VB.NET并行与分布式编程(6)-线程与内核同步[14]
Imports SystemImports System.ThreadingImports System.DiagnosticsImports System.Diagnostics.ThreadStateModule Module1 Sub Main() Dim mythread1 As Thread Dim mythread2 As Thread Dim mythread3 As Thread '创建线程对象 mythread1 = New Thread(AddressOf mythreadrun) mythread2 = New Thread(AddressOf mythreadrun) mythread3 = New Thread(AddressOf mythreadrun) mythread1.Name = "thread_1" mythread2.Name = "thread_2" mythread3.Name = "thread_3" '设置线程是否允许动态优先级 Console.WriteLine(Now.ToLongTimeString & "线程对象创建完毕,开始执行线程") Dim myprocess As Process = Process.GetCurrentProcess() Console.WriteLine("进程名称:" & myprocess.ProcessName) '执行线程 mythread1.Start(myprocess) mythread2.Start(myprocess) mythread3.Start(myprocess) '等待线程完成 mythread1.Join() mythread2.Join() mythread3.Join() '线程执行完毕 Console.WriteLine(Now.ToLongTimeString & "线程执行完毕!") End Sub Public Sub mythreadrun(ByVal myprocess As Object) Dim mynum As Double Static Dim mymonitorobj As New Object Static Dim jg As Double = 100 Try For mynum = 1 To 10 '隐式获取监视器 SyncLock mymonitorobj jg -= mynum Console.WriteLine(Thread.CurrentThread.Name & "==>" & Now.ToLongTimeString & "=>" & (jg + mynum) & "-" & mynum & "，计算结果为：" & jg) End SyncLock Thread.Sleep(0) Next Catch Console.WriteLine(Thread.CurrentThread.Name & " " & Now.ToLongTimeString & "线程异常终止!") '终止线程 Thread.CurrentThread.Abort() Finally Console.WriteLine(Thread.CurrentThread.Name & "优先级: " & Thread.CurrentThread.Priority.ToString) Console.WriteLine(Thread.CurrentThread.Name & " " & Now.ToLongTimeString & "线程运行完毕!") End Try End SubEnd Module?上面的代码我们使用监视器
1)监视器的定义
? Static Dim mymonitorobj As New Object
2)使用 SyncLock关键字隐式获取监视器,制造互斥的临界域
??????????????? SyncLock mymonitorobj
??????????????????? jg -= mynum
??????????????????? Console.WriteLine(Thread.CurrentThread.Name & "==>" & Now.ToLongTimeString & "=>" & (jg + mynum) & "-" & mynum & "，计算结果为：" & jg)
??????????????? End SyncLock
此外，我们可以直接使用Monitor.enter方法和Monitor.exit方法
?
?Monitor.Enter(mymonitorobj)
??????????????? jg -= mynum
??????????????? Console.WriteLine(Thread.CurrentThread.Name & "==>" & Now.ToLongTimeString & "=>" & (jg + mynum) & "-" & mynum & "，计算结果为：" & jg)
??????????????? Monitor.Exit(mymonitorobj)
?
代码如下
Imports SystemImports System.ThreadingImports System.DiagnosticsImports System.Diagnostics.ThreadStateModule Module1 Sub Main() Dim mythread1 As Thread Dim mythread2 As Thread Dim mythread3 As Thread '创建线程对象 mythread1 = New Thread(AddressOf mythreadrun) mythread2 = New Thread(AddressOf mythreadrun) mythread3 = New Thread(AddressOf mythreadrun) mythread1.Name = "thread_1" mythread2.Name = "thread_2" mythread3.Name = "thread_3" '设置线程是否允许动态优先级 Console.WriteLine(Now.ToLongTimeString & "线程对象创建完毕,开始执行线程") Dim myprocess As Process = Process.GetCurrentProcess() Console.WriteLine("进程名称:" & myprocess.ProcessName) '执行线程 mythread1.Start(myprocess) mythread2.Start(myprocess) mythread3.Start(myprocess) '等待线程完成 mythread1.Join() mythread2.Join() mythread3.Join() '线程执行完毕 Console.WriteLine(Now.ToLongTimeString & "线程执行完毕!") End Sub Public Sub mythreadrun(ByVal myprocess As Object) Dim mynum As Double Static Dim mymonitorobj As New Object Static Dim jg As Double = 100 Try For mynum = 1 To 10 '使用 监视器 Monitor.Enter(mymonitorobj) jg -= mynum Console.WriteLine(Thread.CurrentThread.Name & "==>" & Now.ToLongTimeString & "=>" & (jg + mynum) & "-" & mynum & "，计算结果为：" & jg) Monitor.Exit(mymonitorobj) Thread.Sleep(0) Next Catch Console.WriteLine(Thread.CurrentThread.Name & " " & Now.ToLongTimeString & "线程异常终止!") '终止线程 Thread.CurrentThread.Abort() Finally Console.WriteLine(Thread.CurrentThread.Name & "优先级: " & Thread.CurrentThread.Priority.ToString) Console.WriteLine(Thread.CurrentThread.Name & " " & Now.ToLongTimeString & "线程运行完毕!") End Try End SubEnd Module?上述方法将阻塞等待线程， 我们可以使用TryEnter来避免阻塞，在等待的同时做一些其它工作
?
