Measuring how difficult a Threading bug is

re: Measuring how difficult a Threading bug is

Nicholas Allen — Mon, 04 Apr 2005 04:07:35 GMT

Code running in an OS/platform callback. You can be running with internal locks held that aren't documented allowing you to unexpectedly deadlock or silently corrupt OS data structures in a way that causes a bug in the far future. It may not even be possible to debug your code normally because debugging no longer functions. Examples: loader lock, audio subsystem.

6-8 depending on how well documented the callback function is.

Race condition/locks taken against hardware. Debugging the other side is impossible, little chance of getting the hardware changed, and the problem might only be visible below any software (processor, system bus, an expansion card). Examples: video cards, sound cards, anything that electrically resets on fault.

8-10 depending on the hardware quality.

re: Measuring how difficult a Threading bug is

Pavel Lebedinsky — Mon, 04 Apr 2005 08:08:45 GMT

> Win32 events (aka conditional variables)

Condition variables are not the same as win32 events. If anything, they are closer to System.Threading.Monitor.

In general I think that monitor-style code is easier to write and debug than equivalent code using low-level primitives like events.

re: Measuring how difficult a Threading bug is

Dmitriy Zaslavskiy — Mon, 04 Apr 2005 18:53:16 GMT

Somewhere with #9. Is the memory model related issues (that people seem to ignore). CPU reordering is a real issue (for algorithms that try to avoid even critical section, or just trying to be cute). What's very commonly overlooked is that reordering happens not only on IA64 but also on x86 (IA32)

Optimize for Simplicity

Mike Stall's .NET Debugging Blog — Thu, 28 Jun 2007 19:25:06 GMT

For a compiler, the common things are code size vs. speed . The conventional wisdom is to optimize for

Why threading is hard

Noticias externas — Wed, 30 Jan 2008 16:51:33 GMT

Anybody who says "I can write correct multi threaded code" probably should be saying "I