Remove gracefullyFinishThreads (#3057)

it's causing more harm than good due to constant interruptions

Author: pivovarit

vavr/src/test/java/io/vavr/concurrent/Concurrent.java

@@ -21,9 +21,6 @@
 import io.vavr.CheckedFunction0;
 import io.vavr.control.Try;
 import java.util.Random;
-import java.util.concurrent.ForkJoinPool;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
 import java.util.function.Supplier;
 
 import static org.assertj.core.api.Assertions.fail;
@@ -75,13 +72,4 @@ static <T, X extends Throwable> CheckedFunction0<T> zZz(X exception) {
             throw exception;
         };
     }
-
-    static void gracefullyFinishThreads() throws TimeoutException {
-        final boolean isQuiescent = ForkJoinPool.commonPool().awaitQuiescence(1L, TimeUnit.MINUTES);
-        if (isQuiescent) {
-            System.out.println("ForkJoinPool.commonPool() is quiecent");
-        } else {
-            throw new TimeoutException("Timeout while waiting for running threads in ForkJoinPool.commonPool() to finish.");
-        }
-    }
 }

vavr/src/test/java/io/vavr/concurrent/FutureTest.java

@@ -50,7 +50,6 @@
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 import org.assertj.core.api.IterableAssert;
-import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;
@@ -70,11 +69,6 @@ public class FutureTest extends AbstractValueTest {
 
     private static final Executor REJECTING_EXECUTOR = ignored -> {throw new RejectedExecutionException();};
 
-    @AfterAll
-    public static void gracefullyFinishThreads() throws TimeoutException {
-        Concurrent.gracefullyFinishThreads();
-    }
-
     static class TraceUnitExtension implements AfterEachCallback, BeforeEachCallback {
 
         @Override

vavr/src/test/java/io/vavr/concurrent/PromiseTest.java

@@ -19,20 +19,13 @@
 package io.vavr.concurrent;
 
 import io.vavr.control.Try;
-import java.util.concurrent.TimeoutException;
-import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 public class PromiseTest {
 
-    @AfterAll
-    public static void gracefullyFinishThreads() throws TimeoutException {
-        Concurrent.gracefullyFinishThreads();
-    }
-
     @Test
     public void shouldReturnExecutorService() {
         final Promise<Integer> promise = Promise.successful(42);