org.redisson.api

Interface RCountDownLatch

All Superinterfaces:

RCountDownLatchAsync, RObject, RObjectAsync

All Known Implementing Classes:

RedissonCountDownLatch

public interface RCountDownLatch
extends RObject, RCountDownLatchAsync

Distributed alternative to the CountDownLatch It has an advantage over CountDownLatch -- count can be set via trySetCount(long) method.

Author:

Nikita Koksharov

Method Summary

Modifier and Type	Method and Description
void	await() Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted.
boolean	await(long timeout, TimeUnit unit) Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted, or the specified waiting time elapses.
void	countDown() Decrements the count of the latch, releasing all waiting threads if the count reaches zero.
long	getCount() Returns the current count.
boolean	trySetCount(long count) Sets new count value only if previous count already has reached zero or is not set at all.

Methods inherited from interface org.redisson.api.RObject

delete, getCodec, getName, isExists, migrate, move, rename, renamenx

Methods inherited from interface org.redisson.api.RCountDownLatchAsync

countDownAsync, getCountAsync, trySetCountAsync

Methods inherited from interface org.redisson.api.RObjectAsync

deleteAsync, isExistsAsync, migrateAsync, moveAsync, renameAsync, renamenxAsync

Method Detail

await

void await()
    throws InterruptedException

Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted.

If the current count is zero then this method returns immediately.

If the current count is greater than zero then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of two things happen:

• The count reaches zero due to invocations of the countDown() method; or
• Some other thread interrupts the current thread.

If the current thread:

• has its interrupted status set on entry to this method; or
• is interrupted while waiting,

then InterruptedException is thrown and the current thread's interrupted status is cleared.

Throws:

InterruptedException - if the current thread is interrupted while waiting

await

boolean await(long timeout,
              TimeUnit unit)
       throws InterruptedException

Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted, or the specified waiting time elapses.

If the current count is zero then this method returns immediately with the value true.

If the current count is greater than zero then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of three things happen:

• The count reaches zero due to invocations of the countDown() method; or
• Some other thread interrupts the current thread; or
• The specified waiting time elapses.

If the count reaches zero then the method returns with the value true.

If the current thread:

• has its interrupted status set on entry to this method; or
• is interrupted while waiting,

then InterruptedException is thrown and the current thread's interrupted status is cleared.

If the specified waiting time elapses then the value false is returned. If the time is less than or equal to zero, the method will not wait at all.

Parameters:

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

true if the count reached zero and false if the waiting time elapsed before the count reached zero

Throws:

InterruptedException - if the current thread is interrupted while waiting

countDown

void countDown()

Decrements the count of the latch, releasing all waiting threads if the count reaches zero.

If the current count is greater than zero then it is decremented. If the new count is zero then all waiting threads are re-enabled for thread scheduling purposes.

If the current count equals zero then nothing happens.

getCount

long getCount()

Returns the current count.

This method is typically used for debugging and testing purposes.

Returns:

the current count

trySetCount

boolean trySetCount(long count)

Sets new count value only if previous count already has reached zero or is not set at all.

Parameters:

count - - number of times countDown() must be invoked before threads can pass through await()

Returns:

true if new count setted false if previous count has not reached zero