Glassfish example source code file (CoordinatorLog.java)
The Glassfish CoordinatorLog.java source code/*
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//----------------------------------------------------------------------------
//
// Module: CoordinatorLog.java
//
// Description: Coordinator state logging.
//
// Product: com.sun.jts.CosTransactions
//
// Author: Simon Holdsworth
//
// Date: March, 1997
//
// Copyright (c): 1995-1997 IBM Corp.
//
// The source code for this program is not published or otherwise divested
// of its trade secrets, irrespective of what has been deposited with the
// U.S. Copyright Office.
//
// This software contains confidential and proprietary information of
// IBM Corp.
//----------------------------------------------------------------------------
package com.sun.jts.CosTransactions;
// Import required classes.
import java.util.*;
import java.io.*;
import org.omg.CORBA.*;
import java.io.DataOutputStream;
import java.io.DataInputStream;
import java.util.logging.Logger;
import java.util.logging.Level;
import com.sun.logging.LogDomains;
import com.sun.jts.utils.LogFormatter;
/**The CoordinatorLog interface provides operations to record transaction-
* specific information that needs to be persistently stored at a particular
* point in time, and subsequently restored.
* <p>
* The CoordinatorLog contains an attribute value which is the local transaction
* identifier associated with the transaction operating on the log. The
* CoordinatorLog maintains the LSN of the last log record written for the
* transaction, and a flag indicating whether rewrite is required for a
* keypoint.
* <p>
* As an instance of this class may be accessed from multiple threads within
* a process, serialisation for thread-safety and locking during keypoint is
* necessary.
*
* @version 0.01
*
* @author Simon Holdsworth, IBM Corporation
*
* @see
*/
//----------------------------------------------------------------------------
// CHANGE HISTORY
//
// Version By Change Description
// 0.01 SAJH Initial implementation.
//------------------------------------------------------------------------------
class CoordinatorLog extends java.lang.Object implements LogUpcallTarget {
private static final int LOG_DEF_KEY_TRIGGER = 100;
private static final int LOG_THRESHOLD = 10000;
private static final int STRING_TO_REF_RETRIES = 20;
private static final String defaultstring = "DEFAULT_LOG";
/**
// Since muliple logs have to coexist as part of delegated recovery
// support, static data can not be maintained. Now this data is stored
// per log location
private static LogFile logFile = null;
private static Log log = null;
private static Hashtable activeLogs = new Hashtable();
private static Hashtable keypointLogs = new Hashtable();
private static int tranCount = 0;
private static int keypointTrigger = 100;
private static boolean keypointInProgress = false;
private static java.lang.Object keypointLock = new java.lang.Object();
private static java.lang.Object keypointStateLock = new java.lang.Object();
**/
private static int keypointTrigger = 100;
private static Hashtable logStateHoldertable = new Hashtable();
private static final java.lang.Object NULL_ENTRY = new java.lang.Object();
private Hashtable sectionMapping = null;
private boolean rewriteRequired = false;
private boolean writeDone = false;
private String logPath = null;
/*
Logger to log transaction messages
*/
static Logger _logger = LogDomains.getLogger(CoordinatorLog.class, LogDomains.TRANSACTION_LOGGER);
/**The local transaction identifier for the transaction this object is logging.
*/
Long localTID = null;
CoordinatorLogStateHolder logStateHolder = null;
private static CoordinatorLogStateHolder defaultLogStateHolder = getStateHolder(defaultstring);
// Static variables to handle byte array formatting.
private ByteArrayOutputStream byteOutput = new ByteArrayOutputStream(2000);
private DataOutputStream dataOutput = new DataOutputStream(byteOutput);
// All the methods which take "String logPath" as parameter are same as the
// ones with out that parameter. These methods are added for delegated
// recovery support
/**
* Get the state for the given log location.
* If the state does not exists, creates the state and retuns, otherwise existing
* state is returned.
*
* @param str log location.
*
* @return state for the given log location.
*
* @see
*/
static private CoordinatorLogStateHolder getStateHolder(String str) {
synchronized (logStateHoldertable) {
CoordinatorLogStateHolder logStateHolder = (CoordinatorLogStateHolder)logStateHoldertable.get(str);
if (logStateHolder == null) {
logStateHolder = new CoordinatorLogStateHolder();
logStateHolder.logFile = null;
logStateHolder.log = null;
logStateHolder.activeLogs = new Hashtable();
logStateHolder.keypointLogs = new Hashtable();
logStateHolder.tranCount = 0;
logStateHolder.keypointInProgress = false;
// logStateHolder.keypointLock = new java.lang.Object();
logStateHolder.keypointLock = new RWLock();
logStateHolder.keypointStateLock = new java.lang.Object();
logStateHoldertable.put(str,logStateHolder);
}
return logStateHolder;
}
}
/**Default CoordinatorLog constructor.
*
* @param
*
* @return
*
* @see
*/
CoordinatorLog() {
sectionMapping = new Hashtable();
logStateHolder = defaultLogStateHolder;
// Do not inform the metaclass about the existence of this object yet, as it
// does not have a transaction identifier.
}
CoordinatorLog(String logPath) {
sectionMapping = new Hashtable();
logStateHolder = getStateHolder(logPath);
this.logPath = logPath;
// Do not inform the metaclass about the existence of this object yet, as it
// does not have a transaction identifier.
}
/**Default CoordinatorLog destructor.
*
* @param
*
* @return
*
* @see
*/
synchronized public void doFinalize() {
// Clear up the section mapping.
if( sectionMapping != null ) {
Enumeration sections = sectionMapping.elements();
// the traditional way of iterating through the enumeration
// using sections.hasMoreElements was showing up as a
// hot spot during performance tests. Arun 9/27/99
int sz = sectionMapping.size();
while (sz-- > 0) {
CoordinatorLogSection section = (CoordinatorLogSection)sections.nextElement();
section.reUse();
}
sectionMapping.clear();
sectionMapping = null;
}
}
/**
* reUse method is called explicitly to clean up
* and return this instance to the pool
*
* Note: the implementation of the cache does not ensure
* that when an object is re-used there are no
* outstanding references to that object. However, the
* risk involved is minimal since reUse() replaces the
* existing call to finalize(). The existing call to
* finalize also does not ensure that there are no
* outstanding references to the object being finalized.
*
*
* @param
*
* @return
*
* @see
*/
synchronized private void reUse() { // Arun 9/27/99
// Clear up the section mapping.
if( sectionMapping != null ) {
Enumeration sections = sectionMapping.elements();
int sz = sectionMapping.size();
while (sz-- > 0) {
CoordinatorLogSection section = (CoordinatorLogSection)sections.nextElement();
section.reUse();
}
sectionMapping.clear();
}
rewriteRequired = false;
writeDone = false;
localTID = null;
byteOutput.reset();
// cache the coordinator log in the coordinator log pool
CoordinatorLogPool.putCoordinatorLog(this);
}
synchronized private void reUse(String logPath) {
// Clear up the section mapping.
if( sectionMapping != null ) {
Enumeration sections = sectionMapping.elements();
int sz = sectionMapping.size();
while (sz-- > 0) {
CoordinatorLogSection section = (CoordinatorLogSection)sections.nextElement();
section.reUse();
}
sectionMapping.clear();
}
rewriteRequired = false;
writeDone = false;
localTID = null;
byteOutput.reset();
// cache the coordinator log in the coordinator log pool
CoordinatorLogPool.putCoordinatorLog(this, logPath);
}
/**Creates and initialises a new CoordinatorLog object, with the given local
* transaction identifier.
