в 16:40, 26 мая 2010

2010-05-26T16:40:30Z

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2010-05-26T12:56:05Z

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==Producer and consumer==

<source lang="vbnet">Imports System.Threading
Module Module1
Public Buffer As Integer
Public BufferEmpty As Boolean = True
Sub Producer()
Dim Value As Integer = 0
Do
If (BufferEmpty) Then
BufferEmpty = False
Buffer = Value
If (Value = 0) Then
Value = 1
Else
Value = 0
End If
Console.WriteLine("Producer: " & Buffer)
End If
Loop While (True)
End Sub
Sub Consumer()
Dim Value As Integer
Do
If (Not BufferEmpty) Then
BufferEmpty = True
Thread.CurrentThread.Sleep(1000)
Value = Buffer
Console.WriteLine("Consumer: " & Value)
End If
Loop While (True)
End Sub
Sub Main()
Dim ProducerThread As Thread
Dim ConsumerThread As Thread
ProducerThread = New Thread(AddressOf Producer)
ConsumerThread = New Thread(AddressOf Consumer)
ProducerThread.Start()
ConsumerThread.Start()
End Sub
End Module</source>
<pre class=codeResult>Producer: 0
Producer: 1
Consumer: 1
Producer: 0
Consumer: 0
Producer: 1
Consumer: 1
Producer: 0
Consumer: 0
Producer: 1
^CTerminate batch job (Y/N)? n</pre>

==Producer and consumer without synchronization mechanisms==

<source lang="vbnet">Imports System.Threading
Module Tester
Sub Main()
Dim holdInteger As New Buffer()
Dim producer As New Producer(holdInteger)
Dim consumer As New Consumer(holdInteger)
Dim producerThread As New Thread(AddressOf producer.Produce)
Dim consumerThread As New Thread(AddressOf consumer.Consume)
producerThread.Name = "Producer"
consumerThread.Name = "Consumer"
producerThread.Start()
consumerThread.Start()
End Sub
End Module
Public Class Producer
Private buffer As Buffer
Public Sub New(ByVal sharedObject As Buffer)
buffer = sharedObject
End Sub " New
Public Sub Produce()
Dim count As Integer
For count = 1 To 4
Thread.Sleep(4000)
buffer.Buffer = count
Next
Console.WriteLine(Thread.CurrentThread.Name & _
" done producing." & vbCrLf & "Terminating " & _
Thread.CurrentThread.Name & ".")
End Sub
End Class
Public Class Consumer
Private buffer As Buffer
Public Sub New(ByVal sharedObject As Buffer)
buffer = sharedObject
End Sub " New
Public Sub Consume()
Dim count, sum As Integer
For count = 1 To 4
Thread.Sleep(300)
sum += buffer.Buffer
Next
Console.WriteLine(Thread.CurrentThread.Name & _
" read values totaling: " & sum & "." & vbCrLf & _
"Terminating " & Thread.CurrentThread.Name & ".")
End Sub
End Class

Public Class Buffer
Private mBuffer As Integer = -1
Property Buffer() As Integer
Get
Console.WriteLine(Thread.CurrentThread.Name & _
" reads " & mBuffer)
Return mBuffer
End Get
Set(ByVal Value As Integer)
Console.WriteLine(Thread.CurrentThread.Name & _
" writes " & Value)
mBuffer = Value
End Set
End Property " Buffer
End Class</source>
<pre class=codeResult>Consumer reads -1
Consumer reads -1
Consumer reads -1
Consumer reads -1
Consumer read values totaling: -4.
Terminating Consumer.
Producer writes 1
Producer writes 2
Producer writes 3
^CTerminate batch job (Y/N)? ^Cn</pre>

==Producer and consumer with synchronization mechanisms==

<source lang="vbnet">Imports System.Threading
Module Tester
Sub Main()
Dim holdInteger As New Buffer()
Dim producer As New Producer(holdInteger)
Dim consumer As New Consumer(holdInteger)
Dim producerThread As New Thread(AddressOf producer.Produce)
Dim consumerThread As New Thread(AddressOf consumer.Consume)
producerThread.Name = "Producer"
consumerThread.Name = "Consumer"
producerThread.Start()
consumerThread.Start()
End Sub
End Module
Public Class Producer
Private buffer As Buffer
Public Sub New(ByVal sharedObject As Buffer)
buffer = sharedObject
End Sub " New
Public Sub Produce()
Dim count As Integer
For count = 1 To 4
Thread.Sleep(4000)
buffer.Buffer = count
Next
Console.WriteLine(Thread.CurrentThread.Name & _
" done producing." & vbCrLf & "Terminating " & _
Thread.CurrentThread.Name & ".")
End Sub
End Class
Public Class Consumer
Private buffer As Buffer
Public Sub New(ByVal sharedObject As Buffer)
buffer = sharedObject
End Sub " New
Public Sub Consume()
Dim count, sum As Integer
For count = 1 To 4
Thread.Sleep(300)
sum += buffer.Buffer
Next
Console.WriteLine(Thread.CurrentThread.Name & _
" read values totaling: " & sum & "." & vbCrLf & _
"Terminating " & Thread.CurrentThread.Name & ".")
End Sub
End Class
Public Class Buffer
Private mBuffer As Integer = -1
Private occupiedBufferCount As Integer
Public Property Buffer() As Integer
Get
Monitor.Enter(Me)
If occupiedBufferCount = 0 Then
Console.WriteLine("Buffer empty. " & _
Thread.CurrentThread.Name & " waits.")
Monitor.Wait(Me)
End If
occupiedBufferCount -= 1
Console.WriteLine(Thread.CurrentThread.Name & " reads " & _
mBuffer)
Monitor.Pulse(Me)
Dim bufferCopy As Integer = mBuffer
Monitor.Exit(Me)
Return bufferCopy
End Get
Set(ByVal Value As Integer)
Monitor.Enter(Me)
If occupiedBufferCount = 1 Then
Console.WriteLine("Buffer full. " & _
Thread.CurrentThread.Name & " waits.")
Monitor.Wait(Me)
End If
mBuffer = Value
occupiedBufferCount += 1
Console.WriteLine(Thread.CurrentThread.Name & " writes " & _
mBuffer)
Monitor.Pulse(Me)
Monitor.Exit(Me)
End Set
End Property " Buffer
End Class</source>
<pre class=codeResult>Buffer empty. Consumer waits.
Producer writes 1
Consumer reads 1
Buffer empty. Consumer waits.
Producer writes 2
Consumer reads 2
Buffer empty. Consumer waits.
Producer writes 3
Consumer reads 3
Buffer empty. Consumer waits.
Producer writes 4
Consumer reads 4
Consumer read values totaling: 10.
Terminating Consumer.
Producer done producing.
Terminating Producer.</pre>

