Barrier 是一个对象，它可以在并行操作中的所有任务都达到相应的关卡之前，阻止各个任务继续执行。 如果并行操作是分阶段执行的，并且每一阶段要求各任务之间进行同步，则可以使用该对象。 ——MSDN
按照我的理解Barrier其实就是将多个任务同步，而同步需要一个屏障或者是关卡，那么其方法SignalAndWait()就是屏障的作用；
我们来模拟现实中例子，做火车就是很好的参照，大家知道，火车的车次有个发车点，到了那个时间点才能发车，那我们稍微修改下，人到齐后才能发车。
1.首先从家出发，在路上实现：
PRivatestaticvoidOnRoading(stringname,intcostTime)
{
Console.WriteLine(string.Format("[{0}]在去火车站路上.....,花费{1}小时.", name, costTime));
Thread.Sleep(newTimeSpan(0, 0, costTime));
}
2.达到火车站，等候火车，这相当于同步任务，（所模拟的是，乘火车到人到齐后才能发车）
privatestaticvoidOnStationing(stringname)
{
Console.WriteLine(string.Format("[{0}]到达火车站，正在安检等候火车.....", name));gate.SignalAndWait();}
.csharpcode, .csharpcode pre
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.csharpcode .rem { color: #008000; }
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.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp{ background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
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.csharpcode .lnum { color: #606060; }3.人到齐后，发车
privatestaticvoidOnTraining(stringname)
{
Console.WriteLine(string.Format("[{0}]乘坐火车离开.....", name));
}
完整代码实现
staticBarrier gate;staticvoidMain(string[] args)
{try{
ToStationWorkTyp2();
}catch(Exception ex)
{
Console.WriteLine(string.Format("Exception Message:{0}", ex.Message.Trim()));
}finally{
Console.ReadLine();
}
}privatestaticvoidToStationWorkTyp2()
{
gate =newBarrier(3);
Task _taskA = Task.Factory.StartNew(() =>
{
OnRoading("personA", 2);
OnStationing("personA");
OnTraining("personA");
});
Task _taskB = Task.Factory.StartNew(() =>
{
OnRoading("personB", 5);
OnStationing("personB");
OnTraining("personB");
});
Task _taskC = Task.Factory.StartNew(() =>
{
OnRoading("personC", 3);
OnStationing("personC");
OnTraining("personC");
});
Task.WaitAll(_taskA, _taskB, _taskC);
}privatestaticvoidOnTraining(stringname)
{
Console.WriteLine(string.Format("[{0}]乘坐火车离开.....", name));
}privatestaticvoidOnStationing(stringname)
{
Console.WriteLine(string.Format("[{0}]到达火车站，正在安检等候火车.....", name));
gate.SignalAndWait();
}privatestaticvoidOnRoading(stringname,intcostTime)
{
Console.WriteLine(string.Format("[{0}]在去火车站路上.....,花费{1}小时.", name, costTime));
Thread.Sleep(newTimeSpan(0, 0, costTime));
}
.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }代码效果
另外一种代码实现
usingSystem;usingSystem.Collections;usingSystem.Collections.Generic;usingSystem.Diagnostics;usingSystem.Linq;usingSystem.Threading;usingSystem.Threading.Tasks;namespacePLinq
{classProgram
{staticBarrier gate;staticvoidMain(string[] args)
{try{
ToStationWorkTyp1();
}catch(Exception ex)
{
Console.WriteLine(string.Format("Exception Message:{0}", ex.Message.Trim()));
}finally{
Console.ReadLine();
}
}privatestaticvoidToStationWorkTyp1()
{
gate =newBarrier(3);
Task _taskA = Task.Factory.StartNew(() => ToStation("PersonA", 2));
Task _taskB = Task.Factory.StartNew(() => ToStation("PersonB", 3));
Task _taskC = Task.Factory.StartNew(() => ToStation("PersonC", 5));
Task.WaitAll(_taskA, _taskB, _taskC);
}privatestaticvoidToStation(stringname,intcostTime)
{
Console.WriteLine(string.Format("[{0}]在去火车站路上.....,花费{1}小时.", name, costTime));
Thread.Sleep(newTimeSpan(0, 0, costTime));
Console.WriteLine(string.Format("[{0}]到达火车站，正在安检等候火车.....", name));
gate.SignalAndWait();
Console.WriteLine(string.Format("[{0}]乘坐火车离开.....", name));
}
}
}
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font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }同样的实现效果