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 Summary
ConstructorDescriptionCreates a newAtomicBoolean
with initial valuefalse
.AtomicBoolean(boolean initialValue)
Creates a newAtomicBoolean
with the given initial value. -
Method Summary
Modifier and TypeMethodDescriptionboolean
compareAndExchange(boolean expectedValue, boolean newValue)
Atomically sets the value tonewValue
if the current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...)
.boolean
compareAndExchangeAcquire(boolean expectedValue, boolean newValue)
Atomically sets the value tonewValue
if the current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...)
.boolean
compareAndExchangeRelease(boolean expectedValue, boolean newValue)
Atomically sets the value tonewValue
if the current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...)
.boolean
compareAndSet(boolean expectedValue, boolean newValue)
Atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
.boolean
get()
Returns the current value, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...)
.boolean
Returns the current value, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...)
.boolean
getAndSet(boolean newValue)
Atomically sets the value tonewValue
and returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...)
.boolean
Returns the current value, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...)
.boolean
getPlain()
Returns the current value, with memory semantics of reading as if the variable was declared non-volatile
.void
lazySet(boolean newValue)
Sets the value tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.void
set(boolean newValue)
Sets the value tonewValue
, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...)
.void
setOpaque(boolean newValue)
Sets the value tonewValue
, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...)
.void
setPlain(boolean newValue)
Sets the value tonewValue
, with memory semantics of setting as if the variable was declared non-volatile
and non-final
.void
setRelease(boolean newValue)
Sets the value tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.toString()
Returns the String representation of the current value.boolean
weakCompareAndSet(boolean expectedValue, boolean newValue)
Deprecated.boolean
weakCompareAndSetAcquire(boolean expectedValue, boolean newValue)
Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...)
.boolean
weakCompareAndSetPlain(boolean expectedValue, boolean newValue)
Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...)
.boolean
weakCompareAndSetRelease(boolean expectedValue, boolean newValue)
Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...)
.boolean
weakCompareAndSetVolatile(boolean expectedValue, boolean newValue)
Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...)
.
-
Constructor Details
-
AtomicBoolean
public AtomicBoolean(boolean initialValue)Creates a newAtomicBoolean
with the given initial value.- Parameters:
initialValue
- the initial value
-
AtomicBoolean
public AtomicBoolean()Creates a newAtomicBoolean
with initial valuefalse
.
-
-
Method Details
-
get
public final boolean get()Returns the current value, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...)
.- Returns:
- the current value
-
compareAndSet
public final boolean compareAndSet(boolean expectedValue, boolean newValue)Atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful. False return indicates that the actual value was not equal to the expected value.
-
weakCompareAndSet
Deprecated.This method has plain memory effects but the method name implies volatile memory effects (see methods such ascompareAndExchange(boolean, boolean)
andcompareAndSet(boolean, boolean)
). To avoid confusion over plain or volatile memory effects it is recommended that the methodweakCompareAndSetPlain(boolean, boolean)
be used instead.Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- 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 tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
set
public final void set(boolean newValue)Sets the value tonewValue
, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...)
.- Parameters:
newValue
- the new value
-
lazySet
public final void lazySet(boolean newValue)Sets the value tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.- Parameters:
newValue
- the new value- Since:
- 1.6
-
getAndSet
public final boolean getAndSet(boolean newValue)Atomically sets the value tonewValue
and returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...)
.- Parameters:
newValue
- the new value- Returns:
- the previous value
-
toString
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 tonewValue
, 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 byVarHandle.getOpaque(java.lang.Object...)
.- Returns:
- the value
- Since:
- 9
-
setOpaque
public final void setOpaque(boolean newValue)Sets the value tonewValue
, with memory effects as specified byVarHandle.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 byVarHandle.getAcquire(java.lang.Object...)
.- Returns:
- the value
- Since:
- 9
-
setRelease
public final void setRelease(boolean newValue)Sets the value tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.- Parameters:
newValue
- the new value- Since:
- 9
-
compareAndExchange
public final boolean compareAndExchange(boolean expectedValue, boolean newValue)Atomically sets the value tonewValue
if the current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- 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 tonewValue
if the current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- 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 tonewValue
if the current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- 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 tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
weakCompareAndSetAcquire
public final boolean weakCompareAndSetAcquire(boolean expectedValue, boolean newValue)Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
weakCompareAndSetRelease
public final boolean weakCompareAndSetRelease(boolean expectedValue, boolean newValue)Possibly atomically sets the value tonewValue
if the current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...)
.- Parameters:
expectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
compareAndExchange(boolean, boolean)
andcompareAndSet(boolean, boolean)
).