A small toolkit of classes that support compare-and-swap semantics for mutation of variables.
On top of the JVM, this means dealing with lock-free thread-safe programming.
1. boxing values in a smart reference with nice helpers for transformations is always a good idea.
2. on the JVM there are times when synchronization, and when used for synchronization, atomic
references can now cross compile to Scala.js
3. compareAndSet is actually a good idea to have even in an asynchronous, non-multi-threaded
can happen even without multi-threading
The backbone of Atomic references is this method:
def compareAndSet(expect: T, update: T): Boolean
This method atomically sets a variable to the update value if it currently holds
the expect value, reporting true on success or false on failure. The classes in this package
also contain methods to get and unconditionally set values. In comparison with the JVM version,
these Atomic references do not have methods for weakly setting values (i.e. weakCompareAndSet, lazySet),
Building a reference is easy with the provided constructor, which will automatically return the
most specific type needed:
val atomicNumber = Atomic(12L)
In comparison with java.util.concurrent.AtomicReference, these references implement common interfaces
that you can use generically (i.e. Atomic[T], AtomicNumber[T]). And also provide useful helpers for
atomically mutating of values (i.e. transform, transformAndGet, getAndTransform, etc...).
Other differences with the JVM-variant - in Scala.js you do not have access to the methods meant to
block (spin-lock) the current thread (e.g. waitForCompareAndSet, waitForCondition, etc...), as
the semantics of those operations aren't possible on top of Scala.js
Base trait of all atomic references, no matter the type.
Represents an Atomic reference holding a number, providing helpers for easily incrementing and decrementing it.
Provided for source-level compatibility with the JVM version.