实验后的结果表明并行计算的最终效果还是比较明显的，更主要是非常简单。

用计算PI的结果来做实验，算法来自：http://en.wikipedia.org/wiki/Pi

贴一下:)

先用传统的算法、多线程、然后用并行算法。比较结果如下(环境：CPU(双核 T5600 1.83G*2) + 2.5G内存 + WinXPsp2)：

让人意外的结果，基本上并行没有带来什么性能提升。

以下的结果是在另一机器上测得(CPU E8400：双核 3.0G*2 + 2G内存 + win2003Server)

上两张图的明显不同是：CPU的的第一次处理曲线。在2003Server的机器上两个核基本上负担相同。

(是不是在2003SERVER下，已经有过处理均衡优化了？!)

先不管并行有没有带来什么提升性能，2010中的并行处理的确太简单了，只要有多线程的编程经验就足够

下面贴代码(有问题请大家指出来)

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class CPICacu
{
const int iTruncatedNum = 100;
const int m_iCacuTimes = 5000000;
byte[] m_bytaryResult1 = new byte[iTruncatedNum];
byte[] m_bytaryResult2 = new byte[iTruncatedNum];
bool m_bFinish1 = false;
bool m_bFinish2 = false;
void Cacu1()
{
byte[] bytaryTmp = new byte[iTruncatedNum];
int iTopValue = 4;
int iBaseValue = 1;
for (int i = 0; i < m_iCacuTimes; i += 2)
{
iTopValue = 4;
int j = 0;
//计算一个分式
for (; j = iBaseValue)
{
bytaryTmp[j] += 1;
iTopValue -= iBaseValue;
}
iTopValue *= 10;
}
//把计算出来的值相加
int iNeedIncrease = 0;
for (j = iTruncatedNum - 1; j >= 0; --j)
{
iTopValue = m_bytaryResult1[j] + bytaryTmp[j] + iNeedIncrease;
System.Diagnostics.Debug.Assert(iTopValue 9)
{
m_bytaryResult1[j] = Convert.ToByte(iTopValue % 10);
iNeedIncrease = (iTopValue - m_bytaryResult1[j]) - 9;
}
else
{
m_bytaryResult1[j] = Convert.ToByte(iTopValue);
iNeedIncrease = 0;
}
}
iBaseValue += 2 + 2;
}
m_bFinish1 = true;
}
void Cacu2()
{
byte[] bytaryTmp = new byte[iTruncatedNum];
int iTopValue = 4;
int iBaseValue = 1+2;
for (int i = 0; i < m_iCacuTimes; i += 2)
{
iTopValue = 4;
int j = 0;
//计算一个分式
for (; j = iBaseValue)
{
bytaryTmp[j] += 1;
iTopValue -= iBaseValue;
}
iTopValue *= 10;
}
//把计算出来的值相加
int iNeedIncrease = 0;
for (j = iTruncatedNum - 1; j >= 0; --j)
{
iTopValue = m_bytaryResult2[j] + bytaryTmp[j] + iNeedIncrease;
System.Diagnostics.Debug.Assert(iTopValue 9)
{
m_bytaryResult2[j] = Convert.ToByte(iTopValue % 10);
iNeedIncrease = (iTopValue - m_bytaryResult2[j]) - 9;
}
else
{
m_bytaryResult2[j] = Convert.ToByte(iTopValue);
iNeedIncrease = 0;
}
}
iBaseValue += 2 + 2;
}
m_bFinish2 = true;
}
public void Cacu()
{
System.Action[] aryAction = new Action[]{ this.Cacu1,this.Cacu2};
System.Threading.Parallel.Invoke(aryAction);
//sub the two arrary
Program.SubArray(m_bytaryResult1, m_bytaryResult2);
for (int i = 0; i < iTruncatedNum; ++i)
System.Console.Write(m_bytaryResult1[i]);
}
public void CacuByThread()
{
System.Threading.Thread thd0 = new System.Threading.Thread(new System.Threading.ThreadStart(Cacu1));
System.Threading.Thread thd1 = new System.Threading.Thread(new System.Threading.ThreadStart(Cacu2));
thd0.Start();
thd1.Start();
m_bFinish1 = m_bFinish2 = false;
while (m_bFinish1 != true || m_bFinish2 != true) System.Threading.Thread.Sleep(1);
//sub the two arrary
Program.SubArray(m_bytaryResult1, m_bytaryResult2);
for (int i = 0; i = 0; --j)
{
iTmp = bytaryOne[j] - bytaryTwo[j] + iNeedIncrease;
System.Diagnostics.Debug.Assert(iTmp >= -10);
if (iTmp = 0);
iNeedIncrease = -1;
}
else
{
iNeedIncrease = 0;
}
bytaryOne[j] = Convert.ToByte(iTmp);
}
}
public static void CacuPITrid()
{
int iTruncatedNum = 100;
byte[] bytaryResult = new byte[iTruncatedNum];
byte[] bytaryTmp = new byte[iTruncatedNum];
int iTopValue = 4;
int iBaseValue = 1;
bool bAdd = true;
for (int i = 0; i < 5000000; ++i)
{
iTopValue = 4;
int j = 0;
//计算一个分式
for (; j = iBaseValue)
{
bytaryTmp[j] += 1;
iTopValue -= iBaseValue;
}
iTopValue *= 10;
}
//把计算出来的值相加
int iNeedIncrease = 0;
if (bAdd)
{
for (j = iTruncatedNum - 1; j >= 0; --j)
{
iTopValue = bytaryResult[j] + bytaryTmp[j] + iNeedIncrease;
System.Diagnostics.Debug.Assert(iTopValue 9)
{
bytaryResult[j] = Convert.ToByte(iTopValue % 10);
iNeedIncrease = (iTopValue - bytaryResult[j]) - 9;
}
else
{
bytaryResult[j] = Convert.ToByte(iTopValue);
iNeedIncrease = 0;
}
}
}
else
{
for (j = iTruncatedNum - 1; j >= 0; --j)
{
iTopValue = bytaryResult[j] - bytaryTmp[j] + iNeedIncrease;
System.Diagnostics.Debug.Assert(iTopValue >= -10);
if (iTopValue = 0);
iNeedIncrease = -1;
}
else
{
iNeedIncrease = 0;
}
bytaryResult[j] = Convert.ToByte(iTopValue);
}
}
iBaseValue += 2;
bAdd = !bAdd;
}
for (int i = 0; i < iTruncatedNum; ++i)
System.Console.Write(bytaryResult[i]);
}

static void Main(string[] args)
{
System.Console.WriteLine("Traditional algorithm...\n");
DateTime dteStart = DateTime.Now;
CacuPITrid();
TimeSpan ts = DateTime.Now - dteStart;
System.Console.WriteLine("\nTotal used:" + ts.ToString());
System.Console.WriteLine("\nMulti-Thread algorithm...\n");
dteStart = DateTime.Now;
CPICacu parrallelPICacu = new CPICacu();
parrallelPICacu.CacuByThread();
ts = DateTime.Now - dteStart;
System.Console.WriteLine("\nTotal used:" + ts.ToString());
System.Console.WriteLine("\nParallel algorithm...\n");
dteStart = DateTime.Now;
CPICacu parrallelPICacu1 = new CPICacu();
parrallelPICacu1.Cacu();
ts = DateTime.Now - dteStart;
System.Console.WriteLine("\nTotal used:" + ts.ToString());
System.Console.Read();
}
}