* <p>
* If the local transaction identifier is non-NULL,
* the CoordinatorLog adds itself to the static list of instances.
*
* @param localTID The local transaction identifier.
*
* @return
*
* @see
*/
CoordinatorLog( Long localTID ) {
// Set up the local transaction identifier; if it is not NULL, inform the
// metaclass of the object's existence.
this.localTID = localTID;
if( localTID.longValue() != 0 )
addLog(localTID,this);
}
/**
* Creates a subsection in the CoordinatorLog in which to store related
* objects and data.
* <p>
* The object that is returned is used to identify the section on subsequent
* calls.
* <p>
* If the section has already been created, the object for the existing
* section is returned.
*
* @param sectionName The name of the section.
*
* @return An object representing the section.
*
* @see
*/
synchronized java.lang.Object createSection( String sectionName ) {
CoordinatorLogSection result = null;
// Check whether the given name already has a corresponding section.
result = (CoordinatorLogSection) sectionMapping.get(sectionName);
if (result == null) {
int nameLength = sectionName.length();
// Create a new section.
// If a section info structure cannot be allocated, return.
// Note that the section name is added to the end of the section
// info structure to reduce the number of SOMMalloc calls.
// get a new section object from the cache Arun 9/27/99
result = SectionPool.getCoordinatorLogSection(sectionName);
if( result == null ) {
}
// Copy in the name and set initial values of the other variables.
else {
// Add the new section information to the map.
sectionMapping.put(sectionName,result);
}
}
return result;
}
/**Adds the given object to the sequence of those in the given section.
* <p>
* The objects are stored in the order that they are added to the sequence.
* No checking is done for duplicates.
*
* @param sectionObj The object representing the section.
* @param obj The object to be added.
*
* @return Indicates success of the operation.
*
* @see
*/
synchronized boolean addObject( java.lang.Object sectionObj,
org.omg.CORBA.Object obj ) {
boolean result = true;
// Determine if section is valid
if( sectionObj != null ) {
CoordinatorLogSection section = (CoordinatorLogSection)sectionObj;
// Add header length to unwritten data length if section has currently has no
// unwritten information.
section.unwrittenEmpty = false; // Arun 9/27/99
if( section.unwrittenObjects == null )
section.unwrittenObjects = new Vector(10,10);
// Convert the object reference to string value
String objRefStr = null;
try {
objRefStr = Configuration.getORB().object_to_string(obj);
// Add object reference to section and update counts
section.unwrittenObjects.addElement(objRefStr);
//$Write logrecord if threshold is exceeded
//$
//$ if( unwrittenLength >= LOG_THRESHOLD )
//$ try
//$ { formatLogRecords(false); }
//$ catch( IOException exc )
//$ {
//$ if( trc != null ) trc.error(ERR_WRITE).data(exc).write();
//$ result = false;
//$ }
} catch( Throwable exc ) {
result = false;
}
} else {
result = false;
}
return result;
}
/**Adds the given opaque data structure to the sequence of those in the
* given section.
* <p>
* The data structures are stored in the order that they are added to the
* sequence. No checking is done for duplicates.
*
* @param sectionObj The object representing the section.
* @param data The data to be added.
*
* @return Indicates success of the operation.
*
* @see
*/
synchronized boolean addData( java.lang.Object sectionObj,
byte[] data ) {
boolean result = true;
byte[] dataCopy;
// Determine if section is valid
if( sectionObj != null ) {
CoordinatorLogSection section = (CoordinatorLogSection)sectionObj;
// Add header length to unwritten data length if section has currently has no
// unwritten information.
section.unwrittenEmpty = false; // Arun 9/27/99
if( section.unwrittenData == null )
section.unwrittenData = new Vector(4,4);
// Make a copy of the data to add to the unwritten data queue.
dataCopy = new byte[data.length];
System.arraycopy(data,0,dataCopy,0,data.length);
// Add data item (sequence of octets) to section and update counts
section.unwrittenData.addElement(dataCopy);
//$Write logrecord if threshold is exceeded
//$ if( unwrittenLength >= LOG_THRESHOLD )
//$ try
//$ { formatLogRecords(false); }
//$ catch( IOException exc )
//$ {
//$ if( trc != null ) trc.error(ERR_WRITE).data(exc).write();
//$ result = false;
//$ }
} else {
result = false;
}
return result;
}
/**Write the contents of the CoordinatorLog to persistent storage.
* <p>
* If the force parameter is set, this requires that all information defined
* to the CoordinatorLog that has not already been written be recorded before
* the operation returns.
* <p>
* If rewrite is required, all information whether previously written or not
* is recorded.
* <p>
* The log record should include the LSN of the previous record
* written for the same transaction, if any, otherwise it is NULL. Further
* information may be added to the CoordinatorLog after it has been forced,
* and will be separately written in a subsequent log record, whose LSN will
* point to the current one.
* <p>
* This operation discharges the CoordinatorLog's requirement to rewrite. The
* keypoint lock must be obtained from the metaclass before checking whether
* a rewrite is required, and released after the write is complete.
*
* @param force Indicates whether the log data should be forced before this
* method returns.
*
* @return Indicates success of the operation.
*
* @see
*/
boolean write( boolean force ) {
// Format the log records with a forced write.
boolean result = true;
try {
result = formatLogRecords(force);
} catch( IOException exc ) {
result = false;
}
return result;
}
/**Informs the CoordinatorLog object that it must rewrite its entire state
* the next time it writes a log record.
* <p>
* If the CoordinatorLog has state that has previously been written, it records
* the requirement to rewrite, otherwise it does not record the requirement.
*
* @param
*
* @return Indicates success of the operation.
*
* @see
*/
private synchronized boolean requireRewrite() {
boolean result = true;
// Record the fact that a rewrite is required if a write has been done.
if( writeDone )
rewriteRequired = true;
return result;
}
/**Rewrites the contents of the CoordinatorLog to persistent storage.
* <p>
* This requires that all information defined to the CoordinatorLog that has
* already been written be re-written (unforced) to the log.
* <p>
* The CoordinatorLog also writes any unwritten state at this point.
* <p>
* The log record will contain a NULL LSN to indicate that no previous records
* for this transaction should be used for recovery. If no state has previously
* been written, the CoordinatorLog does nothing at this point and waits for
* a subsequent force operation.
* <p>
* This operation discharges the CoordinatorLog's requirement to rewrite.
*
* @param
*
* @return Indicates success of the operation.
*
* @see
*/
private boolean rewrite() {
boolean result = true;
// If a rewrite is required, format a log record with all the CoordinatorLog
// data, with a non-forced write.
if( rewriteRequired )
try {
result = formatLogRecords(false);
} catch( IOException exc ) {
result = false;
}
return result;
}
/**
* Requests that the object reconstructs its state from the given stream.
