org.objectweb.perseus.concurrency.optimistic
Class OptimisticConcurrencyManager

java.lang.Object
  extended byorg.objectweb.perseus.concurrency.optimistic.OptimisticConcurrencyManager
All Implemented Interfaces:
ConcurrencyManager

public abstract class OptimisticConcurrencyManager
extends java.lang.Object
implements ConcurrencyManager

Author:
E. Bruneton

Field Summary
static java.lang.String DEPENDENCY_GRAPH_BINDING
           
protected  Logger logger
           
protected  java.util.Map timeStamps
          A map associating time stamps to all oids in all active contexts.
 
Constructor Summary
OptimisticConcurrencyManager()
           
 
Method Summary
 void abort(java.lang.Object ctx)
          This method allows to release the resources allocated in a given context.
 void begin(java.lang.Object ctx)
          This method records the start of an execution context.
 void bindFc(java.lang.String s, java.lang.Object o)
           
 void closeTimeStamp(TimeStamp timeStamp, java.lang.Object ctx)
           
 void finalize(java.lang.Object ctx)
          This method marks the end of accesses made by the execution context.
protected  java.lang.Object getResourceId(java.lang.Object object)
           
protected abstract  java.lang.Object getState(java.lang.Object ctx, java.lang.Object resourceId, TimeStamp timeStamp, boolean isDirtyBefore, boolean isWrite)
           
 java.lang.String[] listFc()
           
 java.lang.Object lookupFc(java.lang.String s)
           
 java.lang.Object readIntention(java.lang.Object ctx, java.lang.Object resource, java.lang.Object thinLock)
          This method records an access intention to a data object in read mode.
 void unbindFc(java.lang.String s)
           
 boolean validate(java.lang.Object ctx)
          This method requests the validation os accesses made by the context.
 java.lang.Object writeIntention(java.lang.Object ctx, java.lang.Object resource, java.lang.Object thinLock)
          This method records an access intention to a data object in write mode.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEPENDENCY_GRAPH_BINDING

public static final java.lang.String DEPENDENCY_GRAPH_BINDING
See Also:
Constant Field Values

logger

protected Logger logger

timeStamps

protected java.util.Map timeStamps
A map associating time stamps to all oids in all active contexts.

Constructor Detail

OptimisticConcurrencyManager

public OptimisticConcurrencyManager()
Method Detail

getState

protected abstract java.lang.Object getState(java.lang.Object ctx,
                                             java.lang.Object resourceId,
                                             TimeStamp timeStamp,
                                             boolean isDirtyBefore,
                                             boolean isWrite)
                                      throws ConcurrencyException
Parameters:
ctx - is the context using the resource
resourceId - is the resource identifier
timeStamp - is the TimeStamp instance matching the resource
isDirtyBefore - indicates if the object was already dirty before the access.
isWrite - indicates if the access is a write access
Returns:
the resource state to use
Throws:
ConcurrencyException - it is not possible to create a State for this resource identifier. One reason can the unavailibity of the resource.

listFc

public java.lang.String[] listFc()

lookupFc

public java.lang.Object lookupFc(java.lang.String s)

bindFc

public void bindFc(java.lang.String s,
                   java.lang.Object o)

unbindFc

public void unbindFc(java.lang.String s)

begin

public void begin(java.lang.Object ctx)
Description copied from interface: ConcurrencyManager
This method records the start of an execution context. It can be a transaction starting.

Specified by:
begin in interface ConcurrencyManager
Parameters:
ctx - is the context

validate

public boolean validate(java.lang.Object ctx)
Description copied from interface: ConcurrencyManager
This method requests the validation os accesses made by the context. It retrieves a boolean value to indicate if the accesses are validate or not.

Specified by:
validate in interface ConcurrencyManager

finalize

public void finalize(java.lang.Object ctx)
Description copied from interface: ConcurrencyManager
This method marks the end of accesses made by the execution context. This method should be called when the validate method has returned true.

Specified by:
finalize in interface ConcurrencyManager

closeTimeStamp

public void closeTimeStamp(TimeStamp timeStamp,
                           java.lang.Object ctx)

abort

public void abort(java.lang.Object ctx)
Description copied from interface: ConcurrencyManager
This method allows to release the resources allocated in a given context. This method should be called when the validate method has returned false.

Specified by:
abort in interface ConcurrencyManager

getResourceId

protected java.lang.Object getResourceId(java.lang.Object object)

readIntention

public java.lang.Object readIntention(java.lang.Object ctx,
                                      java.lang.Object resource,
                                      java.lang.Object thinLock)
                               throws ConcurrencyException
Description copied from interface: ConcurrencyManager
This method records an access intention to a data object in read mode.

Specified by:
readIntention in interface ConcurrencyManager
Parameters:
resource - is the resource or it identifier (Object used for synchronization)
ctx - is an identifier of the execution context. It can be a transaction handle.
thinLock - permit to take smaller lock than on the resource globaly
Returns:
the TimeStamp.
Throws:
ConcurrencyException - if the no resource are available for this resource identifer or if there is a concurrency problem. In this last case that means the context should be cancelled.

writeIntention

public java.lang.Object writeIntention(java.lang.Object ctx,
                                       java.lang.Object resource,
                                       java.lang.Object thinLock)
                                throws ConcurrencyException
Description copied from interface: ConcurrencyManager
This method records an access intention to a data object in write mode. A call to the readIntention is necessary before a call to this method.

Specified by:
writeIntention in interface ConcurrencyManager
Parameters:
resource - is the resource or its identifier
ctx - is an identifier of the execution context. It can be a transaction handle.
thinLock - permit to take smaller lock than on the resource globaly
Returns:
the TimeStamp.
Throws:
ConcurrencyException - if the no resource are available for this resource identifer or if there is a concurrency problem. In this last case that means the context should be cancelled.


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