Have a look at the runtime, on my system the code is in /usr/local/go/src/runtime/chan.go There are some reflection calls in there, together with mutex loc

Have a look at the runtime, on my system the code is in /usr/local/go/src/runtime/chan.go There are some reflection calls in there, together with mutex lock/unlock and calls to 'typedmemmove' which seems to involve the use of memory barriers (mbarrier.go in the same directory).