CountDownLatch and decomposed refcnt mechanic to separate class

modules/low-level/multithreading/src/commonMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/Condition.kt

@@ -1,9 +1,9 @@
 package ru.landgrafhomyak.bgtu.networks0.low_level.multithreading
 
-expect class TCondition : AutoCloseable {
+expect class Condition : AutoCloseable {
 	constructor()
 
-	fun await(mutex: TMutex)
+	fun await(mutex: Mutex)
 	fun signalOne()
 	fun signalAll()
 }

modules/low-level/multithreading/src/commonMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/CountDownLatch.kt

@@ -0,0 +1,30 @@
+package ru.landgrafhomyak.bgtu.networks0.low_level.multithreading
+
+class CountDownLatch(initialCounterValue: ULong) : AutoCloseable {
+	private val _refcnt = _Refcnt("Latch was destroyed")
+	private var _counter = initialCounterValue
+	private val _mutex = Mutex()
+	private val _condition = Condition()
+
+	fun await() = this._refcnt.withRef {
+		this._mutex.withLock {
+			if (this._counter == 0uL)
+				return
+			this._condition.await(this._mutex)
+		}
+	}
+
+	fun decrement() = this._refcnt.withRef {
+		this._mutex.withLock {
+			if (this._counter == 0uL) return
+			if (--this._counter == 0uL)
+				this._condition.signalAll()
+		}
+	}
+
+	override fun close() {
+		this._refcnt.close("Latch is still in use")
+		this._condition.close()
+		this._mutex.close()
+	}
+}

modules/low-level/multithreading/src/commonMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/Mutex.kt

@@ -1,6 +1,6 @@
 package ru.landgrafhomyak.bgtu.networks0.low_level.multithreading
 
-expect class TMutex : AutoCloseable {
+expect class Mutex : AutoCloseable {
 	constructor()
 
 	fun lock()

modules/low-level/multithreading/src/commonMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/_Refcnt.kt

@@ -0,0 +1,46 @@
+package ru.landgrafhomyak.bgtu.networks0.low_level.multithreading
+
+import kotlinx.atomicfu.AtomicLong
+import kotlinx.atomicfu.atomic
+import kotlinx.atomicfu.update
+
+internal class _Refcnt(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(onAbort = 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)
+	}
+}

modules/low-level/multithreading/src/commonMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/extensions.kt

@@ -5,25 +5,9 @@ import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
 
 @OptIn(ExperimentalContracts::class)
-inline fun <R> TMutex.withLock(synchronizedBlock: () -> R): R {
+inline fun <R> Mutex.withLock(synchronizedBlock: () -> R): R {
 	contract {
 		callsInPlace(synchronizedBlock, InvocationKind.EXACTLY_ONCE)
 	}
-	this.lock()
-	var err1: Throwable? = null
-	try {
-		return synchronizedBlock()
-	} catch (t: Throwable) {
-		err1 = t
-		throw t
-	} finally {
-		try {
-			this.unlock()
-		} catch (err2: Throwable) {
-			if (err1 != null)
-				err1.addSuppressed(err2)
-			else
-				throw err2
-		}
-	}
+	return _safeAutoClose1(finally = this::unlock, synchronizedBlock)
 }

modules/low-level/multithreading/src/commonMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/utilities.kt

@@ -1,5 +1,10 @@
+@file:OptIn(ExperimentalContracts::class)
+
 package ru.landgrafhomyak.bgtu.networks0.low_level.multithreading
 
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
 import kotlinx.atomicfu.AtomicLong
 
 internal fun AtomicLong.compareAndExchange(expected: Long, newValue: Long): Long {
@@ -10,23 +15,48 @@ internal fun AtomicLong.compareAndExchange(expected: Long, newValue: Long): Long
 	}
 }
 
-internal inline fun <R> _safeAutoClose(
+@PublishedApi
+internal inline fun <R> _safeAutoClose1(
 	finally: () -> Unit,
 	action: () -> R
-): R = _safeAutoClose(onAbort = finally, onSuccess = finally, onCrossReturn = finally, action = action)
+): R {
+	@Suppress("WRONG_INVOCATION_KIND")
+	contract {
+		callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+		callsInPlace(finally, InvocationKind.EXACTLY_ONCE)
+	}
+	return _safeAutoClose3(onAbort = finally, onSuccess = finally, onCrossReturn = finally, action = action)
+}
 
