多线程编程

code/Java/java-concurrency/src/main/java/com/heibaiying/reentrantLock/J1_ThreadSafe.java

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+package com.heibaiying.reentrantLock;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * 利用ReentrantLock实现线程安全
+ */
+public class J1_ThreadSafe {
+
+	private static ReentrantLock reentrantLock = new ReentrantLock();
+	private static Integer i = 0;
+
+	static class IncreaseTask implements Runnable {
+		@Override
+		public void run() {
+			for (int j = 0; j < 100000; j++) {
+				try {
+					reentrantLock.lock();
+					i++;
+				} catch (Exception e) {
+					e.printStackTrace();
+				} finally {
+					reentrantLock.unlock();
+				}
+			}
+		}
+
+		public static void main(String[] args) throws InterruptedException {
+			Thread thread1 = new Thread(new IncreaseTask());
+			Thread thread2 = new Thread(new IncreaseTask());
+			thread1.start();
+			thread2.start();
+			thread1.join();
+			thread2.join();
+			System.out.println(i);
+		}
+	}
+}

code/Java/java-concurrency/src/main/java/com/heibaiying/reentrantLock/J2_Reentrant.java

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+package com.heibaiying.reentrantLock;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * 可重入性
+ */
+public class J2_Reentrant {
+
+	private static ReentrantLock reentrantLock = new ReentrantLock();
+	private static Integer i = 0;
+
+	static class IncreaseTask implements Runnable {
+		@Override
+		public void run() {
+			for (int j = 0; j < 100000; j++) {
+				try {
+					reentrantLock.lock();
+					reentrantLock.lock();
+					reentrantLock.lock();
+					i++;
+				} catch (Exception e) {
+					e.printStackTrace();
+				} finally {
+					reentrantLock.unlock();
+					reentrantLock.unlock();
+					reentrantLock.unlock();
+				}
+			}
+		}
+
+		public static void main(String[] args) throws InterruptedException {
+			Thread thread1 = new Thread(new IncreaseTask());
+			Thread thread2 = new Thread(new IncreaseTask());
+			thread1.start();
+			thread2.start();
+			thread1.join();
+			thread2.join();
+			System.out.println(i);
+		}
+	}
+}

code/Java/java-concurrency/src/main/java/com/heibaiying/reentrantLock/J3_TimeLimitedLock.java

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+package com.heibaiying.reentrantLock;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReentrantLock;
+
+public class J3_TimeLimitedLock {
+
+	private static ReentrantLock reentrantLock = new ReentrantLock();
+
+	static class IncreaseTask implements Runnable {
+		@Override
+		public void run() {
+
+			try {
+				String threadName = Thread.currentThread().getName();
+				// 指定锁定时间
+				if (reentrantLock.tryLock(5, TimeUnit.SECONDS)) {
+					System.out.println(threadName + "被执行");
+					Thread.sleep(6000);
+				} else {
+					System.out.println(threadName + "获得锁失败");
+				}
+			} catch (Exception e) {
+				e.printStackTrace();
+			} finally {
+				reentrantLock.unlock();
+			}
+		}
+	}
+
+	public static void main(String[] args) {
+		Thread thread01 = new Thread(new IncreaseTask());
+		thread01.setName("线程1");
+		thread01.start();
+		Thread thread02 = new Thread(new IncreaseTask());
+		thread02.setName("线程2");
+		thread02.start();
+	}
+}

code/Java/java-concurrency/src/main/java/com/heibaiying/reentrantLock/J4_FairLock.java

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+package com.heibaiying.reentrantLock;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * 公平锁
+ */
+public class J4_FairLock {
+
+	// 参数为true,代表使用公平锁
+	private static ReentrantLock fairLock = new ReentrantLock(true);
+
+	static class IncreaseTask implements Runnable {
+		@Override
+		public void run() {
+			while (true) {
+				fairLock.lock();
+				System.out.println(Thread.currentThread().getName() + "获得锁");
+				fairLock.unlock();
+			}
+		}
+	}
+
+	public static void main(String[] args) {
+		Thread thread1 = new Thread(new IncreaseTask());
+		Thread thread2 = new Thread(new IncreaseTask());
+		Thread thread3 = new Thread(new IncreaseTask());
+		thread1.start();
+		thread2.start();
+		thread3.start();
+	}
+}