static final new ConcurrentHashMap<Class, _MethodCache> getMethodCache_chm;

static _MethodCache getMethodCache_chm(Class c) {
  _MethodCache cache = getMethodCache_chm.get(c);
  if (cache == null)
    getMethodCache_chm.put(c, cache = _MethodCache(c));
  ret cache;
}

// This one gets ~44 mill/s cache lookups which is definitely better than the old method
svoid bench_concurrentHashMapBasedMethodCache() {
  print("Loading 1000 classes");
  L<Class> classes = map classForName(takeFirst(1000, classNamesInJigsawModule("java.base")));
  print("Have " + nClasses(classes) + ". Filling method caches");
  time {
    for (c : classes) assertNotNull(getMethodCache_chm(c));
  }
  print("Looking them up again.");
  benchFor5(-> {
    for (c : classes) assertNotNull(getMethodCache_chm(c));
  });

  print("Classes in method cache: " + l(getMethodCache_chm));
}

Began life as a copy of #1034268