thread tutorial (#180)

realDuYuanChao · web-flow · commit a1a1d8d573c2 · 2021-09-11T07:50:00.000+08:00
* thread tutorial

* remove log.txt
diff --git a/src/main/java/com/examplehub/basics/RunnableExample.java b/src/main/java/com/examplehub/basics/RunnableExample.java
diff --git a/src/main/java/com/examplehub/basics/thread/InterruptedThread.java b/src/main/java/com/examplehub/basics/thread/InterruptedThread.java
@@ -0,0 +1,4 @@
+package com.examplehub.basics.thread;
+
+public class InterruptedThread {
+}
diff --git a/src/main/java/com/examplehub/basics/thread/VolatileExample.java b/src/main/java/com/examplehub/basics/thread/VolatileExample.java
@@ -0,0 +1,4 @@
+package com.examplehub.basics.thread;
+
+public class VolatileExample {
+}
diff --git a/src/main/java/com/examplehub/basics/thread/YieldThread.java b/src/main/java/com/examplehub/basics/thread/YieldThread.java
@@ -4,7 +4,7 @@ public class YieldThread implements Runnable {
 
   @Override
   public void run() {
-    System.out.println(Thread.currentThread().getName() + " is running");
+//    System.out.println(Thread.currentThread().getName() + " is running");
     Thread.yield();
     System.out.println(Thread.currentThread().getName() + " is stopped");
   }
diff --git a/src/test/java/com/examplehub/basics/thread/InterruptedThreadTest.java b/src/test/java/com/examplehub/basics/thread/InterruptedThreadTest.java
@@ -0,0 +1,28 @@
+package com.examplehub.basics.thread;
+
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+class InterruptedThreadTest {
+  @Test
+  @Disabled
+  void test() throws InterruptedException {
+    //TODO
+    class MyThread extends Thread {
+      @Override
+      public void run() {
+        while (!isInterrupted()) {
+          System.out.println(Thread.currentThread().getName() + " running");
+        }
+        System.out.println(Thread.currentThread().getName() + " stopped");
+      }
+    }
+
+    Thread thread = new MyThread();
+    thread.start();
+    Thread.sleep(1);
+    thread.interrupt();
+    thread.join();
+    System.out.println(Thread.currentThread().getName() + " stopped");
+  }
+}
diff --git a/src/test/java/com/examplehub/basics/thread/JoinThreadTest.java b/src/test/java/com/examplehub/basics/thread/JoinThreadTest.java
@@ -2,6 +2,10 @@
 
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
 class JoinThreadTest {
   @Test
   void test() throws InterruptedException {
@@ -14,4 +18,21 @@ void test() throws InterruptedException {
       System.out.println(Thread.currentThread().getName() + i);
     }
   }
+
+  @Test
+  void testJoinWithTime() throws InterruptedException {
+    AtomicInteger number = new AtomicInteger();
+    Thread thread = new Thread(()->{
+      try {
+        Thread.sleep(100);
+        number.set(1);
+      } catch (InterruptedException e) {
+        e.printStackTrace();
+      }
+    });
+    thread.start();
+    thread.join(50);
+    assertEquals(0, number.get());
+    assertEquals(Thread.State.TIMED_WAITING, thread.getState());
+  }
 }
diff --git a/src/test/java/com/examplehub/basics/thread/SellTicketThreadTest.java b/src/test/java/com/examplehub/basics/thread/SellTicketThreadTest.java
@@ -1,7 +1,5 @@
 package com.examplehub.basics.thread;
 
-import static org.junit.jupiter.api.Assertions.*;
-
 import org.junit.jupiter.api.Test;
 
 class SellTicketThreadTest {
diff --git a/src/test/java/com/examplehub/basics/thread/SynchronizedThreadTest.java b/src/test/java/com/examplehub/basics/thread/SynchronizedThreadTest.java
@@ -1,10 +1,16 @@
 package com.examplehub.basics.thread;
 
+import org.junit.jupiter.api.Test;
+
 import static org.junit.jupiter.api.Assertions.*;
 
