Re: [ADVANCED-DOTNET] Does CLR support SSE or SSE2?
-Original Message- From: Moderated discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED]]On Behalf Of Richard Birkby Sent: Thursday, 9 January 2003 2:30 AM To: [EMAIL PROTECTED] Subject: Re: [ADVANCED-DOTNET] Does CLR support SSE or SSE2? John St. Clair wrote: In your second example, you mention a 37% speed-up. This may not be worth it if in practice the typical user only spends a few seconds utilizing the zip functionality. However, Array.Copy is used all over the place. Just think about how XML parsing is done and how much of .Net reads XML files. Array.Copy seems to make a call to an unmanaged already but is not much faster than a loop. An assembly routine can be 150-200% quicker for the copy , this is why I used a faster assembly copy routine - unfortunately it does not help as much as I though because of 3 reasons - The system is very efficient at copying already and these do not take long in the total scheme of things ( even though there are a lot) - and Compression uses a LOT of array comparison and copies. - The optimized assembly routines are worse if the array is very small which occur very often eg 2-10 characters. ( An inline unsafe pointer copy works best here - which I do use if n 16) - The instructions only help in moveing Double or Quad words around and are ultimately more limited by the hardware capacity of the machine. If you move 7 bytes you have a routine that does 4 bytes efficiently and then does 3 * a byte normally + call overhead - An inline 7 byte copy is quicker. In some circumstance it can be worth it , but only after you finish the project and decide you need more. Ben Richard You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
Re: [ADVANCED-DOTNET] VS.NET sets breakpoint in wrong source file
DA I am using VS.NET 2002 with SP1. I know there was some kind of problem DA with the first VS release but SP1 fixed that. This particular problem DA really is maddening. Makes debugging a little difficult when you can't set DA a breakpoint where you want it. SP1? Could you tell me where I could download it? I could not find any link. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
Re: [ADVANCED-DOTNET] unsafe code in aspx files
You can add a CompilerOptions attribute to the Page directive like this: %@ Page CompilerOptions=/unsafe Language=C# % -Original Message- From: Moderated discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED]]On Behalf Of Dominick Baier Sent: Thursday, January 09, 2003 3:39 AM To: [EMAIL PROTECTED] Subject: [ADVANCED-DOTNET] unsafe code in aspx files Hi, i try to put some unsafe code directly in an .aspx file (no code behind) on execution i get the the error that i should compile with the /unsafe switch. but i don't have a (il) compilation. msdn talks about a attribute AllowUnsafeBlocks witch sets the /unsafe switch programmatically. but the link to this information is broken. can someone help me??? thanks in advance dominick You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
Re: [ADVANCED-DOTNET] Does CLR support SSE or SSE2?
Somehow related to this, here is an interesting article: http://cedar.intel.com/cgi-bin/ids.dll/content/content.jsp?cntKey=Generic+Editorial::dotnet_boost_perform_frameworkcntType=IDS_EDITORIALcatCode=BZK Christian Weyer [MVP ASP.NET XML Web Services | AspElite Member] ** http://www.xmlwebservices.cc/ * .NET XML Web Services Repertory John Liou wrote: I'm thinking of the CLR performance, so do you know if CLR support SSE or SSE2? Thanks! -John You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
[ADVANCED-DOTNET] Controlling (fine grained) db locks using standard .NET interfaces - possible?
Hello, I have a small problem to solve to the best possible solution, and I am starting to feel that there might not be one. Maybe some of you can comment. Basically, I write a generic db abstraction layer (the generic is important here). I need to keep fine grained control over mydb locks - means: I need to control what locks get placed upon reading, BUT - I want (or: it has been requested) we expose the ability to change this lock. Well, even more specific: Our layer ( a complete O/R mapper) works with optimistic concurrency normally, but people want to have explicit selected locks on top of this. Now, I have no problem selecing a distinct concurrency level for a database transaction. In normal operations we open a db transaction (with whatever lock level we choose), execute the query (aggregating the data into an offline cache), and rollback. Once the user is finished, we basically open a new transaction and write all changes out, then commit. This works perfectly (when not using COM+ - under COM+ there is an issue getting rid of the attached DB connection). Ust that someone wants to be able to explicitly lock a certain record from our API layer. I went through the .NET database interface (which for this case booils down to the IdbTransaction interface), and I basically see that the concurrency level can not be changed. This means, as it looks like, that I am not able to somehow inject a transaction with a separate isolation level into an existing one. I also did not find any mechanism to merge two transactions (open a second transaction in the first one - important for later reads). Anyone else having had a fight with this? I am pretty short to say goodbye to this locking feature - which is a shame, becuase sometimes it really might be useful. Regards Thomas Tomiczek THONA Consulting Ltd. (Microsoft MVP C#/.NET) You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
Re: [ADVANCED-DOTNET] Salt in PasswordDeriveBytes
Gosh, that's being a bit harsh. He already admitted that it's not as secure as a random salt. While it's true that using a derived salt is not as secure as a random salt, it is definitely more secure than using no salt at all. With this approach, it is required that A) the black hat know your salt algorithm (which, unfortunately, is not terribly complicated in this case but is still better than nothing) and B) the black hat generate a hashed dictionary using the now-known salt and a non-hashed dictionary. Again, this approach is nowhere near as secure as when using a random salt, but he is correct in stating that it will slow down, if not keep out, script kiddies. -Andy Hopper - Original Message - From: Thomas Tomiczek [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, January 09, 2003 3:08 AM Subject: Re: [ADVANCED-DOTNET] Salt in PasswordDeriveBytes Congratulations. You have propably managed to completly destroy the advantage of salt in your usage. Using a derived salt value means, at least to my understanding of the maths involved, that you have just KILLED the effect. Regards Thomas Tomiczek THONA Consulting Ltd. (Microsoft MVP C#/.NET) -Original Message- From: Craft, Steve [mailto:[EMAIL PROTECTED]] Sent: Wednesday, January 08, 2003 7:08 PM To: [EMAIL PROTECTED] Subject: Re: [ADVANCED-DOTNET] Salt in PasswordDeriveBytes In the case of storing username/password in a database table, I just use a salt of the username backwards and append that to the password before it gets encrypted and written to the password column. In normal app usage, the username is looked up and then the backwards username is appended to the password and that hash is compared to the password column. That's not the most earth-shattering way of doing things, but it should slow down any script-kiddie that gets the password file; he will have to append the username to every password try on every different table row. It also makes the salt different for each user, but is easier to maintain than a random number (or even a well-known hard-coded number) for each one. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
[ADVANCED-DOTNET] unsafe code in aspx files
Hi, i try to put some unsafe code directly in an .aspx file (no code behind) on execution i get the the error that i should compile with the /unsafe switch. but i don't have a (il) compilation. msdn talks about a attribute AllowUnsafeBlocks witch sets the /unsafe switch programmatically. but the link to this information is broken. can someone help me??? thanks in advance dominick You can read messages from the Advanced DOTNET archive, unsubscribe from Advanced DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
