多线程计算：ThreadPool:Set and Reset

using System;
using System.Threading;
class CalculateTest
{
static void Main()
{
Calculate calc = new Calculate();
Console.WriteLine("Result = {0}.",
calc.Result(55).ToString());
Console.WriteLine("Result = {0}.",
calc.Result(34).ToString());
Console.ReadKey();
}
}
class Calculate
{
double baseNumber, firstTerm, secondTerm, thirdTerm;
AutoResetEvent[] autoEvents;
ManualResetEvent manualEvent;
Random randomGenerator;
public Calculate()
{
autoEvents = new AutoResetEvent[]
{
new AutoResetEvent(false),
new AutoResetEvent(false),
new AutoResetEvent(false)
};
manualEvent = new ManualResetEvent(false);
}
void CalculateBase(object stateInfo)
{
baseNumber = randomGenerator.NextDouble();
manualEvent.Set();
}

void CalculateFirstTerm(object stateInfo)
{
double preCalc = randomGenerator.NextDouble();
manualEvent.WaitOne();
firstTerm = preCalc * baseNumber *
randomGenerator.NextDouble();
autoEvents[0].Set();
}
void CalculateSecondTerm(object stateInfo)
{
double preCalc = randomGenerator.NextDouble();
manualEvent.WaitOne();
secondTerm = preCalc * baseNumber *
randomGenerator.NextDouble();
autoEvents[1].Set();
}
void CalculateThirdTerm(object stateInfo)
{
double preCalc = randomGenerator.NextDouble();
manualEvent.WaitOne();
thirdTerm = preCalc * baseNumber *
randomGenerator.NextDouble();
autoEvents[2].Set();
}
public double Result(int seed)
{
randomGenerator = new Random(seed);

ThreadPool.QueueUserWorkItem(
new WaitCallback(CalculateBase));
ThreadPool.QueueUserWorkItem(
new WaitCallback(CalculateFirstTerm));
ThreadPool.QueueUserWorkItem(
new WaitCallback(CalculateSecondTerm));
ThreadPool.QueueUserWorkItem(
new WaitCallback(CalculateThirdTerm));
WaitHandle.WaitAll(autoEvents);
manualEvent.Reset();
return firstTerm + secondTerm + thirdTerm;
}
}