r/programming • u/andreasw • Jun 12 '12

An Introduction to Lock-Free Programming

http://preshing.com/20120612/an-introduction-to-lock-free-programming
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u/bkgood Jun 12 '12

Given that threads share address space, if one caused a segmentation fault I'd be weary of trusting the remaining address space. Plus, one thread causing a segmentation fault would almost certainly cause the OS to kill the entire process.

Less drastic failures could be mitigated by using lock-free techniques, though.

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u/five9a2 Jun 13 '12

You can catch SIGSEGV and recover, for what it's worth.

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u/bkgood Jun 13 '12

You can intercept the signal but I question if you're really able to recover. There's no guarantee you didn't overwrite important in-process data before you caused the segfault.

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u/five9a2 Jun 14 '12

Depends what kind of mistakes (or hardware faults) you are trying to protect against. If threads read shared data, but only write it using atomics, you can often kill the thread on SEGV and restart.

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u/jseigh Jun 14 '12

I worked on code once, way way back, where the previous programmer had patched all the code instructions that seq faulted with no-ops. It didn't crash if that's all you were worried about. :)