Package nxt.util

Class ReadWriteUpdateLock

java.lang.Object

nxt.util.ReadWriteUpdateLock

public class ReadWriteUpdateLock
extends Object

A read or update lock allows shared access while a write lock enforces exclusive access. Multiple threads can hold the read lock but only one thread can hold the update or write lock. If a thread obtains a lock that it already holds, it must release the lock the same number of times that it obtained the lock.

• An attempt to obtain the read lock while another thread holds the write lock will cause the thread to be suspended until the write lock is released.
• An attempt to obtain the update lock while another thread holds the update or write lock will cause the thread to be suspended until the blocking lock is released. A thread holding the update lock can subsequently obtain the write lock to gain exclusive access. An attempt to obtain the update lock while holding either the read lock or the write lock will result in an exception.
• An attempt to obtain the write lock while another thread holds the read, update or write lock will cause the thread to be suspended until the blocking lock is released. An attempt to obtain the write lock while holding the read lock will result in an exception.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ReadWriteUpdateLock.Lock	Lock interface

Constructor Summary

Constructors

Constructor	Description
ReadWriteUpdateLock()

Method Summary

Modifier and Type	Method	Description
ReadWriteUpdateLock.Lock	readLock()	Return the read lock
ReadWriteUpdateLock.Lock	updateLock()	Return the update lock
ReadWriteUpdateLock.Lock	writeLock()	Return the write lock

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ReadWriteUpdateLock

public ReadWriteUpdateLock()

Method Details

readLock

public ReadWriteUpdateLock.Lock readLock()

Return the read lock

Returns:

Read lock

updateLock

public ReadWriteUpdateLock.Lock updateLock()

Return the update lock

Returns:

Update lock

writeLock

public ReadWriteUpdateLock.Lock writeLock()

Return the write lock

Returns:

Write lock