Merge branch 'master' of https://github.com/Wasabi1234/Concurrency-Progamming-Tuitor

Java.Edge · Java.Edge · commit 22789521a899 · 2020-05-19T10:39:33.000+08:00
diff --git a/concurrency/src/main/java/com/javaedge/concurrency/example/LockSupportBlockerTest.java b/concurrency/src/main/java/com/javaedge/concurrency/example/LockSupportBlockerTest.java
@@ -0,0 +1,25 @@
+public class LockSupportBlockerTest {
+    public static void main(String[] args) {
+        Thread t3 = new Thread(() -> {    
+            Thread.currentThread().setName("t3");
+            System.out.println(Thread.currentThread().getName() + " park 5 seconds");
+            //park 5 seconds, set blocker
+            Object blocker = new String("sss");
+            LockSupport.parkUntil(blocker, System.currentTimeMillis() + TimeUnit.MILLISECONDS.convert(5, TimeUnit.SECONDS));
+            System.out.println(Thread.currentThread().getName() + " after park");
+        });
+        t3.start();
+
+        try {
+            Object t3_blocker = null;
+            while (t3_blocker == null) {
+                t3_blocker = LockSupport.getBlocker(t3);
+                TimeUnit.MILLISECONDS.sleep(10);
+            }
+            System.out.println("t3 blocker is :" + t3_blocker);
+            t3.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/concurrency/src/main/java/com/javaedge/concurrency/example/LockSupportTest.java b/concurrency/src/main/java/com/javaedge/concurrency/example/LockSupportTest.java
@@ -0,0 +1,48 @@
+public class LockSupportExam {
+    public static void main(String[] args) {
+        Thread t1 = new Thread() {
+            @Override
+            public void run() {
+                Thread.currentThread().setName("t1");
+                System.out.println(Thread.currentThread().getName() + " before park");
+                //park 100 seconds
+                LockSupport.parkNanos(TimeUnit.NANOSECONDS.convert(100, TimeUnit.SECONDS));
+                System.out.println(Thread.currentThread().getName() + " after park");
+            }
+        };
+        Thread t2 = new Thread() {
+            @Override
+            public void run() {
+                try {
+                    Thread.currentThread().setName("t2");
+                    TimeUnit.SECONDS.sleep(1);
+                    System.out.println(Thread.currentThread().getName() + " unpark t1");
+                    LockSupport.unpark(t1);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+            }
+        };
+        Thread t3 = new Thread() {
+            @Override
+            public void run() {
+                Thread.currentThread().setName("t3");
+                System.out.println(Thread.currentThread().getName() + " park 5 seconds");
+                //park 5 seconds
+                LockSupport.parkUntil(System.currentTimeMillis() + TimeUnit.MILLISECONDS.convert(5,TimeUnit.SECONDS));
+                System.out.println(Thread.currentThread().getName() + " after park");
+            }
+        };
+        t1.start();
+        t2.start();
+        t3.start();
+        try {
+            t1.join();
+            t2.join();
+            t3.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/concurrency/src/main/java/com/javaedge/concurrency/example/UnsafeTest.java b/concurrency/src/main/java/com/javaedge/concurrency/example/UnsafeTest.java
@@ -0,0 +1,52 @@
+public class UnsafeTest {
+
+    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
+        Field f = Unsafe.class.getDeclaredField("theUnsafe");
+        f.setAccessible(true);
+        Unsafe unsafe = (Unsafe) f.get(null);
+        Thread t1 = new Thread() {
+            @Override
+            public void run() {
+                Thread.currentThread().setName("t1");
+                System.out.println(Thread.currentThread().getName() + " before park");
+                //park 100 seconds
+                unsafe.park(false, TimeUnit.NANOSECONDS.convert(100, TimeUnit.SECONDS));
+                System.out.println(Thread.currentThread().getName() + " after park");
+            }
+        };
+        Thread t2 = new Thread() {
+            @Override
+            public void run() {
+                try {
+                    Thread.currentThread().setName("t2");
+                    TimeUnit.SECONDS.sleep(1);
+                    System.out.println(Thread.currentThread().getName() + " unpark t1");
+                    unsafe.unpark(t1);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+            }
+        };
+        Thread t3 = new Thread() {
+            @Override
+            public void run() {
+                Thread.currentThread().setName("t3");
+                System.out.println(Thread.currentThread().getName() + " park 5 seconds");
+                //park 5 seconds
+                unsafe.park(true, System.currentTimeMillis() + TimeUnit.MILLISECONDS.convert(5,TimeUnit.SECONDS));
+                System.out.println(Thread.currentThread().getName() + " after park");
+            }
+        };
+        t1.start();
+        t2.start();
+        t3.start();
+        try {
+            t1.join();
+            t2.join();
+            t3.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/concurrency/src/main/java/com/javaedge/concurrency/example/aqs/SimpleLock.java b/concurrency/src/main/java/com/javaedge/concurrency/example/aqs/SimpleLock.java
@@ -0,0 +1,70 @@
+public class SimpleLock {
+    private static class Sync extends AbstractQueuedSynchronizer {
+        @Override
+        protected boolean tryAcquire(int ignore) {
+            return compareAndSetState(0, 1);
+        }
+
+        @Override
+        protected boolean tryRelease(int ignore) {
+            setState(0);
+            return true;
+        }
+
+        protected Sync() {
+            super();
+        }
+    }
+
+    private final Sync sync = new Sync();
+
+    public void lock() {
+        sync.acquire(1);
+    }
+
+    public void unlock() {
+        sync.release(1);
+    }
+
+    private static class MyThread extends Thread {
+        private final String name;
+        private final SimpleLock lock;
+
+        private MyThread(String name, SimpleLock lock) {
+            this.name = name;
+            this.lock = lock;
+        }
+
+        @Override
+        public void run() {
+            try {
+                lock.lock();
+                System.out.println(name + " get the lock");
+                TimeUnit.SECONDS.sleep(2);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            } finally {
+                lock.unlock();
+                System.out.println(name + " release the lock");
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        final SimpleLock mutex = new SimpleLock();
+        MyThread t1 = new MyThread("t1", mutex);
+        MyThread t2 = new MyThread("t2", mutex);
+        MyThread t3 = new MyThread("t3", mutex);
+        t1.start();
+        t2.start();
+        t3.start();
+        try {
+            t1.join();
+            t2.join();
+            t3.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        System.out.println("main thread exit!");
+    }
+}
diff --git a/concurrency/src/main/java/com/javaedge/concurrency/example/lock/TicketLock.java b/concurrency/src/main/java/com/javaedge/concurrency/example/lock/TicketLock.java
@@ -0,0 +1,23 @@
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class TicketLock {
+   private AtomicInteger serviceNum = new AtomicInteger(); // 服务号
+   private AtomicInteger ticketNum = new AtomicInteger(); // 排队号
+
+   public int lock() {
+         // 首先原子性地获得一个排队号
+         int myTicketNum = ticketNum.getAndIncrement();
+
+              // 只要当前服务号不是自己的就不断轮询
+       while (serviceNum.get() != myTicketNum) {
+       }
+
+       return myTicketNum;
+    }
+
+    public void unlock(int myTicket) {
+        // 只有当前线程拥有者才能释放锁
+        int next = myTicket + 1;
+        serviceNum.compareAndSet(myTicket, next);
+    }
+}
diff --git a/concurrency/src/main/main.iml b/concurrency/src/main/main.iml
@@ -7,5 +7,15 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="module-library">
+      <library name="JUnit4">
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.12/junit-4.12.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
   </component>
 </module>