==Synchronize access to circular Integer buffer==

<source lang="vbnet">Imports System.Threading
Public Class Tester
Public Shared Sub Main
Dim buffer As New Buffer()
Dim producer As New Producer(buffer)
Dim consumer As New Consumer(buffer)
Dim producerThread As New Thread(AddressOf producer.Produce)
Dim consumerThread As New Thread(AddressOf consumer.Consume)
producerThread.Name = "Producer"
consumerThread.Name = "Consumer"
producerThread.Start()
consumerThread.Start()
End Sub
End Class

Public Class Buffer
Private mBuffer As Integer() = {-1, -1, -1}
Private occupiedBufferCount As Integer
Private readlocation, writeLocation As Integer
Property Buffer() As Integer
Get
SyncLock (Me)
If occupiedBufferCount = 0 Then
Console.WriteLine("All buffers empty. " & _
Thread.CurrentThread.Name & " waits.")
Monitor.Wait(Me)
End If
Dim readValue As Integer = mBuffer(readlocation)
Console.WriteLine(Thread.CurrentThread.Name & " reads " & _
mBuffer(readlocation))
occupiedBufferCount -= 1
readlocation = (readlocation + 1) Mod mBuffer.Length
Monitor.Pulse(Me)
Return readValue
End SyncLock
End Get
Set(ByVal Value As Integer)
SyncLock (Me)
If occupiedBufferCount = mBuffer.Length Then
Console.WriteLine("All buffers full. " & _
Thread.CurrentThread.Name & " waits.")
Monitor.Wait(Me)
End If
mBuffer(writeLocation) = Value
Console.WriteLine(Thread.CurrentThread.Name & " writes " & _
mBuffer(writeLocation) )
occupiedBufferCount += 1
writeLocation = (writeLocation + 1) Mod _
mBuffer.Length
Monitor.Pulse(Me)
End SyncLock
End Set
End Property " Buffer
End Class

Public Class Producer
Private buffer As Buffer
Public Sub New(ByVal sharedObject As Buffer)
buffer = sharedObject
End Sub
Public Sub Produce()
Dim count As Integer
For count = 1 To 10
Thread.Sleep(1000)
buffer.Buffer = count
Next
Console.WriteLine(Thread.CurrentThread.Name & _
" done producing. " & vbCrLf & _
Thread.CurrentThread.Name & " terminated.")
End Sub
End Class
Public Class Consumer
Private buffer As Buffer
Public Sub New(ByVal sharedObject As Buffer)
buffer = sharedObject
End Sub
Public Sub Consume()
Dim count, sum As Integer
For count = 1 To 10
Thread.Sleep(500)
sum += buffer.Buffer
Next
Console.WriteLine("Total " & _
Thread.CurrentThread.Name & " consumed: " & sum & vbCrLf & _
Thread.CurrentThread.Name & " terminated.")
End Sub
End Class</source>
<pre class=codeResult>All buffers empty. Consumer waits.
Producer writes 1
Consumer reads 1
All buffers empty. Consumer waits.
Producer writes 2
Consumer reads 2
All buffers empty. Consumer waits.
Producer writes 3
Consumer reads 3
All buffers empty. Consumer waits.
Producer writes 4
Consumer reads 4
All buffers empty. Consumer waits.
Producer writes 5
Consumer reads 5
All buffers empty. Consumer waits.
Producer writes 6
Consumer reads 6
All buffers empty. Consumer waits.
Producer writes 7
Consumer reads 7
All buffers empty. Consumer waits.
Producer writes 8
Consumer reads 8
All buffers empty. Consumer waits.
Producer writes 9
Consumer reads 9
All buffers empty. Consumer waits.
Producer writes 10
Producer done producing.
Producer terminated.
Consumer reads 10
Total Consumer consumed: 55
Consumer terminated.</pre>

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в 16:40, 26 мая 2010

Admin: 1 версия