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Uniquely Identifying a Module's Build

It is common practice to embed a version resource (VS_VERSIONINFO) into PE images such as DLL and EXE files. While this resource mainly serves informational purposes, the version information is occasionaly used to perform certain checks, such as verifying the module’s suitability for a particular purpose. Under certain circumstances, however, this versioning information may be too imprecise: Versions are not necessarily incremented after each build, so it is possible that two copies of a module carry the same versioning information, yet differ significantly in their implementation. Continue »

RCW Reference Counting Rules != COM Reference Counting Rules

Avoiding COM object leaks in managed applications that make use of COM Interop can be a daunting task. While diligent tracking of COM object references and appropriate usage of Marshal.ReleaseComObject usually works fine, COM Interop is always good for surprises. Recently having been tracking down a COM object leak in a COM/.Net-Interop-centric application, I noticed that the CLR did not quite manage the reference count on my COM object as I expected it to do – more precisely, it incremented the referece count of a COM object when it was passed (from COM) as a method parameter to a callback implemented in . Continue »

cfix 1.3.0 Released, Introducing WinUnit Compatibility

cfix 1.3, the latest version of the unit testing framework for C/C++ on Windows, has just been released. As announced in the last blog post, the major new feature of this release is WinUnit compatibility, i.e. the ability to recompile existing WinUnit test suites into cfix test suites without having to change a single line of code. To demonstrate that this compatibility indeed works, consider the following simple example: Continue »

Embracing WinUnit

Around two years ago, in early 2007, after having read about, having tried, and finally having dismissed numerous existing unit testing frameworks for C, I resigned and started thinking about creating a new unit testing framework. Having been accustomed to NUnit and JUnit, I found most frameworks clumsy to use – some “frameworks” like MinUnit are a joke, some frameworks like CUnit require lots of boilerplate code to be written, some frameworks only support C++ but not C, and some manage to combine the worst properties of them all (CppUnit). Continue »

Bryan Cantrill on Real-World Concurrency

Browsing through ACM Queue’s archives I came across the article Real-World Concurrency by Bryan Cantrill (who, by the way, is the inventor of DTrace) and Jeff Bonwick (Issue 5⁄2008). The article provides a nice summary of actual challenges and best practices for systems programming in a multithreaded/shared memory environment. Worth reading. Continue »

Working Around TlbImp's Cleverness

TlbImp, the .Net tool to create Interop assemblies from COM type libraries, contains an optimization that presumably aims at making the consumption of the Interop assembly easier, but ultimately is a nuisance. Consider the following IDL code: import "oaidl.idl"; import "ocidl.idl"; [ uuid( a657ef35-fea1-40ad-86d8-bb7b6085a0a3 ), version( 1.0 ) ] library Test { [ object, uuid( 84b2f017-b8fe-4c2c-87b8-0587b4bf5507 ), version( 1.0 ), oleautomation ] interface IFoo : IUnknown { HRESULT Foo(); } [ object, uuid( 13d950d6-beb3-4dd3-957b-88b0e5eb5e3f ), version( 1. Continue »