--- SheepShaver/src/Unix/sysdeps.h	2003/09/07 14:19:25	1.5
+++ SheepShaver/src/Unix/sysdeps.h	2003/09/29 08:27:56	1.6
@@ -177,6 +177,129 @@ static inline uint32 tswap32(uint32 x) {
 static inline uint64 tswap64(uint64 x) { return bswap_64(x); }
 #endif
 
+// spin locks
+#ifdef __GNUC__
+
+#ifdef __powerpc__
+#define HAVE_TEST_AND_SET 1
+static inline int testandset(int *p)
+{
+	int ret;
+	__asm__ __volatile__("0:    lwarx %0,0,%1 ;"
+						 "      xor. %0,%3,%0;"
+						 "      bne 1f;"
+						 "      stwcx. %2,0,%1;"
+						 "      bne- 0b;"
+						 "1:    "
+						 : "=&r" (ret)
+						 : "r" (p), "r" (1), "r" (0)
+						 : "cr0", "memory");
+	return ret;
+}
+#endif
+
+#ifdef __i386__
+#define HAVE_TEST_AND_SET 1
+static inline int testandset(int *p)
+{
+	char ret;
+	long int readval;
+	
+	__asm__ __volatile__("lock; cmpxchgl %3, %1; sete %0"
+						 : "=q" (ret), "=m" (*p), "=a" (readval)
+						 : "r" (1), "m" (*p), "a" (0)
+						 : "memory");
+	return ret;
+}
+#endif
+
+#ifdef __s390__
+#define HAVE_TEST_AND_SET 1
+static inline int testandset(int *p)
+{
+	int ret;
+
+	__asm__ __volatile__("0: cs    %0,%1,0(%2)\n"
+						 "   jl    0b"
+						 : "=&d" (ret)
+						 : "r" (1), "a" (p), "0" (*p) 
+						 : "cc", "memory" );
+	return ret;
+}
+#endif
+
+#ifdef __alpha__
+#define HAVE_TEST_AND_SET 1
+static inline int testandset(int *p)
+{
+	int ret;
+	unsigned long one;
+
+	__asm__ __volatile__("0:	mov 1,%2\n"
+						 "	ldl_l %0,%1\n"
+						 "	stl_c %2,%1\n"
+						 "	beq %2,1f\n"
+						 ".subsection 2\n"
+						 "1:	br 0b\n"
+						 ".previous"
+						 : "=r" (ret), "=m" (*p), "=r" (one)
+						 : "m" (*p));
+	return ret;
+}
+#endif
+
+#ifdef __sparc__
+#define HAVE_TEST_AND_SET 1
+static inline int testandset(int *p)
+{
+	int ret;
+
+	__asm__ __volatile__("ldstub	[%1], %0"
+						 : "=r" (ret)
+						 : "r" (p)
+						 : "memory");
+
+	return (ret ? 1 : 0);
+}
+#endif
+
+#ifdef __arm__
+#define HAVE_TEST_AND_SET 1
+static inline int testandset(int *p)
+{
+	register unsigned int ret;
+	__asm__ __volatile__("swp %0, %1, [%2]"
+						 : "=r"(ret)
+						 : "0"(1), "r"(p));
+	
+	return ret;
+}
+#endif
+
+#endif /* __GNUC__ */
+
+#if HAVE_TEST_AND_SET
+#define HAVE_SPINLOCKS 1
+typedef int spinlock_t;
+
+const spinlock_t SPIN_LOCK_UNLOCKED = 0;
+
+static inline void spin_lock(spinlock_t *lock)
+{
+	while (testandset(lock));
+}
+
+static inline void spin_unlock(spinlock_t *lock)
+{
+	*lock = 0;
+}
+
+static inline int spin_trylock(spinlock_t *lock)
+{
+	return !testandset(lock);
+}
+#endif
+
 // Time data type for Time Manager emulation
 #ifdef HAVE_CLOCK_GETTIME
 typedef struct timespec tm_time_t;