OptionValue (Graal OpenJDK Project Documentation)

java.lang.Object
- jdk.internal.jvmci.options.OptionValue<T>

Direct Known Subclasses:

NestedBooleanOptionValue, PrintStreamOption, StableOptionValue
```
public class OptionValue<T>
extends Object
```
An option value.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`OptionValue.MultipleOverridesScope`
`static class`	`OptionValue.OverrideScope` An object whose `OptionValue.OverrideScope.close()` method reverts the option value overriding initiated by `override(OptionValue, Object)` or `override(Map)`.
`(package private) static class`	`OptionValue.SingleOverrideScope`

Field Summary

Fields
Modifier and Type	Field and Description
`private static Object`	`DEFAULT`
`private T`	`defaultValue`
`private OptionDescriptor`	`descriptor`
`private static OptionValue<?>`	`head`
`private OptionValue<?>`	`next`
`private static ThreadLocal<OptionValue.OverrideScope>`	`overrideScopeTL`
`private long`	`reads`
`private static boolean`	`ShowReadsHistogram`
`private static Object`	`UNINITIALIZED`
`protected T`	`value` The raw option value.

Constructor Summary

Constructors
Modifier Constructor and Description

protected OptionValue()
Creates an uninitialized option value for a subclass that initializes itself lazily.

OptionValue(T value)

Constructors
Modifier	Constructor and Description
`protected`	`OptionValue()` Creates an uninitialized option value for a subclass that initializes itself `lazily`.
	`OptionValue(T value)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private static void`	`addToHistogram(OptionValue<?> option)`
`protected T`	`defaultValue()` Lazy initialization of default value.
`T`	`getDefaultValue()` The initial value specified in source code.
`OptionDescriptor`	`getDescriptor()` Returns the descriptor for this option, if it has been set by `setDescriptor(OptionDescriptor)`.
`String`	`getName()` Gets the name of this option.
`protected static OptionValue.OverrideScope`	`getOverrideScope()`
`T`	`getValue()` Gets the value of this option.
`Collection<T>`	`getValues(Collection<T> c)` Gets the values of this option including overridden values.
`boolean`	`hasDefaultValue()` Returns true if the option has the same value that was set in the source code.
`static OptionValue.OverrideScope`	`override(Map<OptionValue<?>,Object> overrides)` Temporarily changes the values for a set of options.
`static OptionValue.OverrideScope`	`override(Object... overrides)` Temporarily changes the values for a set of options.
`static OptionValue.OverrideScope`	`override(OptionValue<?> option, Object value)` Temporarily changes the value for an option.
`void`	`setDescriptor(OptionDescriptor descriptor)` Sets the descriptor for this option.
`protected static void`	`setOverrideScope(OptionValue.OverrideScope overrideScope)`
`void`	`setValue(Object v)` Sets the value of this option.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - overrideScopeTL
```
private static final ThreadLocal<OptionValue.OverrideScope> overrideScopeTL
```
  - defaultValue
```
private T defaultValue
```
  - value
```
protected T value
```
    The raw option value.
  - descriptor
```
private OptionDescriptor descriptor
```
  - reads
```
private long reads
```
  - next
```
private OptionValue<?> next
```
  - head
```
private static OptionValue<?> head
```
  - ShowReadsHistogram
```
private static final boolean ShowReadsHistogram
```
  - DEFAULT
```
private static final Object DEFAULT
```
  - UNINITIALIZED
```
private static final Object UNINITIALIZED
```
- Constructor Detail
  - OptionValue
```
public OptionValue(T value)
```
  - OptionValue
```
protected OptionValue()
```
    Creates an uninitialized option value for a subclass that initializes itself lazily.
- Method Detail
  - override
```
public static OptionValue.OverrideScope override(OptionValue<?> option,
                                                 Object value)
```
    Temporarily changes the value for an option. The value of option is set to value until OptionValue.OverrideScope.close() is called on the object returned by this method.
    Since the returned object is AutoCloseable the try-with-resource construct can be used:
```
 try (OverrideScope s = OptionValue.override(myOption, myValue) {
     // code that depends on myOption == myValue
 }
 
```
  - override
```
public static OptionValue.OverrideScope override(Map<OptionValue<?>,Object> overrides)
```
    Temporarily changes the values for a set of options. The value of each option in overrides is set to the corresponding value in overrides until OptionValue.OverrideScope.close() is called on the object returned by this method.
    Since the returned object is AutoCloseable the try-with-resource construct can be used:
```
 Map<OptionValue, Object> overrides = new HashMap<>();
 overrides.put(myOption1, myValue1);
 overrides.put(myOption2, myValue2);
 try (OverrideScope s = OptionValue.override(overrides) {
     // code that depends on myOption == myValue
 }
 
```
  - override
```
public static OptionValue.OverrideScope override(Object... overrides)
```
    Temporarily changes the values for a set of options. The value of each option in overrides is set to the corresponding value in overrides until OptionValue.OverrideScope.close() is called on the object returned by this method.
    Since the returned object is AutoCloseable the try-with-resource construct can be used:
```
 try (OverrideScope s = OptionValue.override(myOption1, myValue1, myOption2, myValue2) {
     // code that depends on myOption == myValue
 }
 
```
    Parameters:
    
    overrides - overrides in the form [option1, override1, option2, override2, ...]
  - getOverrideScope
```
protected static OptionValue.OverrideScope getOverrideScope()
```
  - setOverrideScope
```
protected static void setOverrideScope(OptionValue.OverrideScope overrideScope)
```
  - addToHistogram
```
private static void addToHistogram(OptionValue<?> option)
```
  - defaultValue
```
protected T defaultValue()
```
    Lazy initialization of default value.
  - setDescriptor
```
public void setDescriptor(OptionDescriptor descriptor)
```
    Sets the descriptor for this option.
  - getDescriptor
```
public OptionDescriptor getDescriptor()
```
    Returns the descriptor for this option, if it has been set by setDescriptor(OptionDescriptor).
  - getName
```
public String getName()
```
    Gets the name of this option. The name for an option value with a null descriptor is the value of Object.toString().
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - getDefaultValue
```
public T getDefaultValue()
```
    The initial value specified in source code. The returned value is not affected by calls to setValue(Object) or registering OptionValue.OverrideScopes. Therefore, it is also not affected by options set on the command line.
  - hasDefaultValue
```
public boolean hasDefaultValue()
```
    Returns true if the option has the same value that was set in the source code.
  - getValue
```
public T getValue()
```
    Gets the value of this option.
  - getValues
```
public Collection<T> getValues(Collection<T> c)
```
    Gets the values of this option including overridden values.
    
    Parameters:
    
    c - the collection to which the values are added. If null, one is allocated.
    
    Returns:
    
    the collection to which the values were added in order from most overridden to current value
  - setValue
```
public void setValue(Object v)
```
    Sets the value of this option.

Class OptionValue<T>

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

overrideScopeTL

defaultValue

value

descriptor

reads

next

head

ShowReadsHistogram

DEFAULT

UNINITIALIZED

Constructor Detail

OptionValue

OptionValue

Method Detail

override

override

override

getOverrideScope

setOverrideScope

addToHistogram

defaultValue

setDescriptor

getDescriptor

getName

toString

getDefaultValue

hasDefaultValue

getValue

getValues

setValue