* <p>
* There may be more than one if the CoordinatorLog elects to write to the
* log before it is asked to force the transaction state.
* <p>
* This operation is invoked when there are log records that need to
* be recovered. The CoordinatorLog should reconstruct the sequences of
* objects and data from each of the sections so that they can be queried by
* the callers that set them up.
*
* @param data The data to be used to create the CoordinatorLog object.
*
* @return Indicates success of the operation.
*
* @see
*/
private boolean reconstruct( DataInputStream dataInput )
throws IOException {
boolean result = true;
// Read in the number of sections.
int numSections = dataInput.readUnsignedShort();
// Reconstruct each of the sections in the log record
while( --numSections >= 0 ) {
// Get the section name, number of objects and number of data items from the
// log record passed in.
int length = dataInput.readUnsignedShort();
// If the section name length is zero, then it contains no data, so skip it.
if( length > 0 ) {
int numObjects = dataInput.readUnsignedShort();
int numData = dataInput.readUnsignedShort();
// Make a copy of the section name.
byte[] stringData = new byte[length];
dataInput.read(stringData);
String sectionName = new String(stringData);
// Create a section in the CoordinatorLog
CoordinatorLogSection section = (CoordinatorLogSection) createSection(sectionName);
// Add each object reference from the log record to the section.
// BUGFIX(Ram J) added (writtenObject == null) check, so that
// the previously collected objects are not discarded.
if (numObjects > 0 && section.writtenObjects == null) {
section.writtenObjects = new Vector(numObjects, 10);
}
for( int i = 0; i < numObjects; i++ ) {
// Get the size of the object reference and allocate a buffer to make a copy
// of it.
length = dataInput.readUnsignedShort();
stringData = new byte[length];
dataInput.read(stringData);
String objRefStr = new String(stringData);
// Add the object reference to the list of written objects.
section.writtenObjects.addElement(objRefStr);
}
// Add each data item from the log record to the section.
// BUGFIX(Ram J) added (writtenData == null) check, so that
// the previously collected data are not discarded.
if (numData > 0 && section.writtenData == null) {
section.writtenData = new Vector(numData, 4);
}
for( int i = 0; i < numData; i++ ) {
// Get the size of the data item and allocate a buffer to make a copy of it.
length = dataInput.readUnsignedShort();
byte[] dataItem = new byte[length];
// Copy the data item into the storage allocated, and add that to the list
// of written data items.
dataInput.read(dataItem);
section.writtenData.addElement(dataItem);
}
}
}
return result;
}
/**Returns a sequence containing all of the objects in the given section.
*
* @param sectionObj The object representing the section.
*
* @return The objects.
*
* @see
*/
java.lang.Object[] getObjects( java.lang.Object sectionObj ) {
java.lang.Object[] result = null;
// Check that the section identifier is valid.
// Browse through the Queue of stringified object references, converting each
// to an actual object reference and adding it to the sequence returned from
// this method.
if( sectionObj != null ) {
CoordinatorLogSection section = (CoordinatorLogSection)sectionObj;
int unwrittenSize = 0;
if( section.unwrittenObjects != null )
unwrittenSize = section.unwrittenObjects.size();
int writtenSize = 0;
if( section.writtenObjects != null )
writtenSize = section.writtenObjects.size();
result = new java.lang.Object[unwrittenSize + writtenSize];
int currObject = 0;
// Obtain the reference of the ORB.
ORB orb = Configuration.getORB();
// Go through the written objects.
for( int i = 0; i < writtenSize; i++ ) {
org.omg.CORBA.Object obj = null;
String refStr = (String)section.writtenObjects.elementAt(i);
// Try ten times to convert the reference to a string.
int retries = STRING_TO_REF_RETRIES;
boolean discard = false;
while( obj == null && retries-- > 0 && !discard ) {
try {
obj = orb.string_to_object(refStr);
} catch( MARSHAL exc ) {
// The MARSHAL exception indicates that the ImplHelper for the object has not been
// started, so try again after two seconds.
try {
Thread.sleep(2000);
} catch( InterruptedException ex2 ) {
_logger.log(Level.WARNING,
"jts.wait_for_resync_complete_interrupted");
String msg = LogFormatter.getLocalizedMessage(_logger,
"jts.wait_for_resync_complete_interrupted");
throw new org.omg.CORBA.INTERNAL(msg);
}
} catch( Throwable exc ) {
// Any other exception indicates that the reference is invalid, so just discard it.
discard = true;
}
}
// Add the valid object to the list.
if( !discard ){
if( obj != null ){
result[currObject++] = obj;
}
else {
_logger.log(Level.SEVERE,
"jts.unable_to_convert_object_reference_to_string_in_recovery");
String msg = LogFormatter.getLocalizedMessage(_logger,
"jts.unable_to_convert_object_reference_to_string_in_recovery");
throw new org.omg.CORBA.INTERNAL(msg);
}
}
}
// Now get the unwritten objects. We do not need to do all the above error
// checking as these objects have not been recovered from the log.
for( int i = 0; i < unwrittenSize; i++ ) {
try {
// Add the valid object to the list.
org.omg.CORBA.Object obj = orb.string_to_object((String)section.unwrittenObjects.elementAt(i));
result[currObject++] = obj;
} catch( Throwable exc ) {
// If the object resulting from the string is invalid, then don't add it to
// the list.
}
}
}
return result;
}
/**Returns a sequence containing all of the opaque data in the given section.
*
* @param sectionObj The object representing the section.
*
* @return The data.
*
* @see
*/
byte[][] getData( java.lang.Object sectionObj ) {
byte[][] result = null;
// Check that the section identifier is valid.
// Browse through the Queues of data items, adding each to the sequence
// returned from this method.
if( sectionObj != null ) {
CoordinatorLogSection section = (CoordinatorLogSection)sectionObj;
int unwrittenSize = 0;
if( section.unwrittenData != null )
unwrittenSize = section.unwrittenData.size();
int writtenSize = 0;
if( section.writtenData != null )
writtenSize = section.writtenData.size();
result = new byte[unwrittenSize+writtenSize][];
if( unwrittenSize > 0 )
section.unwrittenData.copyInto(result);
for( int i = 0; i < writtenSize; i++ )
result[unwrittenSize++] = (byte[])section.writtenData.elementAt(i);
}
return result;
}
/**Sets the local identifier for the CoordinatorLog object.
* <p>
* If the local identifier was previously 0, the CoordinatorLog object is
* added to the static list.
*
* @param localTID The new local identifier.
*
* @return
*
* @see
*/
synchronized void setLocalTID( Long localTID ) {
// Check whether the local identifier is currently NULL.
boolean addToMetaclass = (localTID.longValue() != 0 && (this.localTID == null || this.localTID.longValue() == 0));
// Set the local identifier, and add the object to the metaclass if required.
this.localTID = localTID;
if( addToMetaclass )
addLog(localTID,this);
}
synchronized void setLocalTID( Long localTID, String logPath ) {
// Check whether the local identifier is currently NULL.
boolean addToMetaclass = (localTID.longValue() != 0 && (this.localTID == null || this.localTID.longValue() == 0));
// Set the local identifier, and add the object to the metaclass if required.
this.localTID = localTID;
if( addToMetaclass )
addLog(localTID,this, logPath);
}
/**Formats the information in a single section of the Coordinatorlog into a
* stream.
