SimpleInodeLockList (Alluxio Parent 2.2.3-SNAPSHOT API)

java.lang.Object
- alluxio.master.file.meta.SimpleInodeLockList

All Implemented Interfaces:: InodeLockList, AutoCloseable

@NotThreadSafe
public class SimpleInodeLockList
extends Object
implements InodeLockList

A simple inode lock list.

Constructor Summary

Constructors
Constructor and Description

SimpleInodeLockList(InodeLockManager inodeLockManager)
Creates a new empty lock list.

Constructors
Constructor and Description
`SimpleInodeLockList(InodeLockManager inodeLockManager)` Creates a new empty lock list.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`close()` Closes the lock list, releasing all locks.
`void`	`downgradeEdgeToInode(Inode inode, LockMode mode)` Downgrades from edge write-locking to inode write-locking.
`void`	`downgradeLastEdge()` Downgrades the last edge lock in the lock list from WRITE lock to READ lock.
`void`	`downgradeLastInode()` Downgrades the last inode from a write lock to a read lock.
`boolean`	`endsInInode()`
`Inode`	`get(int index)`
`InodeLockManager`	`getInodeLockManager()`
`List<Inode>`	`getLockedInodes()`
`LockMode`	`getLockMode()`
`boolean`	`isEmpty()`
`void`	`lockEdge(Inode lastInode, String childName, LockMode mode)` Locks an edge leading out of the last inode in the list.
`void`	`lockInode(Inode inode, LockMode mode)` Locks the given inode and adds it to the lock list.
`void`	`lockRootEdge(LockMode mode)` Locks the root edge in the specified mode.
`int`	`numInodes()`
`void`	`pushWriteLockedEdge(Inode inode, String childName)` Leapfrogs the final edge write lock forward, reducing the lock list's write-locked scope.
`String`	`toString()`
`void`	`unlockLastEdge()` Unlocks the last locked edge.
`void`	`unlockLastInode()` Unlocks the last locked inode.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface alluxio.master.file.meta.InodeLockList
getLockedInodeViews

- Constructor Detail
  - SimpleInodeLockList
```
public SimpleInodeLockList(InodeLockManager inodeLockManager)
```
    Creates a new empty lock list.
    
    Parameters:
    
    inodeLockManager - manager for inode locks
- Method Detail
  - lockInode
```
public void lockInode(Inode inode,
                      LockMode mode)
```
    Description copied from interface: InodeLockList
    
    Locks the given inode and adds it to the lock list. This method does *not* check that the inode is still a child of the previous inode, or that the inode still exists. This method should only be called when the edge leading to the inode is locked. Example Starting from [a, a->b] lockInode(b, LockMode.READ) results in [a, a->b, b] lockInode(b, LockMode.WRITE) results in [a, a->b, b*]
    
    Specified by:
    
    lockInode in interface InodeLockList
    
    Parameters:
    
    inode - the inode to lock
    
    mode - the mode to lock in
  - lockEdge
```
public void lockEdge(Inode lastInode,
                     String childName,
                     LockMode mode)
```
    Description copied from interface: InodeLockList
    
    Locks an edge leading out of the last inode in the list. Example Starting from [a, a->b, b] lockEdge(b, c, LockMode.READ) results in [a, a->b, b, b->c] lockEdge(b, c, LockMode.WRITE) results in [a, a->b, b, b->c*]
    
    Specified by:
    
    lockEdge in interface InodeLockList
    
    Parameters:
    
    lastInode - the parent inode of the edge
    
    childName - the child name of the edge
    
    mode - the mode to lock in
  - lockRootEdge
```
public void lockRootEdge(LockMode mode)
```
    Description copied from interface: InodeLockList
    
    Locks the root edge in the specified mode. The lock list must be empty to call this method.
    
    Specified by:
    
    lockRootEdge in interface InodeLockList
    
    Parameters:
    
    mode - the mode to lock in
  - pushWriteLockedEdge
```
public void pushWriteLockedEdge(Inode inode,
                                String childName)
```
    Description copied from interface: InodeLockList
    
    Leapfrogs the final edge write lock forward, reducing the lock list's write-locked scope. Example Starting from [a, a->b*] pushWriteLockedEdge(b, c) results in [a, a->b, b, b->c*] The read lock on a->b is acquired before releasing the write lock. This ensures that no other thread can take the write lock before the read lock is acquired. If this is a composite lock list and the final write lock is part of the base lock list, the new locks will be acquired but no downgrade will occur.
    
