ReadWriteUpdateLock

java.lang.Object
- nxt.util.ReadWriteUpdateLock

```
public class ReadWriteUpdateLock
extends java.lang.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

All Methods Instance Methods Concrete Methods
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 Detail
  - ReadWriteUpdateLock
```
public ReadWriteUpdateLock()
```
- Method Detail
  - 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