md spinlock

2 files changed, 19 insertions, 12 deletions

diff --git a/lib/libpthread/arch/i386/_atomic_lock.c b/lib/libpthread/arch/i386/_atomic_lock.c
index 8ddcb33068e..4794226ad3e 100644
--- a/lib/libpthread/arch/i386/_atomic_lock.c
+++ b/lib/libpthread/arch/i386/_atomic_lock.c
@@ -1,33 +1,34 @@
-/*	$OpenBSD: _atomic_lock.c,v 1.2 1998/12/18 05:59:17 d Exp $	*/
+/*	$OpenBSD: _atomic_lock.c,v 1.3 1998/12/21 07:58:45 d Exp $	*/
 /*
  * Atomic lock for i386
  */
 
 #include "spinlock.h"
 
-register_t
-_atomic_lock(volatile register_t *lock)
+int
+_atomic_lock(volatile _spinlock_lock_t *lock)
 {
-	register_t old;
+	_spinlock_lock_t old;
 
 	/*
 	 * Use the eXCHanGe instruction to swap the lock value with
-	 * a local variable containg '1' (the locked state).
+	 * a local variable containg the locked state.
 	 */
-	old = 1;
+	old = _SPINLOCK_LOCKED;
 	__asm__("xchg %0, %1"
 		: "=r" (old), "=m" (*lock) : "0"(old), "1" (*lock)  );
 	/*
-	 * So now there is a 1 in *lock and 'old' contains what
-	 * used to be in the lock. We return 0 if the lock was acquired,
-	 * (ie its old value was 0) or 1 otherwise.
+	 * So now LOCKED is in *lock and 'old' contains what
+	 * used to be in *lock. We return 0 if the lock was acquired,
+	 * (ie its old value was UNLOCKED) or 1 otherwise.
 	 */
-	return old;
+	return (old != _SPINLOCK_UNLOCKED);
 }
 
 int
-_atomic_is_locked(volatile register_t *lock)
+_atomic_is_locked(volatile _spinlock_lock_t *lock)
 {
 
-	return *lock;
+	/* Return true if the lock is locked (i.e., is not unlocked). */
+	return (*lock != _SPINLOCK_UNLOCKED);
 }
diff --git a/lib/libpthread/arch/i386/_spinlock.h b/lib/libpthread/arch/i386/_spinlock.h
new file mode 100644
index 00000000000..f67c9db8eea
--- /dev/null
+++ b/lib/libpthread/arch/i386/_spinlock.h
@@ -0,0 +1,6 @@
+/*	$OpenBSD: _spinlock.h,v 1.1 1998/12/21 07:58:45 d Exp $	*/
+
+#define _SPINLOCK_UNLOCKED	(0)
+#define _SPINLOCK_LOCKED	(1)
+typedef int _spinlock_lock_t;
+