There was a question at the end of the lecture regarding how message passing is used inside one machine and then talked about message passing for processes and why it's not needed for threads. Just wanted to add that one of the Inter Process Communication(IPC), or in other word message passing mechanisms provided by most OSs include a shared memory mechanism where you can map the same physical memory to two processes' virtual address spaces so that they share this chunk of memory. You still have to take into account the same race conditions you do when sharing memory between threads so that gets a bit tricky.
There was a question at the end of the lecture regarding how message passing is used inside one machine and then talked about message passing for processes and why it's not needed for threads. Just wanted to add that one of the Inter Process Communication(IPC), or in other word message passing mechanisms provided by most OSs include a shared memory mechanism where you can map the same physical memory to two processes' virtual address spaces so that they share this chunk of memory. You still have to take into account the same race conditions you do when sharing memory between threads so that gets a bit tricky.