?
? '使用 监视器，同时为避免阻塞，在等待的过程中做其它工作
??????????????? While Not Monitor.TryEnter(mymonitorobj)
??????????????????? Console.WriteLine(Thread.CurrentThread.Name & "正在等待.....")
??????????????? End While
??????????????? Try
??????????????????? jg -= mynum
??????????????????? Console.WriteLine(Thread.CurrentThread.Name & "==>" & Now.ToLongTimeString & "=>" & (jg + mynum) & "-" & mynum & "，计算结果为：" & jg)
??????????????? Finally
??????????????????? Monitor.Exit(mymonitorobj)
??????????????? End Try
??????????????? Thread.Sleep(0)
?
?
完整代码如下:
Imports SystemImports System.ThreadingImports System.DiagnosticsImports System.Diagnostics.ThreadStateModule Module1 Sub Main() Dim mythread1 As Thread Dim mythread2 As Thread Dim mythread3 As Thread '创建线程对象 mythread1 = New Thread(AddressOf mythreadrun) mythread2 = New Thread(AddressOf mythreadrun) mythread3 = New Thread(AddressOf mythreadrun) mythread1.Name = "thread_1" mythread2.Name = "thread_2" mythread3.Name = "thread_3" '设置线程是否允许动态优先级 Console.WriteLine(Now.ToLongTimeString & "线程对象创建完毕,开始执行线程") Dim myprocess As Process = Process.GetCurrentProcess() Console.WriteLine("进程名称:" & myprocess.ProcessName) '执行线程 mythread1.Start(myprocess) mythread2.Start(myprocess) mythread3.Start(myprocess) '等待线程完成 mythread1.Join() mythread2.Join() mythread3.Join() '线程执行完毕 Console.WriteLine(Now.ToLongTimeString & "线程执行完毕!") End Sub Public Sub mythreadrun(ByVal myprocess As Object) Dim mynum As Double Static Dim mymonitorobj As New Object Static Dim jg As Double = 100 Try For mynum = 1 To 10 '使用 监视器，同时为避免阻塞，在等待的过程中做其它工作 While Not Monitor.TryEnter(mymonitorobj) Console.WriteLine(Thread.CurrentThread.Name & "正在等待.....") End While Try jg -= mynum Console.WriteLine(Thread.CurrentThread.Name & "==>" & Now.ToLongTimeString & "=>" & (jg + mynum) & "-" & mynum & "，计算结果为：" & jg) Finally Monitor.Exit(mymonitorobj) End Try Thread.Sleep(0) Next Catch Console.WriteLine(Thread.CurrentThread.Name & " " & Now.ToLongTimeString & "线程异常终止!") '终止线程 Thread.CurrentThread.Abort() Finally Console.WriteLine(Thread.CurrentThread.Name & "优先级: " & Thread.CurrentThread.Priority.ToString) Console.WriteLine(Thread.CurrentThread.Name & " " & Now.ToLongTimeString & "线程运行完毕!") End Try End SubEnd Module?
?
效果如下:
![VB.NET并行与分布式编程(六)-线程与内核同步[14]](http://img.reader8.net/uploadfile/jiaocheng/20140140/2703/2014012721032425156.jpg)
?
?
?