There are dozens of decent lock-free hashtable implementations. Usually, those data structures, instead of using plain locks, are using CAS-based operations to be lock-free. with this narrative, it might sound I’m gonna use this post to build an argument for lock-free data structures. that’s not the case, quite surprisingly. on the contrary, here we’re going to talk about plain old locks.
Now that everybody’s onboard, let’s implement a concurrent version of Map with this simple contract: