File	Doc	Category	Size	Date	Package
Lock.java	API Doc	Apache Lucene 2.2.0	4354	Sat Jun 16 22:20:36 BST 2007	org.apache.lucene.store

Lock

• java.lang.Object

new Lock.With(directory.makeLock("my.lock")) {
public Object doBody() {
... code to execute while locked ...
}
}.run();

Fields Summary
public static long	LOCK_POLL_INTERVAL
protected Throwable	failureReason If a lock obtain called, this failureReason may be set with the "root cause" Exception as to why the lock was not obtained.

Constructors Summary

Methods Summary
public abstract boolean	isLocked() Returns true if the resource is currently locked. Note that one must still call {@link #obtain()} before using the resource.
public abstract boolean	obtain() Attempts to obtain exclusive access and immediately return upon success or failure. return true iff exclusive access is obtained
public boolean	obtain(long lockWaitTimeout) Attempts to obtain an exclusive lock within amount of time given. Currently polls once per second until lockWaitTimeout is passed. param lockWaitTimeout length of time to wait in ms return true if lock was obtained throws LockObtainFailedException if lock wait times out throws IOException if obtain() throws IOException failureReason = null; boolean locked = obtain(); int maxSleepCount = (int)(lockWaitTimeout / LOCK_POLL_INTERVAL); int sleepCount = 0; while (!locked) { if (sleepCount++ == maxSleepCount) { String reason = "Lock obtain timed out: " + this.toString(); if (failureReason != null) { reason += ": " + failureReason; } LockObtainFailedException e = new LockObtainFailedException(reason); if (failureReason != null) { e.initCause(failureReason); } throw e; } try { Thread.sleep(LOCK_POLL_INTERVAL); } catch (InterruptedException e) { throw new IOException(e.toString()); } locked = obtain(); } return locked;
public abstract void	release() Releases exclusive access.