Module java.base
Package java.util.concurrent.atomic

Class AtomicBoolean

java.lang.Object
java.util.concurrent.atomic.AtomicBoolean
All Implemented Interfaces:
Serializable
public class AtomicBoolean
extends Object
implements Serializable
A boolean value that may be updated atomically. See the VarHandle specification for descriptions of the properties of atomic accesses. An AtomicBoolean is used in applications such as atomically updated flags, and cannot be used as a replacement for a Boolean.
Since:
1.5
See Also:
Serialized Form

  • Constructor Details

    • AtomicBoolean

      public AtomicBoolean​(boolean initialValue)
      Creates a new AtomicBoolean with the given initial value.
      Parameters:
      initialValue - the initial value

    • AtomicBoolean

      public AtomicBoolean()
      Creates a new AtomicBoolean with initial value false.

  • Method Details

    • get

      public final boolean get()
      Returns the current value, with memory effects as specified by VarHandle.getVolatile(java.lang.Object...).
      Returns:
      the current value

    • compareAndSet

      public final boolean compareAndSet​(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.compareAndSet(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful. False return indicates that the actual value was not equal to the expected value.

    • weakCompareAndSet

      @Deprecated(since="9") public boolean weakCompareAndSet​(boolean expectedValue, boolean newValue)
      Deprecated.
      This method has plain memory effects but the method name implies volatile memory effects (see methods such as compareAndExchange(boolean, boolean) and compareAndSet(boolean, boolean)). To avoid confusion over plain or volatile memory effects it is recommended that the method weakCompareAndSetPlain(boolean, boolean) be used instead.
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      See Also:
      weakCompareAndSetPlain(boolean, boolean)

    • weakCompareAndSetPlain

      public boolean weakCompareAndSetPlain​(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • set

      public final void set​(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setVolatile(java.lang.Object...).
      Parameters:
      newValue - the new value

    • lazySet

      public final void lazySet​(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setRelease(java.lang.Object...).
      Parameters:
      newValue - the new value
      Since:
      1.6

    • getAndSet

      public final boolean getAndSet​(boolean newValue)
      Atomically sets the value to newValue and returns the old value, with memory effects as specified by VarHandle.getAndSet(java.lang.Object...).
      Parameters:
      newValue - the new value
      Returns:
      the previous 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

    • getPlain

      public final boolean getPlain()
      Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.
      Returns:
      the value
      Since:
      9

    • setPlain

      public final void setPlain​(boolean newValue)
      Sets the value to newValue, with memory semantics of setting as if the variable was declared non-volatile and non-final.
      Parameters:
      newValue - the new value
      Since:
      9

    • getOpaque

      public final boolean getOpaque()
      Returns the current value, with memory effects as specified by VarHandle.getOpaque(java.lang.Object...).
      Returns:
      the value
      Since:
      9

    • setOpaque

      public final void setOpaque​(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setOpaque(java.lang.Object...).
      Parameters:
      newValue - the new value
      Since:
      9

    • getAcquire

      public final boolean getAcquire()
      Returns the current value, with memory effects as specified by VarHandle.getAcquire(java.lang.Object...).
      Returns:
      the value
      Since:
      9

    • setRelease

      public final void setRelease​(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setRelease(java.lang.Object...).
      Parameters:
      newValue - the new value
      Since:
      9

    • compareAndExchange

      public final boolean compareAndExchange​(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchange(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • compareAndExchangeAcquire

      public final boolean compareAndExchangeAcquire​(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeAcquire(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • compareAndExchangeRelease

      public final boolean compareAndExchangeRelease​(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeRelease(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • weakCompareAndSetVolatile

      public final boolean weakCompareAndSetVolatile​(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSet(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • weakCompareAndSetAcquire

      public final boolean weakCompareAndSetAcquire​(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetAcquire(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • weakCompareAndSetRelease

      public final boolean weakCompareAndSetRelease​(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetRelease(java.lang.Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9