/* a reconstruction event descriptor. The event types currently are:
* RF_REVENT_READDONE -- a read operation has completed
* RF_REVENT_WRITEDONE -- a write operation has completed
* RF_REVENT_BUFREADY -- the buffer manager has produced a full buffer
* RF_REVENT_BLOCKCLEAR -- a reconstruction blockage has been cleared
* RF_REVENT_BUFCLEAR -- the buffer manager has released a process blocked on submission
* RF_REVENT_SKIP -- we need to skip the current RU and go on to the next one, typ. b/c we found recon forced
* RF_REVENT_FORCEDREADONE- a forced-reconstructoin read operation has completed
*/