Visual Basic

 <br />
Imports Microsoft.VisualBasic<br />
Imports System<br />
Imports System.Threading<br />
<br />
Module bub <br />
dim c as Contatore<br />
dim d as Contatore<br />
 <br />
 <br />
Sub ThreadFuncC(stateInfo as Object)  <br />
Dim d as String<br />
d = CType(stateInfo, String )<br />
Console.WriteLine( d )<br />
End SUb<br />
 <br />
Sub ThreadFuncA( )<br />
dim s as integer<br />
For s=0 to 20<br />
   c.IncrementCounter()<br />
   Console.WriteLine("by Thread A {0}", c.GetI())<br />
   Thread.Sleep(100)<br />
Next<br />
End Sub<br />
 <br />
Sub ThreadFuncB( )<br />
Dim s as integer<br />
For s=0 to 10<br />
   d.IncrementCounter()<br />
   Console.WriteLine("by Thread B {0}", d.GetI())<br />
   Thread.Sleep(200)  <br />
Next<br />
End Sub<br />
 <br />
class Contatore<br />
Shared Sub IncrementCounter()<br />
   SyncLock sync_i<br />
   i = i +1<br />
   End SyncLock<br />
End Sub<br />
 <br />
Function GetI() As integer<br />
SyncLock sync_i<br />
Return i<br />
End SyncLock<br />
End Function<br />
 <br />
Shared i as integer = 0<br />
Shared sync_i as object = new object<br />
 <br />
end class<br />
 <br />
Sub Main() <br />
 <br />
  c = new Contatore<br />
  d = new Contatore<br />
 <br />
  dim ta As Thread<br />
  dim tb as Thread<br />
  dim tc as Thread<br />
  ta = new Thread(AddressOf ThreadFuncA)<br />
  tb = new Thread(AddressOf ThreadFuncB)<br />
  tc = new Thread(AddressOf ThreadFuncB)<br />
  ta.Start()    <br />
  tc.Start()<br />
  tb.Start()<br />
  ta.Join()    <br />
  Console.WriteLIne("End TA")<br />
  Dim f as String = "Urka!!"<br />
  ThreadPool.QueueUserWorkItem( AddressOf ThreadFuncC,f )  <br />
End Sub<br />
End Module<br />