* <p>
* This internal method does not need to be synchronized.
* If the rewrite flag is not set, only information that has not already been
* written is formatted, otherwise all information is formatted.
*
* @param section The section.
* @param rewrite Indicates if the record is being rewritten.
* @param dataOutput The stream to which to data is output.
*
* @return
*
* @exception IOException The format failed.
*
* @see
*/
private void formatSection( CoordinatorLogSection section,
boolean rewrite,
DataOutputStream dataOutput )
throws IOException {
// No formatting is done if the section is empty, and if rewrite is required,
// the written section is also empty.
// Note that we still need to write something out to satisfy the number of
// sections originally written, so we write out a name length of zero.
if( section.unwrittenEmpty &&
(!rewrite || section.writtenEmpty) ) {
dataOutput.writeShort(0);
return;
}
// Place length of section name into buffer.
dataOutput.writeShort(section.sectionName.length());
// Place count of number of object references into buffer, including written
// object references if rewrite is required.
int unwrittenObjectsSize = 0;
int writtenObjectsSize = 0;
if( section.unwrittenObjects != null )
unwrittenObjectsSize = section.unwrittenObjects.size();
if( rewrite &&
section.writtenObjects != null )
writtenObjectsSize = section.writtenObjects.size();
dataOutput.writeShort(unwrittenObjectsSize + writtenObjectsSize);
// Place count of number of data items into buffer, including written data
// items if rewrite is required.
int unwrittenDataSize = 0;
int writtenDataSize = 0;
if( section.unwrittenData != null )
unwrittenDataSize = section.unwrittenData.size();
if( rewrite &&
section.writtenData != null )
writtenDataSize = section.writtenData.size();
dataOutput.writeShort(unwrittenDataSize + writtenDataSize);
// Copy the section name into the buffer.
dataOutput.writeBytes(section.sectionName);
// If rewrite is required, first write the already-written object references
for( int i = 0; i < writtenObjectsSize; i++ ) {
String objRefStr = (String)section.writtenObjects.elementAt(i);
dataOutput.writeShort(objRefStr.length());
dataOutput.writeBytes(objRefStr);
}
// Next place length of each stringified object reference and the stringified
// object reference into the buffer. Move each from unwritten to written queue
for( int i = 0; i < unwrittenObjectsSize; i++ ) {
String objRefStr = (String)section.unwrittenObjects.elementAt(i);
dataOutput.writeShort(objRefStr.length());
dataOutput.writeBytes(objRefStr);
if( section.writtenObjects == null )
section.writtenObjects = new Vector(unwrittenObjectsSize,10);
section.writtenObjects.addElement(objRefStr);
}
if( unwrittenObjectsSize > 0 )
section.unwrittenObjects.removeAllElements();
// Now we process the data items.
// If rewrite is required, first write the already-written data items.
for( int i = 0; i < writtenDataSize; i++ ) {
byte[] dataItem = (byte[])section.writtenData.elementAt(i);
dataOutput.writeShort(dataItem.length);
dataOutput.write(dataItem);
}
// Next place length of each stringified object reference and the stringified
// object reference into the buffer. Move each from unwritten to written queue
for( int i = 0; i < unwrittenDataSize; i++ ) {
byte[] dataItem = (byte[])section.unwrittenData.elementAt(i);
dataOutput.writeShort(dataItem.length);
dataOutput.write(dataItem);
if( section.writtenData == null )
section.writtenData = new Vector(unwrittenDataSize,4);
section.writtenData.addElement(dataItem);
}
if( unwrittenDataSize > 0 )
section.unwrittenData.removeAllElements();
// Set unwritten_empty to TRUE and written_empty to FALSE since everything //
// has moved from the unwritten to the written queues. //
section.unwrittenEmpty = true;
section.writtenEmpty = false;
}
/**Formats the information in all sections of the CoordinatorLog.
* <p>
* The formatted information is written to the log.
* <p>
* This internal method does not need to be synchronized.
* If the rewrite flag is not set, only information that has not already been
* written is formatted, otherwise all information is formatted.
*
* @param forced Forced/unforced write indicator.
*
* @return Indicates success of the operation.
*
* @exception IOException The format failed.
*
* @see
*/
private boolean formatLogRecords( boolean forced )
throws IOException {
// If there is no LogFile for this transaction, and one cannot be obtained
// from the metaclass, then no formatting can be done.
if (logPath == null)
openLog();
else
openLog(logPath);
if( logStateHolder.logFile == null ) {
return false;
}
// In order to check whether rewrite is required, we must first obtain the
// keypoint lock to ensure that the metaclass is not in the process of
// informing us that a rewrite is required.
//$We must not wait for the keypoint lock while holding our own lock so
//$release it now.
boolean result = false;
try {
logStateHolder.keypointLock.acquireReadLock();
// Once we have the keypoint lock, it is OK to obtain our own.
synchronized( this ) {
// Place the tid in the buffer.
byteOutput.reset();
dataOutput.writeLong(localTID.longValue());
// Write out the number of sections.
dataOutput.writeShort(sectionMapping.size());
// Format log section within map and add the information to buffer. Browse
// through the CoordinatorLog filling in the buffer for each entry.
Enumeration sections = sectionMapping.elements();
int sz = sectionMapping.size(); // Arun 9/27/99
while (sz-- > 0) { // Arun 9/27/99
formatSection((CoordinatorLogSection)sections.nextElement(),
rewriteRequired,dataOutput);
}
// Write the buffer to the LogFile.
result = logStateHolder.logFile.write( forced ? LogFile.FORCED : LogFile.UNFORCED,
byteOutput.toByteArray(),
rewriteRequired ? LogFile.REWRITE : LogFile.NORMAL,
null );
rewriteRequired = false;
writeDone = true;
}
} finally {
logStateHolder.keypointLock.releaseReadLock();
}
return result;
}
/**Provides static initialisation of the CoordinatorLog class.
*
* @param
*
* @return
*
* @see
*/
static {
// Get the value of the keypoint trigger from the environment.
String keypointCountEnv = Configuration.getPropertyValue(Configuration.KEYPOINT_COUNT);
keypointTrigger = LOG_DEF_KEY_TRIGGER;
if( keypointCountEnv != null )
try {
keypointTrigger = Integer.parseInt(keypointCountEnv);
} catch( Throwable e ) {}
}
/**Opens the log file for all CoordinatorLogs in this process.
* <p>
* If the log has already been opened, the operation uses the opened LogFile.
*
* @param
*
* @return Indicates success of the operation.
*
* @see
*/
private static boolean openLog() {
boolean result = false;
String logName;
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
// If the log has been opened, there is nothing to do.
if( logStateHolder.log == null ) {
logStateHolder.log = new Log();
if( !logStateHolder.log.initialise() ) {
logStateHolder.log = null;
_logger.log(Level.SEVERE,"jts.cannot_initialise_log");
String msg = LogFormatter.getLocalizedMessage(_logger,
"jts.cannot_initialise_log");
throw new org.omg.CORBA.INTERNAL(msg);
}
}
// Open the Log and set the logfile object reference. If there is no
// ImplementationDef object available, then we cannot determine the log file
// name, so the log cannot be opened.
