When you hear about threads and threading, you hear that they allow concurrent execution of code, which is supposed to lead to better performance. Most computers nowadays have more than one CPU, meaning that each CPU can be executing code at the same...

A long time ago I worked in the Green Building (building 54 at MIT) .   Several NASA Apollo lunar missions (I think 11, 12, 14… I know it wasn’t 13 J ) placed seismometers on the moon, in various locations. They didn’t detect earth quakes. The Moonquakes...

  Sometimes your program wakes up and finds itself running in an environment that might not be as suitable as you’d like.   For example, it might be distributed to a user running on a machine with not enough memory, and could be failing. Perhaps...

  I have some code that attaches and injects code into a target application (like Visual Studio or IE) to examine its memory use. In order to do that, my code freezes the target.   I wanted my application to respond to WM_QUERYENDSESSION so...

  Here’s a pattern of code use I’ve seen in a few places. There’s a function DeserializeList that returns an array of various sizes, depending on the input. This code can be called to deserialize (rehydrate) an object from a stream. For example,...

Last time ( Improve your managed debugging skills: examining registers and memory ) we examined some debugging techniques to understand the behavior of managed code. It might take a long time or many manual steps to reproduce a particular software...

  I was helping a colleague and we were deep in the middle of a debug session, single stepping some code and we wanted to see a value in the debugger. The debugger showed either nothing, because the intermediate value has been optimized out, or a...

The sounds that we hear can be recorded via a microphone and can be graphed as a signal of amplitude versus time. Low notes show as a lower frequency wave, and high notes show as higher frequency waves. Over the past few decades, some music players, like...

  As you know, a treeview control is very useful for viewing hierarchical information. Each node in a tree can have its own parent/child relationships.   Some of these trees can be extremely large, and can thus be prohibitively expensive to...

  Last month   in   Dynamically create huge tooltips in WPF TreeView and ListView I showed some code that creates large tooltips to present lots of data.   Today, we’ll talk about creating automatic tests for this feature.   Testing...

  Tooltips are useful. When the mouse hovers over a button a tip can indicate what happens when it’s clicked. The mouse move does not actually invoke the button, but can give information in a passive way.   Sometimes I want to make huge tooltips...

Sometimes you need to write a method that requires recursion to be elegant. Often that method needs to accumulate data between recursion levels There are many ways to do so, and some are more elegant than others. I like the Optional Parameter method...

In the old days (about 16 years ago), FoxPro’s object, containership and inheritance models made it easy to put objects inside other objects. So, for example, a FoxPro grid of Customers could have a column containing a grid of each customer’s orders,...

In this post What is your computer doing with all that memory? Write your own memory browser is sample code that shows how to create a WPF grid view of a memory map of a process. You can click on a column header to sort, and you can see the various loaded...

What is the cost of using nothing? Seems like a silly question. Suppose you see code like this: void * MyClass::DoSomething() { int size = sizeof(MyThing) * m_NumItems; var ptr = malloc(size); return ptr; } It’s a method...

Sometimes you forget that GC’s occur: it’s hard to see it’s effect, but what does Garbage Collection do to your code? A long time ago (3 decades!) I used Fortran and Assembly code for a PDP-11 16 bit computer to design real time...

I was running out of disk space and wanted to see what was eating the most. About 6 years ago I wrote a FoxPro version of a TreeMap program that shows a rectangle subdivided into various subrectangles, each proportional to the amount of space...

Sometimes you just want to see data in a tabular format. It could be stored in a server somewhere in the cloud, in a SQL server, a FoxPro database, an EntityFramework object, or just a local object. You’d like to see all columns, without having...

I tried adding a new ADO.NET Entity Data Model item to a VS 2010 solution, but I got this error message: Error HRESULT E_FAIL has been returned from a call to a COM component. It worked just a few days ago…hmmm…. I had another...

Why does your code take so long to run? How do you improve its performance? When examining code, it’s very difficult to know which piece takes the longest, and thus should be the target of you optimization efforts. For example, you won’t...

Often your code gets run on a machine far away and it’s useful to gather some information about that machine automatically, perhaps for error reporting or statistics gathering. This information could include the Operating System version, how...

When you run your VB or C# application, you might get an OutOfMemoryException thrown, even if your machine has lots of memory. Every 32 bit process has a 2^32 bit (4 Gig) address space. That means every pointer has a size of 32 bits (4 bytes) and...

You can learn all sorts of information about your application using Perfmon. You can also inspect various aspects of managed memory. How much time is spent in garbage collection? When managed code runs, memory management is done for you, but at...

Writing WPF code is made easier in VB because of the built in XML features (XAML is really XML). Here is a sample that creates a TreeView of some folders on disk. Suppose we want to add a Trigger style that will fire when the mouse is over an item...

You can inspect the processes that run on your machine using Task Manager (Ctrl-Shift-Escape) or , Process Explorer from Sysinternals Or you can write your own: here’s source code: What is your computer doing with all that memory? Write your...