Are any of these useful?

ATOMIC(3)                BSD Library Functions Manual                ATOMIC(3)

NAME
     OSAtomicAdd32, OSAtomicAdd32Barrier, OSAtomicIncrement32, OSAtomicIncrement32Barrier, OSAtomicDecrement32, OSAtomicDecrement32Barrier,
     OSAtomicOr32, OSAtomicOr32Barrier, OSAtomicOr32Orig, OSAtomicOr32OrigBarrier, OSAtomicAnd32, OSAtomicAnd32Barrier, OSAtomicAnd32Orig,
     OSAtomicAnd32OrigBarrier, OSAtomicXor32, OSAtomicXor32Barrier, OSAtomicXor32Orig, OSAtomicXor32OrigBarrier, OSAtomicAdd64,
     OSAtomicAdd64Barrier, OSAtomicIncrement64, OSAtomicIncrement64Barrier, OSAtomicDecrement64, OSAtomicDecrement64Barrier,
     OSAtomicCompareAndSwapInt, OSAtomicCompareAndSwapIntBarrier, OSAtomicCompareAndSwapLong, OSAtomicCompareAndSwapLongBarrier,
     OSAtomicCompareAndSwapPtr, OSAtomicCompareAndSwapPtrBarrier, OSAtomicCompareAndSwap32, OSAtomicCompareAndSwap32Barrier,
     OSAtomicCompareAndSwap64, OSAtomicCompareAndSwap64Barrier, OSAtomicTestAndSet, OSAtomicTestAndSetBarrier, OSAtomicTestAndClear,
     OSAtomicTestAndClearBarrier, OSSpinLockTry, OSSpinLockLock, OSSpinLockUnlock, OSAtomicEnqueue, OSAtomicDequeue -- atomic add, increment,
     decrement, or, and, xor, compare and swap, test and set, test and clear, spinlocks, and lockless queues
