LUCENE-1048: fix Lock.obtain(...) to work properly on very large timeouts, eg Long.MAX_VALUE

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@593774 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael McCandless 2007-11-10 13:43:18 +00:00
parent a98a30818f
commit f69f98c0e4
2 changed files with 27 additions and 7 deletions

View File

@ -139,6 +139,11 @@ Bug fixes
DisjunctionMaxQuery, ValueSourceQuery, CustomScoreQuery.
Serialization check added for all queries.
(Kyle Maxwell via Doron Cohen)
22. LUCENE-1048: Fixed incorrect behavior in Lock.obtain(...) when the
timeout argument is very large (eg Long.MAX_VALUE). Also added
Lock.LOCK_OBTAIN_WAIT_FOREVER constant to never timeout. (Nikolay
Diakov via Mike McCandless)
New features

View File

@ -33,8 +33,15 @@ import java.io.IOException;
* @see Directory#makeLock(String)
*/
public abstract class Lock {
/** How long {@link #obtain(long)} waits, in milliseconds,
* in between attempts to acquire the lock. */
public static long LOCK_POLL_INTERVAL = 1000;
/** Pass this value to {@link #obtain(long)} to try
* forever to obtain the lock. */
public static final long LOCK_OBTAIN_WAIT_FOREVER = -1;
/** Attempts to obtain exclusive access and immediately return
* upon success or failure.
* @return true iff exclusive access is obtained
@ -48,21 +55,29 @@ public abstract class Lock {
*/
protected Throwable failureReason;
/** 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
/** Attempts to obtain an exclusive lock within amount of
* time given. Polls once per {@link #LOCK_POLL_INTERVAL}
* (currently 1000) milliseconds until lockWaitTimeout is
* passed.
* @param lockWaitTimeout length of time to wait in
* milliseconds or {@link
* #LOCK_OBTAIN_WAIT_FOREVER} to retry forever
* @return true if lock was obtained
* @throws LockObtainFailedException if lock wait times out
* @throws IllegalArgumentException if lockWaitTimeout is
* out of bounds
* @throws IOException if obtain() throws IOException
*/
public boolean obtain(long lockWaitTimeout) throws LockObtainFailedException, IOException {
failureReason = null;
boolean locked = obtain();
int maxSleepCount = (int)(lockWaitTimeout / LOCK_POLL_INTERVAL);
int sleepCount = 0;
if (lockWaitTimeout < 0 && lockWaitTimeout != LOCK_OBTAIN_WAIT_FOREVER)
throw new IllegalArgumentException("lockWaitTimeout should be LOCK_OBTAIN_WAIT_FOREVER or a non-negative number (got " + lockWaitTimeout + ")");
long maxSleepCount = lockWaitTimeout / LOCK_POLL_INTERVAL;
long sleepCount = 0;
while (!locked) {
if (sleepCount++ == maxSleepCount) {
if (lockWaitTimeout != LOCK_OBTAIN_WAIT_FOREVER && sleepCount++ >= maxSleepCount) {
String reason = "Lock obtain timed out: " + this.toString();
if (failureReason != null) {
reason += ": " + failureReason;