chore: Document how to run concurrent/single account seed comp

objects/benches/account_seed.rs

@@ -1,19 +1,33 @@
+use std::time::Duration;
+
 use criterion::{criterion_group, criterion_main, Criterion};
 use miden_objects::{
     accounts::{AccountId, AccountIdVersion, AccountStorageMode, AccountType},
     Digest,
 };
+use rand::{Rng, SeedableRng};
 
+/// Running this benchmark with --no-default-features will use the single-threaded account seed
+/// computation.
+///
+/// Passing --features concurrent will use the multi-threaded account seed computation.
 fn grind_account_seed(c: &mut Criterion) {
+    let mut group = c.benchmark_group("grind-seed");
+    // Increase measurement time (= target time) from the default 5s as suggested by criterion
+    // during a run.
+    group.measurement_time(Duration::from_secs(20));
+
     let init_seed = [
         1, 18, 222, 14, 56, 94, 222, 213, 12, 57, 86, 1, 22, 34, 187, 100, 210, 1, 18, 222, 14, 56,
         94, 43, 213, 12, 57, 86, 1, 22, 34, 187,
     ];
+    // Use an rng to ensure we're starting from different seeds for each iteration.
+    let mut rng = rand_xoshiro::Xoshiro256PlusPlus::from_seed(init_seed);
 
-    c.bench_function("Grind regular on-chain account seed", |bench| {
+    group.bench_function("Grind regular on-chain account seed", |bench| {
         bench.iter(|| {
             AccountId::compute_account_seed(
-                init_seed,
+                rng.gen(),
                 AccountType::RegularAccountImmutableCode,
                 AccountStorageMode::Public,
                 AccountIdVersion::VERSION_0,
@@ -24,10 +38,12 @@ fn grind_account_seed(c: &mut Criterion) {
         })
     });
 
-    c.bench_function("Grind fungible faucet on-chain account seed", |bench| {
+    // Reinitialize the RNG.
+    let mut rng = rand_xoshiro::Xoshiro256PlusPlus::from_seed(init_seed);
+    group.bench_function("Grind fungible faucet on-chain account seed", |bench| {
         bench.iter(|| {
             AccountId::compute_account_seed(
-                init_seed,
+                rng.gen(),
                 AccountType::FungibleFaucet,
                 AccountStorageMode::Public,
                 AccountIdVersion::VERSION_0,
@@ -37,6 +53,8 @@ fn grind_account_seed(c: &mut Criterion) {
             )
         })
     });
+
+    group.finish();
 }
 
 criterion_group!(account_seed, grind_account_seed);