monix.execution.atomic.AtomicChar.scala Maven / Gradle / Ivy
The newest version!
/*
* Copyright (c) 2014-2019 by The Monix Project Developers.
* See the project homepage at: https://monix.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package monix.execution.atomic
/** Atomic references wrapping `Char` values.
*
* Note that the equality test in `compareAndSet` is value based,
* since `Char` is a primitive.
*/
final class AtomicChar private[atomic] (initialValue: Char) extends AtomicNumber[Char] {
private[this] var ref = initialValue
private[this] val mask = 255 + 255 * 256
def getAndSet(update: Char): Char = {
val current = ref
ref = update
current
}
def compareAndSet(expect: Char, update: Char): Boolean = {
if (ref == expect) {
ref = update
true
} else
false
}
def set(update: Char): Unit = {
ref = update
}
def get(): Char = ref
def getAndSubtract(v: Char): Char = {
val c = ref
ref = ((ref - v) & mask).asInstanceOf[Char]
c
}
def subtractAndGet(v: Char): Char = {
ref = ((ref - v) & mask).asInstanceOf[Char]
ref
}
def subtract(v: Char): Unit = {
ref = ((ref - v) & mask).asInstanceOf[Char]
}
def getAndAdd(v: Char): Char = {
val c = ref
ref = ((ref + v) & mask).asInstanceOf[Char]
c
}
def getAndIncrement(v: Int = 1): Char = {
val c = ref
ref = ((ref + v) & mask).asInstanceOf[Char]
c
}
def addAndGet(v: Char): Char = {
ref = ((ref + v) & mask).asInstanceOf[Char]
ref
}
def incrementAndGet(v: Int = 1): Char = {
ref = ((ref + v) & mask).asInstanceOf[Char]
ref
}
def add(v: Char): Unit = {
ref = ((ref + v) & mask).asInstanceOf[Char]
}
def increment(v: Int = 1): Unit = {
ref = ((ref + v) & mask).asInstanceOf[Char]
}
def decrement(v: Int = 1): Unit = increment(-v)
def decrementAndGet(v: Int = 1): Char = incrementAndGet(-v)
def getAndDecrement(v: Int = 1): Char = getAndIncrement(-v)
}
/** @define createDesc Constructs an [[AtomicChar]] reference, allowing
* for fine-tuning of the created instance.
*
* A [[PaddingStrategy]] can be provided in order to counter
* the "false sharing" problem.
*
* Note that for ''Scala.js'' we aren't applying any padding,
* as it doesn't make much sense, since Javascript execution
* is single threaded, but this builder is provided for
* syntax compatibility anyway across the JVM and Javascript
* and we never know how Javascript engines will evolve.
*/
object AtomicChar {
/** Builds an [[AtomicChar]] reference.
*
* @param initialValue is the initial value with which to initialize the atomic
*/
def apply(initialValue: Char): AtomicChar =
new AtomicChar(initialValue)
/** $createDesc
*
* @param initialValue is the initial value with which to initialize the atomic
* @param padding is the [[PaddingStrategy]] to apply
*/
def withPadding(initialValue: Char, padding: PaddingStrategy): AtomicChar =
new AtomicChar(initialValue)
/** $createDesc
*
* Also this builder on top Java 8 also allows for turning off the
* Java 8 intrinsics, thus forcing usage of CAS-loops for
* `getAndSet` and for `getAndAdd`.
*
* @param initialValue is the initial value with which to initialize the atomic
* @param padding is the [[PaddingStrategy]] to apply
* @param allowPlatformIntrinsics is a boolean parameter that specifies whether
* the instance is allowed to use the Java 8 optimized operations
* for `getAndSet` and for `getAndAdd`
*/
def create(initialValue: Char, padding: PaddingStrategy, allowPlatformIntrinsics: Boolean): AtomicChar =
new AtomicChar(initialValue)
/** $createDesc
*
* This builder guarantees to construct a safe atomic reference that
* does not make use of `sun.misc.Unsafe`. On top of platforms that
* don't support it, notably some versions of Android or on top of
* the upcoming Java 9, this might be desirable.
*
* NOTE that explicit usage of this builder is not usually necessary
* because [[create]] can auto-detect whether the underlying platform
* supports `sun.misc.Unsafe` and if it does, then its usage is
* recommended, because the "safe" atomic instances have overhead.
*
* @param initialValue is the initial value with which to initialize the atomic
* @param padding is the [[PaddingStrategy]] to apply
*/
def safe(initialValue: Char, padding: PaddingStrategy): AtomicChar =
new AtomicChar(initialValue)
}