Performance By Design

As I mentioned in the previous post , run-time libraries in Windows provide services for applications running in User mode. For historical reasons, this run-time layer in Windows was always known as the Win32 libraries, even when these services are requested in the 64-bit OS in 32-bit mode. A good example of a Win32 run-time service is any operation that involves opening and accessing a file somewhere in the file system (or the network, or the cloud). A more involved example is the set of Win32 services an application needs to access to play an audio file, including understanding the specific audio file compressed format, and checking authorization and security. For Windows 8, a portion of the existing Win32 services in Windows were ported to the ARM hardware platform.  The scope of the Win32 API is huge, and it was probably not feasible to convert all of it during the span of a single, time-constrained release cycle. Unfortunately, the fact that the new Windows 8 Runtime librar...

This is the next installment in a series of blog posts on the recent Windows 8 release that I began a few months back . In the last entry I expressed some reservations about the architectural decisions associated with the new Windows Runtime API layer. In this post and the ones that follow, I will provide more detail about my concerns as we look inside the new Windows Runtime layer. But, first, we will need some background on the native C language Win32 API, COM, and the Common Language Runtime (CLR) used in the .NET Framework. Collectively, these three facilities represent the run-time services available to Windows application prior to Windows 8. As I mentioned in the earlier posts, the new Windows Runtime layer in Windows 8 is a port of a subset of the existing Windows Win32 run-time to run on the ARM hardware platform. Windows Run-time Libraries Run-time libraries in Windows provide an API layer that applications running in User mode can call to request services fr...

In the last post on Windows 8 and the new Windows Runtime libraries for Windows Store apps, I mentioned that the key deliverable in the new version of the Windows OS is the port to the ARM platform. In this post, I will discuss the implications of Windows running on ARM, emphasizing the impact of “plug-and-play” device driver technology. In porting the core of the OS to the ARM platform, Microsoft was careful to preserve the interfaces used by device driver developers, ensuring that there was a smooth transition. Microsoft wanted to allow customers to be able to attach most of the peripherals they use today on a Windows 7 machine to any ARM-based tablet running Windows 8. What is ARM? In discussing the Windows 8 port to the ARM platform with some folks, I noticed that not everyone is familiar with the underlying hardware, that it runs a different instruction set than Intel-based computers, that it is not Intel-compatible, etc. So, let’s start with a little bit about the ARM hardw...