GridSpinBusyLock (Ignite 2.17.0)

java.lang.Object
- org.apache.ignite.internal.util.GridSpinBusyLock

```
@GridToStringExclude
public class GridSpinBusyLock
extends Object
```
Synchronization aid to track "busy" state of a subsystem that owns it.
Main difference over GridBusyLock is that this class is implemented over GridSpinReadWriteLock.
For example, there may be a manager that have different threads for some purposes and the manager must not be stopped while at least a single thread is in "busy" state. In this situation each thread must enter to "busy" state calling method enterBusy() in critical pieces of code which, i.e. use grid kernal functionality, notifying that the manager and the whole grid kernal cannot be stopped while it's in progress. Once the activity is done, the thread should leave "busy" state calling method leaveBusy(). The manager itself, when stopping, should call method block() that blocks till all activities leave "busy" state.

See Also:

GridBusyLock, GridSpinReadWriteLock

Constructor Summary

Constructors
Constructor Description

GridSpinBusyLock()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`block()`	Blocks current thread till all activities left "busy" state and prevents them from further entering to "busy" state.
`boolean`	`blockedByCurrentThread()`	Checks if busy lock was blocked by current thread.
`boolean`	`enterBusy()`	Enters "busy" state.
`void`	`leaveBusy()`	Leaves "busy" state.
`boolean`	`tryBlock(long millis)`
`void`	`unblock()`	Makes possible for activities entering busy state again.

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

- Constructor Detail
  - GridSpinBusyLock
```
public GridSpinBusyLock()
```
- Method Detail
  - enterBusy
```
public boolean enterBusy()
```
    Enters "busy" state.
    
    Returns:
    
    true if entered to busy state.
  - blockedByCurrentThread
```
public boolean blockedByCurrentThread()
```
    Checks if busy lock was blocked by current thread.
    
    Returns:
    
    True if busy lock was blocked by current thread.
  - leaveBusy
```
public void leaveBusy()
```
    Leaves "busy" state.
  - block
```
public void block()
```
    Blocks current thread till all activities left "busy" state and prevents them from further entering to "busy" state.
  - tryBlock
```
public boolean tryBlock(long millis)
                 throws InterruptedException
```
    Parameters:
    
    millis - Timeout.
    
    Returns:
    
    True if lock was acquired.
    
    Throws:
    
    InterruptedException - If interrupted.
  - unblock
```
public void unblock()
```
    Makes possible for activities entering busy state again.