Ishai's WebLog

Update on Virtual PC and profiling

Last year, Richard explained why sampling does not work on Virtual PC . Since the sampling failure is quite catastrophic, we blocked all profiling on Virtual PC. Some Beta users noticed that we block profiling also for instrumentation-based profiling.

Bugs that hide from debuggers

Sometimes running a program under a debugger makes it work. Running the same program without a debugger causes a failure or a crash. Here are some reasons why this can happen: 1. Timing - attaching a debugging changes timing and can hide race conditions.

x64 calling convention and the disappearing process syndrome

Raymond Chen describes the parameter passing aspect of the x64 calling convetions . But there is more than parameter passing to the calling convention. Exception handling is an important part of the calling convention. A function that calls another function

Why doesn’t sampling show the actual time spent in each function?

Some people have asked for a “wall clock time” column in the sampling profiler report. Unfortunately, the actual time spent in a function cannot be reliably deduced from the collected data. Sampling counts “hits” on a function when a certain event occurs.

There are no Safe Functions – only Safe Programming

The Platform SDK includes a set of string manipulation functions defined in strsafe.h . These functions were added during the Windows Security push . The functions offer an alternative to the C run-time string functions which is more consistent, and less