commonMain.io.matthewnelson.kmp.process.internal.Instance.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of process-jvm Show documentation

Process for Kotlin Multiplatform

There is a newer version: 0.1.2

/*
 * Copyright (c) 2024 Matthew Nelson
 *
 * 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
 *
 *     https://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 io.matthewnelson.kmp.process.internal

internal class Instance internal constructor(create: () -> T) {

    private var create: (() -> T)? = create
    private val instance = SynchronizedSet()

    internal fun getOrCreate(): T = instance.withLock {
        if (isEmpty()) {
            val create = create ?: throw IllegalStateException()

            create().also { element ->
                [email protected] = null
                add(element)
            }
        } else {
            first()
        }
    }

    internal fun getOrNull(): T? = instance.withLock { firstOrNull() }
}