The Wiert Corner – irregular stream of stuff

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

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Archive for the ‘Conference Topics’ Category

Laptop fan profiling, and debugging them – related to Profiling | CommitStrip

Posted by jpluimers on 2019/07/23

A while back, I posted the “profiling” CommitStrip on[WayBack] Profiling – Jeroen Wiert Pluimers – Google+. Boy how did I not know that within a week, I bumped into a “laptop fan profiling” artefact.

A coworker noticed, that when starting a thread based equivalent of [WayBack] TTimer Class (which cannot be used in services as it depends on the VCL), then sometimes the laptop fans would spin up.

What basically happened was that for certain combinations of Enabled and Interval the Execute would loop burning 100% of one CPU core.

With 3 or more – sometimes 2 – of these threads active on a 4+4 core (4 are hyper-threaded), the processor fan would start to spin like madness.

Finding the solution was somewhat easy too:

  • Process Explorer would show the thread IDs burning the most CPU cycles
  • Delphi shows the Thread IDs in the Thread Status pane (if they are named, the ID is at the end of the name in parenthesis)
  • At around Delphi 2010, you can Freeze or Thaw threads. This allows you to debug only a single thread by freezing all others.

Focussing on one thread, allowed a close inspection of the loop, quickly finding the actual cause and repairing it.

TTimer Thread

A similar and better class is at [WayBack] multithreading – TTimerThread – Threaded timer class – Code Review Stack Exchange, based on [WayBack] timer – Using VCL TTimer in Delphi console application – Stack Overflow.

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Posted in Conference Topics, Conferences, Debugging, Delphi, Development, Event, Fun, Multi-Threading / Concurrency, Profiling-Performance-Measurement, Software Development | Leave a Comment »

CAA Mandated by CA/Browser Forum | Qualys Blog

Posted by jpluimers on 2019/07/22

[WayBack] CAA Mandated by CA/Browser Forum | Qualys Blog

Certification Authority Authorization (CAA), specified in RFC 6844 in 2013, is a proposal to improve the strength of the PKI ecosystem with a new control to restrict which CAs can issue certificates…

Related:

–jeroen

Posted in Conference Topics, Conferences, DNS, Encryption, Event, HTTPS/TLS security, Internet, Power User, Security | Leave a Comment »

delphi – How to hide the inherited TObject constructor while the class has overloaded ones? – Stack Overflow

Posted by jpluimers on 2019/07/18

Interesting, need to try this one day to see how well this works so the base constructor TObject.Create cannot be called.[WayBack] delphi – How to hide the inherited TObject constructor while the class has overloaded ones? – Stack Overflow

–jeroen

Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

DelphiTips/RecordProperty at master · tothpaul/DelphiTips · GitHub

Posted by jpluimers on 2019/06/13

Out of the box, Delphi does not support record properties because of two lacking features:

Paul Toth worked around both at [WayBack] DelphiTips/RecordProperty at master · tothpaul/DelphiTips · GitHub

He uses an intermediate helper where he redirects the get/set methods to from a property registration call.

Note that in the past, Pieter Zijlstra did a similar thing, but bumped into a Delphi 2010 problem where the status indicates it is till open: [WayBack] QualityCentral: 77635 – Open – The new RTTI of D2010 causes components with published record properties to fail to stream in.

Source: Yes ! I’ve published a Record property it could be nice to have this feature…

Via: [WayBack] Yes ! I’ve published a Record property it could be nice to have this feature in Delphi, but we need RTTI for record properties to simplify the code (an… – Paul TOTH – Google+

–jeroen

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Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

Cyclomatic Complexity of switch case statement – Stack Overflow

Posted by jpluimers on 2019/06/12

For my archive: [WayBack/Archive] Cyclomatic Complexity of switch case statement – Stack Overflow.

Ultimate reference: [WayBack/Archive] NIST Special Publication 500-235: Structured Testing: A Testing Methodology Using the Cyclomatic Complexity Metric

Via: [WayBack/Archive] I have a question regarding Cyclometric Complexity… IF versus CASE… – David Hoyle – Google+

–jeroen

Posted in .NET, C#, Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

The red zone, is why you want immutable constructs

Posted by jpluimers on 2019/05/23

Most code I come across is in the red zone, exactly depicting why you want immutable constructs. Immutable constructs will never end-up in the red zone.

