Method ParallelFor

oneflow/core/embedding/persistent_table.cpp:711–729

template<typename Key, typename Engine>
void PersistentTableImpl<Key, Engine>::ParallelFor(size_t total,
                                                   const ForRange<Engine>& for_range) {
  BlockingCounter bc(workers_.size());
  std::atomic<size_t> counter(0);
  for (size_t i = 0; i < workers_.size(); ++i) {
    workers_.at(i)->Schedule([&](Engine* engine) {
      while (true) {
        const size_t start = counter.fetch_add(kParallelForStride, std::memory_order_relaxed);
        if (start >= total) { break; }
        const size_t next_start = start + kParallelForStride;
        const size_t end = std::min(next_start, total);
        for_range(engine, start, end);
      }
      engine->WaitUntilDone();
      bc.Decrease();
    });
  }
  bc.WaitForeverUntilCntEqualZero();
}

template<typename Key, typename Engine>
class SnapshotIteratorImpl : public PersistentTable::Iterator {