// Note that this does not preclude the log file being opened at some later
// time.
String serverName = null;
if( logStateHolder.log != null &&
logStateHolder.logFile == null &&
(serverName = Configuration.getServerName()) != null ) {
// get a coordinator log object from cache instead
// of instantiating a new one Arun 9/27/99
logStateHolder.logFile = logStateHolder.log.open(serverName,
CoordinatorLogPool.getCoordinatorLog());
if( logStateHolder.logFile == null ) {
_logger.log(Level.SEVERE,"jts.cannot_open_log_file",serverName);
String msg = LogFormatter.getLocalizedMessage(_logger,
"jts.cannot_open_log_file");
throw new org.omg.CORBA.INTERNAL(msg);
} else
Configuration.setLogFile(logStateHolder.logFile);
}
result = (logStateHolder.log != null && logStateHolder.logFile != null);
return result;
}
/**Opens the log file for all CoordinatorLogs in this process.
* <p>
* If the log has already been opened, the operation uses the opened LogFile.
*
* @param
*
* @return Indicates success of the operation.
*
* @see
*/
private static boolean openLog(String logPath) {
boolean result = false;
String logName;
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
// If the log has been opened, there is nothing to do.
if( logStateHolder.log == null ) {
logStateHolder.log = new Log(logPath);
if( !logStateHolder.log.initialise() ) {
logStateHolder.log = null;
_logger.log(Level.SEVERE,"jts.cannot_initialise_log");
String msg = LogFormatter.getLocalizedMessage(_logger,
"jts.cannot_initialise_log");
throw new org.omg.CORBA.INTERNAL(msg);
}
}
// Open the Log and set the logfile object reference. If there is no
// ImplementationDef object available, then we cannot determine the log file
// name, so the log cannot be opened.
// Note that this does not preclude the log file being opened at some later
// time.
String serverName = null;
// Always reopen logFile for a delegated recovery: do not check for logStateHolder.logFile == null
if( logStateHolder.log != null &&
(serverName = Configuration.getServerName(logPath)) != null ) {
// get a coordinator log object from cache instead
// of instantiating a new one Arun 9/27/99
logStateHolder.logFile = logStateHolder.log.open(serverName,
CoordinatorLogPool.getCoordinatorLog(logPath));
if( logStateHolder.logFile == null ) {
_logger.log(Level.SEVERE,"jts.cannot_open_log_file",serverName);
String msg = LogFormatter.getLocalizedMessage(_logger,
"jts.cannot_open_log_file");
throw new org.omg.CORBA.INTERNAL(msg);
} else
Configuration.setLogFile(logPath,logStateHolder.logFile);
}
result = (logStateHolder.log != null && logStateHolder.logFile != null);
return result;
}
/**Process the log to build a sequence of CoordinatorLog objects which
* represent all logged transactions.
*
* @param
*
* @return The CoordinatorLog objects, or null if there are none.
*
* @see
*/
synchronized static Enumeration getLogged() {
Vector logRecords = null;
Enumeration coordLogs = null;
// Initialise the Log. If the log cannot be opened, return an empty
// sequence, with whatever exception the open returned.
if( openLog() ) {
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
// Get the log records returned from the log and browse through them. Take
// Take the sequence of log records returned from the LogFile and convert
// them into the sequence of CoordinatorLog objects that are returned from
// this method.
logRecords = logStateHolder.logFile.getLogRecords();
for( int i = 0; i < logRecords.size(); i++ ) {
// Get tid value from the log record. Get the CoordinatorLog reference if
// it exists in map, else create a new CoordinatorLog object; it will
// added to the map when we set the transaction id.
byte[] buffer = (byte[])logRecords.elementAt(i);
ByteArrayInputStream byteInput = new ByteArrayInputStream(buffer);
DataInputStream dataInput = new DataInputStream(byteInput);
try {
Long localTID = new Long(dataInput.readLong());
CoordinatorLog coordLog = (CoordinatorLog)logStateHolder.activeLogs.get(localTID);
if( coordLog == null ) {
// get a coordinator log object from cache instead
// of instantiating a new one Arun 9/27/99
coordLog = CoordinatorLogPool.getCoordinatorLog();
coordLog.setLocalTID(localTID);
}
// Reconstruct the CoordinatorLog information from the log record.
coordLog.reconstruct(dataInput);
} catch( IOException exc ) {
}
}
// Return a copy of the list of active CoordinatorLog objects.
coordLogs = logStateHolder.activeLogs.elements();
}
// If the log could not be opened, return an empty Enumeration.
else
coordLogs = new Hashtable().elements();
return coordLogs;
}
/**Process the log to build a sequence of CoordinatorLog objects which
* represent all logged transactions.
*
* @param
*
* @return The CoordinatorLog objects, or null if there are none.
*
* @see
*/
synchronized static Enumeration getLogged(String logPath) {
Vector logRecords = null;
Enumeration coordLogs = null;
// Initialise the Log. If the log cannot be opened, return an empty
// sequence, with whatever exception the open returned.
if( openLog(logPath) ) {
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
// Get the log records returned from the log and browse through them. Take
// Take the sequence of log records returned from the LogFile and convert
// them into the sequence of CoordinatorLog objects that are returned from
// this method.
logRecords = logStateHolder.logFile.getLogRecords();
for( int i = 0; i < logRecords.size(); i++ ) {
// Get tid value from the log record. Get the CoordinatorLog reference if
// it exists in map, else create a new CoordinatorLog object; it will
// added to the map when we set the transaction id.
byte[] buffer = (byte[])logRecords.elementAt(i);
ByteArrayInputStream byteInput = new ByteArrayInputStream(buffer);
DataInputStream dataInput = new DataInputStream(byteInput);
try {
Long localTID = new Long(dataInput.readLong());
CoordinatorLog coordLog = (CoordinatorLog)logStateHolder.activeLogs.get(localTID);
if( coordLog == null ) {
// get a coordinator log object from cache instead
// of instantiating a new one Arun 9/27/99
coordLog = CoordinatorLogPool.getCoordinatorLog(logPath);
coordLog.setLocalTID(localTID, logPath);
}
// Reconstruct the CoordinatorLog information from the log record.
coordLog.reconstruct(dataInput);
} catch( IOException exc ) {
}
}
// Return a copy of the list of active CoordinatorLog objects.
coordLogs = logStateHolder.activeLogs.elements();
}
// If the log could not be opened, return an empty Enumeration.
else
coordLogs = new Hashtable().elements();
return coordLogs;
}
/**Remembers the mapping between the local transaction identifier and the
* CoordinatorLog object.
*
* @param localTID The local transaction identifier.
* @param clog The CoordinatorLog object.
*
* @return Indicates success of the operation.
*
* @see
*/
private static boolean addLog(Long localTID,
CoordinatorLog clog ) {
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
boolean result = true;
logStateHolder.activeLogs.put(localTID,clog);
return result;
}
private static boolean addLog(Long localTID,
CoordinatorLog clog, String logPath ) {
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
boolean result = true;
logStateHolder.activeLogs.put(localTID,clog);
return result;
}
/**Removes the CoordinatorLog object from the map, and destroys it.
