HDFS-7615. Remove longReadLock. Contributed by Kihwal Lee.

(cherry picked from commit 44eed6cbc9)
This commit is contained in:
Kihwal Lee 2015-01-15 16:40:18 -06:00
parent 450561a934
commit 0090157fff
4 changed files with 3 additions and 64 deletions

View File

@ -250,6 +250,8 @@ Release 2.7.0 - UNRELEASED
HDFS-7454. Reduce memory footprint for AclEntries in NameNode.
(Vinayakumar B via wheat9)
HDFS-7615. Remove longReadLock (kihwal)
BUG FIXES
HDFS-6741. Improve permission denied message when

View File

@ -1456,47 +1456,20 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
this.fsLock.readLock().lock();
}
@Override
public void longReadLockInterruptibly() throws InterruptedException {
this.fsLock.longReadLock().lockInterruptibly();
try {
this.fsLock.readLock().lockInterruptibly();
} catch (InterruptedException ie) {
// In the event we're interrupted while getting the normal FSNS read lock,
// release the long read lock.
this.fsLock.longReadLock().unlock();
throw ie;
}
}
@Override
public void longReadUnlock() {
this.fsLock.readLock().unlock();
this.fsLock.longReadLock().unlock();
}
@Override
public void readUnlock() {
this.fsLock.readLock().unlock();
}
@Override
public void writeLock() {
this.fsLock.longReadLock().lock();
this.fsLock.writeLock().lock();
}
@Override
public void writeLockInterruptibly() throws InterruptedException {
this.fsLock.longReadLock().lockInterruptibly();
try {
this.fsLock.writeLock().lockInterruptibly();
} catch (InterruptedException ie) {
// In the event we're interrupted while getting the normal FSNS write
// lock, release the long read lock.
this.fsLock.longReadLock().unlock();
throw ie;
}
this.fsLock.writeLock().lockInterruptibly();
}
@Override
public void writeUnlock() {
this.fsLock.writeLock().unlock();
this.fsLock.longReadLock().unlock();
}
@Override
public boolean hasWriteLock() {
@ -6915,11 +6888,6 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
return fsLock.coarseLock;
}
@VisibleForTesting
public ReentrantLock getLongReadLockForTests() {
return fsLock.longReadLock;
}
@VisibleForTesting
public ReentrantLock getCpLockForTests() {
return cpLock;

View File

@ -34,24 +34,6 @@ class FSNamesystemLock implements ReadWriteLock {
@VisibleForTesting
protected ReentrantReadWriteLock coarseLock;
/**
* When locking the FSNS for a read that may take a long time, we take this
* lock before taking the regular FSNS read lock. All writers also take this
* lock before taking the FSNS write lock. Regular (short) readers do not
* take this lock at all, instead relying solely on the synchronization of the
* regular FSNS lock.
*
* This scheme ensures that:
* 1) In the case of normal (fast) ops, readers proceed concurrently and
* writers are not starved.
* 2) In the case of long read ops, short reads are allowed to proceed
* concurrently during the duration of the long read.
*
* See HDFS-5064 for more context.
*/
@VisibleForTesting
protected final ReentrantLock longReadLock = new ReentrantLock(true);
FSNamesystemLock(boolean fair) {
this.coarseLock = new ReentrantReadWriteLock(fair);
}
@ -66,10 +48,6 @@ class FSNamesystemLock implements ReadWriteLock {
return coarseLock.writeLock();
}
public Lock longReadLock() {
return longReadLock;
}
public int getReadHoldCount() {
return coarseLock.getReadHoldCount();
}

View File

@ -22,15 +22,6 @@ public interface RwLock {
/** Acquire read lock. */
public void readLock();
/**
* Acquire the long read lock, unless interrupted while waiting. The long
* read lock should also serve to block all concurrent writers.
**/
void longReadLockInterruptibly() throws InterruptedException;
/** Release the long read lock. */
public void longReadUnlock();
/** Release read lock. */
public void readUnlock();