Image: [WayBackWayback Machine.

The red zone is just one quadrant on the mutability/shareability diagram and getting outside that red zone quadrant is key.

With processor cores now becoming ubiquitous: you cannot get outside of the “Shard” half, so you have to get outside of the “Mutable” half.

Explaining the why and how, is part of a few presentations that Kevlin Henney gave:

Related YouTube videos are below.

–jeroen

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Posted in Conference Topics, Conferences, Development, Event, Multi-Threading / Concurrency, Software Development | Leave a Comment »

Useful settings for FastMM4 to tracking bottlenecks in multi-threaded memory allocation

Posted by jpluimers on 2019/05/23

Interesting thread that reminded me of the relatively new FastMM feature to track down lock contention and cope with it using release stacks:

[WayBack] I try use FastMM4 to tracking bottleneck in allocating memory. I was inspired by this Primož movie: https://www.youtube.com/watch?v=p-5mJyXvmrc When I… – Jacek Laskowski – Google+

The changes by Primož have added these two new conditional defines to the FastMM4 codebase:

These options are mutually exclusive.

This was the original post it got introduced in [WayBack] The Delphi Geek: Finding Memory Allocation Bottlenecks with FastMM4 and merged into the main repository.

FastMM introduction: [WayBack] The New Memory Manager In BDS 2006 – by Pierre le Riche.

It also taught me about [WayBack] RAMDisk – Software that Accelerates, Protects, Optimizes – Server Memory Products & Services – Dataram.

Primož stores his DCU files there: much faster than SSD, and far less wear on your SSD; see https://youtu.be/p-5mJyXvmrc?t=2675

–jeroen

Read the rest of this entry »

Posted in Conference Topics, Conferences, Delphi, Development, Event, FastMM, Software Development | Leave a Comment »

web services – Accessing the original TWebRequest object in a Delphi SOAP Server – Stack Overflow

Posted by jpluimers on 2019/05/22

Thanks Ondrej Kelle for answering this:

uses
  System.SysUtils,
  Web.HTTPApp,
  Soap.WebBrokerSOAP;

function TTest.CallMe: string;
var
  WebDispatcher: IWebDispatcherAccess;
begin
  Result := '';
  if Supports(GetSOAPWebModule, IWebDispatcherAccess, WebDispatcher) then
    Result := Format('You are calling me from: %s', [WebDispatcher.Request.RemoteIP]);
end;

Source: [WayBack] web services – Accessing the original TWebRequest object in a Delphi SOAP Server – Stack Overflow

–jeroen

Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

How to Design Early Returns in C++ (Based on Procedural Programming) – Fluent C++

Posted by jpluimers on 2019/05/15

One more thing to take away from Procedural Programming: It’s Back? It Never Went Away – Kevlin Henney [ACCU 2018] – YouTube was explained in [WayBack] How to Design Early Returns in C++ (Based on Procedural Programming) – Fluent C++.

Though in C++, it applies to all programming languages that stem from a procedural background (Pascal, C#, Java, golang, to name just a few).

The article is about keeping an if/else-if/else tree, even when they can be removed becomes some of their bodies perform an early return, as

In C++, as well as in other languages, the return keyword has two responsibilities:

  • interrupting control flow,
  • yielding a value.

It basically comes down to this argument:

Essentially, the argument for Code #1 is that you need to know less to understand the structure of the code.

Indeed, if we fold away the contents of the if statements, Code #1 becomes this:

The structure of the code is very clear. There are 4 different paths based on the year, they’re independent from each other, and each path will determine the boolean result of the function (if it doesn’t throw an exception).

Now let’s see how Code #2 looks like when we fold away the if statements:

And now we know much less. Do the if statements contain a return? Maybe.

Do they depend on each other? Potentially.

Do some of them rely on the last return false of the function? Can’t tell.

With Code #2, you need to look inside of the if statement to understand the structure of the function. For that reason, Code #1 requires a reader to know less to understand the structure. It gives away information more easily than Code #2.

–jeroen

via [WayBack] Kevlin Henney – Google+: How to Design Early Returns in C++ (Based on Procedural Programming) – Fluent C++

Posted in .NET, C, C#, C++, Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

More Delphi debug visualizers

Posted by jpluimers on 2019/05/07

I hope that by now they are available for more Delphi versions:

Some other posts around the Debug Visualiser topic:

–jeroen

Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »