删除冗余代码

Author: JavaScalaDeveloper

01.并发编程的优缺点/并发编程的优缺点.md

@@ -30,73 +30,73 @@
 
 多线程编程中最难以把握的就是临界区线程安全问题，稍微不注意就会出现死锁的情况，一旦产生死锁就会造成系统功能不可用。
 
-
-	public class DeadLockDemo {
-	    private static String resource_a = "A";
-	    private static String resource_b = "B";
-	
-	    public static void main(String[] args) {
-	        deadLock();
-	    }
-	
-	    public static void deadLock() {
-	        Thread threadA = new Thread(new Runnable() {
-	            @Override
-	            public void run() {
-	                synchronized (resource_a) {
-	                    System.out.println("get resource a");
-	                    try {
-	                        Thread.sleep(3000);
-	                        synchronized (resource_b) {
-	                            System.out.println("get resource b");
-	                        }
-	                    } catch (InterruptedException e) {
-	                        e.printStackTrace();
-	                    }
-	                }
-	            }
-	        });
-	        Thread threadB = new Thread(new Runnable() {
-	            @Override
-	            public void run() {
-	                synchronized (resource_b) {
-	                    System.out.println("get resource b");
-	                    synchronized (resource_a) {
-	                        System.out.println("get resource a");
-	                    }
-	                }
-	            }
-	        });
-	        threadA.start();
-	        threadB.start();
-	
-	    }
-	}
-
+```java
+public class DeadLockDemo {
+    private static String resource_a = "A";
+    private static String resource_b = "B";
+
+    public static void main(String[] args) {
+        deadLock();
+    }
+
+    public static void deadLock() {
+        Thread threadA = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                synchronized (resource_a) {
+                    System.out.println("get resource a");
+                    try {
+                        Thread.sleep(3000);
+                        synchronized (resource_b) {
+                            System.out.println("get resource b");
+                        }
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        });
+        Thread threadB = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                synchronized (resource_b) {
+                    System.out.println("get resource b");
+                    synchronized (resource_a) {
+                        System.out.println("get resource a");
+                    }
+                }
+            }
+        });
+        threadA.start();
+        threadB.start();
+
+    }
+}
+```
 在上面的这个demo中，开启了两个线程threadA, threadB,其中threadA占用了resource_a, 并等待被threadB释放的resource _b。threadB占用了resource _b正在等待被threadA释放的resource _a。因此threadA,threadB出现线程安全的问题，形成死锁。同样可以通过jps,jstack证明这种推论：
-
-	"Thread-1":
-	  waiting to lock monitor 0x000000000b695360 (object 0x00000007d5ff53a8, a java.lang.String),
-	  which is held by "Thread-0"
-	"Thread-0":
-	  waiting to lock monitor 0x000000000b697c10 (object 0x00000007d5ff53d8, a java.lang.String),
-	  which is held by "Thread-1"
-	
-	Java stack information for the threads listed above:
-	===================================================
-	"Thread-1":
-	        at learn.DeadLockDemo$2.run(DeadLockDemo.java:34)
-	        - waiting to lock <0x00000007d5ff53a8(a java.lang.String)
-	        - locked <0x00000007d5ff53d8(a java.lang.String)
-	        at java.lang.Thread.run(Thread.java:722)
-	"Thread-0":
-	        at learn.DeadLockDemo$1.run(DeadLockDemo.java:20)
-	        - waiting to lock <0x00000007d5ff53d8(a java.lang.String)
-	        - locked <0x00000007d5ff53a8(a java.lang.String)
-	        at java.lang.Thread.run(Thread.java:722)
-	
-	Found 1 deadlock.
-
+```java
+"Thread-1":
+  waiting to lock monitor 0x000000000b695360 (object 0x00000007d5ff53a8, a java.lang.String),
+  which is held by "Thread-0"
+"Thread-0":
+  waiting to lock monitor 0x000000000b697c10 (object 0x00000007d5ff53d8, a java.lang.String),
+  which is held by "Thread-1"
+
+Java stack information for the threads listed above:
+===================================================
+"Thread-1":
+        at learn.DeadLockDemo$2.run(DeadLockDemo.java:34)
+        - waiting to lock <0x00000007d5ff53a8(a java.lang.String)
+        - locked <0x00000007d5ff53d8(a java.lang.String)
+        at java.lang.Thread.run(Thread.java:722)
+"Thread-0":
+        at learn.DeadLockDemo$1.run(DeadLockDemo.java:20)
+        - waiting to lock <0x00000007d5ff53d8(a java.lang.String)
+        - locked <0x00000007d5ff53a8(a java.lang.String)
+        at java.lang.Thread.run(Thread.java:722)
+
+Found 1 deadlock.
+```
 
 如上所述，完全可以看出当前死锁的情况。