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 ‘Development’ Category

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Note that the Delphi superobject library has changed to “not maintained” in december 2018, has problems with large address aware

Posted by jpluimers on 2019/05/02

A while ago I found out the [WayBack] not maintained status · hgourvest/superobject@f1c42db · GitHub.

This means you should not use the [WayBack] superobject JSON library in Delphi any more: there won’t be any fixes.

Many people use it, especially because it used to be much more stable than the built-in JSON support of Delphi.

One breaking issue in superobject is the lack of large address space support: due to the pointer calculations in various places, it does not support pointers above the 2 gibibyte boundary as filed in the 2016 [WayBack] Issues with {$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE} · Issue #22 · hgourvest/superobject · GitHub

This gives problems in at least this case:

  • enabling {$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE} (in older Delphi 7 through 2006 also versions this was {$SetPEFlags $20})
  • using top-down memory allocation, for instance by:
    • a user setting HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management value AllocationPreference to hex value 00100000
    • using FastMM4 with the (default) {$define AlwaysAllocateTopDown} setting

Example registry file and batch file to enable top-down memory (reboot afterwards):

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"AllocationPreference"=dword:00100000

Command to view:

reg query "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" | findstr "AllocationPreference"

Command to enable:

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v AllocationPreference /t REG_DWORD /d 00100000 /f

Command to disable:

reg delete "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v AllocationPreference /f

Large Address Aware is a nightmare

Be very very very careful with this, and by enabling Large Address Aware to your executables, as many times they can load 3rd party libraries that often are beyond your control.

Even if there is a slight chance that your code is being used with Large Address Aware enabled, then follow guidelines line in [WayBack] windows – Unit Testing for x86 LargeAddressAware compatibility – Stack Overflow

Summary of [WayBack] memory – Drawbacks of using /LARGEADDRESSAWARE for 32 bit Windows executables? – Stack Overflow:

blindly applying the LargeAddressAware flag to your 32bit executable deploys a ticking time bomb!

by setting this flag you are testifying to the OS:

yes, my application (and all DLLs being loaded during runtime) can cope with memory addresses up to 4 GB.
so don’t restrict the VAS for the process to 2 GB but unlock the full range (of 4 GB)”.

but can you really guarantee?
do you take responsibility for all the system DLLs, microsoft redistributables and 3rd-party modules your process may use?

Edit 20240628

Earlier this year, the SuperObject Delphi library got archived on GitHub. Definitely unmaintained: [Wayback/Archive] GitHub – hgourvest/superobject: This repository has been archived by the owner on Feb 27, 2024. It is now read-only.

The XSuperObject library mentioned below in a comment has not been maintained for 4 years either ( [Wayback/Archive] GitHub – onryldz/x-superobject: Delphi Cross Platform Rapid JSON: “vkrapotkin Now ParseFromFile can read UTF8-BOM files (#136) 2d3ec01 · 2020-12-09”), so I wonder what alternatives are still available.

--jeroen

Posted in Conference Topics, Conferences, Delphi, Development, EKON, Event, Software Development | 4 Comments »

@rw@mastodon.social on Twitter: “Personally, I prefer to increase the spacing for each successive indent according to the Fibbonaci sequence:… “

Posted by jpluimers on 2019/05/01

Awesome! [WayBack] @rw@mastodon.social on Twitter: “Personally, I prefer to increase the spacing for each successive indent according to the Fibbonaci sequence:… “

Via [WayBack] The indentation debate just ended – G+ – CodeProject

–jeroen

Posted in Development, Fun, Software Development | Leave a Comment »

Delphi function result assignments before the function returns…

Posted by jpluimers on 2019/05/01

Eric Grange:

Actually it is not that assignments of function return values can happen “when the function raises an exception” but rather than they can happen before the function returns.

Note that this is not limited to large return types, it can also happen on reference counted types (string, dynamic array, variant and interface), though this is contextual as well…

Got bit by the interface thing a few months ago, an interface release was triggering an exception when the result was assigned, the call stack looked way out of synch with the code, so various compilation and and map file mismatch issues got investigated, before I dropped in asm view in the debugger, which made it all obvious.

I’ve quoted it in full as I’ve been bitten by this a few times as well, but never got to making a proper blog post on it.

Thanks Eric for phrasing this and David for bringing it up.

It actually has been the case since somewhere toward the end of the Turbo Pascal era.

Source: [WayBack] This program: {$APPTYPE CONSOLE} uses System.SysUtils; type TRec1 = r…

–jeroen

Posted in Delphi, Development, History, Pascal, Software Development, Turbo Pascal | Leave a Comment »

No, Visual Studio Community 2017 is not a 30 day trial – via Stack Overflow

Posted by jpluimers on 2019/04/30

Visual Studio Community 2017 needs a license renewal every ~30 days with a Microsoft account: [WayBack] Visual Studio Community 2017 is a 30 day trial? – Stack Overflow.

This means it is not a trial, but it does not a Microsoft account, and communicate with it every ~30 days which you can get at [WayBack] Microsoft account | Sign In or Create Your Account Today.

