Expect.kt
/*
* Copyright 2019 The Android Open Source Project
*
* 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 androidx.compose.runtime
// TODO(aelias): Mark the typealiases internal when https://youtrack.jetbrains.com/issue/KT-36695 is fixed.
// Currently, they behave as internal because the actual is internal, even though the expect is public.
internal expect open class ThreadLocal<T>(initialValue: () -> T) {
fun get(): T
fun set(value: T)
}
internal fun <T> ThreadLocal() = ThreadLocal<T?> { null }
/**
* This is similar to a [ThreadLocal] but has lower overhead because it avoids a weak reference.
* This should only be used when the writes are delimited by a try...finally call that will clean
* up the reference such as [androidx.compose.runtime.snapshots.Snapshot.enter] else the reference
* could get pinned by the thread local causing a leak.
*
* [ThreadLocal] can be used to implement the actual for platforms that do not exhibit the same
* overhead for thread locals as the JVM and ART.
*/
internal expect class SnapshotThreadLocal<T>() {
fun get(): T?
fun set(value: T?)
}
internal expect fun identityHashCode(instance: Any?): Int
@PublishedApi
internal expect inline fun <R> synchronized(lock: Any, block: () -> R): R
expect class AtomicReference<V>(value: V) {
fun get(): V
fun set(value: V)
fun getAndSet(value: V): V
fun compareAndSet(expect: V, newValue: V): Boolean
}
@MustBeDocumented
@Retention(AnnotationRetention.SOURCE)
@Target(
AnnotationTarget.FUNCTION,
AnnotationTarget.CONSTRUCTOR,
AnnotationTarget.PROPERTY_GETTER,
AnnotationTarget.PROPERTY_SETTER
)
expect annotation class TestOnly()
@Target(
AnnotationTarget.FUNCTION,
AnnotationTarget.PROPERTY_GETTER,
AnnotationTarget.PROPERTY_SETTER
)
@Retention(AnnotationRetention.BINARY)
@MustBeDocumented
expect annotation class CheckResult(
val suggest: String
)
/**
* The [MonotonicFrameClock] used by [withFrameNanos] and [withFrameMillis] if one is not present
* in the calling [kotlin.coroutines.CoroutineContext].
*
* This value is no longer used by compose runtime.
*/
@Deprecated(
"MonotonicFrameClocks are not globally applicable across platforms. " +
"Use an appropriate local clock."
)
expect val DefaultMonotonicFrameClock: MonotonicFrameClock