Class XactFactory

    • Field Detail

      • USER_CONTEXT_ID

        protected static final java.lang.String USER_CONTEXT_ID
        See Also:
        Constant Field Values
      • NESTED_READONLY_USER_CONTEXT_ID

        protected static final java.lang.String NESTED_READONLY_USER_CONTEXT_ID
        See Also:
        Constant Field Values
      • NESTED_UPDATE_USER_CONTEXT_ID

        protected static final java.lang.String NESTED_UPDATE_USER_CONTEXT_ID
        See Also:
        Constant Field Values
      • INTERNAL_CONTEXT_ID

        protected static final java.lang.String INTERNAL_CONTEXT_ID
        See Also:
        Constant Field Values
      • tranId

        private final java.util.concurrent.atomic.AtomicLong tranId
        The id of the next transaction to be started.
      • inCreateNoLog

        private boolean inCreateNoLog
      • xa_resource

        private java.lang.Object xa_resource
      • backupSemaphore

        private java.lang.Object backupSemaphore
      • backupBlockingOperations

        private long backupBlockingOperations
      • inBackup

        private boolean inBackup
    • Constructor Detail

      • XactFactory

        public XactFactory()
    • Method Detail

      • canSupport

        public boolean canSupport​(java.util.Properties startParams)
        Description copied from interface: ModuleSupportable
        See if this implementation can support any attributes that are listed in properties. This call may be made on a newly created instance before the boot() method has been called, or after the boot method has been called for a running module.

        The module can check for attributes in the properties to see if it can fulfill the required behaviour. E.g. the raw store may define an attribute called RawStore.Recoverable. If a temporary raw store is required the property RawStore.recoverable=false would be added to the properties before calling bootServiceModule. If a raw store cannot support this attribute its canSupport method would return null. Also see the Monitor class's prologue to see how the identifier is used in looking up properties.
        Actually a better way maybe to have properties of the form RawStore.Attributes.mandatory=recoverable,smallfootprint and RawStore.Attributes.requested=oltp,fast

        Specified by:
        canSupport in interface ModuleSupportable
        Returns:
        true if this instance can be used, false otherwise.
      • boot

        public void boot​(boolean create,
                         java.util.Properties properties)
                  throws StandardException
        Description copied from interface: ModuleControl
        Boot this module with the given properties. Creates a module instance that can be found using the findModule() methods of Monitor. The module can only be found using one of these findModule() methods once this method has returned.

        An implementation's boot method can throw StandardException. If it is thrown the module is not registered by the monitor and therefore cannot be found through a findModule(). In this case the module's stop() method is not called, thus throwing this exception must free up any resources.

        When create is true the contents of the properties object will be written to the service.properties of the persistent service. Thus any code that requires an entry in service.properties must explicitly place the value in this properties set using the put method.
        Typically the properties object contains one or more default properties sets, which are not written out to service.properties. These default sets are how callers modify the create process. In a JDBC connection database create the first set of defaults is a properties object that contains the attributes that were set on the jdbc:derby: URL. This attributes properties set has the second default properties set as its default. This set (which could be null) contains the properties that the user set on their DriverManager.getConnection() call, and are thus not owned by Derby code, and thus must not be modified by Derby code.

        When create is false the properties object contains all the properties set in the service.properties file plus a limited number of attributes from the JDBC URL attributes or connection properties set. This avoids properties set by the user compromising the boot process. An example of a property passed in from the JDBC world is the bootPassword for encrypted databases.

        Code should not hold onto the passed in properties reference after boot time as its contents may change underneath it. At least after the complete boot is completed, the links to all the default sets will be removed.

