Strange Problem????

[Scott Slater]

I have been pulling my hair out on this one, but have narrowed it down. I was writing a large stream of data to a binary file under Windows Vista 64 with Trend Micro Internet Security virus suite and noticed unusually long delays in my code at times. I started placing MsgBox's in various parts of the code so that I knew where it was and found it to be the Close statement that was taking a long time. BUT: only when hyphens were present in large number in the written data stream. :confused2: Does this make sense? Why should the data stream matter?

Here's a test snippet:

#Compile Exe
#Dim All
   
Function PBMain
   
   Local idx As Dword
   Local blob As String
   Local tt As Double
   
   ? "Begin Build"
'   blob = Repeat$(20971520, "Repeated-String-")   ' Build 320 MB String   This string takes 27 seconds
   blob = Repeat$(20971520, "Repeated String ")   ' Build 320 MB String   This string takes 5.5 seconds
   
   ? "End Build: Len = " & Format$(Len(blob)),,"Len(blob)"
   
   ? "begin write file"
   tt = Timer
   Open "blob.dat" For Binary As 1
   Put$ 1, blob
   Close 1
   
   ? "done in " & Format$(Timer-tt, "0.000") & " seconds."
      
   Kill "blob.dat"
   
End Function

If I build and write the string with hyphens it takes roughly 27 seconds for the file operation to complete (most of the time on the Close statement). If I build and write the string with spaces instead, it only takes 5.5 seconds for the same block of code to run.

I haven't tested this on other machines yet, but intend to. If you have a chance give it a shot on yours. I tried the code above with both PBWin8 and PBWin9 with the same results. I am guessing it may be the virus scanner, but have not made that conclusion just yet. I figured I'd let a few others see if they had similar results.

If you run this please show times for hyphens vs. spaces and your OS and virus software (if any).

Thanks!

[Michael Mattias]

I've never known it to be data-dependent, but the PB "CLOSE" is translated into CloseHandle(), which is one of those functions Windows regards as "low priority" and it does not get done immediately; that is, delays on CLOSE/CloseHandle() are not something new.

For it to be data-dependent, though, I think you almost have no options other than looking at 'other processes with an interest in new files.'

MCM

[Scott Slater]

It seems that it is indeed the anti-virus software doing this. It must examine I/O streams and something with the hyphens causes it to take a much longer time than without.

[Gösta H. Lovgren-2]

I just tried it Scott and had the same experience as you. Also have Trend Micro installed (Which I have found WAY better than any other anti-virii checkers).

Times are 5.61 & 50.19 secs with 'PBWIN 9.01 - WinApi 05/2008 - XP Pro SP3.

I'll be curious to see if others with different Virus Checkers have the same experience.

=================================
"Success has a thousand fathers,
And defeat is an orphan."
JFK
=================================

[Rod Macia]

PBwin 9.01, WinApi 05/2008, Vista 64, Avast Home 4.8

hyphens 7.681 secs

spaces 7.702 secs

Rod

[Iain Johnstone]

PBWin 9.01; XP3, AMD64 3800+;2.42GHz;3Gb RAM, AVG/Ad-aware/Zone Alarm

Spaces = 4.407 secs
Hyphens = 4.391 secs (????)

Checked (repeatedly!)

Iain Johnstone

[Barry Erick]

Using ms live one,
no hyphens - 4.094
hyphens 3.844

[Gösta H. Lovgren-2]

At odd times, I find certain keys don't work (Delete/Backspace, C&P functions, ??) when in the forum editor. I've always thought it was a forum editor quirk of some kind, but now I bet it's Trend Micro. Bummer, but even with shortcomings it's still worth it for me. Of course I haven't had such serious slowdown experriences like Scott has.

==============================================
"I don't feel good."
The last words of Luther Burbank (1849-1926)
==============================================

[George Bleck]

McAfee 8.5.0i
5301.4018 Scan engine
5653.0000 Dat version

Windows XP SP3 3.4ghz 4gb Ram Dell Optiplex GX620

PB/CC 5.01

Spaces: 7.100
Hyphens: 7.711