Go

What Mutex is and examples showing the difference between unsynchronized access and access protected by sync.Mutex.

What sync.RWMutex is and an example using write locks and read locks around a shared map.

What sync.Cond is, Wait/Broadcast/Signal semantics, and a blocking-queue example using condition variables.

What atomicity is, what atomic.Value is, how to use it, and the implementation of Store and Load.

CSP concurrency model, channel usage and closing patterns, happens-before, hchan internals, creation, receive, send, close, and references.

Goroutine and channel, the sync package, synchronization, happens-before rules, concurrency patterns, and multi-core CPU references.

What a goroutine is, how to create one, how go f(args) maps to runtime.newproc, goroutine pools, and GMP scheduling.

What a goroutine pool is, why it is usually unnecessary, and two example designs for reusing goroutines.

Goroutine scheduler, GM model, GMP model, P/M/G, goroutine creation flow, preemptive scheduling, and references.

How Go uses escape analysis to decide whether values created with new are allocated on the heap or stack, why escape analysis matters, and a compiler-output example.