org.glassfish.config.support.ConfigurationAccess Maven / Gradle / Ivy
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package org.glassfish.config.support;
import org.jvnet.hk2.annotations.Contract;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.Lock;
/**
* Service to lock the configuration elements for a particular domain
* configuration. All changes to the domain configuration changes
* being the domain.xml or the security artifacts must go through
* this service to ensure proper synchronization.
*
* The access gate must be implemented using a read-write locking
* where multiple users can access in read mode the configuration
* while a write access requires a exclusive lock.
*
* A try {...} finally {...} block should be used to ensure the
* Lock returned for access is released when the access to the
* configuration is not needed any longer.
*
* @author Jerome Dochez
*/
@Contract
public interface ConfigurationAccess {
/**
* Wait and return an read access {@link Lock} to the configuration
* elements. Once the lock is returned, other threads can access
* the configuration is read mode, but no thread can access it in
* write mode.
*
* The lock instance must be released in the same thread that
* obtained it.
*
* @return the read access lock to be released once the
* configuration access is not needed any longer.
* @throws IOException if the configuration cannot be accessed
* due to a file access error.
* @throws TimeoutException if the lock cannot be obtained
* before the system defined time out runs out.
*/
public Lock accessRead() throws IOException, TimeoutException;
/**
* Wait and return an exclusive write access {@link Lock} to the configuration
* elements. Once the lock is returned, no other thread can
* access the configuration is read or write mode.
*
* The lock instance must be released in the same thread that
* obtained it.
*
* @return the read access lock to be released once the
* configuration access is not needed any longer.
* @throws IOException if the configuration cannot be accessed
* due to a file access error.
* @throws TimeoutException if the lock cannot be obtained
* before the system defined time out runs out.
*/
public Lock accessWrite() throws IOException, TimeoutException;
}