<saurabhgarg2k@gmail.com> wrote in message
news:1113384356.507394.303760@l41g2000cwc.googlegroups.com...
> Hi there guys,
>
> Here is the code snippet which in which i am trying to read a file and
> taking two cases in first one i promote the object to Gen1 so that it
> will be saved from frequent Gen0 Collections and dont have to read file
> again which is a costly business.In second case, normal process without
> promoting.So trying to prove that first case works faster
>
> Module Module1
> Sub main()
> Dim objTest1 As New Test1
> Dim someNumber As Integer = 500
> Dim i As Integer
> Dim t As DateTime
> Dim CurrentTime As DateTime
>
> t = DateTime.Now
> For i = 0 To 100000
> objTest1.ReadFile()
> Next
>
> CurrentTime = DateTime.Now
> Console.WriteLine(String.Format("Time taken with promotion:
> {0}:{1}", CurrentTime.Subtract(t).Seconds,
> CurrentTime.Subtract(t).Milliseconds))
> Console.WriteLine("File Read: {0} times",
> TextFile._fileReadCount)
> TextFile._fileReadCount = 0
>
> Dim objTest2 As Test1 = New Test1
> t = DateTime.Now
> For i = 0 To 100000
> If (i Mod someNumber = 0 AndAlso i > 0) Then
> GC.Collect(0)
> End If
> objTest2.ReadFileWithoutPromotion()
> Next
>
> CurrentTime = DateTime.Now
> Console.WriteLine(String.Format("Time taken without promotion:
> {0}:{1}", CurrentTime.Subtract(t).Seconds,
> CurrentTime.Subtract(t).Milliseconds))
>
> Console.WriteLine("File Read: {0} times",
> TextFile._fileReadCount)
> TextFile._fileReadCount = Nothing
> GC.Collect()
> GC.WaitForPendingFinalizers()
> Console.ReadLine()
> End Sub
> End Module
>
> Class TextFile
> Public ReadOnly Filename As String
> Private wrText As WeakReference
> Public Shared _fileReadCount As Integer = 0
>
> Public Sub New(ByVal filename As String)
> Me.Filename = filename
> End Sub
>
> Public ReadOnly Property Contents() As String
> Get
> Dim txt As String
> If Not (wrText Is Nothing) Then
> ' if the weakly referenced string is
> ' still there, return it to caller
> txt = DirectCast(wrText.Target, String)
> If Not (txt Is Nothing) Then _
> Return txt
> End If
> ' else we need to read (again) the file
> Dim sr As System.IO.StreamReader
> Try
> _fileReadCount += 1
> ' read the entire file in one shot
> sr = New System.IO.StreamReader(Filename)
> txt = sr.ReadToEnd()
> ' create a weak-reference to it
> ' and return to main app
> wrText = New WeakReference(txt)
> Return txt
> Finally
> ' close the stream if necessary
> If Not (sr Is Nothing) Then _
> sr.Close()
> End Try
> End Get
> End Property
> End Class
>
> Public Class Test1
> Dim objText As New TextFile("C:\Log.txt")
> Private _flag As Boolean = False
>
> Public Sub ReadFile()
> Dim t As String = objText.Contents
> If GC.GetGeneration(t) = 0 Then
> GC.Collect(0)
> Console.WriteLine("File Contents Promoted to Next
> Generation")
> End If
> End Sub
>
> Public Sub ReadFileWithoutPromotion()
> Dim t As String = objText.Contents
> End Sub
> End Class
>
> Problem:
> For my utter surprise in the First iteration of first for loop when it
> goes into Contents property and after reading the File, the generation
> of the variable "txt" is 2.I cant solve this mystery.Can any1 pick out
> what is happening.
>
> Thanks and Regards
> Saurabh Garg
>