Backend Engineering · Concurrency · Distributed Systems

Following Java platform and virtual threads, Go G-M-P, and CPython threads from their runtime representations to OS threads and ultimately CPU execution.

Starting from the von Neumann architecture and instruction execution, this article follows count++ down to the hardware-level problems of atomicity, visibility, and ordering.

Moves from hardware memory models back to the language layer: why languages need their own concurrency semantics, and what Java, Go, and CPython guarantee to concurrent programs.

Defines the scope as concurrency within a single process on a single machine, then connects shared variables, shared memory, message passing, language concurrency semantics, and hardware implementation.

Traces the actual implementation paths of Java synchronized, Go sync.Mutex, and CPython threading.Lock to show how mutexes rely on atomic operations, memory ordering, and waiting and wake-up mechanisms.