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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘.NET’ Category

Great diagram on composing a LINQ query – via Mastering C# – CodeProject

Posted by jpluimers on 2017/08/17

One of the best to graphs diagrams of LINQ I know is in Mastering C# – Lecture Notes Part 2 of 4 – CodeProject [WayBack]

The LINQ explanation in that article [WayBack] is top notch as well. Thanks Florian Rappl [WayBack]!

–jeroen

Posted in .NET, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C# 6 (Roslyn), Development, Software Development | Leave a Comment »

Closed: HDD Guardian – Home

Posted by jpluimers on 2017/08/16

Too bad: it was fun while it lasted.

Mid april 2017 [WayBackHDD Guardian – Home closed down, so the latest commit removed all the [WayBackHDD Guardian – Source Code.

HDD Guardian provides a Windows front-end for smartctl, a utility which monitors your hard drive(s) and SSD(s) for health status, taking advantage of S.M.AR.T.

The WayBack machine and Archive.is have archived some links though:

Anyone interested in getting it before codeplex itself shuts down:

git svn clone https://hddguardian.svn.codeplex.com/svn

–jeroen

Posted in .NET, Development, Power User, Software Development, VB.NET, Windows | Leave a Comment »

On List growth strategies and memory managers

Posted by jpluimers on 2017/08/03

Interesting for anybody working on list growth strategies.

In this case with some Delphi background information and in depth coverage of FastMM memory (re)allocation strategies.

Stefan Glienke (of Spring4D fame) needed some help with allocation strategies and observed the difference between:

  • TList.Grow (and TStringList.Grow) growing like this: 4, 8, 12, 28, 44, 60, 76, 95, 118, 147, 183, 228, 285, 356, 445, 556, 695, 868, 1085
  • Generic TList<T> growing  the same way as the .NET List<T>: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024

There is this nice Dynamic array – Growth factor – Wikipedia, the free encyclopedia mentioning this table:

Implementation Growth factor (a)
Java ArrayList[1] 1.5 (3/2)
Python PyListObject[7] 1.125 (9/8)
Microsoft Visual C++ 2013[8] 1.5 (3/2)
G++ 5.2.0[5] 2
Clang 3.6[5] 2
Facebook folly/FBVector[9] 1.5 (3/2)

Javier Hernández mentioned he doesn’t think exponential is better than n^2.

Eric Grange (of DWS and beginend.net fame) mentions he tends to use 1.5, it is about as good as 2 for small lists, but reduces waste for large ones. He also uses a constant delta to accelerate growth early on, so something like:

n := n + (n div 2) + 8

Since allocation strategies highly depend on the memory allocator as well, I was glad Primož Gabrijelčič (of OnmiThreadLibrary and Smart Mobile Studio fame) elaborated on FastMM:

  • FastMM small block allocator sizes (size includes the leading header) are: 8, 16, 24, 32, … 160 (in +8 steps), 176, 192, … 320 (+16), 352, 384 … 480 (+32), 528, 576, … 672 (+48), 736, 800, 880, 960, 1056, 1152, 1264, 1376, 1504, 1648, 1808 , 1984, 2176, 2384. [FastMM4.pas, SmallBlockTypes global var]
  • While the size of reallocated region fits inside a small block (with a different size than a previous block), the data is moved around (new block is allocated from a new suballocator). If it is too big (>2384 bytes), it gets allocated from the medium block allocator (which handles all block sizes up to 264752 bytes; larger blocks come directly from VirtualAlloc).
  • When small blocks are reallocated (to a larger size), allocator always allocates at least 100% + 32 bytes larger block, even if less is requested by the RTL (example: 8 bytes will grow to 2*8 + 32 = 48 bytes). When medium blocks are reallocated, allocator always allocates at least 125% of the old size. This boosts the performance when blocks are enlarged by small values as they can be enlarged “in place” (no data moved around, just the header is adjusted).

Stefan Glienke and Primož Gabrijelčič then concluded that:

  • Resizing an array from say 4 elements (pointer size) to 1000 (in multiple steps) will for sure move several times when jumping from one region into the next larger one.
  • Changing to a growth factor of 1.5 vs 2 won’t change anything in terms of memory fragmentation in FastMM4.

Source: I was just looking at TList.Grow (and TStringList.Grow) and I realized that the…

–jeroen

Posted in .NET, Delphi, Development, Java, Java Platform, Software Development | 7 Comments »

Microsoft Research’s manual memory management for .NET: exactly one owner which provides shields for accessing the objects

Posted by jpluimers on 2017/08/01

A very interesting piece of research, in which I see a very familiar concept of single owners and I new concept of them providing shields for accessing the manually managed memory. I do miss mentions of Anders Hejlsberg, Chuck (Charles) Jazdzewski, or others that lay the foundation of ownership in the [WayBackTComponent Branch.

Microsoft Research’s manual memory management for .NET: https://www.microsoft.com/en-us/research/wp-content/uploads/2017/07/snowflake-extended.pdf

Interesting concept of manual but safe memory management with exactly one owner of an object at any given moment and shields that prevent an object’s destruction while it’s still in use by other threads.

Source: [WayBackChristopher Wosinski – Google+

–jeroen

Posted in Delphi, .NET, Software Development, Development, History | Leave a Comment »

Anyone having a solution for “Microsoft Visual Studio” throwing “The operation could not be completed” when including a file in a PowerShell project?

Posted by jpluimers on 2017/06/22

The operation could not be completed.

The operation could not be completed.

Include In Project

Include In Project

I’ve got a bunch of PowerShell projects in a solution. In some of them, I can include new files, in others I get the below error.

The diff of a good/bad project is below as well.

Two questions:

  1. Does anybody know how to work around this?
  2. Does anybody know how to find the actual error for this?

---------------------------
Microsoft Visual Studio
---------------------------
The operation could not be completed
---------------------------
OK
---------------------------

Good file: WindowsLogsCbsInquiry.pssproj

Bad file: WindowsTempInquiry.pssproj

–jeroen

Read the rest of this entry »

Posted in CommandLine, Development, PowerShell, Software Development, Visual Studio 2015, Visual Studio and tools | Leave a Comment »

 
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