Package org.wildfly.common.lock

Class SpinLock

  • All Implemented Interfaces:
    java.util.concurrent.locks.Lock, ExtendedLock
    public class SpinLock
extends java.lang.Object
implements ExtendedLock
    A spin lock. Such locks are designed to only be held for a very short time - for example, long enough to compare and swap two fields. The lock may degrade to yielding the thread after a certain number of spins if it is held for too long.

    Spin locks do not support conditions, and they do not support timed waiting. Normally only the uninterruptible lock, tryLock, and unlock methods should be used to control the lock.

    • Constructor Summary

      Constructors 
      Constructor Description
      SpinLock()
      Construct a new instance.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean isFair()
      Determine if this lock is fair.
      boolean isHeldByCurrentThread()
      Determine if this spin lock is held by the calling thread.
      boolean isLocked()
      Determine if this spin lock is held.
      void lock()
      Acquire the lock by spinning until it is held.
      void lockInterruptibly()
      Acquire the lock by spinning until it is held or the thread is interrupted.
      java.util.concurrent.locks.Condition newCondition()
      Unsupported.
      boolean tryLock()
      Try to acquire the lock, returning immediately whether or not the lock was acquired.
      boolean tryLock​(long time, java.util.concurrent.TimeUnit unit)
      Unsupported.
      void unlock()
      Release the lock.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • SpinLock

        public SpinLock()
        Construct a new instance.

    • Method Detail

      • isLocked

        public boolean isLocked()
        Determine if this spin lock is held. Useful for assertions.
        Specified by:
        isLocked in interface ExtendedLock
        Returns:
        true if the lock is held by any thread, false otherwise

      • isHeldByCurrentThread

        public boolean isHeldByCurrentThread()
        Determine if this spin lock is held by the calling thread. Useful for assertions.
        Specified by:
        isHeldByCurrentThread in interface ExtendedLock
        Returns:
        true if the lock is held by the calling thread, false otherwise

      • isFair

        public boolean isFair()
        Determine if this lock is fair.
        Specified by:
        isFair in interface ExtendedLock
        Returns:
        true; the lock is fair

      • lock

        public void lock()
        Acquire the lock by spinning until it is held.
        Specified by:
        lock in interface java.util.concurrent.locks.Lock

      • lockInterruptibly

        public void lockInterruptibly()
                       throws java.lang.InterruptedException
        Acquire the lock by spinning until it is held or the thread is interrupted.
        Specified by:
        lockInterruptibly in interface java.util.concurrent.locks.Lock
        Throws:
        java.lang.InterruptedException - if the thread is interrupted before the lock can be acquired

      • tryLock

        public boolean tryLock()
        Try to acquire the lock, returning immediately whether or not the lock was acquired.
        Specified by:
        tryLock in interface java.util.concurrent.locks.Lock
        Returns:
        true if the lock was acquired, false otherwise

      • unlock

        public void unlock()
        Release the lock.
        Specified by:
        unlock in interface java.util.concurrent.locks.Lock
        Throws:
        java.lang.IllegalMonitorStateException - if the lock is not held by the current thread

      • tryLock

        public boolean tryLock​(long time,
                       java.util.concurrent.TimeUnit unit)
                throws java.lang.UnsupportedOperationException
        Unsupported.
        Specified by:
        tryLock in interface java.util.concurrent.locks.Lock
        Parameters:
        time - ignored
        unit - ignored
        Returns:
        nothing
        Throws:
        java.lang.UnsupportedOperationException - always

      • newCondition

        public java.util.concurrent.locks.Condition newCondition()
                                                  throws java.lang.UnsupportedOperationException
        Unsupported.
        Specified by:
        newCondition in interface java.util.concurrent.locks.Lock
        Returns:
        nothing
        Throws:
        java.lang.UnsupportedOperationException - always