Package org.redisson.api

Interface RPermitExpirableSemaphoreRx

All Superinterfaces:
RExpirableRx, RObjectRx
public interface RPermitExpirableSemaphoreRx extends RExpirableRx
RxJava2 interface for Semaphore object with lease time parameter support 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

  • Method Details

    • acquire

      io.reactivex.rxjava3.core.Single<String> acquire()
      Acquires a permit from this semaphore, blocking until one is available, or the thread is 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 release(String) method for this semaphore and the current thread is next to be assigned a permit; or
      • Some other thread interrupts the current thread.
      Returns:
      permit id

    • acquire

      io.reactivex.rxjava3.core.Single<String> acquire(long leaseTime, TimeUnit unit)
      Acquires a permit with defined lease time from this semaphore, blocking until one is available, or the thread is 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 release(java.lang.String) method for this semaphore and the current thread is next to be assigned a permit; or
      • Some other thread interrupts the current thread.
      Parameters:
      leaseTime - - permit lease time
      unit - - time unit
      Returns:
      permit id

    • tryAcquire

      io.reactivex.rxjava3.core.Maybe<String> tryAcquire()
      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 null.

      Returns:
      permit id if a permit was acquired and null otherwise

    • tryAcquire

      io.reactivex.rxjava3.core.Maybe<String> tryAcquire(long waitTime, TimeUnit unit)
      Acquires a permit from this semaphore, if one becomes available within the given waiting time and the current thread has not been 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 release(String) method for this semaphore and the current thread is next to be assigned a permit; or
      • Some other thread 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 null is returned. If the time is less than or equal to zero, the method will not wait at all.

      Parameters:
      waitTime - the maximum time to wait for a permit
      unit - the time unit of the timeout argument
      Returns:
      permit id if a permit was acquired and null if the waiting time elapsed before a permit was acquired

    • tryAcquire

      io.reactivex.rxjava3.core.Maybe<String> tryAcquire(long waitTime, long leaseTime, 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 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 release(String) method for this semaphore and the current thread is next to be assigned a permit; or
      • Some other thread 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 null is returned. If the time is less than or equal to zero, the method will not wait at all.

      Parameters:
      waitTime - the maximum time to wait for a permit
      leaseTime - permit lease time
      unit - the time unit of the timeout argument
      Returns:
      permit id if a permit was acquired and null if the waiting time elapsed before a permit was acquired

    • tryRelease

      io.reactivex.rxjava3.core.Single<Boolean> 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 acquire(). Correct usage of a semaphore is established by programming convention in the application.

      Parameters:
      permitId - - permit id
      Returns:
      true if a permit has been released and false otherwise

    • release

      io.reactivex.rxjava3.core.Completable release(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 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

      Parameters:
      permitId - - permit id
      Returns:
      void

    • availablePermits

      io.reactivex.rxjava3.core.Single<Integer> availablePermits()
      Returns the current number of available permits.
      Returns:
      number of available permits

    • trySetPermits

      io.reactivex.rxjava3.core.Single<Boolean> trySetPermits(int permits)
      Sets number of permits.
      Parameters:
      permits - - number of permits
      Returns:
      true if permits has been set successfully, otherwise false.

    • addPermits

      io.reactivex.rxjava3.core.Completable addPermits(int permits)
      Increases or decreases the number of available permits by defined value.
      Parameters:
      permits - - number of permits to add/remove
      Returns:
      void

    • updateLeaseTime

      io.reactivex.rxjava3.core.Single<Boolean> updateLeaseTime(String permitId, long leaseTime, TimeUnit unit)
      Overrides and updates lease time for defined permit id.
      Parameters:
      permitId - - permit id
      leaseTime - - permit lease time, use -1 to make it permanent
      unit - - the time unit of the timeout argument
      Returns:
      true if permits has been updated successfully, otherwise false.