Changing the List Elements in a List Widget Crashes VM
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Changing the List Elements in a List Widget Crashes VM
 
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I am trying to build a GUI that queues up a list of files that need to
be processed (I'll try to attach a small picture here, if the list accepts attachments). I have added a button 'Add' that when clicked, calls the method #addFiles shown here: addFiles | dialog fileSet | dialog := MultiOpenFileDialog new. dialog windowTitle: 'Select Files To Process'; defaultDirectory: workingDirectory. dialog open ifTrue: [fileSet := filesToProcess list asSet. "Set prevents duplicates filenames" fileSet addAll: (dialog selectionStrings). filesToProcess list: (fileSet asList sorted). "Sorted order seems better than random" workingDirectory := (fileSet asList at: 1) asFilename directory] What is supposed to happen is the user selects a bunch of files and I add them to the list of files already in displayed in the List widget. This works for the first couple of clicks, but after clicking on the add button a few times, it always crashes the virtual machine. (Totally bombs out of VisualWorks). Why? What am I doing wrong here? #filesToProcess returns a MultiSelectionInList used by the List widget. -- David Finlayson _______________________________________________ vwnc mailing list [hidden email] http://lists.cs.uiuc.edu/mailman/listinfo/vwnc |
Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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Re: Changing the List Elements in a List Widget Crashes VM
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In reply to this post by David Finlayson
Hi,
I ran into the same problem (too many files selected in a native windows file selection dialog - how dare they :-) and fixed it with the attached code. I didnt see any crashes thou... Usage: | dialog | dialog := FileDialogWin32Surrogate forOpenMultiFileDialog. dialog windowTitle: (#titleOpenChartFiles << #smallCharts >> 'Öffne Chartdateien') asString; addFileFilter: #pdfFilesLabel << #smallCharts >> 'PDF Dateien (*.pdf)' pattern: '*.pdf'; addFileFilter: #csvFilesLabel << #smallCharts >> 'Komma separierte Dateien (*.csv)' pattern: '*.csv'; addFileFilter: #textFilesLabel << #smallCharts >> 'Textdateien (*.txt)' pattern: '*.txt'; addFileFilter: #allFilesLabel << #smallCharts >> 'Alle Dateien (*.*)' pattern: '*.*'; defaultFilename: '*', self defaultFileExtension; defaultDirectory: self lastDirectoryForSave; fileCondition: #multipleOld; setCallbackForMultiselect. ^dialog select HTH, Christian > -----Ursprüngliche Nachricht----- > Von: [hidden email] > [mailto:[hidden email]] Im Auftrag von Valloud, Andres > Gesendet: Donnerstag, 1. April 2010 07:46 > An: David Finlayson > Cc: VWNC, > Betreff: Re: [vwnc] Changing the List Elements in a List > Widget Crashes VM > > David, thank you for this most useful code. I tried it in one of our > recent next release builds, and I could not reproduce the crash. > Instead, I get a FNERR_BUFFERTOOSMALL error. However, I do see a > potential problem. The function called is a Unicode function, and the > MSDN docs state that in that case, the struct passed in to > GetOpenFileNameW must have a buffer and a buffer size specified in > TCHARS. For Unicode, each TCHAR is 2 bytes long. So there is this > method called fileNameBufferSize, which answers 1024. If you check > senders, you will see that > > initializeFor: aCommdlgInterface > > | empty | > interface := aCommdlgInterface. > ofn := aCommdlgInterface OPENFILENAME gcMalloc. > filename := CIntegerType unsignedChar gcMalloc: self > fileNameBufferSize. > empty := interface encodeWide: ''. "Null terminated > empty string" > filename copyAt: 0 from: empty size: empty size startingAt: 1. > ofn > zeroFill; > memberAt: #lStructSize put: ofn type referentType > sizeof; > memberAt: #lpstrFile put: filename; > memberAt: #nMaxFile put: self fileNameBufferSize. > self setFlag: interface OFN_EXPLORER. > interface CoInitialize: nil. > self initialDirectory: Filename defaultDirectory asString > > creates a filename buffer 1024 *BYTES* long (because > unsignedChar is not > a TCHAR). Consequently, Windows will think the buffer can hold 1024 > TCHARS, which in Unicode requires 2048 bytes. Unfortunately > there's not > enough memory reserved in the filename buffer, so you have a buffer > overflow condition. I think I must have gotten FNERR_BUFFERTOOSMALL > because the answer was larger than 1024 TCHARS. However, in the cases > you describe, it seems possible to get an answer between 1024 and 2048 > bytes which should result in undefined behavior. > > I have not thoroughly verified this problem, but I am very suspicious > this analysis leads to potential trouble that needs to be checked out. > At first glance, it looks like the buffer should be allocated in terms > of unsigned shorts, as opposed to unsigned chars. Thank you > for letting > us know. AR 59745. > > Andres. > > -----Original Message----- > From: David Finlayson [mailto:[hidden email]] > Sent: Wednesday, March 31, 2010 9:39 PM > To: Valloud, Andres > Cc: VWNC, > Subject: Re: [vwnc] Changing the List Elements in a List > Widget Crashes > VM > > Version: VisualWorks(r) NonCommercial, 7.7 of December 15, > 2009 Running > on Windows XP > > You can reproduce the problem with this code in a workspace on both > windows XP and windows 7: > > " Create a directory with a lot of files (more than 255 will do it for > sure)" > tempDir := 'temp' asFilename. > tempDir makeDirectory. > 1 to: 300 do: [ :i | > tempFile := ('temp\temp_', i printString) asFilename. > stream := tempFile writeStream. > stream close.] > > " Try to reading in every file in the directory - no problem with VW > MultiOpenFileDialog. I've tested it on hundreds of files." > Dialog useNativeDialogs: false. > list := List new. > dialog := MultiOpenFileDialog new. > dialog > windowTitle: 'Select Files To Process'; > defaultDirectory: tempDir. > dialog open > ifTrue: [list addAll: (dialog selectionStrings)]. > > "Now try to read in a bunch of files (> 50) with Native > MultiOpenFileDialog (this WILL crash eventually). You may need to do > this 2 or 3 times before you get the crash. Selecting all files in the > directory crashes every time. This may be a 255 file limit of > the native > dialog. I've seen this bug before in C++ programs. There is a > work-around." > > Dialog useNativeDialogs: true. > list := List new. > dialog := MultiOpenFileDialog new. > dialog > windowTitle: 'Select Files To Process'; > defaultDirectory: tempDir. > dialog open > ifTrue: [list addAll: (dialog selectionStrings)]. > > Hope that helps. > > _______________________________________________ > vwnc mailing list > [hidden email] > http://lists.cs.uiuc.edu/mailman/listinfo/vwnc > > > > _______________________________________________ vwnc mailing list [hidden email] http://lists.cs.uiuc.edu/mailman/listinfo/vwnc  OpenMultiFilenameRequest.st (5K) Download Attachment FileDialogWin32Surrogate-initializeOpenMultiFileName.st (1K) Download Attachment FileDialogWin32Surrogate class-forOpenMultiFileDialog.st (624 bytes) Download Attachment |
Re: Changing the List Elements in a List Widget Crashes VM
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In reply to this post by Andres Valloud-6
It changes the problem(s):
1. I didn't see the whole VM crash, so maybe the undefined behavior problem is fixed. 2. You still can only select <255 files or you get that FNERR_BUFFERTOOSMALL error. 3. The change mangled actual file names returned. Instead of files like temp_1, temp_2, temp_3, etc. I got: p_1, p_2, p_3 and the last filename returned was just Unicode goop (UniGoop??). See the attached image. Switching back to unsignedChar fixed the file name mangling but the random crashes returned also. I haven't tried Christian's suggestion (I am a novice at VW and I need to digest what Christian's code is doing differently). David _______________________________________________ vwnc mailing list [hidden email] http://lists.cs.uiuc.edu/mailman/listinfo/vwnc |
Re: Changing the List Elements in a List Widget Crashes VM
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