Messages you can get:

  • “We could not download a license. Please check your network connection or proxy settings” – meaning: sign in with a Microsoft account by clicking “Add an account…”
  • “We could not download a license, Please ensure your accounts are authenticated.” – meaning you have to click “Reenter your credentials”

–jeroen

Posted in .NET, Development, Software Development, Visual Studio 2017, Visual Studio and tools | Leave a Comment »

bash – aliasing cd to pushd – is it a good idea? – Unix & Linux Stack Exchange

Posted by jpluimers on 2019/04/30

On my research list: [WayBack] bash – aliasing cd to pushd – is it a good idea? – Unix & Linux Stack Exchange

It has a nice discussion on complements to pushd/popd/cd/dirs including a very nice set of navd scripts that eases the navigation of the directory stack.

I found it because the ESXi busybox does not have pushd and popd and a cd won’t work from inside a shell script: [WayBack] linux – Why doesn’t “cd” work in a bash shell script? – Stack Overflow

It also made me find out that the ESXi busybox does support cd - to go to the previous directory. More info on that cd syntax is at [WayBack] bash – Difference between “cd -” and “cd ~-” – Unix & Linux Stack Exchange

–jeroen

Posted in *nix, bash, Development, ESXi5, ESXi5.1, ESXi5.5, ESXi6, ESXi6.5, Power User, Scripting, Software Development, Virtualization, VMware, VMware ESXi | Leave a Comment »

compiling – Where do executables look for shared objects at runtime? – Unix & Linux Stack Exchange

Posted by jpluimers on 2019/04/30

Thanks Gilles for answering [WayBack] compiling – Where do executables look for shared objects at runtime? – Unix & Linux Stack Exchange.

Abstract:

In a nutshell, when it’s looking for a dynamic library (.so file) the linker tries:

  • directories listed in the LD_LIBRARY_PATH environment variable (DYLD_LIBRARY_PATH on OSX);
  • directories listed in the executable’s rpath;
  • directories on the system search path, which (on Linux at least) consists of the entries in /etc/ld.so.conf plus /lib and /usr/lib.

–jeroen

Posted in Development, Software Development | Leave a Comment »

Does anyone have the source from the book: The Tomes of Delphi: Algorithms and Data Structures…

Posted by jpluimers on 2019/04/25

Since I need this one day: [WayBack] Does anyone have the source from the book: The Tomes of Delphi: Algorithms and Data Structures by Julian Bucknall? – John Kouraklis – Google+

–jeroen

Read the rest of this entry »

Posted in Delphi, Development, Software Development | Leave a Comment »

UPDATE OR INSERT

Posted by jpluimers on 2019/04/25

I totally forgot that Firebird as of 2.5 supports [WayBack] UPDATE OR INSERT, so as a reminder to self:

UPDATE OR INSERT INTO
   {target} [({column_list})]
   VALUES ({value_list})
   [MATCHING ({column_list})]
   [RETURNING {values} [INTO {variables}]]

{column_list}      ::=  colname    [, colname   ...]
{value_list}       ::=  value      [, value     ...]
{ret_values}       ::=  ret_value  [, ret_value ...]
{variables}        ::=  varname    [, varname   ...]

–jeroen

Posted in Database Development, Development, Firebird | Leave a Comment »

Getting rid of bugs: mark them as “new feature” – as cancelling a  THTTPClient.BeginGet() does not work as intended

Posted by jpluimers on 2019/04/24

I have seen this happen before, but it seems to be a habit on the Quality Portal: getting rid of bugs by marking them as “new feature”:

[WayBack] I’m using THTTPClient.BeginGet() to create an async get request to a webservice that holds a connection open until it has data to return (sort of like a… – Brian Ford – Google+. which basically was another person finding out about [RSP-20827] THTTPClient request can not be canceld – Embarcadero Technologies, which got marked (a month after submission!) as “Issue is reclassified as ‘New Feature'”.

I get why it happens (there was something exposed, but some of the functionality is missing a feature which needs to be added).

Marking it as such however sends the wrong signal to your users: we do not see bugs as bugs, so they get on the “new feature” pile with no estimate on when the feature will be done.

–jeroen

Posted in Delphi, Development, Issue/Bug tracking, Software Development | Leave a Comment »

Firefox 29 and up: “The connection has timed out”

Posted by jpluimers on 2019/04/24

A few years ago, Firefox changed the default “network.http.response.timeout” value from zero to 300 seconds (5 minutes).

Display style systems that show refreshing web pages, this can be a problem as when the connection to the web-server is unavailable for more than 5 minutes, then the page will show “The connection has timed out” and stop refreshing.

The solution – apart from fixing each and every connection problem – is to either restore the value or make it very long:

  • network.http.response.timeout=0
  • network.http.response.timeout=30000

Changing this works similarly like in A way to skip the Firefox “Well, this is embarrassing” during a sudden reboot « The Wiert Corner – irregular stream of stuff:

  • Open Firefox
  • Type about:config in the addressbar
  • Confirm the
    This might void your warranty!
    by clicking
    I accept the risk!
  • Search for network.http.response.timeout
  • Double click it so the value changes from the default value 0 to the user set value 0

–jeroen

Via:

Posted in Development, Firefox, Power User, Scripting, Software Development, Web Browsers, Web Development | Leave a Comment »

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