*
* @param localTID The local transaction identifier.
*
* @return Indicates success of the operation.
*
* @see
*/
synchronized static boolean removeLog( Long localTID ) {
boolean result = true;
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
// Remove the given CoordinatorLog and local identifier from the map.
// If the CoordinatorLog could be removed, we need to check whether a
// keypoint is in progress, and if so, prevent the CoordinatorLog from being
// called during the keypoint.
CoordinatorLog clog = (CoordinatorLog)logStateHolder.activeLogs.remove(localTID);
if( clog != null ) {
// Obtaining the keypoint state lock prevents us from doing this while the
// keypoint method is using the map.
synchronized( logStateHolder.keypointStateLock ) {
// If a keypoint is in progress, look up the entry for the transaction in the
// map and replace the value with a NULL entry.
if( logStateHolder.keypointInProgress && logStateHolder.keypointLogs != null )
logStateHolder.keypointLogs.put(localTID,NULL_ENTRY);
}
// If the transaction is read-only, then do not increment the transaction count.
if( clog.writeDone )
logStateHolder.tranCount++;
// return the CoordinatorLog object to the pool to be reused.
// Arun 9/27/99
clog.reUse();
// Check whether a keypoint is required. This is based solely on the number
// of (non-readonly) transactions since the last keypoint.
if( logStateHolder.tranCount >= keypointTrigger ) {
logStateHolder.tranCount = 0;
keypoint();
}
}
return result;
}
synchronized static boolean removeLog( Long localTID , String logPath) {
boolean result = true;
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
// Remove the given CoordinatorLog and local identifier from the map.
// If the CoordinatorLog could be removed, we need to check whether a
// keypoint is in progress, and if so, prevent the CoordinatorLog from being
// called during the keypoint.
CoordinatorLog clog = (CoordinatorLog)logStateHolder.activeLogs.remove(localTID);
if( clog != null ) {
// Obtaining the keypoint state lock prevents us from doing this while the
// keypoint method is using the map.
synchronized( logStateHolder.keypointStateLock ) {
// If a keypoint is in progress, look up the entry for the transaction in the
// map and replace the value with a NULL entry.
if( logStateHolder.keypointInProgress && logStateHolder.keypointLogs != null )
logStateHolder.keypointLogs.put(localTID,NULL_ENTRY);
}
// If the transaction is read-only, then do not increment the transaction count.
if( clog.writeDone )
logStateHolder.tranCount++;
// return the CoordinatorLog object to the pool to be reused.
// Arun 9/27/99
clog.reUse(logPath);
// Check whether a keypoint is required. This is based solely on the number
// of (non-readonly) transactions since the last keypoint.
if( logStateHolder.tranCount >= keypointTrigger ) {
logStateHolder.tranCount = 0;
keypoint(logPath);
}
}
return result;
}
/**Performs a keypoint operation to allow old information in the log to be
* discarded.
* <p>
* This operation is not synchronized as we do not want the latter part of the
* operation to block other logging operations. The start of the keypoint is
* in a separate method which is synchronized.
*
* @param
*
* @return
*
* @see
*/
static void keypoint() {
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
byte[] keypointEndRecord = {
(byte) 'K',
(byte) 'E',
(byte) 'Y',
(byte) 'E',
(byte) 'N',
(byte) 'D'};
LogLSN previousLSN = new LogLSN();
LogLSN keypointStartLSN = new LogLSN();
boolean keypointRequired = false;
// Obtain the global keypoint lock to prevent any activity until the keypoint
// start has been recorded.
// Once the keypoint start has been completed, we can release the
// keypoint lock. This will allow waiting CoordinatorLog writes to complete.
try {
logStateHolder.keypointLock.acquireWriteLock();
keypointRequired = startKeypoint(keypointStartLSN);
} finally {
logStateHolder.keypointLock.releaseWriteLock();
}
// If no keypoint start record was written, then just return.
if( keypointStartLSN.isNULL() ) {
return;
}
// Once all of the CoordinatorLog objects have been unlocked, we must make
// sure each of them has been rewritten before the keypoint end record is
// written. Note that it is possible that one or more of the CoordinatorLog
// objects in this list has already been deleted. We must be careful
// to make sure that we do not invoke a method on a deleted object.
if( keypointRequired ) {
Enumeration keypointLocalTIDs = logStateHolder.keypointLogs.keys();
while( keypointLocalTIDs.hasMoreElements() )
// Obtain the keypoint state lock before obtaining the value from the map, as the
// remove operation might be changing the value to NULL. Note that the
// remove operation only changes the value of an entry in this map, it does
// not change the number of entries in the map, so we do not need to hold the
// mutex for the browse.
synchronized( logStateHolder.keypointStateLock ) {
CoordinatorLog currentLog = (CoordinatorLog)logStateHolder.keypointLogs.get(keypointLocalTIDs.nextElement());
// Get the value out of the map, and if not NULL entry, tell it to rewrite itself.
if( currentLog != NULL_ENTRY )
currentLog.rewrite();
}
}
// Now we know all CoordinatorLog objects have either independently rewritten
// themselves, or we have done it explicitly. A keypoint end record is
// written to indicate that the keypoint is complete.
logStateHolder.logFile.write(LogFile.UNFORCED,
keypointEndRecord,
LogFile.KEYPOINT_END,
previousLSN);
// All that is left to do is to inform the LogFile that the records before
// the keypoint start record are no longer required.
// Checkpoint the log. This allows the log to discard previous entries that
// are no longer required.
logStateHolder.logFile.checkpoint(keypointStartLSN);
// Clear the keypoint in progress flag, empty the map of CoordinatorLog
// objects being keypointed, release muteces and return.
logStateHolder.keypointInProgress = false;
logStateHolder.keypointLogs.clear();
}
static void keypoint(String logPath) {
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
byte[] keypointEndRecord = {
(byte) 'K',
(byte) 'E',
(byte) 'Y',
(byte) 'E',
(byte) 'N',
(byte) 'D'};
LogLSN previousLSN = new LogLSN();
LogLSN keypointStartLSN = new LogLSN();
boolean keypointRequired = false;
// Obtain the global keypoint lock to prevent any activity until the keypoint
// start has been recorded.
// Once the keypoint start has been completed, we can release the
// keypoint lock. This will allow waiting CoordinatorLog writes to complete.
try {
logStateHolder.keypointLock.acquireWriteLock();
keypointRequired = startKeypoint(keypointStartLSN, logPath);
} finally {
logStateHolder.keypointLock.releaseWriteLock();
}
// If no keypoint start record was written, then just return.
if( keypointStartLSN.isNULL() ) {
return;
}
// Once all of the CoordinatorLog objects have been unlocked, we must make
// sure each of them has been rewritten before the keypoint end record is
// written. Note that it is possible that one or more of the CoordinatorLog
// objects in this list has already been deleted. We must be careful
// to make sure that we do not invoke a method on a deleted object.
if( keypointRequired ) {
Enumeration keypointLocalTIDs = logStateHolder.keypointLogs.keys();
while( keypointLocalTIDs.hasMoreElements() )
// Obtain the keypoint state lock before obtaining the value from the map, as the
// remove operation might be changing the value to NULL. Note that the
// remove operation only changes the value of an entry in this map, it does
// not change the number of entries in the map, so we do not need to hold the
// mutex for the browse.
synchronized( logStateHolder.keypointStateLock ) {
CoordinatorLog currentLog = (CoordinatorLog)logStateHolder.keypointLogs.get(keypointLocalTIDs.nextElement());
// Get the value out of the map, and if not NULL entry, tell it to rewrite itself.
if( currentLog != NULL_ENTRY )
currentLog.rewrite();
}
}
// Now we know all CoordinatorLog objects have either independently rewritten
// themselves, or we have done it explicitly. A keypoint end record is
// written to indicate that the keypoint is complete.
logStateHolder.logFile.write(LogFile.UNFORCED,
keypointEndRecord,
LogFile.KEYPOINT_END,
previousLSN);
// All that is left to do is to inform the LogFile that the records before
// the keypoint start record are no longer required.
// Checkpoint the log. This allows the log to discard previous entries that
// are no longer required.
logStateHolder.logFile.checkpoint(keypointStartLSN);
// Clear the keypoint in progress flag, empty the map of CoordinatorLog
// objects being keypointed, release muteces and return.
logStateHolder.keypointInProgress = false;
logStateHolder.keypointLogs.clear();
}
/**Handles a short-on-storage situation in the log by taking a keypoint.
/**Handles a short-on-storage situation in the log by taking a keypoint.
*
* @param reason The reason for the upcall.
*
* @return
*
* @see
*/
public void upcall( int reason ){
// Just perform a keypoint.
if (logPath == null)
CoordinatorLog.keypoint();
else
CoordinatorLog.keypoint(logPath);
}
/**Destroys the state of the CoordinatorLog class.
*
* @param
*
* @return
*
* @see
*/
synchronized static void finalizeAll(){
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
boolean deleteFile = false;
// Obtain the keypoint state lock for this operation.
synchronized( logStateHolder.keypointStateLock ) {
// Close the LogFile.
if( logStateHolder.activeLogs != null ) {
// If there are no active log records sete delete_file to TRUE so that
// LogFile_close will cause the logfile to be deleted
if( logStateHolder.activeLogs.size() == 0 )
deleteFile = true;
logStateHolder.activeLogs.clear();
logStateHolder.activeLogs = null;
}
if( logStateHolder.logFile != null ) logStateHolder.logFile.close(deleteFile);
logStateHolder.logFile = null;
// Discard the CoordinatorLog mappings.
if( logStateHolder.keypointLogs != null )
logStateHolder.keypointLogs.clear();
logStateHolder.keypointLogs = null;
}
// Discard the locks.
logStateHolder.keypointStateLock = null;
logStateHolder.keypointLock = null;
}
synchronized static void finalizeAll(String logPath){
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
boolean deleteFile = false;
// Obtain the keypoint state lock for this operation.
synchronized( logStateHolder.keypointStateLock ) {
// Close the LogFile.
if( logStateHolder.activeLogs != null ) {
// If there are no active log records sete delete_file to TRUE so that
// LogFile_close will cause the logfile to be deleted
if( logStateHolder.activeLogs.size() == 0 )
deleteFile = true;
logStateHolder.activeLogs.clear();
logStateHolder.activeLogs = null;
}
if( logStateHolder.logFile != null ) logStateHolder.logFile.close(deleteFile);
logStateHolder.logFile = null;
// Discard the CoordinatorLog mappings.
if( logStateHolder.keypointLogs != null )
logStateHolder.keypointLogs.clear();
logStateHolder.keypointLogs = null;
}
// Discard the locks.
logStateHolder.keypointStateLock = null;
logStateHolder.keypointLock = null;
}
/**Starts a keypoint.
*
* @param keypointStartLSN The LSN to hold the keypoint start LSN.
*
* @return Indicates whether keypoint is required.
*
* @see
*/
synchronized static boolean startKeypoint( LogLSN keypointStartLSN ) {
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
boolean keypointRequired = false;
// If a keypoint is in progress, return and do nothing.
if( logStateHolder.keypointInProgress ) {
return false;
}
logStateHolder.keypointInProgress = true;
// Initialise the Log. If this fails, then return whatever exception the
// open raised.
if( !openLog() ) {
logStateHolder.keypointInProgress = false;
return false;
}
// If there are no known CoordinatorLog objects, then all that the keypoint
// operation does is checkpoint the log at the head.
if( logStateHolder.activeLogs.size() == 0 )
keypointRequired = false;
// Else go round all currently known CoordinatorLog objects and build a list
// of them. New CoordinatorLog objects that are created during this time
// will be suspended when they try to do an CoordinatorLog.addLog operation as
// this thread has the lock.
else {
// Go through all current CoordinatorLog objects, telling them that they
// must rewrite their state if necessary.
// Each CoordinatorLog that exists at this time is copied to a separate list.
Enumeration clogs = logStateHolder.activeLogs.elements();
while( clogs.hasMoreElements() ) {
CoordinatorLog currentLog = (CoordinatorLog)clogs.nextElement();
Long localTID = currentLog.localTID;
currentLog.requireRewrite();
logStateHolder.keypointLogs.put(localTID,currentLog);
}
keypointRequired = logStateHolder.keypointLogs.size() > 0;
}
// Write a keypoint start record now that we know no logging activity is
// taking place.
byte[] keypointStartRecord = {(byte) 'K',
(byte) 'E',
(byte) 'Y',
(byte) 'S',
(byte) 'T',
(byte) 'A',
(byte) 'R',
(byte) 'T'};
logStateHolder.logFile.write(LogFile.UNFORCED,
keypointStartRecord,
LogFile.KEYPOINT_START,
keypointStartLSN);
return keypointRequired;
}
synchronized static boolean startKeypoint( LogLSN keypointStartLSN, String logPath ) {
CoordinatorLogStateHolder logStateHolder = getStateHolder(logPath);
boolean keypointRequired = false;
// If a keypoint is in progress, return and do nothing.
if( logStateHolder.keypointInProgress ) {
return false;
}
logStateHolder.keypointInProgress = true;
// Initialise the Log. If this fails, then return whatever exception the
// open raised.
if( !openLog(logPath) ) {
logStateHolder.keypointInProgress = false;
return false;
}
// If there are no known CoordinatorLog objects, then all that the keypoint
// operation does is checkpoint the log at the head.
if( logStateHolder.activeLogs.size() == 0 )
keypointRequired = false;
// Else go round all currently known CoordinatorLog objects and build a list
// of them. New CoordinatorLog objects that are created during this time
// will be suspended when they try to do an CoordinatorLog.addLog operation as
// this thread has the lock.
else {
// Go through all current CoordinatorLog objects, telling them that they
// must rewrite their state if necessary.
// Each CoordinatorLog that exists at this time is copied to a separate list.
