Package org.datanucleus

Class ExecutionContextThreadedImpl

java.lang.Object

org.datanucleus.ExecutionContextImpl

org.datanucleus.ExecutionContextThreadedImpl

All Implemented Interfaces:

ExecutionContextReference, ExecutionContext, TransactionEventListener

public class ExecutionContextThreadedImpl
extends ExecutionContextImpl

ExecutionContext to attempt to handle multi-threaded PM/EM cases. Intercepts various methods in an attempt to prevent conflicting thread updates by locking the current thread. Note we could have just put this code in ExecutionContextImpl but better to split it out since the majority use-case is to have a non-thread-safe PM/EM. Note also that having thread-safe ExecutionContext usage depends on much more than having this class, since SCO wrappers would need to coordinate with such locks, as would the Transaction for the ExecutionContext. TODO Evaluate all of the places we currently lock (when multithreaded) to find corner cases not caught. TODO We currently try to lock the ExecutionContext and not individual objects. To lock individual objects we would need a Lock object on the DNStateManager

This class *tries to be* thread-safe, but there is no guarantee. You are better advised to design your application to use PM/EM for a single thread.

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.ExecutionContextImpl

ExecutionContextImpl.NullCallbackHandler

Nested classes/interfaces inherited from interface org.datanucleus.ExecutionContext

ExecutionContext.EmbeddedOwnerRelation, ExecutionContext.LifecycleListener

Field Summary

Fields

Modifier and Type	Field	Description
protected Lock	lock	Lock object to lock to the current thread, and then release when the operation is complete.

Fields inherited from class org.datanucleus.ExecutionContextImpl

cache, stateManagerAssociatedValuesMap

Fields inherited from interface org.datanucleus.ExecutionContext

OPTION_JTA_AUTOJOIN, OPTION_PASSWORD, OPTION_USERNAME

Constructor Summary

Constructors

Constructor	Description
ExecutionContextThreadedImpl(PersistenceNucleusContext ctx, Object owner, Map<String,Object> options)

Method Summary

Modifier and Type	Method	Description
void	addStateManagerToCache(DNStateManager sm)	Method to add the object managed by the specified StateManager to the (L1) cache.
void	attachObject(DNStateManager ownerSM, Object pc, boolean sco)	Method to attach a persistent detached object.
Object	attachObjectCopy(DNStateManager ownerSM, Object pc, boolean sco)	Method to attach a persistent detached object returning an attached copy of the object.
void	clearDirty()	Method to clear all objects marked as dirty (whether directly or indirectly).
void	clearDirty(DNStateManager sm)	Method to clear an object from the list of dirty objects.
void	close()	Method to close the context.
void	deleteObject(Object obj)	Method to delete an object from the datastore.
void	deleteObjects(Object... objs)	Method to delete an array of objects from the datastore.
void	detachObject(FetchPlanState state, Object obj)	Method to detach a persistent object without making a copy.
Object	detachObjectCopy(Object pc, FetchPlanState state)
void	detachObjects(FetchPlanState state, Object... objs)	Method to detach the passed object(s).
void	enlistInTransaction(DNStateManager sm)	Method to enlist the specified StateManager in the current transaction.
void	evictAllObjects()	Method to evict all current objects from L1 cache.
void	evictFromTransaction(DNStateManager sm)	Method to evict the specified StateManager from the current transaction.
void	evictObject(Object obj)	Internal method to evict an object from L1 cache.
void	evictObjects(Class cls, boolean subclasses)	Method to evict all objects of the specified type (and optionally its subclasses) that are present in the L1 cache.
DNStateManager	findStateManager(Object pc)	Method to return StateManager for an object (if managed).
void	flush()	Method callable from external APIs for user-management of flushing.
void	flushInternal(boolean flushToDatastore)	This method flushes all dirty, new, and deleted instances to the datastore.
Extent	getExtent(Class pcClass, boolean subclasses)	Extents are collections of datastore objects managed by the datastore, not by explicit user operations on collections.
boolean	getMultithreaded()	Accessor for whether the usage is multi-threaded.
List<DNStateManager>	getObjectsToBeFlushed()	Convenience method to inspect the list of objects with outstanding changes to flush.
void	makeObjectTransactional(Object obj)	Method to make an object transactional.
void	makeObjectTransient(Object obj, FetchPlanState state)	Method to migrate an object to transient state.
void	markDirty(DNStateManager sm, boolean directUpdate)	Method to mark an object (StateManager) as dirty.
Object	persistObject(Object obj, boolean merging)	Method to make an object persistent.
Object[]	persistObjects(Object... objs)	Method to persist an array of objects to the datastore.
void	postBegin()	Method to perform any post-begin checks.
void	postCommit()	Commit any changes made to objects managed by the object manager to the database.
void	postRollback()	Callback invoked after the actual datastore rollback.
void	preCommit()	Method to perform any pre-commit checks.
void	preRollback()	Rollback any changes made to objects managed by the object manager to the database.
void	processNontransactionalUpdate()	Method called when a non-tx update has been performed (via setter call on the persistable object, or via use of mutator methods of a field).
void	refreshAllObjects()	Method to do a refresh of all objects.
void	refreshObject(Object obj)	Method to do a refresh of an object, updating it from its datastore representation.
void	removeStateManagerFromCache(DNStateManager sm)	Method to remove the object managed by the specified StateManager from the cache.
void	replaceObjectId(Persistable pc, Object oldID, Object newID)	Replace the previous object id for a persistable object with a new one.
void	retrieveObjects(boolean useFetchPlan, Object... pcs)	Method to retrieve the (fields of the) passed object(s).
void	threadLock()	Method to lock this ExecutionContext for threading
void	threadUnlock()	Method to unlock this ExecutionContext for threading

