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.
[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.
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.
Or a dozen. Or a whole flock.
You may all know about String concatenation in Delphi, but do you know about the implicit String variables the compiler may create for you?
Along with the implicit variables come implicit exception frames, and a whole lot of hidden stack juggling, which can quickly become hidden complexity bottlenecks.