September 2014 Entries
One common thing while debugging is to search who owns/references a handle. For x86 processes you can simply search the full address space but in x64 this approach no longer works. While debugging a hang from a memory dump I did find out that the process MainWindowHandle did change to a different window which was not the main window handle. Searching for the values of NativeWindow objects did also lead to no trace on the managed heap so it must be some unmanaged window handle. First I look at the ......
When you have a performance bug you usually look at your code why something takes longer than expected. In conjunction with a debugger this is a great approach for easy bugs. Things get much harder if the issue only surfaces sporadically at customer sites. Application logging which is always on helps you to see that there was a problem but since logging must not flood the hard disc you cannot log every method call with all parameters like IntelliTrace tries to do. The next level is application tracing ......
Recently I have seen an interesting performance question on SO which deals with Parallel.For in .NET. The code was basically Parallel.For(0,1000*1000*1000, i => {}); The actual work is simulated by an empty delegate which is an easy measure the overhead of Parallel.For. When you let this run on some multicore machines in x86 Release you get number like The running time is not constant as one might expect but sometimes there are slowdowns in the order of 6 times or more. With WPT is was quickly ......