Enumeration clogs = logStateHolder.activeLogs.elements();
while( clogs.hasMoreElements() ) {
CoordinatorLog currentLog = (CoordinatorLog)clogs.nextElement();
Long localTID = currentLog.localTID;
currentLog.requireRewrite();
logStateHolder.keypointLogs.put(localTID,currentLog);
}
keypointRequired = logStateHolder.keypointLogs.size() > 0;
}
// Write a keypoint start record now that we know no logging activity is
// taking place.
byte[] keypointStartRecord = {(byte) 'K',
(byte) 'E',
(byte) 'Y',
(byte) 'S',
(byte) 'T',
(byte) 'A',
(byte) 'R',
(byte) 'T'};
logStateHolder.logFile.write(LogFile.UNFORCED,
keypointStartRecord,
LogFile.KEYPOINT_START,
keypointStartLSN);
return keypointRequired;
}
/**Dumps the state of the class.
*
* @param
*
* @return
*
* @see
*/
static void dumpClass() {
// Dump the contained objects.
CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
logStateHolder.log.dump();
logStateHolder.logFile.dump();
}
/**Dumps the state of the object.
*
* @param
*
* @return
*
* @see
*/
void dump() {
// NOT USED: CoordinatorLogStateHolder logStateHolder = defaultLogStateHolder;
//$ somtrDUMP_OBJECT_HEADER;
// First dump the local transaction id.
// Dump each section in the CoordinatorLog object.
if( sectionMapping != null ) {
//$ somtrDUMP_LIST_START;
Enumeration sections = sectionMapping.elements();
while( sections.hasMoreElements() ) {
CoordinatorLogSection section = (CoordinatorLogSection)sections.nextElement();
// Dump the section name.
//$ somtrDUMP_LIST_ELEMENT;
// Dump Written objects.
if( section.writtenObjects != null ) {
//$ somtrDUMP_LIST_START;
Enumeration objects = section.writtenObjects.elements();
while( objects.hasMoreElements() ) {
String objStr = (String)objects.nextElement();
//$ somtrDUMP_LIST_ELEMENT;
}
//$ somtrDUMP_LIST_END;
}
// Dump unwritten objects.
if( section.unwrittenObjects != null ) {
//$ somtrDUMP_LIST_START;
Enumeration objects = section.unwrittenObjects.elements();
while( objects.hasMoreElements() ) {
String objStr = (String)objects.nextElement();
//$ somtrDUMP_LIST_ELEMENT;
}
//$ somtrDUMP_LIST_END;
}
// Dump Written data.
if( section.writtenData != null ) {
//$ somtrDUMP_LIST_START;
Enumeration data = section.writtenData.elements();
while( data.hasMoreElements() ) {
byte[] dataItem = (byte[])data.nextElement();
//$ somtrDUMP_LIST_ELEMENT;
}
//$ somtrDUMP_LIST_END;
}
// Dump unwritten data.
if( section.unwrittenData != null ) {
//$ somtrDUMP_LIST_START;
Enumeration data = section.unwrittenData.elements();
while( data.hasMoreElements() ) {
byte[] dataItem = (byte[])data.nextElement();
//$ somtrDUMP_LIST_ELEMENT;
}
//$ somtrDUMP_LIST_END;
}
// That is the end of the section.
}
//$ somtrDUMP_LIST_END;
}
}
// START IASRI 4662745
public static void setKeypointTrigger(int keypoint)
{
keypointTrigger = keypoint;
}
// END IASRI 4662745
}
/**The CoordinatorLogSection class stores information relevant to a section.
*
* @version 0.1
*
* @author Simon Holdsworth, IBM Corporation
*
* @see
*/
// CHANGE HISTORY
//
// Version By Change Description
// 0.1 SAJH Initial implementation.
//------------------------------------------------------------------------------
class CoordinatorLogSection extends java.lang.Object {
String sectionName = null;
boolean unwrittenEmpty = true;
boolean writtenEmpty = true;
Vector unwrittenObjects = null;
Vector unwrittenData = null;
Vector writtenObjects = null;
Vector writtenData = null;
int headerLength = 0;
/**Creates a CoordinatorLogSection with the given name.
*
* @param sectionName The name of the section.
*
* @return
*
* @see
*/
CoordinatorLogSection( String sectionName ) {
this.sectionName = sectionName;
}
/**Destroys the contents of a CoordinatorLogSection.
*
* @param
*
* @return
*
* @see
*/
public void doFinalize() {
if( unwrittenObjects != null )
unwrittenObjects.removeAllElements();
if( unwrittenData != null )
unwrittenData.removeAllElements();
if( writtenObjects != null )
writtenObjects.removeAllElements();
if( writtenData != null )
writtenData.removeAllElements();
sectionName = null;
unwrittenObjects = null;
unwrittenData = null;
writtenObjects = null;
writtenData = null;
}
/**Cleans up the CoordinatorLogSection and
* returns it to the pool for re-use
*
* Note: the implementation of the cache does not ensure
* that when an object is re-used there are no
* outstanding references to that object. However, the
* risk involved is minimal since reUse() replaces the
* existing call to finalize(). The existing call to
* finalize also does not ensure that there are no
* outstanding references to the object being finalized.
*
* @param
*
* @return
*
* @see
*/
synchronized void reUse() { // Arun 9/27/99
if( unwrittenObjects != null )
unwrittenObjects.removeAllElements();
if( unwrittenData != null )
unwrittenData.removeAllElements();
if( writtenObjects != null )
writtenObjects.removeAllElements();
if( writtenData != null )
writtenData.removeAllElements();
sectionName = null;
unwrittenEmpty = true;
writtenEmpty = true;
headerLength = 0;
SectionPool.putCoordinatorLogSection(this);
}
}
/**
* The SectionPool is used as a cache for CoordinatorLogSection objects.
* This pool allows the re-use of these objects which are very expensive
* to instantiate.
*
* The pool was added to improve performance of trnasaction logging
*
* @version 0.01
*
* @author Arun Krishnan
*
* @see
*/
class SectionPool {
private Stack pool;
private static final int MAXSTACKSIZE = 15;
static SectionPool SPool = new SectionPool();
public SectionPool() {
pool = new Stack();
}
/**
* Fetch a CoordinatorLogSection object from the cache. This method
* should be called instead of "new CoordinatorLogSection()". If the
* cache is empty this method will instantiate a new
* CoordinatorLogSection object.
*
* @param String name the section name
*
* @return CoordinatorLogSection
*
*/
public static synchronized
CoordinatorLogSection getCoordinatorLogSection(String name) {
CoordinatorLogSection cls;
if (SPool.pool.empty()) {
return new CoordinatorLogSection(name);
}
else {
cls = (CoordinatorLogSection) SPool.pool.pop();
cls.sectionName = name;
return cls;
}
}
/**
* Return a CoordinatorLogSection object to cache. Cache size is
* limited to MAXSTACKSIZE by discarding objects when the cache
* is already at max size.
*
* @param CoordinatorLogSection object to be returned to cache
*
*/
public static void putCoordinatorLogSection(CoordinatorLogSection cls) {
if (SPool.pool.size() <= MAXSTACKSIZE) {
SPool.pool.push(cls);
}
}
}
class CoordinatorLogStateHolder {
LogFile logFile = null;
Log log = null;
Hashtable activeLogs = null;
Hashtable keypointLogs = null;
int tranCount = 0;
boolean keypointInProgress = false;
// java.lang.Object keypointLock = new java.lang.Object();
RWLock keypointLock = null;
java.lang.Object keypointStateLock = null;
}
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