-import org.junit.jupiter.api.Test;
+class Counter {
+  public static final Object lock = new Object();
+  public static int count = 0;
+}
 
 class SynchronizedThreadTest {
+
   @Test
   void test() {
     SynchronizedThread synchronizedThread = new SynchronizedThread();
@@ -14,4 +20,105 @@ void test() {
     first.start();
     second.start();
   }
+
+  @Test
+  void testCounter() throws InterruptedException {
+    class AddThread extends Thread {
+      @Override
+      public void run() {
+        for (int i = 0; i < 100; ++i) {
+          synchronized (Counter.lock) {
+            Counter.count++;
+          }
+        }
+      }
+    }
+    class DesThread extends Thread {
+      @Override
+      public void run() {
+        for (int i = 0; i < 100; i++) {
+          synchronized (Counter.lock) {
+            Counter.count--;
+          }
+        }
+      }
+    }
+    AddThread addThread = new AddThread();
+    DesThread desThread = new DesThread();
+    addThread.start();
+    desThread.start();
+    addThread.join();
+    desThread.join();
+    assertEquals(0, Counter.count);
+  }
+
+  @Test
+  void testSynchronizedThis() throws InterruptedException {
+    class Counter {
+      private int count = 0;
+      public void dec() {
+        synchronized (this) {
+          count = count - 1;
+        }
+      }
+      public void add() {
+        synchronized (this) {
+          count = count + 1;
+        }
+      }
+
+      public int getCount() {
+        return count;
+      }
+    }
+    Counter counter = new Counter();
+    var firstThread = new Thread(() -> {
+      for (int i = 0; i < 100; i++) {
+        counter.add();
+      }
+    });
+    var secondThread = new Thread(() -> {
+      for (int i = 0; i < 100; i++) {
+        counter.dec();
+      }
+    });
+    firstThread.start();
+    secondThread.start();
+    firstThread.join();
+    secondThread.join();
+    assertEquals(0, counter.getCount());
+  }
+
+  @Test
+  void testSynchronizedFunction() throws InterruptedException {
+    class Counter {
+      private int count = 0;
+      public synchronized void dec() {
+          count = count - 1;
+      }
+      public synchronized void add() {
+          count = count + 1;
+      }
+
+      public int getCount() {
+        return count;
+      }
+    }
+    Counter counter = new Counter();
+    var firstThread = new Thread(() -> {
+      for (int i = 0; i < 100; i++) {
+        counter.add();
+      }
+    });
+    var secondThread = new Thread(() -> {
+      for (int i = 0; i < 100; i++) {
+        counter.dec();
+      }
+    });
+    firstThread.start();
+    secondThread.start();
+    firstThread.join();
+    secondThread.join();
+    assertEquals(0, counter.getCount());
+  }
 }
diff --git a/src/test/java/com/examplehub/basics/thread/VolatileExampleTest.java b/src/test/java/com/examplehub/basics/thread/VolatileExampleTest.java
@@ -0,0 +1,30 @@
+package com.examplehub.basics.thread;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class VolatileExampleTest {
+  int number = 0;
+  @Test
+  void test() throws InterruptedException {
+    class MyThread extends Thread {
+      @Override
+      public void run() {
+        for (int i = 1; i <= 10; ++i) {
+          number++;
+        }
+      }
+    }
+    MyThread firstThread = new MyThread();
+    MyThread secondThread = new MyThread();
+    MyThread thirdThread = new MyThread();
+    firstThread.start();
+    secondThread.start();
+    thirdThread.start();
+    firstThread.join();
+    secondThread.join();
+    thirdThread.join();
+    assertEquals(30, number);
+  }
+}
diff --git a/src/test/java/com/examplehub/basics/thread/YieldThreadTest.java b/src/test/java/com/examplehub/basics/thread/YieldThreadTest.java
@@ -1,7 +1,5 @@
 package com.examplehub.basics.thread;
 
-import static org.junit.jupiter.api.Assertions.*;
-
 import org.junit.jupiter.api.Test;
 
 class YieldThreadTest {

-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +package com.examplehub.basics.thread;
++
 +public class InterruptedThread {
 +}
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@ public class YieldThread implements Runnable {`
`4`	`4`
`5`	`5`	`@Override`
`6`	`6`	`public void run() {`
`7`		`- System.out.println(Thread.currentThread().getName() + " is running");`
	`7`	`+// System.out.println(Thread.currentThread().getName() + " is running");`
`8`	`8`	`Thread.yield();`
`9`	`9`	`System.out.println(Thread.currentThread().getName() + " is stopped");`
`10`	`10`	`}`