Tips, Hints and Documentation Posts for SamplingProfiler and other Delphi Tools
Here are a few findings on Multi-Read Exclusive-Write Synchronizer from a recent upgrade of DWScript‘s GlobalVar functions.
I ran some comparisons between a plain Critical Section, Delphi’s TMultiReadExclusiveWriteSynchronizer and Windows Slim Reader/Writer Lock, of which an implementation was added to the dwsXPlatform unit.
I’ve activated a small random pass phrase secure service based on DWScript Web Server.
You can reach it at
Here is a small utility I made whose purpose is to flush (empty) the Windows file cache. It can also flush and purge memory working sets, standby and modified lists.
It can be useful to reduce memory usage of a particular VM (on a host with dynamic memory) or for testing and bench-marking purposes.
Delphi offers two ways of enumerating files in a directory and its sub-directories, the first is the classic (and buggy) FindFirst/FindNext, the second is IOUtils TDirectory.GetFiles and not very efficient.
Here is why and how I implemented DWScript‘s dwsXPlatform.CollectFiles, and a tip about getting a small system-wide boost as a bonus.
Or in other words, before getting to the gory details, DWScript now works when compiled with {$HIGHCHARUNICODE ON} on a machine with Cyrillic code-page 1251.
DWScript was converted years ago to Unicode, and been working just fine.
But there was a leftover bug from that crossing of the Styx.
[This is a guest post, written by Primož Gabrijelčič, www.
One thing interested me since I started reading Eric’s series on string concatenation performance – how would different memory managers compare in a multi-threaded scenario. Today I decided to spend an hour finding out…
edit 18/11: the tests were run with debug mode, which affected TTextWriter very negatively (TWOBS is also affected a negatively, but less, and StringBuilder and Trivial aren’t affected much). I’ll be repeating tests with more memory managers and in more stable conditions in the next few weeks.
By popular request, here is the source code used for the previous String benchmarks StringConcatBench.zip, essentially to test alternative memory managers.
The source is nothing complicated as you will see, just a set of simple function with the test cases, and a couple function that measure run times.
After looking at String concatenation and String Building in Delphi, and as a conclusion, it’s time to have a brief look at what happens in multi-threaded settings, such as in a server pushing JSON, XML or some other text data.
Time for some Halloween silliness: here is a quick & dirty JavaScript to pimp your website, blog or whatever with a randomly moving vampire bat animation.
Or a dozen. Or a whole flock.
As a followup to the String Concatenation article, let’s take a look at a less trivial case: what if instead of concatenating a couple strings, you want to concatenate a few hundred?
Sounds like a task at which TStringBuilder should excel, but one should never assume, and always measure.