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Posted to common-commits@hadoop.apache.org by za...@apache.org on 2024/04/23 01:53:44 UTC
(hadoop) 03/23: HDFS-17398. [FGL] Implement the FGL lock for FSNLockManager (#6599)
This is an automated email from the ASF dual-hosted git repository.
zanderxu pushed a commit to branch HDFS-17384
in repository https://gitbox.apache.org/repos/asf/hadoop.git
commit 03170885c13321db211bb49f4b5fad04085aea50
Author: ZanderXu <za...@apache.org>
AuthorDate: Tue Mar 5 22:10:59 2024 +0800
HDFS-17398. [FGL] Implement the FGL lock for FSNLockManager (#6599)
---
.../namenode/fgl/FineGrainedFSNamesystemLock.java | 300 +++++++++++++++++++++
.../fgl/TestFineGrainedFSNamesystemLock.java | 275 +++++++++++++++++++
2 files changed, 575 insertions(+)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FineGrainedFSNamesystemLock.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FineGrainedFSNamesystemLock.java
new file mode 100644
index 000000000000..c2e3980476a9
--- /dev/null
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FineGrainedFSNamesystemLock.java
@@ -0,0 +1,300 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.namenode.fgl;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.server.namenode.FSNamesystemLock;
+import org.apache.hadoop.metrics2.lib.MutableRatesWithAggregation;
+
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+import java.util.function.Supplier;
+
+/**
+ * Splitting the global FSN lock into FSLock and BMLock.
+ * FSLock is used to protect directory tree-related operations.
+ * BMLock is used to protect block-related and dn-related operations.
+ * The lock order should be: FSLock,BMLock.
+ */
+public class FineGrainedFSNamesystemLock implements FSNLockManager {
+ private final FSNamesystemLock fsLock;
+ private final FSNamesystemLock bmLock;
+
+ public FineGrainedFSNamesystemLock(Configuration conf, MutableRatesWithAggregation aggregation) {
+ this.fsLock = new FSNamesystemLock(conf, aggregation);
+ this.bmLock = new FSNamesystemLock(conf, aggregation);
+ }
+
+ @Override
+ public void readLock(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.fsLock.readLock();
+ this.bmLock.readLock();
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.readLock();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.readLock();
+ }
+ }
+
+ public void readLockInterruptibly(FSNamesystemLockMode lockMode) throws InterruptedException {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.fsLock.readLockInterruptibly();
+ try {
+ this.bmLock.readLockInterruptibly();
+ } catch (InterruptedException e) {
+ // The held FSLock should be released if the current thread is interrupted
+ // while acquiring the BMLock.
+ this.fsLock.readUnlock("BMReadLockInterruptiblyFailed");
+ throw e;
+ }
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.readLockInterruptibly();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.readLockInterruptibly();
+ }
+ }
+
+ @Override
+ public void readUnlock(FSNamesystemLockMode lockMode, String opName) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.bmLock.readUnlock(opName);
+ this.fsLock.readUnlock(opName);
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.readUnlock(opName);
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.readUnlock(opName);
+ }
+ }
+
+ public void readUnlock(FSNamesystemLockMode lockMode, String opName,
+ Supplier<String> lockReportInfoSupplier) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.bmLock.readUnlock(opName, lockReportInfoSupplier);
+ this.fsLock.readUnlock(opName, lockReportInfoSupplier);
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.readUnlock(opName, lockReportInfoSupplier);
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.readUnlock(opName, lockReportInfoSupplier);
+ }
+ }
+
+ @Override
+ public void writeLock(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.fsLock.writeLock();
+ this.bmLock.writeLock();
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.writeLock();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.writeLock();
+ }
+ }
+
+ @Override
+ public void writeUnlock(FSNamesystemLockMode lockMode, String opName) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.bmLock.writeUnlock(opName);
+ this.fsLock.writeUnlock(opName);
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.writeUnlock(opName);
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.writeUnlock(opName);
+ }
+ }
+
+ @Override
+ public void writeUnlock(FSNamesystemLockMode lockMode, String opName,
+ boolean suppressWriteLockReport) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.bmLock.writeUnlock(opName, suppressWriteLockReport);
+ this.fsLock.writeUnlock(opName, suppressWriteLockReport);
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.writeUnlock(opName, suppressWriteLockReport);
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.writeUnlock(opName, suppressWriteLockReport);
+ }
+ }
+
+ public void writeUnlock(FSNamesystemLockMode lockMode, String opName,
+ Supplier<String> lockReportInfoSupplier) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.bmLock.writeUnlock(opName, lockReportInfoSupplier);
+ this.fsLock.writeUnlock(opName, lockReportInfoSupplier);
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.writeUnlock(opName, lockReportInfoSupplier);
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.writeUnlock(opName, lockReportInfoSupplier);
+ }
+ }
+
+ @Override
+ public void writeLockInterruptibly(FSNamesystemLockMode lockMode)
+ throws InterruptedException {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ this.fsLock.writeLockInterruptibly();
+ try {
+ this.bmLock.writeLockInterruptibly();
+ } catch (InterruptedException e) {
+ // The held FSLock should be released if the current thread is interrupted
+ // while acquiring the BMLock.
