--- /dev/null
+++ Libc/Libc-391.2.9/include/libkern/OSAtomic.h
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#ifndef _OSATOMIC_H_
+#define _OSATOMIC_H_
+
+#include    <stddef.h>
+#include    <sys/cdefs.h>
+#include    <stdint.h>
+#include    <stdbool.h>
+
+/* These are the preferred versions of the atomic and synchronization operations.
+ * Their implementation is customized at boot time for the platform, including
+ * late-breaking errata fixes as necessary.   They are thread safe.
+ *
+ * WARNING: all addresses passed to these functions must be "naturally aligned", ie
+ * int32_t's must be 32-bit aligned (low 2 bits of address zero), and int64_t's
+ * must be 64-bit aligned (low 3 bits of address zero.)
+ *
+ * Note that some versions of the atomic functions incorporate memory barriers,
+ * and some do not.  Barriers strictly order memory access on a weakly-ordered
+ * architecture such as PPC.  All loads and stores executed in sequential program
+ * order before the barrier will complete before any load or store executed after
+ * the barrier.  On a uniprocessor, the barrier operation is typically a nop.
+ * On a multiprocessor, the barrier can be quite expensive.
+ *
+ * Most code will want to use the barrier functions to insure that memory shared
+ * between threads is properly synchronized.  For example, if you want to initialize
+ * a shared data structure and then atomically increment a variable to indicate
+ * that the initialization is complete, then you MUST use OSAtomicIncrement32Barrier()
+ * to ensure that the stores to your data structure complete before the atomic add.
+ * Likewise, the consumer of that data structure MUST use OSAtomicDecrement32Barrier(),
+ * in order to ensure that their loads of the structure are not executed before
+ * the atomic decrement.  On the other hand, if you are simply incrementing a global
+ * counter, then it is safe and potentially faster to use OSAtomicIncrement32().
+ *
+ * If you are unsure which version to use, prefer the barrier variants as they are
+ * safer.
+ *
+ * The spinlock and queue operations always incorporate a barrier.
+ */ 
+__BEGIN_DECLS
+
+
+/* Arithmetic functions.  They return the new value.  All the "or", "and", and "xor"
+ * operations, and the barrier forms of add, are layered on top of compare-and-swap.
+ */
+int32_t	OSAtomicAdd32( int32_t theAmount, int32_t *theValue );
+int32_t	OSAtomicAdd32Barrier( int32_t theAmount, int32_t *theValue );
+
+inline static
+int32_t	OSAtomicIncrement32( int32_t *theValue )
+            { return OSAtomicAdd32(  1, theValue); }
+inline static
+int32_t	OSAtomicIncrement32Barrier( int32_t *theValue )
+            { return OSAtomicAdd32Barrier(  1, theValue); }
+
+inline static
+int32_t	OSAtomicDecrement32( int32_t *theValue )
+            { return OSAtomicAdd32( -1, theValue); }
+inline static
+int32_t	OSAtomicDecrement32Barrier( int32_t *theValue )
+            { return OSAtomicAdd32Barrier( -1, theValue); }
+
+int32_t	OSAtomicOr32( uint32_t theMask, uint32_t *theValue );
+int32_t	OSAtomicOr32Barrier( uint32_t theMask, uint32_t *theValue );
+
+int32_t	OSAtomicAnd32( uint32_t theMask, uint32_t *theValue ); 
+int32_t	OSAtomicAnd32Barrier( uint32_t theMask, uint32_t *theValue ); 
+
+int32_t	OSAtomicXor32( uint32_t theMask, uint32_t *theValue );
+int32_t	OSAtomicXor32Barrier( uint32_t theMask, uint32_t *theValue );
+
+#if defined(__ppc64__) || defined(__i386__)
+
+int64_t	OSAtomicAdd64( int64_t theAmount, int64_t *theValue );
+int64_t	OSAtomicAdd64Barrier( int64_t theAmount, int64_t *theValue );
+
+inline static
+int64_t	OSAtomicIncrement64( int64_t *theValue )
+            { return OSAtomicAdd64(  1, theValue); }
+inline static
+int64_t	OSAtomicIncrement64Barrier( int64_t *theValue )
+            { return OSAtomicAdd64Barrier(  1, theValue); }
+
+inline static
+int64_t	OSAtomicDecrement64( int64_t *theValue )
+            { return OSAtomicAdd64( -1, theValue); }
+inline static
+int64_t	OSAtomicDecrement64Barrier( int64_t *theValue )
+            { return OSAtomicAdd64Barrier( -1, theValue); }
+
+#endif  /* defined(__ppc64__) || defined(__i386__) */
+
+
+/* Compare and swap.  They return true if the swap occured.
+ */
+bool    OSAtomicCompareAndSwap32( int32_t oldValue, int32_t newValue, int32_t *theValue );
+bool    OSAtomicCompareAndSwap32Barrier( int32_t oldValue, int32_t newValue, int32_t *theValue );
+
+#if defined(__ppc64__) || defined(__i386__)
+
+bool    OSAtomicCompareAndSwap64( int64_t oldValue, int64_t newValue, int64_t *theValue );
+bool    OSAtomicCompareAndSwap64Barrier( int64_t oldValue, int64_t newValue, int64_t *theValue );
+
+#endif  /* defined(__ppc64__) || defined(__i386__) */
+
+
+/* Test and set.  They return the original value of the bit, and operate on bit (0x80>>(n&7))
+ * in byte ((char*)theAddress + (n>>3)).  They are layered on top of the compare-and-swap
+ * operation.
+ */
+bool    OSAtomicTestAndSet( uint32_t n, void *theAddress );
+bool    OSAtomicTestAndSetBarrier( uint32_t n, void *theAddress );
+bool    OSAtomicTestAndClear( uint32_t n, void *theAddress );
+bool    OSAtomicTestAndClearBarrier( uint32_t n, void *theAddress );
+ 
+/* Spinlocks.  These use memory barriers as required to synchronize access to shared
+ * memory protected by the lock.  The lock operation spins, but employs various strategies
+ * to back off if the lock is held, making it immune to most priority-inversion livelocks.
+ * The try operation immediately returns false if the lock was held, true if it took the
+ * lock.  The convention is that unlocked is zero, locked is nonzero.
+ */
+#define	OS_SPINLOCK_INIT    0
+
+typedef	int32_t OSSpinLock;
+
+bool    OSSpinLockTry( OSSpinLock *lock );
+void    OSSpinLockLock( OSSpinLock *lock );
+void    OSSpinLockUnlock( OSSpinLock *lock );
+
+
+/* Memory barrier.  It is both a read and write barrier.
+ */
+void    OSMemoryBarrier( void );
+
+__END_DECLS
+
+#endif /* _OSATOMIC_H_ */