        Specified by:
        boot in interface ModuleControl
        Throws:
        StandardException - Module cannot be started.
        See Also:
        Monitor, ModuleFactory
      • stop

        public void stop()
        Description copied from interface: ModuleControl
        Stop the module. The module may be found via a findModule() method until some time after this method returns. Therefore the factory must be prepared to reject requests to it once it has been stopped. In addition other modules may cache a reference to the module and make requests of it after it has been stopped, these requests should be rejected as well.
        Specified by:
        stop in interface ModuleControl
        See Also:
        Monitor, ModuleFactory
      • startCommonTransaction

        private Xact startCommonTransaction​(RawStoreFactory rsf,
                                            Xact parentTransaction,
                                            ContextManager cm,
                                            boolean readOnly,
                                            CompatibilitySpace compatibilitySpace,
                                            java.lang.String xact_context_id,
                                            java.lang.String transName,
                                            boolean excludeMe,
                                            boolean flush_log_on_xact_end)
                                     throws StandardException
        Common work done to create local or global transactions.
        Parameters:
        rsf - the raw store factory creating this xact.
        parentTransaction - parent transaction (if this is a nested user transaction)
        cm - the current context manager to associate the xact with.
        compatibilitySpace - if null, use the transaction being created, else if non-null use this compatibilitySpace.
        Throws:
        StandardException - Standard exception policy.
      • findTransaction

        public boolean findTransaction​(TransactionId id,
                                       RawTransaction tran)
        Find the TransactionTableEntry with the given ID and make the passed in transaction assume the identity and properties of that TransactionTableEntry. Used in recovery only.
        Specified by:
        findTransaction in interface TransactionFactory
      • rollbackAllTransactions

        public void rollbackAllTransactions​(RawTransaction recoveryTransaction,
                                            RawStoreFactory rsf)
                                     throws StandardException
        Rollback all active transactions that has updated the raw store. Use the recovery Transaction that is passed in to do all the work. Used in recovery only.

        Transactions are rolled back in the following order:

        1. internal transactions in reversed beginXact chronological order,
        2. all other transactions in reversed beginXact chronological order,
        Specified by:
        rollbackAllTransactions in interface TransactionFactory
        Parameters:
        recoveryTransaction - use this transaction to do all the user transaction work
        Throws:
        StandardException - any exception thrown during rollback
      • handlePreparedXacts

        public void handlePreparedXacts​(RawStoreFactory rsf)
                                 throws StandardException
        Run through all prepared transactions known to this factory and restore their state such that they remain after recovery, and can be found and handled by a XA transaction manager. This includes creating a context manager for each, pushing a xact context, and reclaiming update locks on all data changed by the transaction. Expected to be called just after the redo and undo recovery loops, where the transaction table should be empty except for prepared xacts. Used only in recovery.
        Specified by:
        handlePreparedXacts in interface TransactionFactory
        Throws:
        StandardException - Derby Standard Error policy
      • firstUpdateInstant

        public LogInstant firstUpdateInstant()
        Get the earliest log instant that is still active, ie, the first log record logged by the earliest transaction that is still active.
        The logging system must guarentee that the transaction table is populated in the order transactions are started. Used in recovery only.
        Specified by:
        firstUpdateInstant in interface TransactionFactory
      • markCorrupt

        public StandardException markCorrupt​(StandardException originalError)
        Really this is just a convience routine for callers that might not have access to a log factory.
        Specified by:
        markCorrupt in interface Corruptable
        Returns:
        Must always return its parameter.
      • setNewTransactionId

        public void setNewTransactionId​(TransactionId oldxid,
                                        Xact t)
      • resetTranId

        public void resetTranId()
        Set the shortTranId, this is called by the log factory after recovery
        Specified by:
        resetTranId in interface TransactionFactory
      • pushTransactionContext

        protected void pushTransactionContext​(ContextManager cm,
                                              java.lang.String contextName,
                                              Xact xact,
                                              boolean abortAll,
                                              RawStoreFactory rsf,
                                              boolean excludeMe)
                                       throws StandardException
        Create a new RawTransaction, a context for it and push the context onto the current context manager. Then add the transacion to the transaction table.
        Parameters:
        contextName - the name of the transaction context
        xact - the Transaction object
        abortAll - if true, then any error will abort the whole transaction. Otherwise, let XactContext.cleanupOnError decide what to do
        rsf - the raw store factory
        excludeMe - during systeme quiesce, i.e., this transaction should not be allowed to be active during a quiesce state.
        Throws:
        StandardException - Standard Derby error policy
      • addUpdateTransaction

        protected void addUpdateTransaction​(TransactionId id,
                                            RawTransaction t,
                                            int transactionStatus)
        Add a transaction to the list of transactions that has updated the raw store.