+ this.fsLock.writeUnlock("BMWriteLockInterruptiblyFailed");
+ throw e;
+ }
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ this.fsLock.writeLockInterruptibly();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ this.bmLock.writeLockInterruptibly();
+ }
+ }
+
+ @Override
+ public boolean hasWriteLock(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ if (this.fsLock.isWriteLockedByCurrentThread()) {
+ // The bm writeLock should be held by the current thread.
+ assert this.bmLock.isWriteLockedByCurrentThread();
+ return true;
+ } else {
+ // The bm writeLock should not be held by the current thread.
+ assert !this.bmLock.isWriteLockedByCurrentThread();
+ return false;
+ }
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ return this.fsLock.isWriteLockedByCurrentThread();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ return this.bmLock.isWriteLockedByCurrentThread();
+ }
+ return false;
+ }
+
+ @Override
+ public boolean hasReadLock(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ if (hasWriteLock(FSNamesystemLockMode.GLOBAL)) {
+ return true;
+ } else if (this.fsLock.getReadHoldCount() > 0) {
+ // The bm readLock should be held by the current thread.
+ assert this.bmLock.getReadHoldCount() > 0;
+ return true;
+ } else {
+ // The bm readLock should not be held by the current thread.
+ assert this.bmLock.getReadHoldCount() <= 0;
+ return false;
+ }
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ return this.fsLock.getReadHoldCount() > 0 || this.fsLock.isWriteLockedByCurrentThread();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ return this.bmLock.getReadHoldCount() > 0 || this.bmLock.isWriteLockedByCurrentThread();
+ }
+ return false;
+ }
+
+ @Override
+ /**
+ * This method is only used for ComputeDirectoryContentSummary.
+ * For the GLOBAL mode, just return the FSLock's ReadHoldCount.
+ */
+ public int getReadHoldCount(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ return this.fsLock.getReadHoldCount();
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ return this.fsLock.getReadHoldCount();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ return this.bmLock.getReadHoldCount();
+ }
+ return -1;
+ }
+
+ @Override
+ public int getQueueLength(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ return -1;
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ return this.fsLock.getQueueLength();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ return this.bmLock.getQueueLength();
+ }
+ return -1;
+ }
+
+ @Override
+ public long getNumOfReadLockLongHold(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ return -1;
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ return this.fsLock.getNumOfReadLockLongHold();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ return this.bmLock.getNumOfReadLockLongHold();
+ }
+ return -1;
+ }
+
+ @Override
+ public long getNumOfWriteLockLongHold(FSNamesystemLockMode lockMode) {
+ if (lockMode.equals(FSNamesystemLockMode.GLOBAL)) {
+ return -1;
+ } else if (lockMode.equals(FSNamesystemLockMode.FS)) {
+ return this.fsLock.getNumOfWriteLockLongHold();
+ } else if (lockMode.equals(FSNamesystemLockMode.BM)) {
+ return this.bmLock.getNumOfWriteLockLongHold();
+ }
+ return -1;
+ }
+
+ @Override
+ public boolean isMetricsEnabled() {
+ return this.fsLock.isMetricsEnabled();
+ }
+
+ public void setMetricsEnabled(boolean metricsEnabled) {
+ this.fsLock.setMetricsEnabled(metricsEnabled);
+ this.bmLock.setMetricsEnabled(metricsEnabled);
+ }
+
+ @Override
+ public void setReadLockReportingThresholdMs(long readLockReportingThresholdMs) {
+ this.fsLock.setReadLockReportingThresholdMs(readLockReportingThresholdMs);
+ this.bmLock.setReadLockReportingThresholdMs(readLockReportingThresholdMs);
+ }
+
+ @Override
+ public long getReadLockReportingThresholdMs() {
+ return this.fsLock.getReadLockReportingThresholdMs();
+ }
+
+ @Override
+ public void setWriteLockReportingThresholdMs(long writeLockReportingThresholdMs) {
+ this.fsLock.setWriteLockReportingThresholdMs(writeLockReportingThresholdMs);
+ this.bmLock.setWriteLockReportingThresholdMs(writeLockReportingThresholdMs);
+ }
+
+ @Override
+ public long getWriteLockReportingThresholdMs() {
+ return this.fsLock.getWriteLockReportingThresholdMs();
+ }
+
+ @Override
+ public void setLockForTests(ReentrantReadWriteLock lock) {