-internal inline fun <R> _safeAutoClose(
+@PublishedApi
+internal inline fun <R> _safeAutoClose2(
 	onAbort: () -> Unit = {},
 	onSuccess: () -> Unit = {},
 	action: () -> R
-): R = _safeAutoClose(onAbort = onAbort, onSuccess = onSuccess, onCrossReturn = onSuccess, action = action)
+): R {
+	@Suppress("WRONG_INVOCATION_KIND")
+	contract {
+		callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+		callsInPlace(onAbort, InvocationKind.AT_MOST_ONCE)
+		callsInPlace(onSuccess, InvocationKind.AT_MOST_ONCE)
+	}
+	return _safeAutoClose3(onAbort = onAbort, onSuccess = onSuccess, onCrossReturn = onSuccess, action = action)
+}
 
-internal inline fun <R> _safeAutoClose(
+@PublishedApi
+internal inline fun <R> _safeAutoClose3(
 	onAbort: () -> Unit = {},
 	onSuccess: () -> Unit = {},
 	onCrossReturn: () -> Unit = {},
 	action: () -> R
 ): R {
+	contract {
+		callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+		callsInPlace(onAbort, InvocationKind.AT_MOST_ONCE)
+		callsInPlace(onSuccess, InvocationKind.AT_MOST_ONCE)
+		callsInPlace(onCrossReturn, InvocationKind.AT_MOST_ONCE)
+	}
+
 	val ret: R
 	var wasError = false
 	var crossReturned = true

modules/low-level/multithreading/src/posixMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/Condition.kt

@@ -15,13 +15,12 @@ import platform.posix.pthread_cond_destroy
 import platform.posix.pthread_cond_wait
 import platform.posix.pthread_cond_broadcast
 import ru.landgrafhomyak.bgtu.networks0.low_level.c_interop_utilities.PosixUtilities
-import ru.landgrafhomyak.bgtu.networks0.low_level.multithreading.TMutex.RefcntAccess
 
 
 @OptIn(ExperimentalForeignApi::class)
-actual class TCondition : AutoCloseable {
+actual class Condition : AutoCloseable {
+	private val _refcnt = _Refcnt("Pthreads condition was destroyed")
 	val _descriptor: CPointer<pthread_cond_t>
-	private var _refcnt: AtomicLong = atomic(0L)
 
 	actual constructor() {
 		this._descriptor = nativeHeap.alloc<pthread_cond_t>().ptr
@@ -30,52 +29,29 @@ actual class TCondition : AutoCloseable {
 			PosixUtilities.throwErrno { d -> RuntimeException("Failed to initialize pthreads condition: $d") }
 	}
 
-
-	private fun _throwClosed(): Nothing =
-		throw IllegalStateException("Pthreads condition was destroyed")
-
-	private inline fun <R> _withRefcnt(protectedBlock: () -> R): R {
-		this._refcnt.update { o ->
-			if (o < 0) this._throwClosed()
-			return@update o + 1
-		}
-		_safeAutoClose(finally = { this._refcnt.update(Long::dec) }) {
-			return protectedBlock()
-		}
-	}
-
-	internal fun _decref() {
-		this._refcnt.update(Long::dec)
-	}
-
-	@OptIn(TMutex.RefcntAccess::class)
-	actual fun await(mutex: TMutex) = this._withRefcnt {
-		mutex._incref()
-		_safeAutoClose(finally = { mutex._decref() }) {
+	@OptIn(Mutex.RefcntAccess::class)
+	actual fun await(mutex: Mutex) = this._refcnt.withRef {
+		mutex._refcnt.withRef {
 			var err = pthread_cond_wait(this._descriptor, mutex._descriptor)
 			if (err != 0)
 				PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to wait on pthreads condition: $d") }
 		}
 	}
 
-	actual fun signalAll() = this._withRefcnt {
+	actual fun signalAll() = this._refcnt.withRef {
 		var err = pthread_cond_broadcast(this._descriptor)
 		if (err != 0)
 			PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to signal pthreads condition: $d") }
 	}
 
