HDFS-17697. [FGL] hasWriteLock and hasReadLock in FineGrainedFSNamesystemLock shouldn't throw assert error (#7250)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FSNLockManager.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FSNLockManager.java
index a0452fe..0dc5eaa 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FSNLockManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/fgl/FSNLockManager.java
@@ -35,6 +35,7 @@ public interface FSNLockManager {
/**
* Acquire read lock according to the lock mode, unless interrupted while waiting.
* @param lockMode locking mode
+ * @throws InterruptedException If the thread is interrupted, an InterruptedException is thrown.
*/
void readLockInterruptibly(RwLockMode lockMode) throws InterruptedException;
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
index 934ac95..f109c0f 100644
--- 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
@@ -166,15 +166,8 @@ public void writeLockInterruptibly(RwLockMode lockMode)
@Override
public boolean hasWriteLock(RwLockMode lockMode) {
if (lockMode.equals(RwLockMode.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;
- }
+ return this.fsLock.isWriteLockedByCurrentThread()
+ && this.bmLock.isWriteLockedByCurrentThread();
} else if (lockMode.equals(RwLockMode.FS)) {
return this.fsLock.isWriteLockedByCurrentThread();
} else if (lockMode.equals(RwLockMode.BM)) {
@@ -186,17 +179,8 @@ public boolean hasWriteLock(RwLockMode lockMode) {
@Override
public boolean hasReadLock(RwLockMode lockMode) {
if (lockMode.equals(RwLockMode.GLOBAL)) {
- if (hasWriteLock(RwLockMode.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;
- }
+ return hasWriteLock(RwLockMode.GLOBAL) ||
+ (this.fsLock.getReadHoldCount() > 0 && this.bmLock.getReadHoldCount() > 0);
} else if (lockMode.equals(RwLockMode.FS)) {
return this.fsLock.getReadHoldCount() > 0 || this.fsLock.isWriteLockedByCurrentThread();
} else if (lockMode.equals(RwLockMode.BM)) {
@@ -205,11 +189,11 @@ public boolean hasReadLock(RwLockMode lockMode) {
return false;
}
- @Override
/**
* This method is only used for ComputeDirectoryContentSummary.
* For the GLOBAL mode, just return the FSLock's ReadHoldCount.
*/
+ @Override
public int getReadHoldCount(RwLockMode lockMode) {
if (lockMode.equals(RwLockMode.GLOBAL)) {
return this.fsLock.getReadHoldCount();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/RwLock.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/RwLock.java
index 2a5d325..26fbc0f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/RwLock.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/RwLock.java
@@ -24,7 +24,9 @@ default void readLock() {
readLock(RwLockMode.GLOBAL);
}
- /** Acquire read lock. */
+ /** Acquire read lock.
+ * @param lockMode The lock type for acquiring a read lock
+ */
void readLock(RwLockMode lockMode);
/** Acquire read lock, unless interrupted while waiting. */
@@ -32,7 +34,9 @@ default void readLockInterruptibly() throws InterruptedException {
readLockInterruptibly(RwLockMode.GLOBAL);
}
- /** Acquire read lock, unless interrupted while waiting. */
+ /** Acquire read lock, unless interrupted while waiting.
+ * @param lockMode The lock type for acquiring a read lock
+ */
void readLockInterruptibly(RwLockMode lockMode) throws InterruptedException;
/** Release read lock. */
@@ -50,16 +54,22 @@ default void readUnlock(String opName) {
/**
* Release read lock with operation name.
+ * @param lockMode The lock type for releasing the read lock
* @param opName Option name.
*/
void readUnlock(RwLockMode lockMode, String opName);
- /** Check if the current thread holds read lock. */
+ /** Check if the current thread holds read lock.
+ * @return true if the read lock is held by the current thread, else false
+ */
default boolean hasReadLock() {
return hasReadLock(RwLockMode.GLOBAL);
}
- /** Check if the current thread holds read lock. */
+ /** Check if the current thread holds read lock.
+ * @param lockMode The lock type used to check whether a read lock is held
+ * @return true if the read lock is held by the current thread, else false
+ */
boolean hasReadLock(RwLockMode lockMode);
/** Acquire write lock. */
@@ -67,7 +77,9 @@ default void writeLock() {
writeLock(RwLockMode.GLOBAL);
}
- /** Acquire write lock. */
+ /** Acquire write lock.
+ * @param lockMode The lock type for acquiring a write lock
+ */
void writeLock(RwLockMode lockMode);
/** Acquire write lock, unless interrupted while waiting. */
@@ -75,7 +87,9 @@ default void writeLockInterruptibly() throws InterruptedException {
writeLockInterruptibly(RwLockMode.GLOBAL);
}
- /** Acquire write lock, unless interrupted while waiting. */
+ /** Acquire write lock, unless interrupted while waiting.
+ * @param lockMode The lock type for acquiring a write lock
+ */
void writeLockInterruptibly(RwLockMode lockMode) throws InterruptedException;
/** Release write lock. */
@@ -93,15 +107,21 @@ default void writeUnlock(String opName) {
/**
* Release write lock with operation name.
+ * @param lockMode The lock type for releasing the write lock
* @param opName Option name.
*/
void writeUnlock(RwLockMode lockMode, String opName);
- /** Check if the current thread holds write lock. */
+ /** Check if the current thread holds write lock.
+ * @return true if the write lock is held by the current thread, else false
+ */
default boolean hasWriteLock() {
return hasWriteLock(RwLockMode.GLOBAL);
}
- /** Check if the current thread holds write lock. */
+ /** Check if the current thread holds write lock.
+ * @param lockMode The lock type used to check whether a write lock is held
+ * @return true if the write lock is held by the current thread, else false.
+ */
boolean hasWriteLock(RwLockMode lockMode);
}
