I have a question about making a thread lock method ... I'm not talking about pthread lock or any other lock ... I'm talking about atomic operations and finally, futex (on Linux (we are talking about Linux only)) ...
I know there is a function named futex and it takes a UINT32 memory address and performs wait and wake without and its waiting is without involving CPU ... In fact, I know there is a different between a loop + atomic operations and atoimc, then futex ... the first one involving CPU (CPU usage) and the second one doesn't ... I thought about futex and I know there is an instruction in Assembly named nop which has no CPU involving, but it comes with 1 latency so in my mind I thought maybe the futex is something like about a loop with for example, 2000 nop operations and at the end, it just jumps back to the top and checks if our condition is right ... and if it doesn't, runs that 2000 nop operations again and this continues, until the condition become right ... Am I right about futex? Or if I'm wrong about how futex works, is it possible to create a thread-lock function with this behaviour ? Will be a good thing ?
UPDATE
I created a Linux executable ... a loop with 30000 nop inside it and a condition check at the top of the loop ... but when i execute the program, my CPU usage went to 99% !!!