Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Most of the implementations I find require a hardware instruction to do this. However I strongly doubt this is required (if it is, I can’t figure out why…)
You don’t need a test and set instruction to get mutual exclusion locking, if thats what you’re asking. Dijkstra described the first mutual exclusion algorithm I am aware of, in 1965. The title of the paper was ‘Solution of a problem in concurrent programming control’, search Google for a copy near you. The original algorithm required no special support from the hardware at all, but providing an atomic instruction in the CPU dramatically improves the performance.
Test-and-set, atomic swap, and load-linked + store-conditional are all common primitives for CPUs to provide. All can be used to implement mutual exclusion, which can then be used to implement whatever locking semantics you want.