internal Nack(Nack next, int i0)
{
this.State = Running;
this.Next = next;
this.I0 = i0;
this.I1 = Int32.MaxValue;
}
internal static Nack AddNack(Pick pk, int i0)
{
TryClaim:
var state = pk.State;
if (state > 0)
{
goto AlreadyPicked;
}
if (state < 0)
{
goto TryClaim;
}
if (0 != Interlocked.CompareExchange(ref pk.State, ~state, state))
{
goto TryClaim;
}
var nk = new Nack(pk.Nacks, i0);
pk.Nacks = nk;
return(nk); // Leaves the pick claimed on purpose!
AlreadyPicked:
return(null);
}
internal static void SetNacks(ref Worker wr, int i, Pick pk)
{
Nack nk = pk.Nacks;
if (null != nk)
{
SetNacks(ref wr, i, nk);
}
}
private static void SetNacks(ref Worker wr, int i, Nack nk)
{
do
{
if (i < nk.I0 || nk.I1 <= i)
{
Nack.Signal(ref wr, nk);
}
nk = nk.Next;
} while (null != nk);
}
internal static void Signal(ref Worker wr, Nack nk)
{
Spin:
var state = nk.State;
if (state < Delayed)
{
goto Spin;
}
if (Running != Interlocked.CompareExchange(ref nk.State, state + 1, state))
{
goto Spin;
}
WaitQueue.PickReaders(ref nk.Readers, null, ref wr);
}
public static Nack AddNack(Pick pk, int i0)
{
TryClaim:
var st = TryClaim(pk);
if (st > 0)
{
goto AlreadyPicked;
}
if (st < 0)
{
goto TryClaim;
}
var nk = new Nack(pk.Nacks, i0);
pk.Nacks = nk;
Unclaim(pk);
return(nk);
AlreadyPicked:
return(null);
}
internal static void Signal(ref Worker wr, Nack nk)
{
Spin:
var state = nk.State;
if (state > Initial)
{
goto JustExit; // XXX Can this happen?
}
if (state < Initial)
{
goto Spin;
}
if (Initial != Interlocked.CompareExchange(ref nk.State, state + 1, state))
{
goto Spin;
}
var takers = nk.Takers;
if (null == takers)
{
goto JustExit;
}
nk.Takers = null;
var me = 0;
Work cursor = takers;
TryTaker:
var taker = cursor as Cont <Unit>;
cursor = cursor.Next;
var pk = taker.GetPick(ref me);
if (null == pk)
{
goto GotTaker;
}
TryPick:
var st = Pick.TryPick(pk);
if (st > 0)
{
goto TryNextTaker;
}
if (st < 0)
{
goto TryPick;
}
Pick.SetNacks(ref wr, me, pk);
GotTaker:
Worker.Push(ref wr, taker);
TryNextTaker:
if (cursor != takers)
{
goto TryTaker;
}
JustExit:
return;
}