MemoryOrderMode

java.lang.Object
- java.lang.Enum<MemoryOrderMode>
- - org.graalvm.compiler.core.common.memory.MemoryOrderMode

All Implemented Interfaces:

Serializable, Comparable<MemoryOrderMode>
```
public enum MemoryOrderMode
extends Enum<MemoryOrderMode>
```
The new memory order modes (JDK9+) are defined with cumulative effect, from weakest to strongest: Plain, Opaque, Release/Acquire, and Volatile. The existing Plain and Volatile modes are defined compatibly with their pre-JDK 9 forms. Any guaranteed property of a weaker mode, plus more, holds for a stronger mode. (Conversely, implementations are allowed to use a stronger mode than requested for any access.) In JDK 9, these are provided without a full formal specification.

Enum Constant Summary

Enum Constants
Enum Constant and Description
`ACQUIRE` `ACQUIRE` accesses are guaranteed to execute before all subsequent memory accesses on the same thread.
`OPAQUE` `OPAQUE` accesses are similar to `MemoryOrderMode.PLAIN` accesses; they also do not have any memory ordering guarantees.
`PLAIN` `PLAIN` accesses are "normal" Java memory operations.
`RELEASE` `RELEASE` accesses are guaranteed to execute after all prior memory accesses on the same thread.
`RELEASE_ACQUIRE` `RELEASE_ACQUIRE` accesses are guaranteed to execute after all prior memory access and before all subsequent memory accesses on the same thread.
`VOLATILE` The behavior of `VOLATILE` is dependent on the type of access (load, store, load&store): Load: same ordering requirements as `MemoryOrderMode.ACQUIRE` Store: same ordering requirements as `MemoryOrderMode.RELEASE` Load&Store (i.e., atomic): same ordering requirements as `MemoryOrderMode.RELEASE_ACQUIRE` In addition, all volatile accesses are strictly ordered.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static MemoryOrderMode`	`getMemoryOrder(ResolvedJavaField field)`
`static boolean`	`ordersMemoryAccesses(MemoryOrderMode memoryOrder)`
`static MemoryOrderMode`	`valueOf(String name)` Returns the enum constant of this type with the specified name.
`static MemoryOrderMode[]`	`values()` Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

- Enum Constant Detail
  - PLAIN
```
public static final MemoryOrderMode PLAIN
```
    PLAIN accesses are "normal" Java memory operations. They do not have any memory ordering guarantees.
  - OPAQUE
```
public static final MemoryOrderMode OPAQUE
```
    OPAQUE accesses are similar to MemoryOrderMode.PLAIN accesses; they also do not have any memory ordering guarantees. However, opaque writes are guaranteed to eventually become visible to other threads.
  - ACQUIRE
```
public static final MemoryOrderMode ACQUIRE
```
    ACQUIRE accesses are guaranteed to execute before all subsequent memory accesses on the same thread. However, they do not impose any ordering requirements on prior memory accesses (prior memory accesses can be executed after a subsequent acquire). Traditionally ACQUIREs are associated with loads.
  - RELEASE
```
public static final MemoryOrderMode RELEASE
```
    RELEASE accesses are guaranteed to execute after all prior memory accesses on the same thread. However, they do not impose any ordering requirements on subsequent memory accesses (subsequent memory accesses can be executed before a prior release). Traditionally RELEASEs are associated with stores.
  - RELEASE_ACQUIRE
```
public static final MemoryOrderMode RELEASE_ACQUIRE
```
    RELEASE_ACQUIRE accesses are guaranteed to execute after all prior memory access and before all subsequent memory accesses on the same thread. Traditionally RELEASE_ACQUIREs are associated with atomic operations.
  - VOLATILE
```
public static final MemoryOrderMode VOLATILE
```
    The behavior of VOLATILE is dependent on the type of access (load, store, load&store):
    - Load: same ordering requirements as MemoryOrderMode.ACQUIRE
    - Store: same ordering requirements as MemoryOrderMode.RELEASE
    - Load&Store (i.e., atomic): same ordering requirements as MemoryOrderMode.RELEASE_ACQUIRE
    In addition, all volatile accesses are strictly ordered. This means that, within a given thread, every volatile access must execute in program order w.r.t every other volatile access in that same thread.
- Method Detail
  - values
```
public static MemoryOrderMode[] values()
```
    Returns:
    
    an array containing the constants of this enum type, in the order they are declared
  - valueOf
```
public static MemoryOrderMode valueOf(String name)
```
    Parameters:
    
    name - the name of the enum constant to be returned.
    
    Returns:
    
    the enum constant with the specified name
    
    Throws:
    
    IllegalArgumentException - if this enum type has no constant with the specified name
    
    NullPointerException - if the argument is null
  - ordersMemoryAccesses
```
public static boolean ordersMemoryAccesses(MemoryOrderMode memoryOrder)
```
  - getMemoryOrder
```
public static MemoryOrderMode getMemoryOrder(ResolvedJavaField field)
```

Enum MemoryOrderMode

Enum Constant Summary

Method Summary

Methods inherited from class java.lang.Enum

Methods inherited from class java.lang.Object

Enum Constant Detail

PLAIN

OPAQUE

ACQUIRE

RELEASE

RELEASE_ACQUIRE

VOLATILE

Method Detail

values

valueOf

ordersMemoryAccesses

getMemoryOrder