diff --git a/lib/libthr/thread/thr_cancel.c b/lib/libthr/thread/thr_cancel.c
index 7e1bace02cf3..311cf1e9b11b 100644
--- a/lib/libthr/thread/thr_cancel.c
+++ b/lib/libthr/thread/thr_cancel.c
@@ -80,12 +80,12 @@ retry:
 			 * Disconnect the thread from the joinee:
 			 */
 			if ((joined = pthread->join_status.thread) != NULL) {
-				if (_spintrylock(&joined->lock) == EBUSY) {
+				if (THR_TRYLOCK(&joined->lock) == EBUSY) {
 					_thread_critical_exit(pthread);
 					goto retry;
 				}
 				pthread->join_status.thread->joiner = NULL;
-				_spinunlock(&joined->lock);
+				THR_UNLOCK(&joined->lock);
 				joined = pthread->join_status.thread = NULL;
 			}
 			pthread->cancelflags |= PTHREAD_CANCELLING;
diff --git a/lib/libthr/thread/thr_detach.c b/lib/libthr/thread/thr_detach.c
index 23e985f72f4b..6161e869bf3f 100644
--- a/lib/libthr/thread/thr_detach.c
+++ b/lib/libthr/thread/thr_detach.c
@@ -44,10 +44,10 @@ _pthread_detach(pthread_t pthread)
 	if (pthread == NULL || pthread->magic != PTHREAD_MAGIC)
 		return (EINVAL);
 
-	_SPINLOCK(&pthread->lock);
+	THR_LOCK(&pthread->lock);
 
 	if (pthread->attr.flags & PTHREAD_DETACHED) {
-		_SPINUNLOCK(&pthread->lock);
+		THR_UNLOCK(&pthread->lock);
 		return (EINVAL);
 	}
 
@@ -73,7 +73,7 @@ _pthread_detach(pthread_t pthread)
 		_thread_critical_exit(joiner);
 	}
 
-	_SPINUNLOCK(&pthread->lock);
+	THR_UNLOCK(&pthread->lock);
 
 	return (0);
 }
diff --git a/lib/libthr/thread/thr_exit.c b/lib/libthr/thread/thr_exit.c
index bea78742e739..441e730aaec3 100644
--- a/lib/libthr/thread/thr_exit.c
+++ b/lib/libthr/thread/thr_exit.c
@@ -146,7 +146,7 @@ retry:
 	/* Check if there is a thread joining this one: */
 	if (curthread->joiner != NULL) {
 		pthread = curthread->joiner;
-		_SPINLOCK(&pthread->lock);
+		THR_LOCK(&pthread->lock);
 		curthread->joiner = NULL;
 
 		/* Make the joining thread runnable: */
@@ -156,7 +156,7 @@ retry:
 		pthread->join_status.ret = curthread->ret;
 		pthread->join_status.error = 0;
 		pthread->join_status.thread = NULL;
-		_SPINUNLOCK(&pthread->lock);
+		THR_UNLOCK(&pthread->lock);
 
 		/* Make this thread collectable by the garbage collector. */
 		PTHREAD_ASSERT(((curthread->attr.flags & PTHREAD_DETACHED) ==
diff --git a/lib/libthr/thread/thr_gc.c b/lib/libthr/thread/thr_gc.c
index e2aa75331893..09489967635c 100644
--- a/lib/libthr/thread/thr_gc.c
+++ b/lib/libthr/thread/thr_gc.c
@@ -106,7 +106,7 @@ _thread_gc(pthread_addr_t arg)
 			if (pthread == _thread_initial) 
 				continue;
 
-			_SPINLOCK(&pthread->lock);
+			THR_LOCK(&pthread->lock);
 
 			/*
 			 * Check if the stack was not specified by
@@ -128,7 +128,7 @@ _thread_gc(pthread_addr_t arg)
 			 * it on the dead thread list.
 			 */
 			if ((pthread->attr.flags & PTHREAD_DETACHED) == 0) {
-				_SPINUNLOCK(&pthread->lock);
+				THR_UNLOCK(&pthread->lock);
 				continue;
 			}
 
@@ -141,7 +141,7 @@ _thread_gc(pthread_addr_t arg)
 			 */
 			pthread_cln = pthread;
 
-			_SPINUNLOCK(&pthread->lock);
+			THR_UNLOCK(&pthread->lock);
 
