private long slowPathWriteAcquire(final long wrapPoint) {
      final long currHead = lvConsumerIndex(); // LoadLoad
      if (currHead <= wrapPoint) {
         return EOF; // FULL :(
      }
      else {
         // update cached value of the consumerIndex
         spConsumerIndexCache(currHead);
         return currHead;
      }
   }
This is to be used for an IPC queue with the direct buffer used being a memory mapped file.

@param buff
@param capacity
jctools-channels/src/main/java/org/jctools/channels/mpsc/MpscFFLamportOffHeapFixedSizeRingBuffer.java