cond_t *cond,
          the cancellation hook to simplify the cancellation procedure, i.e.
          if the thread is queued, it can be cancelled, otherwise it is
          already unblocked, progressing on the return path.  */
-      __pthread_spin_lock (&cond->__lock);
+      __pthread_spin_wait (&cond->__lock);
       __pthread_enqueue (&cond->__queue, self);
       if (cond->__attr != NULL)
 	clock_id = cond->__attr->__clock;
@@ -135,7 +135,7 @@ __pthread_cond_timedwait_internal (pthread_cond_t *cond,
       __pthread_block (self);
     }
 
-  __pthread_spin_lock (&cond->__lock);
+  __pthread_spin_wait (&cond->__lock);
   if (self->prevp == NULL)
     {
       /* Another thread removed us from the list of waiters, which means a

sysdeps/htl/pt-once.c

@@ -36,7 +36,7 @@ __pthread_once (pthread_once_t *once_control, void (*init_routine) (void))
   atomic_full_barrier ();
   if (once_control->__run == 0)
     {
-      __pthread_spin_lock (&once_control->__lock);
+      __pthread_spin_wait (&once_control->__lock);
 
       if (once_control->__run == 0)
 	{

sysdeps/htl/pt-rwlock-timedrdlock.c

@@ -33,7 +33,7 @@ __pthread_rwlock_timedrdlock_internal (struct __pthread_rwlock *rwlock,
   int drain;
   struct __pthread *self;
 
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
   if (__pthread_spin_trylock (&rwlock->__held) == 0)
     /* Successfully acquired the lock.  */
     {
@@ -79,7 +79,7 @@ __pthread_rwlock_timedrdlock_internal (struct __pthread_rwlock *rwlock,
       __pthread_block (self);
     }
 
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
   if (self->prevp == NULL)
     /* Another thread removed us from the queue, which means a wakeup message
        has been sent.  It was either consumed while we were blocking, or

sysdeps/htl/pt-rwlock-timedwrlock.c

@@ -33,7 +33,7 @@ __pthread_rwlock_timedwrlock_internal (struct __pthread_rwlock *rwlock,
   int drain;
   struct __pthread *self;
 
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
   if (__pthread_spin_trylock (&rwlock->__held) == 0)
     /* Successfully acquired the lock.  */
     {
@@ -65,7 +65,7 @@ __pthread_rwlock_timedwrlock_internal (struct __pthread_rwlock *rwlock,
       __pthread_block (self);
     }
 
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
   if (self->prevp == NULL)
     /* Another thread removed us from the queue, which means a wakeup message
        has been sent.  It was either consumed while we were blocking, or

sysdeps/htl/pt-rwlock-tryrdlock.c

@@ -25,7 +25,7 @@
 int
 pthread_rwlock_tryrdlock (struct __pthread_rwlock *rwlock)
 {
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
   if (__pthread_spin_trylock (&rwlock->__held) == 0)
     /* Successfully acquired the lock.  */
     {

sysdeps/htl/pt-rwlock-trywrlock.c

@@ -25,7 +25,7 @@
 int
 pthread_rwlock_trywrlock (struct __pthread_rwlock *rwlock)
 {
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
   if (__pthread_spin_trylock (&rwlock->__held) == 0)
     /* Successfully acquired the lock.  */
     {

sysdeps/htl/pt-rwlock-unlock.c

@@ -28,7 +28,7 @@ __pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
 {
   struct __pthread *wakeup;
 
-  __pthread_spin_lock (&rwlock->__lock);
+  __pthread_spin_wait (&rwlock->__lock);
 
   assert (__pthread_spin_trylock (&rwlock->__held) == EBUSY);
 

sysdeps/htl/sem-getvalue.c

@@ -22,7 +22,7 @@
 int
 __sem_getvalue (sem_t *restrict sem, int *restrict value)
 {
-  __pthread_spin_lock (&sem->__lock);
+  __pthread_spin_wait (&sem->__lock);
   *value = sem->__value;
   __pthread_spin_unlock (&sem->__lock);
 

sysdeps/htl/sem-post.c

@@ -26,7 +26,7 @@ __sem_post (sem_t *sem)
 {
   struct __pthread *wakeup;
 
-  __pthread_spin_lock (&sem->__lock);
+  __pthread_spin_wait (&sem->__lock);
   if (sem->__value > 0)
     /* Do a quick up.  */
     {

sysdeps/htl/sem-timedwait.c

@@ -32,7 +32,7 @@ __sem_timedwait_internal (sem_t *restrict sem,
   struct __pthread *self;
   clockid_t clock_id = CLOCK_REALTIME;
 
-  __pthread_spin_lock (&sem->__lock);
+  __pthread_spin_wait (&sem->__lock);
   if (sem->__value > 0)
     /* Successful down.  */
     {
@@ -59,7 +59,7 @@ __sem_timedwait_internal (sem_t *restrict sem,
   else
     err = __pthread_block_intr (self);
 
-  __pthread_spin_lock (&sem->__lock);
+  __pthread_spin_wait (&sem->__lock);
   if (self->prevp == NULL)
     /* Another thread removed us from the queue, which means a wakeup message
        has been sent.  It was either consumed while we were blocking, or

sysdeps/htl/sem-trywait.c

@@ -24,7 +24,7 @@
 int
 __sem_trywait (sem_t *sem)
 {
-  __pthread_spin_lock (&sem->__lock);
+  __pthread_spin_wait (&sem->__lock);
   if (sem->__value > 0)
     /* Successful down.  */
     {

sysdeps/mach/htl/bits/spin-lock-inline.h

@@ -71,6 +71,15 @@ __pthread_spin_lock (__pthread_spinlock_t *__lock)
   return 0;
 }
 
+__PT_SPIN_INLINE int __pthread_spin_wait (__pthread_spinlock_t *__lock);
+
+__PT_SPIN_INLINE int
+__pthread_spin_wait (__pthread_spinlock_t *__lock)
+{
+  __spin_lock ((__spin_lock_t *) __lock);
+  return 0;
+}
+
 __PT_SPIN_INLINE int __pthread_spin_unlock (__pthread_spinlock_t *__lock);
 
 __PT_SPIN_INLINE int

sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c

@@ -56,7 +56,7 @@ __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond,
   {
     int unblock;
 
-    __pthread_spin_lock (&cond->__lock);
+    __pthread_spin_wait (&cond->__lock);
     /* The thread only needs to be awaken if it's blocking or about to block.
        If it was already unblocked, it's not queued any more.  */
     unblock = self->prevp != NULL;
@@ -81,7 +81,7 @@ __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond,
      the condition variable's lock.  */
 
   __spin_lock (&ss->lock);
-  __pthread_spin_lock (&cond->__lock);
+  __pthread_spin_wait (&cond->__lock);
   cancel = ss->cancel;
   if (cancel)
     /* We were cancelled before doing anything.  Don't block at all.  */
@@ -123,7 +123,7 @@ __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond,
       /* As it was done when enqueueing, prevent hurd_thread_cancel from
          suspending us while the condition lock is held.  */
       __spin_lock (&ss->lock);
-      __pthread_spin_lock (&cond->__lock);
+      __pthread_spin_wait (&cond->__lock);
       if (self->prevp == NULL)
 	/* Another thread removed us from the list of waiters, which means
 	   a wakeup message has been sent.  It was either consumed while