 			/*
 		 	 * Retire the architecture specific id so it may be
diff --git a/lib/libthr/thread/thr_join.c b/lib/libthr/thread/thr_join.c
index 2a5433aeb80e..8b579781ef1b 100644
--- a/lib/libthr/thread/thr_join.c
+++ b/lib/libthr/thread/thr_join.c
@@ -33,6 +33,7 @@
  */
 #include <errno.h>
 #include <pthread.h>
+#include <stdlib.h>
 #include "thr_private.h"
 
 __weak_reference(_pthread_join, pthread_join);
@@ -69,7 +70,7 @@ _pthread_join(pthread_t pthread, void **thread_return)
 	THREAD_LIST_LOCK;
 	TAILQ_FOREACH(thread, &_thread_list, tle)
 		if (thread == pthread) {
-			_SPINLOCK(&pthread->lock);
+			THR_LOCK(&pthread->lock);
 			break;
 		}
 
@@ -79,7 +80,7 @@ _pthread_join(pthread_t pthread, void **thread_return)
 		 */
 		TAILQ_FOREACH(thread, &_dead_list, dle)
 			if (thread == pthread) {
-				_SPINLOCK(&pthread->lock);
+				THR_LOCK(&pthread->lock);
 				break;
 			}
 
@@ -87,7 +88,7 @@ _pthread_join(pthread_t pthread, void **thread_return)
 	if (thread == NULL ||
 	    ((pthread->attr.flags & PTHREAD_DETACHED) != 0)) {
 		if (thread != NULL)
-			_SPINUNLOCK(&pthread->lock);
+			THR_UNLOCK(&pthread->lock);
 		THREAD_LIST_UNLOCK;
 		DEAD_LIST_UNLOCK;
 		ret = ESRCH;
@@ -97,7 +98,7 @@ _pthread_join(pthread_t pthread, void **thread_return)
 	if (pthread->joiner != NULL) {
 		/* Multiple joiners are not supported. */
 		/* XXXTHR - support multiple joiners. */
-		_SPINUNLOCK(&pthread->lock);
+		THR_UNLOCK(&pthread->lock);
 		THREAD_LIST_UNLOCK;
 		DEAD_LIST_UNLOCK;
 		ret = ENOTSUP;
@@ -109,7 +110,7 @@ _pthread_join(pthread_t pthread, void **thread_return)
 	if (pthread->state != PS_DEAD) {
 		/* Set the running thread to be the joiner: */
 		pthread->joiner = curthread;
-		_SPINUNLOCK(&pthread->lock);
+		THR_UNLOCK(&pthread->lock);
 		_thread_critical_enter(curthread);
 
 		/* Keep track of which thread we're joining to: */
@@ -159,7 +160,7 @@ _pthread_join(pthread_t pthread, void **thread_return)
 
 		/* Make the thread collectable by the garbage collector. */
 		pthread->attr.flags |= PTHREAD_DETACHED;
-		_SPINUNLOCK(&pthread->lock);
+		THR_UNLOCK(&pthread->lock);
 		THREAD_LIST_UNLOCK;
 		if (pthread_cond_signal(&_gc_cond) != 0)
 			PANIC("Cannot signal gc cond");
diff --git a/lib/libthr/thread/thr_kern.c b/lib/libthr/thread/thr_kern.c
index 4a60bfe21f46..481cc835ce0f 100644
--- a/lib/libthr/thread/thr_kern.c
+++ b/lib/libthr/thread/thr_kern.c
@@ -56,13 +56,13 @@ void
 _thread_critical_enter(pthread_t pthread)
 {
 	_thread_sigblock();
-	_SPINLOCK(&pthread->lock);
+	THR_LOCK(&pthread->lock);
 }
 
 void
 _thread_critical_exit(pthread_t pthread)
 {
-	_SPINUNLOCK(&pthread->lock);
+	THR_UNLOCK(&pthread->lock);
 	_thread_sigunblock();
 }
 
diff --git a/lib/libthr/thread/thr_mutex.c b/lib/libthr/thread/thr_mutex.c
index 40921ec6e952..067f0f0288c8 100644
--- a/lib/libthr/thread/thr_mutex.c
+++ b/lib/libthr/thread/thr_mutex.c
@@ -1263,9 +1263,9 @@ _mutex_lock_backout(pthread_t pthread)
 	/* _thread_kern_sig_defer();*/
 
 	/* XXX - Necessary to obey lock order */
-	_SPINLOCK(&pthread->lock);
+	THR_LOCK(&pthread->lock);
 	mutex = pthread->data.mutex;
-	_SPINUNLOCK(&pthread->lock);
+	THR_UNLOCK(&pthread->lock);
 
 	_SPINLOCK(&mutex->lock);