org.redisson.api

Interface RSemaphore

All Superinterfaces:

RExpirable, RExpirableAsync, RObject, RObjectAsync, RSemaphoreAsync

All Known Implementing Classes:

RedissonQueueSemaphore, RedissonSemaphore

public interface RSemaphore
extends RExpirable, RSemaphoreAsync

Redis based implementation of Semaphore.

Works in non-fair mode. Therefore order of acquiring is unpredictable.

Author:

Nikita Koksharov

Method Summary

Modifier and Type	Method and Description
void	acquire() Acquires a permit.
void	acquire(int permits) Acquires defined amount of permits.
void	addPermits(int permits) Increases or decreases the number of available permits by defined value.
int	availablePermits() Returns amount of available permits.
int	drainPermits() Acquires and returns all permits that are immediately available.
void	reducePermits(int permits) Deprecated.
void	release() Releases a permit.
void	release(int permits) Releases defined amount of permits.
boolean	tryAcquire() Tries to acquire currently available permit.
boolean	tryAcquire(int permits) Tries to acquire defined amount of currently available permits.
boolean	tryAcquire(int permits, long waitTime, TimeUnit unit) Tries to acquire defined amount of currently available permits.
boolean	tryAcquire(long waitTime, TimeUnit unit) Tries to acquire currently available permit.
boolean	trySetPermits(int permits) Tries to set number of permits.

Methods inherited from interface org.redisson.api.RExpirable

clearExpire, expire, expireAt, expireAt, remainTimeToLive

Methods inherited from interface org.redisson.api.RObject

addListener, copy, delete, dump, getCodec, getName, isExists, migrate, move, removeListener, rename, renamenx, restore, restore, restoreAndReplace, restoreAndReplace, sizeInMemory, touch, unlink

Methods inherited from interface org.redisson.api.RSemaphoreAsync

acquireAsync, acquireAsync, addPermitsAsync, availablePermitsAsync, drainPermitsAsync, reducePermitsAsync, releaseAsync, releaseAsync, tryAcquireAsync, tryAcquireAsync, tryAcquireAsync, tryAcquireAsync, trySetPermitsAsync

Methods inherited from interface org.redisson.api.RExpirableAsync

clearExpireAsync, expireAsync, expireAtAsync, expireAtAsync, remainTimeToLiveAsync

Methods inherited from interface org.redisson.api.RObjectAsync

addListenerAsync, copyAsync, deleteAsync, dumpAsync, isExistsAsync, migrateAsync, moveAsync, removeListenerAsync, renameAsync, renamenxAsync, restoreAndReplaceAsync, restoreAndReplaceAsync, restoreAsync, restoreAsync, sizeInMemoryAsync, touchAsync, unlinkAsync

Method Detail

acquire

void acquire()
      throws InterruptedException

Acquires a permit. Waits if necessary until a permit became available.

Throws:

InterruptedException - if the current thread was interrupted

acquire

void acquire(int permits)
      throws InterruptedException

Acquires defined amount of permits. Waits if necessary until all permits became available.

Parameters:

permits - the number of permits to acquire

Throws:

InterruptedException - if the current thread is interrupted

IllegalArgumentException - if permits is negative

tryAcquire

boolean tryAcquire()

Tries to acquire currently available permit.

Returns:

true if a permit was acquired and false otherwise

tryAcquire

boolean tryAcquire(int permits)

Tries to acquire defined amount of currently available permits.

Parameters:

permits - the number of permits to acquire

Returns:

true if permits were acquired and false otherwise

tryAcquire

boolean tryAcquire(long waitTime,
                   TimeUnit unit)
            throws InterruptedException

Tries to acquire currently available permit. Waits up to defined waitTime if necessary until a permit became available.

Parameters:

waitTime - the maximum time to wait

unit - the time unit

Returns:

true if a permit was acquired and false otherwise

Throws:

InterruptedException - if the current thread was interrupted

tryAcquire

boolean tryAcquire(int permits,
                   long waitTime,
                   TimeUnit unit)
            throws InterruptedException

Tries to acquire defined amount of currently available permits. Waits up to defined waitTime if necessary until all permits became available.

Parameters:

permits - amount of permits

waitTime - the maximum time to wait

unit - the time unit

Returns:

true if permits were acquired and false otherwise

Throws:

InterruptedException - if the current thread was interrupted

release

void release()

Releases a permit. Increases the number of available permits.

release

void release(int permits)

Releases defined amount of permits. Increases the number of available permits by permits amount.

Parameters:

permits - amount of permits

availablePermits

int availablePermits()

Returns amount of available permits.

Returns:

number of permits

drainPermits

int drainPermits()

Acquires and returns all permits that are immediately available.

Returns:

number of permits

trySetPermits

boolean trySetPermits(int permits)

Tries to set number of permits.

Parameters:

permits - - number of permits

Returns:

true if permits has been set successfully, otherwise false if permits were already set.

reducePermits

@Deprecated
void reducePermits(int permits)

Deprecated.

addPermits

void addPermits(int permits)

Increases or decreases the number of available permits by defined value.

Parameters:

permits - amount of permits to add/remove