Is rendezvous latency cumulative?

Developers Motoko
1 
actor A {
  public shared func f(): async () {
    await B.g();
  }
}

actor B {
  public shared func g(): async () {
    await C.h();
  }
}

actor C {
  public shared func h(): async () {}
}

Is the latency of calling A.f about two times (because of two awaits) above the latency of calling B.g or is about the same (constituting a single rendezvous of two awaits?)? (Assume that network is infinitely fast.)

2

As the following experiment seems to prove, the time for one rendezvous and 20 consecutive rendezvouses is almost the same.

actor A {
  public shared func f(times: Nat): async () {
    if (times == 0) return;
    await A.f(times - 1);
  };
}

dfx deploy
dfx ledger fabricate-cycles --amount 1000000000 --canister A

time for i in `seq 20`; do dfx canister call A f '(20)'; done
real	0m34.313s
user	0m0.388s
sys	0m0.114s

time for i in `seq 20`; do dfx canister call A f '(1)'; done
real	0m33.990s
user	0m0.344s
sys	0m0.164s

When I add --artificial-delay 2000 to dfx start, the measurements become:

time for i in `seq 20`; do dfx canister call A f '(20)'; done
real	1m22.212s
user	0m0.643s
sys	0m0.125s

time for i in `seq 20`; do dfx canister call A f '(1)'; done
real	1m20.884s
user	0m0.563s
sys	0m0.123s

Again, almost the same.

Did I do anything wrong while measuring?

3

The scheduler is smart. If there is little enough traffic it can run the next message (the one you’re awaiting) in the same round, so you won’t waste time unnecessarily