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Everything posted by Anders Melander
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Unified Memory Management - Coming with 10.4 Beta
Anders Melander replied to a topic in Tips / Blogs / Tutorials / Videos
You should probably rephrase that "and only slows me down". In my experience laziness always comes at a price. Not bothering to use descriptive identifiers saves a few keystrokes at the price of readability. ARC and GC relieves the developer of having to deal with some of the complexities of resource management, at the price of performance. Etc. I would honestly rather have good performance and full control of what's going on with the resources. Yes. Let's break COM support so we can save some keystrokes. -
Unified Memory Management - Coming with 10.4 Beta
Anders Melander replied to a topic in Tips / Blogs / Tutorials / Videos
How is that relevant to the topic? -
Generics and Classes on Windows 2000 = OOM
Anders Melander replied to aehimself's topic in General Help
FWIW, Windows 2000 isn't supported by the version of Delphi you're using. Also, please read the event log message again. It has all the clues: It isn't your application that is experiencing an "out of memory" error. It's Windows that is experiencing an "out of virtual memory" error. To fix it: Increase the size of the page file. My guess is that the W2K system has a fixed size page file - or no page file at all. Otherwise it would just increase the size automatically - or maybe that feature was added later. I forget. and who cares anymore. If you're really interested in why you get a windows error and not an application error, read some books on Windows internals and the virtual memory manager, or just google it. -
Image pointer and buffer size
Anders Melander replied to dkprojektai's topic in Algorithms, Data Structures and Class Design
You're not giving us much to work with here. Do you have any documentation about what kind of data ReadFromMemFile expect the input buffer to hold? -
Image pointer and buffer size
Anders Melander replied to dkprojektai's topic in Algorithms, Data Structures and Class Design
You didn't really answer @Vandrovnik's question. For Windows bitmaps the bitmap file image (i.e. bitmap header and pixel data) isn't stored in memory. When TBitmap loads a bmp file it reads the header information then the pixel data. From this it stores the relevant meta data (width/height, color depth, palette, etc) and pixel data in memory. Of these you only have direct access to the raw pixel data. If you need the file bitmap image in memory then you will either have to save the bitmap to a memory stream or construct the image yourself in memory. btw, when I write "image" I don't mean in the picture/graphic/bitmap sense. Maybe you should try to explain what problem you are trying to solve. -
Why TList uses a lot more memory than TArray?
Anders Melander replied to Mike Torrettinni's topic in Algorithms, Data Structures and Class Design
Technically it's the page file. The terms page file and swap file have their roots in VMS. Both Windows NT and VMS were designed by his holiness, Dave Cutler. The swap file doesn't exist anymore in Windows (I believe it was there in early versions) but was used when a process working set was completely removed from physical memory. E.g. in low memory situations or if the process went into extended hibernation. -
Why TList uses a lot more memory than TArray?
Anders Melander replied to Mike Torrettinni's topic in Algorithms, Data Structures and Class Design
No. You still don't understand the difference between physical and virtual memory. -
Why TList uses a lot more memory than TArray?
Anders Melander replied to Mike Torrettinni's topic in Algorithms, Data Structures and Class Design
Please google "64-bit" -
Why TList uses a lot more memory than TArray?
Anders Melander replied to Mike Torrettinni's topic in Algorithms, Data Structures and Class Design
True, but even in 2003 it was a 16-bit leftover from the DOS days. -
Why TList uses a lot more memory than TArray?
Anders Melander replied to Mike Torrettinni's topic in Algorithms, Data Structures and Class Design
Please google "virtual memory". -
Anything sensible for source code documentation?
Anders Melander replied to A.M. Hoornweg's topic in General Help
Try Documentation Insight. It supports both XMLDOC (which I agree makes the source unreadable) and external documentation files: I've been using it to generate library help files (in CHM-format) but it can also display the help as tooltips in the Delphi editor. -
What breaking changes are those? At one of my clients we upgraded all projects (many millions LOC) directly from Delphi XE & XE2 (for 64-bit) to Delphi 10.2 with no significant effort. The worst part was the tasks you'll have to do anyway every time you migrate a project from one version of Delphi to another. If they had kept up to date all the way through, they would have had to pay maintenance on 20+ licenses to get the occasional new feature they didn't really need and they would have had to fix and work around all the new bugs they got as well.
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Windows does a better job of making old applications behave well under high DPI than the VCL has so far managed. I would prefer to have the UI consistently scaled than having some parts support high DPI, some parts scaled and some messed up.
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You must love the Windows Update policy in Windows 10.
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Yes, we've had that discussion already. No thanks.
