// Returns true if low, high, or current has changed
private Boolean SetValues(Boolean lockAlreadyTaken, Int64? low, Int64? high, Int64? current) {
if (!lockAlreadyTaken) m_lock.Enter(true);
try {
// If any value is null, set it to its current value (assume no change)
low = low.GetValueOrDefault(m_low);
high = high.GetValueOrDefault(m_high);
current = current.GetValueOrDefault(m_current);
if (low > high) throw new InvalidOperationException("Low can't be greater than high");
Int64 oldLow = m_low, oldHigh = m_high, oldCurrent = m_current;
m_low = low.Value;
m_high = high.Value;
// Make sure Current stays between Low and High inclusive
if (current < m_low) current = m_low;
if (current > m_high) current = m_high;
m_current = current.Value;
return (oldLow != m_low) || (oldHigh != m_high) || (oldCurrent != m_current);
}
finally {
if (!lockAlreadyTaken) m_lock.Leave();
}
}