    Specified by:
    
    pushWriteLockedEdge in interface InodeLockList
    
    Parameters:
    
    inode - the inode to add to the lock list
    
    childName - the child name for the edge to add to the lock list
  - unlockLastInode
```
public void unlockLastInode()
```
    Description copied from interface: InodeLockList
    
    Unlocks the last locked inode. Example Starting from [a, a->b, b] unlockLastInode() results in [a, a->b]
    
    Specified by:
    
    unlockLastInode in interface InodeLockList
  - unlockLastEdge
```
public void unlockLastEdge()
```
    Description copied from interface: InodeLockList
    
    Unlocks the last locked edge. Example Starting from [a, a->b] unlockLastEdge results in [a]
    
    Specified by:
    
    unlockLastEdge in interface InodeLockList
  - downgradeLastInode
```
public void downgradeLastInode()
```
    Description copied from interface: InodeLockList
    
    Downgrades the last inode from a write lock to a read lock. The read lock is acquired before releasing the write lock. Example Starting from [a, a->b, b*] downgradeLastInode() results in [a, a->b, b] If the last inode is not the only write-locked inode, no downgrade occurs.
    
    Specified by:
    
    downgradeLastInode in interface InodeLockList
  - downgradeLastEdge
```
public void downgradeLastEdge()
```
    Description copied from interface: InodeLockList
    
    Downgrades the last edge lock in the lock list from WRITE lock to READ lock. Example Starting from [a, a->b*] downgradeLastEdge() results in [a, a->b]
    
    Specified by:
    
    downgradeLastEdge in interface InodeLockList
  - downgradeEdgeToInode
```
public void downgradeEdgeToInode(Inode inode,
                                 LockMode mode)
```
    Description copied from interface: InodeLockList
    
    Downgrades from edge write-locking to inode write-locking. This reduces the scope of the write lock by pushing it forward one entry. Example Starting from [a, a->b*] downgradeEdgeToInode(b, LockMode.READ) results in [a, a->b, b] downgradeEdgeToInode(b, LockMode.WRITE) results in [a, a->b, b*] The read lock on a->b is acquired before releasing the write lock. This ensures that no other thread can take the write lock before the read lock is acquired.
    
    Specified by:
    
    downgradeEdgeToInode in interface InodeLockList
    
    Parameters:
    
    inode - the next inode in the lock list
    
    mode - the mode to downgrade to
  - getLockMode
```
public LockMode getLockMode()
```
    Specified by:
    
    getLockMode in interface InodeLockList
    
    Returns:
    
    LockMode.WRITE if the last entry in the list is write-locked, otherwise LockMode.READ
  - getLockedInodes
```
public List<Inode> getLockedInodes()
```
    Specified by:
    
    getLockedInodes in interface InodeLockList
    
    Returns:
    
    a copy of all locked inodes
  - get
```
public Inode get(int index)
```
    Specified by:
    
    get in interface InodeLockList
    
    Parameters:
    
    index - the index of the list
    
    Returns:
    
    the inode at the specified index
  - numInodes
```
public int numInodes()
```
    Specified by:
    
    numInodes in interface InodeLockList
    
    Returns:
    
    the size of the list in terms of locked inodes
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface InodeLockList
    
    Returns:
    
    true if the locklist is empty
  - getInodeLockManager
```
public InodeLockManager getInodeLockManager()
```
    Specified by:
    
    getInodeLockManager in interface InodeLockList
    
    Returns:
    
    the inode lock manager for this lock list
  - endsInInode
```
public boolean endsInInode()
```
    Specified by:
    
    endsInInode in interface InodeLockList
    
    Returns:
    
    whether this lock list ends in an inode (as opposed to an edge)
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - close
```
public void close()
```
    Description copied from interface: InodeLockList
    
    Closes the lock list, releasing all locks.
    
    Specified by:
    
    close in interface InodeLockList
    
    Specified by:
    
    close in interface AutoCloseable

Class SimpleInodeLockList

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface alluxio.master.file.meta.InodeLockList

Constructor Detail

SimpleInodeLockList

Method Detail

lockInode

lockEdge

lockRootEdge

pushWriteLockedEdge

unlockLastInode

unlockLastEdge

downgradeLastInode

downgradeLastEdge

downgradeEdgeToInode

getLockMode

getLockedInodes

get

numInodes

isEmpty

getInodeLockManager

endsInInode

toString

close