java.util.concurrent.atomic

Class AtomicLong

  • All Implemented Interfaces:
    Serializable

    public class AtomicLong
    extends Number
    implements Serializable
    A long value that may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables. An AtomicLong is used in applications such as atomically incremented sequence numbers, and cannot be used as a replacement for a Long. However, this class does extend Number to allow uniform access by tools and utilities that deal with numerically-based classes.
    Since:
    1.5
    See Also:
    Serialized Form
    • Constructor Summary

      Constructors 
      Constructor and Description
      AtomicLong()
      Creates a new AtomicLong with initial value 0.
      AtomicLong(long initialValue)
      Creates a new AtomicLong with the given initial value.

        

    • Method Summary

      Methods 
      Modifier and Type Method and Description
      long addAndGet(long delta)
      Atomically adds the given value to the current value.
      boolean compareAndSet(long expect, long update)
      Atomically sets the value to the given updated value if the current value == the expected value.
      long decrementAndGet()
      Atomically decrements by one the current value.
      double doubleValue()
      Returns the value of the specified number as a double.
      float floatValue()
      Returns the value of the specified number as a float.
      long get()
      Gets the current value.
      long getAndAdd(long delta)
      Atomically adds the given value to the current value.
      long getAndDecrement()
      Atomically decrements by one the current value.
      long getAndIncrement()
      Atomically increments by one the current value.
      long getAndSet(long newValue)
      Atomically sets to the given value and returns the old value.
      long incrementAndGet()
      Atomically increments by one the current value.
      int intValue()
      Returns the value of the specified number as an int.
      void lazySet(long newValue)
      Eventually sets to the given value.
      long longValue()
      Returns the value of the specified number as a long.
      void set(long newValue)
      Sets to the given value.
      String toString()
      Returns the String representation of the current value.
      boolean weakCompareAndSet(long expect, long update)
      Atomically sets the value to the given updated value if the current value == the expected value.

        

    • Constructor Detail

      • AtomicLong

        public AtomicLong(long initialValue)
        Creates a new AtomicLong with the given initial value.
        Parameters:
        initialValue - the initial value
      • AtomicLong

        public AtomicLong()
        Creates a new AtomicLong with initial value 0.
    • Method Detail

      • get

        public final long get()
        Gets the current value.
        Returns:
        the current value
      • set

        public final void set(long newValue)
        Sets to the given value.
        Parameters:
        newValue - the new value
      • lazySet

        public final void lazySet(long newValue)
        Eventually sets to the given value.
        Parameters:
        newValue - the new value
        Since:
        1.6
      • getAndSet

        public final long getAndSet(long newValue)
        Atomically sets to the given value and returns the old value.
        Parameters:
        newValue - the new value
        Returns:
        the previous value
      • compareAndSet

        public final boolean compareAndSet(long expect,
                            long update)
        Atomically sets the value to the given updated value if the current value == the expected value.
        Parameters:
        expect - the expected value
        update - the new value
        Returns:
        true if successful. False return indicates that the actual value was not equal to the expected value.
      • weakCompareAndSet

        public final boolean weakCompareAndSet(long expect,
                                long update)
        Atomically sets the value to the given updated value if the current value == the expected value.

        May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

        Parameters:
        expect - the expected value
        update - the new value
        Returns:
        true if successful.
      • getAndIncrement

        public final long getAndIncrement()
        Atomically increments by one the current value.
        Returns:
        the previous value
      • getAndDecrement

        public final long getAndDecrement()
        Atomically decrements by one the current value.
        Returns:
        the previous value
      • getAndAdd

        public final long getAndAdd(long delta)
        Atomically adds the given value to the current value.
        Parameters:
        delta - the value to add
        Returns:
        the previous value
      • incrementAndGet

        public final long incrementAndGet()
        Atomically increments by one the current value.
        Returns:
        the updated value
      • decrementAndGet

        public final long decrementAndGet()
        Atomically decrements by one the current value.
        Returns:
        the updated value
      • addAndGet

        public final long addAndGet(long delta)
        Atomically adds the given value to the current value.
        Parameters:
        delta - the value to add
        Returns:
        the updated value
      • toString

        public String toString()
        Returns the String representation of the current value.
        Overrides:
        toString in class Object
        Returns:
        the String representation of the current value.
      • intValue

        public int intValue()
        Description copied from class: Number
        Returns the value of the specified number as an int. This may involve rounding or truncation.
        Specified by:
        intValue in class Number
        Returns:
        the numeric value represented by this object after conversion to type int.
      • longValue

        public long longValue()
        Description copied from class: Number
        Returns the value of the specified number as a long. This may involve rounding or truncation.
        Specified by:
        longValue in class Number
        Returns:
        the numeric value represented by this object after conversion to type long.
      • floatValue

        public float floatValue()
        Description copied from class: Number
        Returns the value of the specified number as a float. This may involve rounding.
        Specified by:
        floatValue in class Number
        Returns:
        the numeric value represented by this object after conversion to type float.
      • doubleValue

        public double doubleValue()
        Description copied from class: Number
        Returns the value of the specified number as a double. This may involve rounding.
        Specified by:
        doubleValue in class Number
        Returns:
        the numeric value represented by this object after conversion to type double.

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Document créé le 01/09/2006, dernière modification le 29/10/2018
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