class Fibonacci
{
//share
public static int [] item; //read from it
public static int[] result; //write into it
//instance
public int N { get { return _n; } }
public int _start, _end;
private int _n;
public int FibOfN { get { return _fibOfN; } }
private int _fibOfN;
private ManualResetEvent _doneEvent;
public Fibonacci(int start, int end, ManualResetEvent doneEvent)
{
_start = start;
_end = end;
_doneEvent = doneEvent;
}
public Fibonacci(int start, int end)
{
_start = start;
_end = end;
}
// Wrapper method for use with thread pool.
public void ThreadPoolCallback(Object threadContext)
{
int threadIndex = (int)threadContext;
Calculate();
_doneEvent.Set();
}
// Recursive method that calculates the Nth Fibonacci number.
public void Calculate()
{
for (int i = _start; i < _end; i++)
{
int d = item[i];
for (int j = 0; j < 10000; j++) //注意，这里设置大值使单个线程对单个共享数据的运算时间较大
d += 0;
lock(this) //在本程序中可以不加，因为没有互斥
result[i] = d;
}
}
}
class TestThreading
{
public static void test()
{
Fibonacci.item = new int[10000];
Fibonacci.result = new int[10000];
for (int i = 0; i < 10000; i++)
{
Fibonacci.item[i] = i + 1;
}
Stopwatch watch = new Stopwatch();
watch.Start();
Fibonacci f = new Fibonacci(0, 10000);
f.Calculate();
watch.Stop();
Console.WriteLine("Time no thrading takes " + watch.Elapsed);
Console.ReadLine();
for (int i = 0; i < 10000; i++)
{
Console.Write(Fibonacci.result[i] + " ");
}
Console.ReadLine();
//thread 5
watch = new Stopwatch();
watch.Start();
Fibonacci[] fibarray = new Fibonacci[5];
ManualResetEvent[] doneEvents = new ManualResetEvent[5];
for (int i = 0; i < 5; i++)
{
int start = i * 2000;
int end = (i + 1) * 2000;
doneEvents[i] = new ManualResetEvent(false);
fibarray [i] = new Fibonacci (start ,end ,doneEvents[i]);
ThreadPool.QueueUserWorkItem(fibarray[i].ThreadPoolCallback, i);
}
WaitHandle.WaitAll(doneEvents);
watch.Stop();
Console.WriteLine("Time 5 threads takes " + watch.Elapsed);
Console.ReadLine();
for (int i = 0; i < 10000; i++)
{
Console.Write(Fibonacci.result[i] + " ");
}
Console.ReadLine();