}

  // Acquire the cache entry lock and compile, if necessary.
  // TODO(phawkins): this locking will need to be restructured when we implement
  // cache eviction.
  mutex_lock cluster_compile_lock(*cluster_mutex);
  auto cache_value = cache_->LookupOrCreate(signature);

  int64_t current_request_count = cache_value.request_count;
  VLOG(2) << "Compilation cache entry hit: "