In one embodiment, {HEAD ~ a peek operation} may be used as {TAIL ~ a mechanism} to see if any message has arrived in the pipes queue 
used as
In one embodiment , { HEAD ~ a peek operation } may be used as { TAIL ~ a mechanism } to see if any message has arrived in the pipes queue
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH