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Core classes and tools while developing kmp projects
/*
* MIT License
*
* Copyright (c) 2023 Telereso
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package io.telereso.kmp.core
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
/**
* https://github.com/Kotlin/kotlinx.coroutines/issues/706
*/
class LazySuspend(initializer: suspend () -> T) {
private var initializer: (suspend () -> T)? = initializer
private var mutex: Mutex? = Mutex()
private var _value: T? = null
suspend fun value(): T {
val m = mutex ?: return _value as T // Warning: unchecked cast.
m.withLock {
val i = initializer ?: return _value as T // Warning: unchecked cast.
val v = i()
_value = v
initializer = null
mutex = null
return v
}
}
}