CacheLoaderTask implementation should be thread safe ---------------------------------------------------- Key: ISPN-3528 URL: https://issues.jboss.org/browse/ISPN-3528 Project: Infinispan Issue Type: Bug Components: Locking and Concurrency Affects Versions: 6.0.0.Alpha4 Reporter: Dan Berindei Assignee: Mircea Markus Priority: Critical Fix For: 6.0.0.Beta2 {{PersistenceManager.processOnAllStores}} receives a {{CacheLoaderTask}} parameter and calls it on potentially many threads concurrently. So the task object must be thread-safe. The {{CacheLoaderTask}}‍s used by {{CacheLoaderInterceptor.visitEntrySetCommand}}/{{visitKeySetCommand}}/{{visitValuesCommand}} are not thread-safe. They use a {{HashSet}} without any synchronization, and when accessed from concurrent threads the map can be corrupted. When this happens, the thread will block in an infinite loop: {noformat} "testng-LocalModeNoPassivationTest" prio=10 tid=0x00007f19141ac800 nid=0x622c runnable [0x00007f1902a62000] java.lang.Thread.State: RUNNABLE at java.util.HashMap.put(HashMap.java:498) at java.util.HashSet.add(HashSet.java:217) at java.util.AbstractCollection.addAll(AbstractCollection.java:342) at org.infinispan.interceptors.CacheLoaderInterceptor.visitEntrySetCommand(CacheLoaderInterceptor.java:195) ... {noformat}