[history] Functionality extracted from some class

src/commonMain/kotlin/ru/landrafhomyak/utility/reference_counter/CloseableReferenceCounter.kt

@@ -0,0 +1,56 @@
+package ru.landrafhomyak.utility.reference_counter
+
+import kotlinx.atomicfu.AtomicLong
+import kotlinx.atomicfu.atomic
+import kotlinx.atomicfu.update
+import ru.landgrafhomyak.utility.highlevel_try_finally.safeAutoClose1
+import ru.landgrafhomyak.utility.highlevel_try_finally.safeAutoClose2
+
+internal class CloseableReferenceCounter(private val _errMessage: String) {
+	private val _value: AtomicLong = atomic(0L)
+
+	fun throwClosed() {
+		throw IllegalStateException(this._errMessage)
+	}
+
+	fun incref() {
+		this._value.update { o ->
+			if (o < 0) this.throwClosed()
+			return@update o + 1
+		}
+	}
+
+	inline fun <R> tryIncref(block: () -> R): R {
+		this.incref()
+		return safeAutoClose2(onError = this::decref, action = block)
+	}
+
+	fun checkNotClosed() {
+		if (this._value.value < 0) this.throwClosed()
+	}
+
+	fun decref() {
+		this._value.update(Long::dec)
+	}
+
+	fun close(errExistRefs: String) {
+		val state = this._value.compareAndExchange(0, -1)
+		when {
+			state > 0 -> throw IllegalStateException(errExistRefs)
+			state < 0 -> this.throwClosed()
+		}
+	}
+
+	inline fun <R> withRef(protected: () -> R): R {
+		this.incref()
+		return safeAutoClose1(finally = this::decref, action = protected)
+	}
+
+	private fun AtomicLong.compareAndExchange(expected: Long, newValue: Long): Long {
+		while (true) {
+			val old = this@compareAndExchange.value
+			if (old != expected) return old
+			if (this@compareAndExchange.compareAndSet(old, newValue)) return old
+		}
+	}
+}