Fix DirectoryCache concurrency

2017-11-06 05:28:17,112 ERROR [Nuxeo-Work-default-3] [org.nuxeo.ecm.core.work.WorkManagerImpl] Uncaught error on thread: Nuxeo-Work-default-3, current work might be lost, WorkManager metrics might be corrupted.
java.util.ConcurrentModificationException
        at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
        at java.util.HashMap$ValueIterator.next(HashMap.java:1458)
        at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1042)
        at org.nuxeo.ecm.core.api.model.impl.ComplexProperty.internalGetValue(ComplexProperty.java:161)
        at org.nuxeo.ecm.core.api.model.impl.AbstractProperty.getValue(AbstractProperty.java:453)
        at org.nuxeo.ecm.core.api.impl.DataModelImpl.getMap(DataModelImpl.java:107)
        at org.nuxeo.ecm.core.api.impl.DocumentModelImpl.clone(DocumentModelImpl.java:1399)
        at org.nuxeo.ecm.directory.DirectoryCache.getEntry(DirectoryCache.java:138)
        at org.nuxeo.ecm.directory.BaseSession.getEntry(BaseSession.java:331)
        at org.nuxeo.ecm.directory.BaseSession.getEntry(BaseSession.java:319)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.getGroupModel(UserManagerImpl.java:1112)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.getGroup(UserManagerImpl.java:608)
        at org.nuxeo.ecm.platform.computedgroups.UserManagerWithComputedGroups.getGroup(UserManagerWithComputedGroups.java:123)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.getGroup(UserManagerImpl.java:604)
        at org.nuxeo.ecm.platform.computedgroups.UserManagerWithComputedGroups.getGroup(UserManagerWithComputedGroups.java:111)
        at org.nuxeo.ecm.platform.usermanager.NuxeoPrincipalImpl.updateAllGroups(NuxeoPrincipalImpl.java:332)
        at org.nuxeo.ecm.platform.usermanager.NuxeoPrincipalImpl.setVirtualGroups(NuxeoPrincipalImpl.java:388)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.makePrincipal(UserManagerImpl.java:556)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.makePrincipal(UserManagerImpl.java:527)
        at org.nuxeo.ecm.platform.computedgroups.UserManagerWithComputedGroups.makePrincipal(UserManagerWithComputedGroups.java:73)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.makePrincipal(UserManagerImpl.java:523)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.getPrincipal(UserManagerImpl.java:1166)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.getPrincipalUsingCache(UserManagerImpl.java:582)
        at org.nuxeo.ecm.platform.usermanager.UserManagerImpl.getPrincipal(UserManagerImpl.java:574)
        at org.nuxeo.ecm.platform.usermanager.NuxeoPrincipalImpl$TransferableClone$DataTransferObject.lambda$readResolve$0(NuxeoPrincipalImpl.java:486)
        at org.nuxeo.runtime.api.Framework.doPrivileged(Framework.java:278)
        at org.nuxeo.ecm.platform.usermanager.NuxeoPrincipalImpl$TransferableClone$DataTransferObject.readResolve(NuxeoPrincipalImpl.java:486)
        at sun.reflect.GeneratedMethodAccessor263.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at java.io.ObjectStreamClass.invokeReadResolve(ObjectStreamClass.java:1148)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1810)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2000)
        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1924)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1801)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2000)
        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1924)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1801)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:371)
        at java.util.ArrayList.readObject(ArrayList.java:791)
        at sun.reflect.GeneratedMethodAccessor238.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1058)
        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1900)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1801)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2000)
        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1924)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1801)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2000)
        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1924)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1801)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2000)
        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1924)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1801)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:371)
        at org.nuxeo.ecm.core.redis.contribs.RedisWorkQueuing.deserializeWork(RedisWorkQueuing.java:455)