private List<ResourceToken> requestResourceToken(
        final Allocation allocInfo, final int tryAmount, final int maxAmount) throws Exception {
      ServiceConfiguration config =
          Topology.lookup(ClusterController.class, allocInfo.getPartition());
      Cluster cluster = Clusters.lookup(config);
      /**
       * TODO:GRZE: this is the call path which needs to trigger gating.
       * It shouldn't be handled directly here, but instead be handled in {@link ResourceState#requestResourceAllocation().
       *
       */
      if (cluster.getGateLock().readLock().tryLock(60, TimeUnit.SECONDS)) {
        try {
          final ResourceState state = cluster.getNodeState();
          /**
           * NOTE: If the defined instance type has an ordering conflict w/ some other type then it
           * isn't safe to service TWO requests which use differing types during the same resource
           * refresh duty cycle. This determines whether or not an asynchronous allocation is safe
           * to do for the request instance type or whether a synchronous resource availability
           * refresh is needed.
           */
          boolean unorderedType = VmTypes.isUnorderedType(allocInfo.getVmType());
          boolean forceResourceRefresh = state.hasUnorderedTokens() || unorderedType;
          /**
           * GRZE: if the vm type is not "nicely" ordered then we force a refresh of the actual
           * cluster state. Note: we already hold the cluster gating lock here so this update will
           * be mutual exclusive wrt both resource allocations and cluster state updates.
           */
          if (forceResourceRefresh) {
            cluster.refreshResources();
          }
          final List<ResourceToken> tokens =
              state.requestResourceAllocation(allocInfo, tryAmount, maxAmount);
          final Iterator<ResourceToken> tokenIterator = tokens.iterator();
          try {
            final Supplier<ResourceToken> allocator =
                new Supplier<ResourceToken>() {
                  @Override
                  public ResourceToken get() {
                    final ResourceToken ret = tokenIterator.next();
                    allocInfo.getAllocationTokens().add(ret);
                    return ret;
                  }
                };

            RestrictedTypes.allocateUnitlessResources(tokens.size(), allocator);
          } finally {
            // release any tokens that were not allocated
            Iterators.all(
                tokenIterator,
                new Predicate<ResourceToken>() {
                  @Override
                  public boolean apply(final ResourceToken resourceToken) {
                    state.releaseToken(resourceToken);
                    return true;
                  }
                });
          }
          return allocInfo.getAllocationTokens();
        } finally {
          cluster.getGateLock().readLock().unlock();
        }
      } else {
        throw new ServiceStateException(
            "Failed to allocate resources in the zone "
                + cluster.getPartition()
                + ", it is currently locked for maintenance.");
      }
    }