From 7cb9a7951f29caad9c9f28d599ca66adac464ca2 Mon Sep 17 00:00:00 2001
From: DBotThePony <dbotthepony@yandex.ru>
Date: Wed, 11 Oct 2023 23:29:52 +0700
Subject: [PATCH] Use immediateFuture

---
 .../kstarbound/util/ManualExecutorService.kt  | 49 +++++++------------
 1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/src/main/kotlin/ru/dbotthepony/kstarbound/util/ManualExecutorService.kt b/src/main/kotlin/ru/dbotthepony/kstarbound/util/ManualExecutorService.kt
index abc25490..9ffc09d9 100644
--- a/src/main/kotlin/ru/dbotthepony/kstarbound/util/ManualExecutorService.kt
+++ b/src/main/kotlin/ru/dbotthepony/kstarbound/util/ManualExecutorService.kt
@@ -1,5 +1,6 @@
 package ru.dbotthepony.kstarbound.util
 
+import com.google.common.util.concurrent.Futures
 import java.util.concurrent.Callable
 import java.util.concurrent.ConcurrentLinkedQueue
 import java.util.concurrent.ExecutorService
@@ -12,32 +13,6 @@ class ManualExecutorService(val thread: Thread = Thread.currentThread()) : Execu
 	private val executeQueue = ConcurrentLinkedQueue<Runnable>()
 	private val futureQueue = ConcurrentLinkedQueue<FutureTask<*>>()
 
-	private data class InPlaceFuture<V>(private val value: V) : Future<V> {
-		override fun cancel(mayInterruptIfRunning: Boolean): Boolean {
-			return false
-		}
-
-		override fun isCancelled(): Boolean {
-			return false
-		}
-
-		override fun isDone(): Boolean {
-			return true
-		}
-
-		override fun get(): V {
-			return value
-		}
-
-		override fun get(timeout: Long, unit: TimeUnit): V {
-			return value
-		}
-
-		companion object {
-			val EMPTY = InPlaceFuture(Unit)
-		}
-	}
-
 	fun isSameThread(): Boolean {
 		return Thread.currentThread() === thread
 	}
@@ -91,24 +66,23 @@ class ManualExecutorService(val thread: Thread = Thread.currentThread()) : Execu
 	}
 
 	override fun <T : Any?> submit(task: Callable<T>): Future<T> {
-		if (isSameThread()) return InPlaceFuture(task.call())
+		if (isSameThread()) return Futures.immediateFuture(task.call())
 		return FutureTask(task).also { futureQueue.add(it); LockSupport.unpark(thread) }
 	}
 
 	override fun <T : Any?> submit(task: Runnable, result: T): Future<T> {
-		if (isSameThread()) { task.run(); return InPlaceFuture(result) }
+		if (isSameThread()) { task.run(); return Futures.immediateFuture(result) }
 		return FutureTask { task.run(); result }.also { futureQueue.add(it); LockSupport.unpark(thread) }
 	}
 
 	override fun submit(task: Runnable): Future<*> {
-		if (isSameThread()) { task.run(); return InPlaceFuture.EMPTY
-		}
+		if (isSameThread()) { task.run(); return Futures.immediateVoidFuture() }
 		return FutureTask { task.run() }.also { futureQueue.add(it); LockSupport.unpark(thread) }
 	}
 
 	override fun <T : Any?> invokeAll(tasks: Collection<Callable<T>>): List<Future<T>> {
 		if (isSameThread()) {
-			return tasks.map { InPlaceFuture(it.call()) }
+			return tasks.map { Futures.immediateFuture(it.call()) }
 		} else {
 			return tasks.map { submit(it) }.onEach { it.get() }
 		}
@@ -120,7 +94,7 @@ class ManualExecutorService(val thread: Thread = Thread.currentThread()) : Execu
 		unit: TimeUnit
 	): List<Future<T>> {
 		if (isSameThread()) {
-			return tasks.map { InPlaceFuture(it.call()) }
+			return tasks.map { Futures.immediateFuture(it.call()) }
 		} else {
 			return tasks.map { submit(it) }.onEach { it.get(timeout, unit) }
 		}
@@ -148,4 +122,15 @@ class ManualExecutorService(val thread: Thread = Thread.currentThread()) : Execu
 		}
 	}
 
+	fun <V> join(future: Future<V>): V {
+		if (!isSameThread())
+			return future.get()
+
+		while (!future.isDone) {
+			executeQueuedTasks()
+			LockSupport.parkNanos(1_000_000L)
+		}
+
+		return future.get()
+	}
 }