remove cerr warning

offloading-cacher/cache.hpp

@@ -392,7 +392,6 @@ inline std::unique_ptr<dsacache::CacheData> dsacache::Cache::Access(uint8_t* dat
     // data source location
 
     if (CheckFlag(flags, FLAG_ACCESS_WEAK)) {
-        std::cerr << "[!] CacheAccess with WEAK set encountered miss!" << std::endl;
         task->SetCacheToSource();
         return std::move(task);
     }
@@ -740,8 +739,12 @@ inline void dsacache::CacheData::WaitOnCompletion() {
     // exchange the global handlers pointer with nullptr to have a local
     // copy - this signals that this thread is the sole owner and therefore
     // responsible for waiting for them. we can not set to nullptr here but
-    // set to maximum of 64-bit in order to prevent deadlocks from the above
-    // waiting construct
+    // set to secondary invalid value in order to prevent deadlocks from
+    // the above waiting construct, where threads may miss the short period
+    // in which the handlers are not nullptr. we could use double width cas
+    // which however is more expensive and therefore introduce the second
+    // invalid state to solve the aba occurring here
+    // see https://en.wikipedia.org/wiki/ABA_problem for more info
 
     std::vector<dml_handler>* local_handlers = handlers_->exchange(invalid_handlers_);