+ throw new UnsupportedOperationException("SetLockTests is unsupported");
+ }
+
+ @Override
+ public ReentrantReadWriteLock getLockForTests() {
+ throw new UnsupportedOperationException("SetLockTests is unsupported");
+ }
+}
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/fgl/TestFineGrainedFSNamesystemLock.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/fgl/TestFineGrainedFSNamesystemLock.java
new file mode 100644
index 000000000000..88d66cb3e9b6
--- /dev/null
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/fgl/TestFineGrainedFSNamesystemLock.java
@@ -0,0 +1,275 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.namenode.fgl;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.util.concurrent.HadoopExecutors;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class TestFineGrainedFSNamesystemLock {
+
+ private final Logger log = LoggerFactory.getLogger(TestFineGrainedFSNamesystemLock.class);
+
+ private int getLoopNumber() {
+ return ThreadLocalRandom.current().nextInt(2000, 3000);
+ }
+
+ /**
+ * Test read/write lock of Global, FS and BM model through multi-threading.
+ */
+ @Test(timeout=120000)
+ public void testMultipleThreadsUsingLocks()
+ throws InterruptedException, ExecutionException {
+ FineGrainedFSNamesystemLock fsn = new FineGrainedFSNamesystemLock(new Configuration(), null);
+ ExecutorService service = HadoopExecutors.newFixedThreadPool(1000);
+
+ AtomicLong globalCount = new AtomicLong(0);
+ AtomicLong fsCount = new AtomicLong(0);
+ AtomicLong bmCount = new AtomicLong(0);
+ AtomicLong globalNumber = new AtomicLong(0);
+ AtomicLong fsNumber = new AtomicLong(0);
+ AtomicLong bmNumber = new AtomicLong(0);
+
+ List<Callable<Boolean>> callableList = new ArrayList<>(1000);
+ for (int i = 0; i < 1000; i++) {
+ int index = i % 12;
+ String opName = Integer.toString(i);
+ if (index == 0) { // Test the global write lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ writeLock(fsn, FSNamesystemLockMode.GLOBAL, opName, globalCount);
+ globalNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 1) { // Test the fs write lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ writeLock(fsn, FSNamesystemLockMode.FS, opName, fsCount);
+ fsNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 2) { // Test the bm write lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ writeLock(fsn, FSNamesystemLockMode.BM, opName, bmCount);
+ bmNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 3) { // Test the bm read lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ readLock(fsn, FSNamesystemLockMode.BM, opName, bmCount);
+ bmNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 4) { // Test the fs read lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ readLock(fsn, FSNamesystemLockMode.FS, opName, fsCount);
+ fsNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 5) { // Test the global read lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ readLock(fsn, FSNamesystemLockMode.GLOBAL, opName, globalCount);
+ globalNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 6) { // Test the global interruptable write lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ writeLockInterruptibly(fsn, FSNamesystemLockMode.GLOBAL, opName, globalCount);
+ globalNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 7) { // Test the fs interruptable write lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ writeLockInterruptibly(fsn, FSNamesystemLockMode.FS, opName, fsCount);
+ fsNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 8) { // Test the bm interruptable write lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ writeLockInterruptibly(fsn, FSNamesystemLockMode.BM, opName, bmCount);
+ bmNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 9) { // Test the bm interruptable read lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ readLockInterruptibly(fsn, FSNamesystemLockMode.BM, opName, bmCount);
+ bmNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else if (index == 10) { // Test the fs interruptable read lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ readLockInterruptibly(fsn, FSNamesystemLockMode.FS, opName, fsCount);
+ fsNumber.incrementAndGet();
+ }
+ return true;
+ });
+ } else { // Test the global interruptable read lock via multiple threads.
