Make borrow/update always get new created object

Signed-off-by: Coldwings <coldwings@me.com>

common/objectcachev2.h

@@ -48,13 +48,12 @@ class ObjectCacheV2 {
 
  // Returned RefPtr is the old one
  // other reader will get new one after updated
- std::shared_ptr<V> update(V* val, uint64_t ts = 0) {
- while (box->reflock.try_lock() != 0) {
- photon::thread_yield();
- }
- DEFER(box->reflock.unlock());
+ std::shared_ptr<V> update(V* val, uint64_t ts = 0,
+ std::shared_ptr<V>* newptr = nullptr) {
+ SCOPED_LOCK(box->reflock);
  auto r = std::shared_ptr<V>(val);
- if (ts) box->lastcreate = ts;
+ if (newptr) *newptr = r;
+ box->lastcreate = ts;
  std::swap(r, box->ref);
  return r;
  }
@@ -103,9 +102,11 @@ class ObjectCacheV2 {
  uint64_t lifespan;
  photon::Timer _timer;
 
- void __update(Box* item, V* val) {
- reclaim_queue.template send<PhotonPause>(
- new std::shared_ptr<V>(item->writer().update(val, photon::now)));
+ std::shared_ptr<V> __update(Box* item, V* val) {
+ std::shared_ptr<V> ret;
+ reclaim_queue.template send<PhotonPause>(new std::shared_ptr<V>(
+ item->writer().update(val, photon::now, &ret)));
+ return ret;
  }
 
  template <typename KeyType>
@@ -199,19 +200,19 @@ class ObjectCacheV2 {
  while (!r) {
  if (item->boxlock.try_lock() == 0) {
  DEFER(item->boxlock.unlock());
- auto lr = item->reader();
- if (!lr) {
+ r = item->reader();
+ if (!r) {
  if (photon::sat_add(item->lastcreate, cooldown) <=
  photon::now) {
- __update(item, ctor());
+ r = __update(item, ctor());
  }
- return Borrow(this, item, item->reader());
+ return Borrow(this, item, std::move(r));
  }
  }
  photon::thread_yield();
  r = item->reader();
  }
- return Borrow(this, item, item->reader());
+ return Borrow(this, item, std::move(r));
  }
 
  template <typename KeyType>
@@ -222,8 +223,8 @@ class ObjectCacheV2 {
  template <typename KeyType, typename Ctor>
  Borrow update(KeyType&& key, Ctor&& ctor) {
  auto item = __find_or_create_item(std::forward<KeyType>(key));
- __update(item, ctor());
- return Borrow(this, item, item->reader());
+ auto r = __update(item, ctor());
+ return Borrow(this, item, std::move(r));
  }
 
  ObjectCacheV2(uint64_t lifespan)