Discussion Over Apple's Modification Of Sun's DTrace

One of the most anticipated features of Mac OS X Leopard amongst the technical community was the port of Sun's DTrace utility for application and system profiling. DTrace is a powerful, low-level dynamic tracing framework that allows system administrators and developers to trace applications for tuning or troubleshooting purposes.

Recently, Adam Leventhal, one of DTrace's initial developers, discovered that Apple's implementation creates a way for a program to exclude itself from being traced. Namely, he was unsuccessful at tracing iTunes, and found that Apple had added a method of disabling probing on certain applications defined with the directive P_LNOATTACH.

Wow. So Apple is explicitly preventing DTrace from examining or recording data for processes which don't permit tracing. This is antithetical to the notion of systemic tracing, antithetical to the goals of DTrace, and antithetical to the spirit of open source. I'm sure this was inserted under pressure from ISVs, but that makes the pill no easier to swallow.

Since the initial publication of the blog entry last week, the story has begun to pop up around the mac web.

The practice is not entirely new to Apple. A commenter on Adam Leventhal's blog noted that Apple used the same directive to prevent GDB tracing on iTunes. Additionally, the implementation of this directive appears to be limited to iTunes (for the moment?), so many are speculating that the move is to protect Apple's FairPlay DRM.

To present an alternate view, Apple has extended Java, Ruby, Python, and Perl to include DTrace support, and Apple has built a GUI front-end called Instruments. Also the issue may eventually become moot with Apple's stated desire to move towards DRM-free music (though DRM video remains common).

Related Forum: Mac Apps

Popular Stories

new best buy blue

Best Buy's Memorial Day Sale Has Record Low Prices on iPads, MacBooks, and Much More

Friday May 24, 2024 7:12 am PDT by
Best Buy today kicked off its Memorial Day weekend sale, and it has some of the best prices we've tracked in weeks on iPads and MacBooks. Specifically, you'll find record low prices on the 5th generation iPad Air, iPad mini 6, M2 MacBook Air, and M3 MacBook Pro. Note: MacRumors is an affiliate partner with Best Buy. When you click a link and make a purchase, we may receive a small payment,...
macOS 15 Feature

macOS 15 System Settings to Get Design Overhaul

Thursday May 23, 2024 12:51 pm PDT by
With the macOS 15 update that is set to debut at WWDC in June, Apple plans to rearrange "menus and app UIs," according to a report from AppleInsider. The System Settings app, which was last updated with macOS Ventura, will get one of the biggest updates. With macOS Ventura, Apple renamed the System Preferences app to System Settings, introducing a design similar to the Settings app on the...
6chatgpt mac app

5 Reasons to Use OpenAI's ChatGPT App for Mac

Thursday May 23, 2024 6:07 am PDT by
On May 13, OpenAI during its Spring Update announced that it would be releasing a desktop ChatGPT app for the Mac in the "coming weeks," and said that ahead of a wider launch it had started rolling out the app to some ChatGPT Plus subscribers. Subscribe to the MacRumors YouTube channel for more videos. After testing the app for a few days, we thought it was worth sharing some reasons why...
iOS 17

Apple Sheds More Light on iOS 17.5 Bug That Resurfaced Deleted Photos

Friday May 24, 2024 2:36 am PDT by
Last week, some iPhone users reported that Apple's iOS 17.5 update had introduced a bug that caused old photos that were deleted to reappear in the Photos app. Apple quickly released an iOS 17.5.1 update to fix the issue, but for many users, its explanation of "database corruption" in the release notes was all too brief, and did little to allay concerns about the privacy of their data. Apple ...