Methods inherited from class org.datanucleus.ExecutionContextImpl

acquireThreadContextInfo, addInternalFetchGroup, addOperationToQueue, assertActiveTransaction, assertClassPersistable, assertDetachable, assertIsOpen, assertNotDetached, closeCallbackHandler, containsStateManagerAssociatedValue, deleteObjectInternal, deregisterEmbeddedRelation, deregisterExecutionContextListener, detachAll, detachObjectCopy, exists, findObject, findObject, findObject, findObject, findObjectByUnique, findObjects, findObjectsById, findStateManager, findStateManagerForEmbedded, findStateManagerOfOwnerForAttachingObject, flushOperationsForBackingStore, getAttachDetachReferencedObject, getAttachedObjectForId, getBooleanProperty, getCallbackHandler, getClassLoaderResolver, getCurrentUser, getEmbeddedInformationForOwner, getFetchGroupManager, getFetchGroupsWithName, getFetchPlan, getFlushMode, getInternalFetchGroup, getIntProperty, getL2CacheableObject, getLevel1Cache, getLevel2CacheRetrieveMode, getLevel2CacheStoreMode, getLockManager, getManagedObjects, getManagedObjects, getManagedObjects, getManagedObjects, getManageRelations, getNucleusContext, getObjectFromCache, getObjectFromLevel1Cache, getObjectFromLevel2Cache, getObjectFromLevel2CacheForUnique, getObjectsFromCache, getObjectsFromLevel2Cache, getOperationQueue, getOwner, getOwnerForEmbeddedStateManager, getOwnerInformationForEmbedded, getProperties, getProperty, getRelationshipManager, getSerializeReadForClass, getStateManagerAssociatedValue, getStatistics, getStringProperty, getSupportedProperties, getTenantId, getThreadContextInfo, getTransaction, hasIdentityInCache, hasPersistenceInformationForClass, initialise, initialiseLevel1Cache, isClosed, isDelayDatastoreOperationsEnabled, isEnlistedInTransaction, isFlushing, isInserting, isManagingRelations, isObjectModifiedInTransaction, isRunningDetachAllOnCommit, makeObjectNontransactional, markFieldsForUpdateInLevel2Cache, newInstance, newObjectId, newObjectId, operationQueueIsActive, persistObjectInternal, processNontransactionalAtomicChanges, putObjectIntoLevel1Cache, putObjectIntoLevel2Cache, putObjectIntoLevel2CacheInternal, putObjectsIntoLevel2Cache, registerEmbeddedRelation, registerExecutionContextListener, releaseThreadContextInfo, removeEmbeddedOwnerRelation, removeInternalFetchGroup, removeObjectFromLevel1Cache, removeObjectFromLevel2Cache, removeStateManagerAssociatedValue, setAttachDetachReferencedObject, setLevel2Cache, setProperties, setProperty, setStateManagerAssociatedValue, transactionCommitted, transactionEnded, transactionFlushed, transactionPreCommit, transactionPreFlush, transactionPreRollBack, transactionReleaseSavepoint, transactionRollbackToSavepoint, transactionRolledBack, transactionSetSavepoint, transactionStarted

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.datanucleus.ExecutionContext

getApiAdapter, getMetaDataManager, getStoreManager, getTypeManager, persistObjectInternal

Field Detail

lock

protected Lock lock

Lock object to lock to the current thread, and then release when the operation is complete.

