no request yet
me running
curr running
me spinning
me running
new
List for each lock
q node{
go-it;// T/F
next;
}
Lock(L,me)
* join L; //atomic
* await predecessor to signal; //spin
unlock(L, me)
* remove me from L;
* signal successor;
Barrier Synchronization
t1, t2, … Tn
Count = N;//init
Decrement(count);
if (count == 0)
count = N;
else
while(count > 0);
* spin by all excepiton
Communications
Tree barrier
Count locksense: arrival at the barrier