-	actual fun signalOne() = this._withRefcnt {
+	actual fun signalOne() = this._refcnt.withRef {
 		var err = pthread_cond_broadcast(this._descriptor)
 		if (err != 0)
 			PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to signal pthreads condition: $d") }
 	}
 
 	override fun close() {
-		val state = this._refcnt.compareAndExchange(0, -1)
-		when {
-			state > 0 -> throw IllegalStateException("There are waiting threads on this pthreads condition")
-			state < 0 -> this._throwClosed()
-		}
+		this._refcnt.close("There are waiting threads on this pthreads condition")
 		var err = pthread_cond_destroy(this._descriptor)
 		if (err != 0)
 			PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to destroy pthreads condition: $d") }

modules/low-level/multithreading/src/posixMain/kotlin/ru/landgrafhomyak/bgtu/networks0/low_level/multithreading/Mutex.kt

@@ -1,8 +1,5 @@
 package ru.landgrafhomyak.bgtu.networks0.low_level.multithreading
 
-import kotlinx.atomicfu.AtomicLong
-import kotlinx.atomicfu.atomic
-import kotlinx.atomicfu.update
 import kotlinx.cinterop.CPointer
 import kotlinx.cinterop.ExperimentalForeignApi
 import kotlinx.cinterop.alloc
@@ -16,9 +13,13 @@ import platform.posix.pthread_mutex_t
 import platform.posix.pthread_mutex_unlock
 import ru.landgrafhomyak.bgtu.networks0.low_level.c_interop_utilities.PosixUtilities
 
-@OptIn(ExperimentalForeignApi::class)
-actual class TMutex : AutoCloseable {
-	private var _refcnt: AtomicLong = atomic(0L)
+@OptIn(ExperimentalForeignApi::class, Mutex.RefcntAccess::class)
+actual class Mutex : AutoCloseable {
+	@RequiresOptIn
+	internal annotation class RefcntAccess
+
+	@RefcntAccess
+	internal val _refcnt = _Refcnt("Pthreads mutex was destroyed")
 	internal val _descriptor: CPointer<pthread_mutex_t>
 
 	actual constructor() {
@@ -29,48 +30,25 @@ actual class TMutex : AutoCloseable {
 	}
 
 	private fun _throwClosed(): Nothing =
-		throw IllegalStateException("Pthreads mutex was destroyed")
+		throw IllegalStateException()
 
-	@RequiresOptIn
-	annotation class RefcntAccess
 
-	@RefcntAccess
-	internal fun _incref() {
-		this._refcnt.update { o ->
-			if (o < 0) this._throwClosed()
-			return@update o + 1
-		}
-	}
-
-	@RefcntAccess
-	internal fun _decref() {
-		this._refcnt.update(Long::dec)
-	}
-
-	actual fun lock() {
-		this._refcnt.update { o ->
-			if (o < 0) this._throwClosed()
-			return@update o + 1
-		}
+	actual fun lock() = this._refcnt.tryIncref {
 		var err = pthread_mutex_lock(this._descriptor)
 		if (err != 0)
 			PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to lock pthreads mutex: $d") }
 	}
 
 	actual fun unlock() {
-		if (this._refcnt.value < 0) this._throwClosed()
+		this._refcnt.checkNotClosed()
 		var err = pthread_mutex_unlock(this._descriptor)
 		if (err != 0)
 			PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to unlock pthreads mutex: $d") }
-		this._refcnt.update(Long::dec)
+		this._refcnt.decref()
 	}
 
 	override fun close() {
-		val state = this._refcnt.compareAndExchange(0, -1)
-		when {
-			state > 0 -> throw IllegalStateException("There are waiting threads on this pthreads mutex")
-			state < 0 -> this._throwClosed()
-		}
+		this._refcnt.close("There are waiting threads on this pthreads mutex")
 		var err = pthread_mutex_destroy(this._descriptor)
 		if (err != 0)
 			PosixUtilities.throwErrno(err) { d -> RuntimeException("Failed to destroy pthreads mutex: $d") }