io.atomix.core.semaphore

Interface AtomicSemaphore

All Superinterfaces:

DistributedPrimitive, SyncPrimitive

public interface AtomicSemaphore
extends SyncPrimitive

Distributed implementation of Semaphore.

Field Summary

Fields inherited from interface io.atomix.primitive.DistributedPrimitive

DEFAULT_OPERATION_TIMEOUT_MILLIS

Method Summary

Modifier and Type	Method and Description
Version	acquire() Acquires a permit from this semaphore.
Version	acquire(int permits) Acquires the given number of permits from this semaphore, blocking until all are available.
AsyncAtomicSemaphore	async() Returns the underlying asynchronous primitive.
int	availablePermits() Returns the current number of permits available.
int	drainPermits() Acquires and returns all permits that are immediately available.
int	increasePermits(int permits) Increases the number of available permits by the indicated amount.
QueueStatus	queueStatus() Query the waiting queue status.
int	reducePermits(int permits) Shrinks the number of available permits by the indicated reduction.
void	release() Releases a permit.
void	release(int permits) Releases the given number of permits.
Optional<Version>	tryAcquire() Acquires a permit, if one is available and returns immediately.
Optional<Version>	tryAcquire(Duration timeout) Acquires a permit from this semaphore if one becomes available within the given waiting time.
Optional<Version>	tryAcquire(int permits) Acquires the given number of permits, if they are available and returns immediately.
Optional<Version>	tryAcquire(int permits, Duration timeout) Acquires the given number of permits, if they are available within the given waiting time.

Methods inherited from interface io.atomix.primitive.SyncPrimitive

close, delete

Methods inherited from interface io.atomix.primitive.DistributedPrimitive

addStateChangeListener, name, protocol, removeStateChangeListener, type

Method Detail

acquire

Version acquire()

Acquires a permit from this semaphore.

acquire

Version acquire(int permits)

Acquires the given number of permits from this semaphore, blocking until all are available.

Parameters:

permits - permits to acquire

tryAcquire

Optional<Version> tryAcquire()

Acquires a permit, if one is available and returns immediately.

Returns:

true if a permit was acquired and false otherwise

tryAcquire

Optional<Version> tryAcquire(int permits)

Acquires the given number of permits, if they are available and returns immediately.

Parameters:

permits - permits to acquire

Returns:

true if a permit was acquired and false otherwise

tryAcquire

Optional<Version> tryAcquire(Duration timeout)

Acquires a permit from this semaphore if one becomes available within the given waiting time.

Parameters:

timeout - the maximum time to wait for a permit

Returns:

true if a permit was acquired and false otherwise

tryAcquire

Optional<Version> tryAcquire(int permits,
                             Duration timeout)

Acquires the given number of permits, if they are available within the given waiting time.

Parameters:

permits - permits to acquire

timeout - the maximum time to wait for a permit

Returns:

true if a permit was acquired and false otherwise

release

void release()

Releases a permit.

release

void release(int permits)

Releases the given number of permits.

Parameters:

permits - permits to release

availablePermits

int availablePermits()

Returns the current number of permits available.

Returns:

the number of permits available

drainPermits

int drainPermits()

Acquires and returns all permits that are immediately available. If the initial permits is negative, this will set available permits to 0, and return a negative number. If a positive number is returned, the acquired permits will be recorded. If the Client disconnects, these permits will be automatically released.

Returns:

the number of permits acquired

increasePermits

int increasePermits(int permits)

Increases the number of available permits by the indicated amount. This method differs from release in that it does not effect the amount of permits this caller has acquired.

Parameters:

permits - the number of permits to add

Returns:

available permits after increase

reducePermits

int reducePermits(int permits)

Shrinks the number of available permits by the indicated reduction. This method differs from acquire in that it does not block waiting for permits to become available and can be reduced to negative.

Parameters:

permits - the number of permits to remove

Returns:

available permits after increase

queueStatus

QueueStatus queueStatus()

Query the waiting queue status.

Returns:

the waiting queue status

async

AsyncAtomicSemaphore async()

Description copied from interface: SyncPrimitive

Returns the underlying asynchronous primitive.

Specified by:

async in interface SyncPrimitive

Returns:

the underlying asynchronous primitive