Constructor Detail

ExecutionContextThreadedImpl

public ExecutionContextThreadedImpl(PersistenceNucleusContext ctx,
                                    Object owner,
                                    Map<String,Object> options)

Parameters:

ctx - NucleusContext

owner - Owner object (PM, EM)

options - Any options affecting startup

Method Detail

threadLock

public void threadLock()

Description copied from interface: ExecutionContext

Method to lock this ExecutionContext for threading

threadUnlock

public void threadUnlock()

Description copied from interface: ExecutionContext

Method to unlock this ExecutionContext for threading

getMultithreaded

public boolean getMultithreaded()

Accessor for whether the usage is multi-threaded.

Specified by:

getMultithreaded in interface ExecutionContext

Overrides:

getMultithreaded in class ExecutionContextImpl

Returns:

True

processNontransactionalUpdate

public void processNontransactionalUpdate()

Description copied from class: ExecutionContextImpl

Method called when a non-tx update has been performed (via setter call on the persistable object, or via use of mutator methods of a field). Only hands the update across to be "committed" if not part of an owning persist/delete call.

Specified by:

processNontransactionalUpdate in interface ExecutionContext

Overrides:

processNontransactionalUpdate in class ExecutionContextImpl

enlistInTransaction

public void enlistInTransaction(DNStateManager sm)

Description copied from interface: ExecutionContext

Method to enlist the specified StateManager in the current transaction.

Specified by:

enlistInTransaction in interface ExecutionContext

Overrides:

enlistInTransaction in class ExecutionContextImpl

Parameters:

sm - StateManager

evictFromTransaction

public void evictFromTransaction(DNStateManager sm)

Description copied from interface: ExecutionContext

Method to evict the specified StateManager from the current transaction.

Specified by:

evictFromTransaction in interface ExecutionContext

Overrides:

evictFromTransaction in class ExecutionContextImpl

Parameters:

sm - StateManager

addStateManagerToCache

public void addStateManagerToCache(DNStateManager sm)

Description copied from class: ExecutionContextImpl

Method to add the object managed by the specified StateManager to the (L1) cache.

Specified by:

addStateManagerToCache in interface ExecutionContext

Overrides:

addStateManagerToCache in class ExecutionContextImpl

Parameters:

sm - StateManager

removeStateManagerFromCache

public void removeStateManagerFromCache(DNStateManager sm)

Description copied from class: ExecutionContextImpl

Method to remove the object managed by the specified StateManager from the cache.

Specified by:

removeStateManagerFromCache in interface ExecutionContext

Overrides:

removeStateManagerFromCache in class ExecutionContextImpl

Parameters:

sm - StateManager

findStateManager

public DNStateManager findStateManager(Object pc)

Description copied from class: ExecutionContextImpl

Method to return StateManager for an object (if managed).

Specified by:

findStateManager in interface ExecutionContext

Overrides:

findStateManager in class ExecutionContextImpl

Parameters:

pc - The object we are checking

Returns:

StateManager, null if not found.

close

public void close()

Description copied from class: ExecutionContextImpl

Method to close the context.

Specified by:

close in interface ExecutionContext

Overrides:

close in class ExecutionContextImpl

evictObject

public void evictObject(Object obj)

Description copied from class: ExecutionContextImpl

Internal method to evict an object from L1 cache.

Specified by:

evictObject in interface ExecutionContext

Overrides:

evictObject in class ExecutionContextImpl

Parameters:

obj - The object

refreshObject

public void refreshObject(Object obj)

Description copied from interface: ExecutionContext

Method to do a refresh of an object, updating it from its datastore representation. Also updates the object in the L1/L2 caches.

Specified by:

refreshObject in interface ExecutionContext

Overrides:

refreshObject in class ExecutionContextImpl

Parameters:

obj - The object

retrieveObjects

public void retrieveObjects(boolean useFetchPlan,
                            Object... pcs)

Description copied from interface: ExecutionContext

Method to retrieve the (fields of the) passed object(s).

Specified by:

retrieveObjects in interface ExecutionContext

Overrides:

retrieveObjects in class ExecutionContextImpl

Parameters:

useFetchPlan - Whether to retrieve the current fetch plan

pcs - The objects

persistObject

public Object persistObject(Object obj,
                            boolean merging)

Description copied from interface: ExecutionContext

Method to make an object persistent. Should be called by EXTERNAL APIs (JDO/JPA) only. All INTERNAL (DataNucleus) calls should go via persistObjectInternal(...).

