Method setExclusiveToShared

bolt/common/caching/AsyncDataCache.cpp:54–84

}

void AsyncDataCacheEntry::setExclusiveToShared(bool cacheable) {
  BOLT_CHECK(isExclusive());
  numPins_ = 1;
  std::unique_ptr<folly::SharedPromise<bool>> promise;
  {
    std::lock_guard<std::mutex> l(shard_->mutex());
    // Enter the shard's mutex to make sure a promise is not being added during
    // the move.
    promise = std::move(promise_);
  }
  if (promise != nullptr) {
    promise->setValue(true);
  }

  // The entry may now have other readers, It is safe to do read-only ops like
  // integrity and notifying SSD cache of another candidate.
  const auto& hook = shard_->cache()->verifyHook();
  if (hook != nullptr) {
    hook(*this);
  }

  if (cacheable && (ssdFile_ == nullptr) &&
      (shard_->cache()->ssdCache() != nullptr)) {
    auto* ssdCache = shard_->cache()->ssdCache();
    assert(ssdCache); // for lint only.
    if (ssdCache->groupStats().shouldSaveToSsd(groupId_, trackingId_)) {
      ssdSaveable_ = true;
      shard_->cache()->possibleSsdSave(size_);
    }
  }
}

void AsyncDataCacheEntry::release() {
  BOLT_CHECK_NE(0, numPins_);