org.redisson.api.RPermitExpirableSemaphoreReactive Maven / Gradle / Ivy
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/**
* Copyright (c) 2013-2019 Nikita Koksharov
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.redisson.api;
import java.util.concurrent.TimeUnit;
import reactor.core.publisher.Mono;
/**
* Semaphore object with support of lease time parameter for each acquired permit.
*
* Each permit identified by own id and could be released only using its id.
* Permit id is a 128-bits unique random identifier generated each time during acquiring.
*
*
Works in non-fair mode. Therefore order of acquiring is unpredictable.
*
* @author Nikita Koksharov
*
*/
public interface RPermitExpirableSemaphoreReactive extends RExpirableReactive {
/**
* Acquires a permit from this semaphore, blocking until one is
* available, or the thread is {@linkplain Thread#interrupt interrupted}.
*
*
Acquires a permit, if one is available and returns its id,
* reducing the number of available permits by one.
*
*
If no permit is available then the current thread becomes
* disabled for thread scheduling purposes and lies dormant until
* one of two things happens:
*
* - Some other thread invokes the {@link #release(String)} method for this
* semaphore and the current thread is next to be assigned a permit; or
*
- Some other thread {@linkplain Thread#interrupt interrupts}
* the current thread.
*
*
* @return permit id
*/
Mono acquire();
/**
* Acquires a permit with defined lease time from this semaphore,
* blocking until one is available,
* or the thread is {@linkplain Thread#interrupt interrupted}.
*
* Acquires a permit, if one is available and returns its id,
* reducing the number of available permits by one.
*
*
If no permit is available then the current thread becomes
* disabled for thread scheduling purposes and lies dormant until
* one of two things happens:
*
* - Some other thread invokes the {@link #release} method for this
* semaphore and the current thread is next to be assigned a permit; or
*
- Some other thread {@linkplain Thread#interrupt interrupts}
* the current thread.
*
*
* @param leaseTime - permit lease time
* @param unit - time unit
* @return permit id
*/
Mono acquire(long leaseTime, TimeUnit unit);
/**
* Acquires a permit only if one is available at the
* time of invocation.
*
* Acquires a permit, if one is available and returns immediately,
* with the permit id,
* reducing the number of available permits by one.
*
*
If no permit is available then this method will return
* immediately with the value {@code null}.
*
* @return permit id if a permit was acquired and {@code null}
* otherwise
*/
Mono tryAcquire();
/**
* Acquires a permit from this semaphore, if one becomes available
* within the given waiting time and the current thread has not
* been {@linkplain Thread#interrupt interrupted}.
*
* Acquires a permit, if one is available and returns immediately,
* with the permit id,
* reducing the number of available permits by one.
*
*
If no permit is available then the current thread becomes
* disabled for thread scheduling purposes and lies dormant until
* one of three things happens:
*
* - Some other thread invokes the {@link #release(String)} method for this
* semaphore and the current thread is next to be assigned a permit; or
*
- Some other thread {@linkplain Thread#interrupt interrupts}
* the current thread; or
*
- The specified waiting time elapses.
*
*
* If a permit is acquired then the permit id is returned.
*
*
If the specified waiting time elapses then the value {@code null}
* is returned. If the time is less than or equal to zero, the method
* will not wait at all.
*
* @param waitTime the maximum time to wait for a permit
* @param unit the time unit of the {@code timeout} argument
* @return permit id if a permit was acquired and {@code null}
* if the waiting time elapsed before a permit was acquired
*/
Mono tryAcquire(long waitTime, TimeUnit unit);
/**
* Acquires a permit with defined lease time from this semaphore,
* if one becomes available
* within the given waiting time and the current thread has not
* been {@linkplain Thread#interrupt interrupted}.
*
* Acquires a permit, if one is available and returns immediately,
* with the permit id,
* reducing the number of available permits by one.
*
*
If no permit is available then the current thread becomes
* disabled for thread scheduling purposes and lies dormant until
* one of three things happens:
*
* - Some other thread invokes the {@link #release(String)} method for this
* semaphore and the current thread is next to be assigned a permit; or
*
- Some other thread {@linkplain Thread#interrupt interrupts}
* the current thread; or
*
- The specified waiting time elapses.
*
*
* If a permit is acquired then the permit id is returned.
*
*
If the specified waiting time elapses then the value {@code null}
* is returned. If the time is less than or equal to zero, the method
* will not wait at all.
*
* @param waitTime the maximum time to wait for a permit
* @param leaseTime permit lease time
* @param unit the time unit of the {@code timeout} argument
* @return permit id if a permit was acquired and {@code null}
* if the waiting time elapsed before a permit was acquired
*/
Mono tryAcquire(long waitTime, long leaseTime, TimeUnit unit);
/**
* Releases a permit by its id, returning it to the semaphore.
*
* Releases a permit, increasing the number of available permits by
* one. If any threads of Redisson client are trying to acquire a permit,
* then one is selected and given the permit that was just released.
*
*
There is no requirement that a thread that releases a permit must
* have acquired that permit by calling {@link #acquire()}.
* Correct usage of a semaphore is established by programming convention
* in the application.
*
* @param permitId - permit id
* @return {@code true} if a permit has been released and {@code false}
* otherwise
*/
Mono tryRelease(String permitId);
/**
* Releases a permit by its id, returning it to the semaphore.
*
* Releases a permit, increasing the number of available permits by
* one. If any threads of Redisson client are trying to acquire a permit,
* then one is selected and given the permit that was just released.
*
*
There is no requirement that a thread that releases a permit must
* have acquired that permit by calling {@link #acquire()}.
* Correct usage of a semaphore is established by programming convention
* in the application.
*
*
Throws an exception if permit id doesn't exist or has already been release
*
* @param permitId - permit id
* @return void
*/
Mono release(String permitId);
/**
* Returns the current number of available permits.
*
* @return number of available permits
*/
Mono availablePermits();
/**
* Sets number of permits.
*
* @param permits - number of permits
* @return true if permits has been set successfully, otherwise false.
*/
Mono trySetPermits(int permits);
/**
* Increases or decreases the number of available permits by defined value.
*
* @param permits - number of permits to add/remove
* @return void
*/
Mono addPermits(int permits);
/**
* Overrides and updates lease time for defined permit id.
*
* @param permitId - permit id
* @param leaseTime - permit lease time, use -1 to make it permanent
* @param unit - the time unit of the {@code timeout} argument
* @return true if permits has been updated successfully, otherwise false.
*/
Mono updateLeaseTime(String permitId, long leaseTime, TimeUnit unit);
}