Specified by:

persistObject in interface ExecutionContext

Overrides:

persistObject in class ExecutionContextImpl

Parameters:

obj - The object

merging - Whether this object (and dependents) is being merged

Returns:

The persisted object

persistObjects

public Object[] persistObjects(Object... objs)

Description copied from interface: ExecutionContext

Method to persist an array of objects to the datastore. Should be called by EXTERNAL APIs (JDO/JPA) only.

Specified by:

persistObjects in interface ExecutionContext

Overrides:

persistObjects in class ExecutionContextImpl

Parameters:

objs - The objects to persist

Returns:

The persisted objects

deleteObject

public void deleteObject(Object obj)

Description copied from interface: ExecutionContext

Method to delete an object from the datastore. NOT to be called by internal methods. Only callable by external APIs (JDO/JPA).

Specified by:

deleteObject in interface ExecutionContext

Overrides:

deleteObject in class ExecutionContextImpl

Parameters:

obj - The object

deleteObjects

public void deleteObjects(Object... objs)

Description copied from interface: ExecutionContext

Method to delete an array of objects from the datastore.

Specified by:

deleteObjects in interface ExecutionContext

Overrides:

deleteObjects in class ExecutionContextImpl

Parameters:

objs - The objects to delete

makeObjectTransient

public void makeObjectTransient(Object obj,
                                FetchPlanState state)

Description copied from interface: ExecutionContext

Method to migrate an object to transient state.

Specified by:

makeObjectTransient in interface ExecutionContext

Overrides:

makeObjectTransient in class ExecutionContextImpl

Parameters:

obj - The object

state - Object containing the state of the fetch plan process (if any)

makeObjectTransactional

public void makeObjectTransactional(Object obj)

Description copied from interface: ExecutionContext

Method to make an object transactional.

Specified by:

makeObjectTransactional in interface ExecutionContext

Overrides:

makeObjectTransactional in class ExecutionContextImpl

Parameters:

obj - The object

attachObject

public void attachObject(DNStateManager ownerSM,
                         Object pc,
                         boolean sco)

Description copied from interface: ExecutionContext

Method to attach a persistent detached object. If a different object with the same identity as this object exists in the L1 cache then an exception will be thrown.

Specified by:

attachObject in interface ExecutionContext

Overrides:

attachObject in class ExecutionContextImpl

Parameters:

ownerSM - StateManager of the owner object that has this in a field that causes this attach

pc - The persistable object

sco - Whether the PC object is stored without an identity (embedded/serialised)

attachObjectCopy

public Object attachObjectCopy(DNStateManager ownerSM,
                               Object pc,
                               boolean sco)

Description copied from interface: ExecutionContext

Method to attach a persistent detached object returning an attached copy of the object. If the object is of class that is not detachable, a ClassNotDetachableException will be thrown.

Specified by:

attachObjectCopy in interface ExecutionContext

Overrides:

attachObjectCopy in class ExecutionContextImpl

Parameters:

ownerSM - StateManager of the owner object that has this in a field that causes this attach

pc - The object

sco - Whether it has no identity (second-class object)

Returns:

The attached object

detachObject

public void detachObject(FetchPlanState state,
                         Object obj)

Description copied from interface: ExecutionContext

Method to detach a persistent object without making a copy. Note that also all the objects which are refered to from this object are detached. If the object is of class that is not detachable a ClassNotDetachableException will be thrown. If the object is not persistent a NucleusUserException is thrown.

Specified by:

detachObject in interface ExecutionContext

Overrides:

detachObject in class ExecutionContextImpl

Parameters:

state - State for the detachment process

obj - The object

detachObjects

public void detachObjects(FetchPlanState state,
                          Object... objs)

Description copied from interface: ExecutionContext

Method to detach the passed object(s).

Specified by:

detachObjects in interface ExecutionContext

Overrides:

detachObjects in class ExecutionContextImpl

Parameters:

state - State for the detachment process.

objs - The object(s) to detach

detachObjectCopy

public Object detachObjectCopy(Object pc,
                               FetchPlanState state)

clearDirty

public void clearDirty(DNStateManager sm)

Description copied from class: ExecutionContextImpl

Method to clear an object from the list of dirty objects.

Specified by:

clearDirty in interface ExecutionContext

Overrides:

clearDirty in class ExecutionContextImpl

Parameters:

sm - StateManager

clearDirty

public void clearDirty()

Description copied from class: ExecutionContextImpl

Method to clear all objects marked as dirty (whether directly or indirectly).

Specified by:

clearDirty in interface ExecutionContext

Overrides:

clearDirty in class ExecutionContextImpl

evictAllObjects

public void evictAllObjects()

Method to evict all current objects from L1 cache.