        This is called underneath the BeginXact log operation's doMe method. The logging system must guarentee that transactions are added in the true order they are started, as defined by the order of beginXact log record in the log.

      • removeUpdateTransaction

        protected void removeUpdateTransaction​(TransactionId id)
        Remove a transaction from the list of transactions that has updated the raw store.
      • prepareTransaction

        protected void prepareTransaction​(TransactionId id)
        Change state of transaction to prepared. Used by recovery to update the transaction table entry to prepared state.
      • submitPostCommitWork

        public boolean submitPostCommitWork​(Serviceable work)
        Submit this post commit work to the post commit daemon
        Specified by:
        submitPostCommitWork in interface TransactionFactory
        Returns:
        true if the daemon indicates it is being overloaded, false it's happy. must be MT-safe
      • noActiveUpdateTransaction

        public boolean noActiveUpdateTransaction()
        Returns true if there is no in flight updating tranasaction. Caller must be aware that if there is no other mechanism to stop transactions from starting and ending, then this information is outdated as soon as it is reported. Only call this function in special times - e.g, during recovery
        Specified by:
        noActiveUpdateTransaction in interface TransactionFactory
      • hasPreparedXact

        public boolean hasPreparedXact()
        Check if there are any prepared transanctions in the transaction table. Caller must be aware that if there is no other mechanism to stop transactions from starting and ending, then this information is outdated as soon as it is reported.
        Specified by:
        hasPreparedXact in interface TransactionFactory
        Returns:
        true if there are prepared transactions in the transaction table, false otherwise.
      • remove

        protected boolean remove​(TransactionId xactId)
        remove the transaction Id an return false iff the transaction is found in the table and it doesn't need exclusion from quiesce state
      • add

        protected void add​(Xact xact,
                           boolean excludeMe)
      • makeNewUUID

        public UUID makeNewUUID()
        Make a new UUID for whomever that wants it
      • getLockingPolicy

        final LockingPolicy getLockingPolicy​(int mode,
                                             int isolation,
                                             boolean stricterOk)
        Get a locking policy for a transaction.
      • inDatabaseCreation

        public boolean inDatabaseCreation()
        Returns:
        false, if the Database creation finished
      • blockBackup

        protected boolean blockBackup​(boolean wait)
        Block the online backup. Backup needs to be blocked while executing any unlogged operations or any opearation that prevents from making a consistent backup.
        Parameters:
        wait - if true, waits until the backup is blocked.
        Returns:
        true if backup is blocked. false otherwise.
      • unblockBackup

        protected void unblockBackup()
        Unblock the backup, a backup blocking operation finished.
      • blockBackupBlockingOperations

        public boolean blockBackupBlockingOperations​(boolean wait)
        Checks if there are any backup blocking operations in progress and prevents new ones from starting until the backup is finished. If backup blocking operations are in progress and wait parameter value is true, then it will wait for the current backup blocking operations to finish. A Consistent backup can not be made if there are any backup blocking operations (like unlogged operations) are in progress
        Specified by:
        blockBackupBlockingOperations in interface TransactionFactory
        Parameters:
        wait - if true, waits for the current backup blocking operation in progress to finish.
        Returns:
        true if no backup blocking operations are in progress false otherwise.
        Throws:
        java.lang.RuntimeException - if runtime exception occurs, in which case other threads blocked on backupSemaphore are notified
      • getContextService

        private static ContextService getContextService()
        Privileged lookup of the ContextService. Private so that user code can't call this entry point.
      • getMonitor

        private static ModuleFactory getMonitor()
        Privileged Monitor lookup. Must be private so that user code can't call this entry point.
      • bootServiceModule

        private static java.lang.Object bootServiceModule​(boolean create,
                                                          java.lang.Object serviceModule,
                                                          java.lang.String factoryInterface,
                                                          java.util.Properties properties)
                                                   throws StandardException
        Privileged startup. Must be private so that user code can't call this entry point.
        Throws:
        StandardException
      • findServiceModule

        private static java.lang.Object findServiceModule​(java.lang.Object serviceModule,
                                                          java.lang.String factoryInterface)
                                                   throws StandardException
        Privileged startup. Must be private so that user code can't call this entry point.
        Throws:
        StandardException