What is the difference between non-contact and non-blocking?

Question

In the context of synchronizing data structures, can someone clarify the difference between “non-blocking” and “non-blocking”? These terms seem to be used interchangeably by many people, but I'm still not sure that somewhere there is some subtle difference.

I mean, locking is “no locking,” and non-locking is more like guaranteeing progress. I suspect that one implies the other, but not vice versa, I'm not sure.

Links are welcome.

Answer 1

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Answer 2

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Answer 3

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Answer 4

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Answer 5

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