Specified by:

evictAllObjects in interface ExecutionContext

Overrides:

evictAllObjects in class ExecutionContextImpl

markDirty

public void markDirty(DNStateManager sm,
                      boolean directUpdate)

Description copied from class: ExecutionContextImpl

Method to mark an object (StateManager) as dirty.

Specified by:

markDirty in interface ExecutionContext

Overrides:

markDirty in class ExecutionContextImpl

Parameters:

sm - StateManager

directUpdate - Whether the object has had a direct update made on it (if known)

flush

public void flush()

Description copied from class: ExecutionContextImpl

Method callable from external APIs for user-management of flushing. Called by JDO PM.flush, or JPA EM.flush(). Performs management of relations, prior to performing internal flush of all dirty/new/deleted instances to the datastore.

Specified by:

flush in interface ExecutionContext

Overrides:

flush in class ExecutionContextImpl

flushInternal

public void flushInternal(boolean flushToDatastore)

Description copied from class: ExecutionContextImpl

This method flushes all dirty, new, and deleted instances to the datastore.

Specified by:

flushInternal in interface ExecutionContext

Overrides:

flushInternal in class ExecutionContextImpl

Parameters:

flushToDatastore - Whether to ensure any changes reach the datastore Otherwise they will be flushed to the datastore manager and leave it to decide the opportune moment to actually flush them to the datastore

replaceObjectId

public void replaceObjectId(Persistable pc,
                            Object oldID,
                            Object newID)

Description copied from class: ExecutionContextImpl

Replace the previous object id for a persistable object with a new one. This is used where we have already added the object to the cache(s) and/or enlisted it in the txn before its real identity was fixed (attributed in the datastore).

Specified by:

replaceObjectId in interface ExecutionContext

Overrides:

replaceObjectId in class ExecutionContextImpl

Parameters:

pc - The Persistable object

oldID - the old id it was known by

newID - the new id

getExtent

public Extent getExtent(Class pcClass,
                        boolean subclasses)

Description copied from class: ExecutionContextImpl

Extents are collections of datastore objects managed by the datastore, not by explicit user operations on collections. Extent capability is a boolean property of classes that are persistence capable. If an instance of a class that has a managed extent is made persistent via reachability, the instance is put into the extent implicitly.

Specified by:

getExtent in interface ExecutionContext

Overrides:

getExtent in class ExecutionContextImpl

Parameters:

pcClass - The class to query

subclasses - Whether to include subclasses in the query.

Returns:

returns an Extent that contains all of the instances in the parameter class, and if the subclasses flag is true, all of the instances of the parameter class and its subclasses.

evictObjects

public void evictObjects(Class cls,
                         boolean subclasses)

Description copied from class: ExecutionContextImpl

Method to evict all objects of the specified type (and optionally its subclasses) that are present in the L1 cache.

Specified by:

evictObjects in interface ExecutionContext

Overrides:

evictObjects in class ExecutionContextImpl

Parameters:

cls - Type of persistable object

subclasses - Whether to include subclasses

refreshAllObjects

public void refreshAllObjects()

Description copied from interface: ExecutionContext

Method to do a refresh of all objects.

Specified by:

refreshAllObjects in interface ExecutionContext

Overrides:

refreshAllObjects in class ExecutionContextImpl

getObjectsToBeFlushed

public List<DNStateManager> getObjectsToBeFlushed()

Description copied from class: ExecutionContextImpl

Convenience method to inspect the list of objects with outstanding changes to flush.

Specified by:

getObjectsToBeFlushed in interface ExecutionContext

Overrides:

getObjectsToBeFlushed in class ExecutionContextImpl

Returns:

StateManagers for the objects to be flushed.

postBegin

public void postBegin()

Description copied from class: ExecutionContextImpl

Method to perform any post-begin checks.

Overrides:

postBegin in class ExecutionContextImpl

preCommit

public void preCommit()

Description copied from class: ExecutionContextImpl

Method to perform any pre-commit checks.

Overrides:

preCommit in class ExecutionContextImpl

postCommit

public void postCommit()

Description copied from class: ExecutionContextImpl

Commit any changes made to objects managed by the object manager to the database.

Overrides:

postCommit in class ExecutionContextImpl

preRollback

public void preRollback()

Description copied from class: ExecutionContextImpl

Rollback any changes made to objects managed by the object manager to the database.

Overrides:

preRollback in class ExecutionContextImpl

postRollback

public void postRollback()

Description copied from class: ExecutionContextImpl

Callback invoked after the actual datastore rollback.

Overrides:

postRollback in class ExecutionContextImpl