WorkerThread包装类
WorkerThread类是围绕基本.NET线程类的一个高层包装类。WorkerThread类定义为：
public class WorkerThread : IDisposable {
public WorkerThread();
public WorkerThread(bool autoStart);
public int ManagedThreadId {get;}
public Thread Thread {get;}
public WaritHandle Handle {get;}
public void Start();
public void Dispose();
public void Kill();
public void Join();
public bool Join(int millisecondsTimeout);
public bool Join(TimeSpan timeout);
public string Name {get;set;}
public bool IsAlive {get;}
public void Dispose();
}
WorkerThread提供了简单的线程创建和其他特性，包括终止线程的Kill()方法(而不是使用Abort())。Thread类中的一些有潜在危险的方法没包含在WorkerThread的接口中，但是好的方法仍然保留了下来。WorkerThread还强调我们已经讨论过的关于使用.NET线程的最佳实践。下面的示例说明了WorkerThread的执行。由于Thread类是sealed的，在定义WorkerThread时，必须使用包含(containment)而不是派生。WorkerThread拥有Thread类型的m_ThreadObj成员变量，代表了低层的被包装的线程。如果想要进行直接线程操作，可以通过WorkerThread的Thread属性访问底层线程。
WorkerThread包装类
public class WorkerThread : IDisposable {
ManualResetEvent m_ThreadHandle;
Thread m_ThreadObj;
bool m_EndLoop;
Mutext m_EndLoopMutex;
public override int GetHashCode() {
return m_ThreadObj.GetHashCode();
}
public override bool Equals(object obj) {
return m_ThreadObj.Equals(obj);
}
public int ManagedThreadId {
get {
return m_ThreadObj.ManagedThreadId;
}
}
public Thread Thread {
get {
return m_ThreadObj;
}
}
protected bool EndLoop {
set {
m_EndLoopMutex.WaitOne();
m_EndLoop = value;
m_EndLoopMutex.ReleaseMutex();
}
get {
bool result = false;
m_EndLoopMutex.WaitOne();
result = m_EndLoop;
m_EndLoopMutex.ReleaseMutex();
return result;
}
}
public WokerThread() {
m_EndLoop = false;
m_ThreadObj = null;
m_EndLoopMutex = new Mutex();
m_ThreadHandle = new ManualResetEvent(false);
m_ThreadObj = new Thread(Run);
Name = "Worker Thread";
}
public WorkerThread(bool autoStart) : this() {
if(autoStart) {
Start();
}
}
public WaitHandle Handle {
get {
return m_ThreadHandle;
}
}
public void Start() {
Debug.Assert(m_ThreadObj != null);
Debug.Assert(m_ThreadObj.IsAlive == false);
m_ThreadObj.Start();
}
public void Dispose() {
Kill();
}
void Run() {
try {
int i = 0;
while(EndLoop == false) {
Trace.WriteLine("Thread is alive, Counter is "+i);
i++;
}
}
finally {
m_ThreadHandle.Set();
}
}
public void Kill() {
//Kill()在客户线程那里被调用，必须使用缓存的Thread对象
Debug.Assert(m_ThreadObj != null);
if(IsAlive == false) {
return;
}
EndLoop = true;
//等待线程死亡
Join();
m_EndLoopMutex.Close();
m_ThreadHandle.Close();
}
public void Join() {
Join(Timeout.Infinite);
}
public bool Join(int millisecondsTimeout) {
TimeSpan timeout =
TimeSpan.FromMilliseconds(millisecondsTimeout);
return Join(timeout);
}
public bool Join(TimeSpan timeout) {
//Join()在客户线程被调用，必须使用缓存的Thread对象
Debug.Assert(m_ThreadObj != null);
if(IsAlive == false) {
return true;
}
Debug.Assert(Thread.CurrentThread.ManagedThreadIsd !=
m_ThreadObj.ManagedThreadId);
return m_ThreadObj.Join(timeout);
}
public string Name {
get {
return m_ThreadObj.Name;
}
set {
m_ThreadObj.Name = value;
}
}
public bool IsAlive {
get {
Debug.Assert(m_ThreadObj != null);
bool handleSignaled = m_ThreadHandle.WaitOne(0,true);
while(handleSignaled == m_ThreadObj.IsAlive) {
Thread.Sleep(0);
}
return m_ThreadObj.IsAlive;
}
}
}
