/// <summary>
/// Updates with the given value.
/// </summary>
/// <param name="x"> the value </param>
public virtual void Accumulate(double x)
{
Cell[] @as;
long b, v, r;
int m;
Cell a;
if ((@as = Cells) != null || (r = Double.doubleToRawLongBits(Function.ApplyAsDouble(Double.longBitsToDouble(b = @base), x))) != b && !CasBase(b, r))
{
bool uncontended = true;
if (@as == null || (m = @as.Length - 1) < 0 || (a = @as[Probe & m]) == null || !(uncontended = (r = Double.doubleToRawLongBits(Function.ApplyAsDouble(Double.longBitsToDouble(v = a.Value), x))) == v || a.Cas(v, r)))
{
DoubleAccumulate(x, Function, uncontended);
}
}
}
/// <summary>
/// Same as longAccumulate, but injecting long/double conversions
/// in too many places to sensibly merge with long version, given
/// the low-overhead requirements of this class. So must instead be
/// maintained by copy/paste/adapt.
/// </summary>
internal void DoubleAccumulate(double x, DoubleBinaryOperator fn, bool wasUncontended)
{
int h;
if ((h = Probe) == 0)
{
ThreadLocalRandom.Current(); // force initialization
h = Probe;
wasUncontended = true;
}
bool collide = false; // True if last slot nonempty
for (;;)
{
Cell[] @as;
Cell a;
int n;
long v;
if ((@as = Cells) != null && (n = @as.Length) > 0)
{
if ((a = @as[(n - 1) & h]) == null)
{
if (CellsBusy == 0) // Try to attach new Cell
{
Cell r = new Cell(Double.doubleToRawLongBits(x));
if (CellsBusy == 0 && CasCellsBusy())
{
bool created = false;
try // Recheck under lock
{
Cell[] rs;
int m, j;
if ((rs = Cells) != null && (m = rs.Length) > 0 && rs[j = (m - 1) & h] == null)
{
rs[j] = r;
created = true;
}
}
finally
{
CellsBusy = 0;
}
if (created)
{
break;
}
continue; // Slot is now non-empty
}
}
collide = false;
}
else if (!wasUncontended) // CAS already known to fail
{
wasUncontended = true; // Continue after rehash
}
else if (a.Cas(v = a.Value, ((fn == null) ? Double.doubleToRawLongBits(Double.longBitsToDouble(v) + x) : Double.doubleToRawLongBits(fn.ApplyAsDouble(Double.longBitsToDouble(v), x)))))
{
break;
}
else if (n >= NCPU || Cells != @as)
{
collide = false; // At max size or stale
}
else if (!collide)
{
collide = true;
}
else if (CellsBusy == 0 && CasCellsBusy())
{
try
{
if (Cells == @as) // Expand table unless stale
{
Cell[] rs = new Cell[n << 1];
for (int i = 0; i < n; ++i)
{
rs[i] = @as[i];
}
Cells = rs;
}
}
finally
{
CellsBusy = 0;
}
collide = false;
continue; // Retry with expanded table
}
h = AdvanceProbe(h);
}
else if (CellsBusy == 0 && Cells == @as && CasCellsBusy())
{
bool init = false;
try // Initialize table
{
if (Cells == @as)
{
Cell[] rs = new Cell[2];
rs[h & 1] = new Cell(Double.doubleToRawLongBits(x));
Cells = rs;
init = true;
}
}
finally
{
CellsBusy = 0;
}
if (init)
{
break;
}
}
else if (CasBase(v = @base, ((fn == null) ? Double.doubleToRawLongBits(Double.longBitsToDouble(v) + x) : Double.doubleToRawLongBits(fn.ApplyAsDouble(Double.longBitsToDouble(v), x)))))
{
break; // Fall back on using base
}
}
}