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pre-generic dictionary class
Anders Melander replied to dummzeuch's topic in Algorithms, Data Structures and Class Design
Probably not, but either use Duplicates=dupIgnore or do the test manually. Don't do both. -
pre-generic dictionary class
Anders Melander replied to dummzeuch's topic in Algorithms, Data Structures and Class Design
IMO it's not that clear what he needs. dupError is set which means that duplicates should cause an exception, but the code explicitly produce duplicates - and prevents them from being added. Anyhow, I don't think I have anything to contribute on the topic that a quick google search couldn't have provided in the first place. -
pre-generic dictionary class
Anders Melander replied to dummzeuch's topic in Algorithms, Data Structures and Class Design
Here: Okay, but setting Sorted=True and then adding to the list will keep the list sorted; It's using binary search to find the insertion point so it's not that bad, but it might be better to add unsorted and then sort at the end. It depends on the dataset. -
Tell them you agree. If the applications are in maintenance mode then I don't see any reason to upgrade, potentially introducing new problems with no benefit to the company or its customers. Keeping Delphi, and 3rd party libraries, up to date is a costly investment and unless a product is being actively developed that investment might not yield a sensible return. Whenever someone mentions the idea of a completely rewriting something from scratch I simply respond "Like Netscape?" https://www.joelonsoftware.com/2000/04/06/things-you-should-never-do-part-i/ I've been through a couple of successful complete rewrites myself, but they were architectural rewrites that were done incrementally. We basically refactored everything one tiny thing at a time until we finally arrived at the destination, many years later. And we stayed with Delphi. An incremental rewrite isn't really possible when you're replacing the platform.
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Threads in PPL thread pool not returning to idle as expected
Anders Melander replied to GeMeMe's topic in RTL and Delphi Object Pascal
I see. But I'm guessing the introduction of a lock, even if it's a spin lock, might influence the thread schedule. IMO an interlocked increment would have been better for the verification part. -
Threads in PPL thread pool not returning to idle as expected
Anders Melander replied to GeMeMe's topic in RTL and Delphi Object Pascal
Is that change relevant to your patch? It's hard to compare the results when more than one factor has changed. -
pre-generic dictionary class
Anders Melander replied to dummzeuch's topic in Algorithms, Data Structures and Class Design
It's a bit hard to see what exactly it is you're benchmarking with that code. Your first loop is supposedly meant to measure Add performance, but it also contains a Lookup. And after the first iteration of the outer loop it just produces duplicates, but then skips all those duplicates. Also your test is too synthetic. Use realistic data instead. I'm guessing your actual data isn't all possible three character strings with perfect distribution... And is sorting the stringlist after each insert really a realistic scenario? If you're really that interested in the performance of your dictionary I suggest you profile with real data instead of this guesswork. -
AddFontResource/Ex not working on some machines
Anders Melander replied to Dave Nottage's topic in Windows API
Have you tried installing the fonts manually on these machines? -
Interesting size reduction algorithm for HashTable
Anders Melander replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
There was nothing in what I wrote that was directed at you personally but if I have offended you I apologize for that. I really do understand your POW and I agree with most of the problems you and others have, repeatedly, pointed to. What I object against is the one sided, two dimensional, demonization of Embarcadero. I too have been down the road of a disgruntled customer. I experienced a great misalignment between the needs of me and my company as a customer and the direction Embarcadero took with Delphi. There was also the whole Resource Editor debacle, which I won't go into here. We knew from experience that complaining about things didn't make any difference, so we decided to vote with our money. After Delphi XE we cancelled all maintenance contracts and recommended to our clients that they do the same. Personally I stopped participating in the community and I no longer released any open source stuff. Basically I took my ball and went home. That was 10 years ago. Around the time Delphi 10.2 was released I had finally cooled down. I had also come to the realization that the primary reason why I became a disgruntled customer in the first place was that my expectations were wrong. I had once seen Borland as "my friend" and I hadn't adjusted to the new reality of Delphi struggling to survive and stay relevant. I expected them to behave in a certain way and when they didn't I was disappointed. I not taking all the blame for that because they certainly tried to make us believe in the dream. I'm taking the blame for believing it. -
Interesting size reduction algorithm for HashTable
Anders Melander replied to Tommi Prami's topic in Algorithms, Data Structures and Class Design
I don't like it either. Like everyone else I would love for every bug to be fixed yesterday, the compiler to produce better code, the VCL and RTL to support all the new shiny stuff and that my wife was 20 again. I'm assuming Embarcadero has the same wishes (Okay, maybe they don't care about my wife) but obviously their first priority is to make money. They're not in it for the Karma. I myself used to be very vocal in the field test newsgroups in my critique of the decisions made by the various owners of Delphi during the years, to the point that I was asked not to participate in the field tests. So it's not like I don't understand the frustration or the need to vent it. However I also know that I don't know all about why they make the decisions they do. If I were in their shoes I might make the exact same decisions. Of course they make mistakes. They make huge mistakes sometimes *cough* Delphi 8 *cough*. That is obvious to all. But it gets really tiresome to constantly read this whining about how bad Delphi is or how evil Embarcadero are. It's leading nowhere. Not a day goes by that I don't curse some part of Delphi to hell, but at the same time Delphi has payed for my house, my cars, my children's education and all my vacations. Anyway, this has nothing to do with hash tables. Sorry for hijacking the thread.