concurrent test

whatsmars-common/src/test/java/org/hongxi/java/util/concurrent/CountDownLatchTest.java

+package org.hongxi.java.util.concurrent;
+
+import java.util.concurrent.CountDownLatch;
+
+/**
+ * Created on 2019/8/11.
+ *
+ * @author shenhongxi
+ */
+public class CountDownLatchTest {
+
+    public static void main(String[] args) {
+        int nThreads = 3;
+        CountDownLatch latch = new CountDownLatch(nThreads);
+        long begin = System.currentTimeMillis();
+        for (int i = 0; i < nThreads; i++) {
+            new Thread(new Task(i + 1, latch)).start();
+        }
+        try {
+            latch.await();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        System.out.println(System.currentTimeMillis() - begin);
+    }
+
+    static class Task implements Runnable {
+        private int id;
+        private CountDownLatch latch;
+
+        Task(int id, CountDownLatch latch) {
+            this.id = id;
+            this.latch = latch;
+        }
+
+        @Override
+        public void run() {
+            try {
+                Thread.sleep(1000 * id);
+                System.out.println(String.format("Sub Thread %d finished", id));
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            } finally {
+                latch.countDown();
+            }
+        }
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/util/concurrent/InvokeAllTest.java

+package org.hongxi.java.util.concurrent;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.*;
+
+/**
+ * Created on 2019/8/11.
+ *
+ * @author shenhongxi
+ */
+public class InvokeAllTest {
+
+    public static void main(String[] args) {
+        ExecutorService executorService = Executors.newCachedThreadPool();
+        Collection<Callable<Long>> tasks = new ArrayList<>();
+        for (int i = 0; i < 3; i++) {
+            final int j = i + 1;
+            tasks.add(() -> {
+                Thread.sleep(1000 * j);
+                return System.currentTimeMillis();
+            });
+        }
+        try {
+            long begin = System.currentTimeMillis();
+            List<Future<Long>> futures = executorService.invokeAll(tasks);
+            futures.forEach(f -> {
+                try {
+                    System.out.println(f.get());
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                } catch (ExecutionException e) {
+                    e.printStackTrace();
+                }
+            });
+            System.out.println(System.currentTimeMillis() - begin);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        } finally {
+            executorService.shutdown();
+        }
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/util/concurrent/JoinTest.java

+package org.hongxi.java.util.concurrent;
+
+import java.util.Arrays;
+
+/**
+ * Created on 2019/8/11.
+ *
+ * @author shenhongxi
+ */
+public class JoinTest {
+
+    public static void main(String[] args) {
+        int nThreads = 3;
+        Thread[] threads = new Thread[nThreads];
+        for (int i = 0; i < nThreads; i++) {
+            final int j = i + 1;
+            threads[i] = new Thread(() -> {
+                try {
+                    Thread.sleep(1000 * j);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            });
+        }
+
+        long begin = System.currentTimeMillis();
+        Arrays.stream(threads).forEach(t -> t.start());
+        Arrays.stream(threads).forEach(t -> {
+            try {
+                t.join();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        });
+        System.out.println(System.currentTimeMillis() - begin);
+    }
+}