+ callableList.add(() -> {
+ for (int startIndex = 0; startIndex < getLoopNumber(); startIndex++) {
+ readLockInterruptibly(fsn, FSNamesystemLockMode.GLOBAL, opName, globalCount);
+ globalNumber.incrementAndGet();
+ }
+ return true;
+ });
+ }
+ }
+
+ List<Future<Boolean>> futures = service.invokeAll(callableList);
+ for (Future<Boolean> f : futures) {
+ f.get();
+ }
+ log.info("Global executed {} times, FS executed {} times, BM executed {} times.",
+ globalNumber.get(), fsNumber.get(), bmNumber.get());
+ assert globalCount.get() == 0;
+ assert fsCount.get() == 0;
+ assert bmCount.get() == 0;
+ }
+
+ /**
+ * Test write lock for the input lock mode.
+ * @param fsn FSNLockManager
+ * @param mode LockMode
+ * @param opName operation name
+ * @param counter counter to trace this lock mode
+ */
+ private void writeLock(FSNLockManager fsn, FSNamesystemLockMode mode,
+ String opName, AtomicLong counter) {
+ fsn.writeLock(mode);
+ try {
+ counter.incrementAndGet();
+ } finally {
+ fsn.writeUnlock(mode, opName);
+ }
+ fsn.writeLock(mode);
+ try {
+ counter.decrementAndGet();
+ } finally {
+ fsn.writeUnlock(mode, opName);
+ }
+ }
+
+ /**
+ * Test read lock for the input lock mode.
+ * @param fsn FSNLockManager
+ * @param mode LockMode
+ * @param opName operation name
+ * @param counter counter to trace this lock mode
+ */
+ private void readLock(FSNLockManager fsn, FSNamesystemLockMode mode,
+ String opName, AtomicLong counter) {
+ fsn.readLock(mode);
+ try {
+ counter.get();
+ } finally {
+ fsn.readUnlock(mode, opName);
+ }
+ }
+
+ /**
+ * Test write lock for the input lock mode.
+ * @param fsn FSNLockManager
+ * @param mode LockMode
+ * @param opName operation name
+ * @param counter counter to trace this lock mode
+ */
+ private void writeLockInterruptibly(FSNLockManager fsn, FSNamesystemLockMode mode,
+ String opName, AtomicLong counter) {
+ boolean success = false;
+ try {
+ fsn.writeLockInterruptibly(mode);
+ try {
+ counter.incrementAndGet();
+ success = true;
+ } finally {
+ fsn.writeUnlock(mode, opName);
+ }
+ } catch (InterruptedException e) {
+ log.info("InterruptedException happens in thread {}" +
+ " during increasing the Count.", opName);
+ // ignore;
+ }
+ while (success) {
+ try {
+ fsn.writeLockInterruptibly(mode);
+ try {
+ counter.decrementAndGet();
+ success = false;
+ } finally {
+ fsn.writeUnlock(mode, opName);
+ }
+ } catch (InterruptedException e) {
+ log.info("InterruptedException happens in thread {}" +
+ " during decreasing the Count.", opName);
+ // ignore.
+ }
+ }
+ }
+
+ /**
+ * Test read lock for the input lock mode.
+ * @param fsn FSNLockManager
+ * @param mode LockMode
+ * @param opName operation name
+ * @param counter counter to trace this lock mode
+ */
+ private void readLockInterruptibly(FSNLockManager fsn, FSNamesystemLockMode mode,
+ String opName, AtomicLong counter) {
+ try {
+ fsn.readLockInterruptibly(mode);
+ try {
+ counter.get();
+ } finally {
+ fsn.readUnlock(mode, opName);
+ }
+ } catch (InterruptedException e) {
+ log.info("InterruptedException happens in thread {}" +
+ " during getting the Count.", opName);
+ // ignore
+ }
+ }
+}
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