One thread adds an operation, one thread does a subtraction, and multiple threads alternately run--synchronized

using synchronized

 PackageCom.pb.thread.demo5;/**using synchronized * One thread plus one operation, one thread doing subtraction, multiple threads running alternately *@authorDenny **/ Public classCount {Private intnum = 0; Private BooleanFlag =false;//Identification//addition     Public synchronized voidAdd () { while(flag) {Try{wait (); } Catch(interruptedexception e) {e.printstacktrace (); }        }         This. num++;//PlusSystem.out.println (Thread.CurrentThread (). GetName () + "..." + This. Num);  This. flag=true;//set Identity to TrueNotifyall ();//wake all threads that are frozen in the thread pool and wake them all up            }    //Subtraction     Public synchronized voidSub () { while(!flag) {            Try{wait (); } Catch(interruptedexception e) {e.printstacktrace (); }        }         This. num--;//minusSystem.out.println (Thread.CurrentThread (). GetName () + "..." + This. Num);  This. flag=false;//set Identity to TrueNotifyall ();//wake all threads that are frozen in the thread pool and wake them all up    }}

 PackageCom.pb.thread.demo5; Public classAddImplementsRunnable {Privatecount Count;  PublicAdd (count count) { This. count=count; } @Override Public voidrun () { while(true) {count.add (); }    }}//================ PackageCom.pb.thread.demo5; Public classSubImplementsRunnable {Privatecount Count;  PublicSub (count count) { This. count=count; } @Override Public voidrun () { while(true) {count.sub (); }    }} 

Test class

 PackageCom.pb.thread.demo5; Public classCounttest { Public Static voidMain (string[] args) {Count C=NewCount (); Add Add=NewAdd (c); Sub Sub=NewSub (c); Thread T1=NewThread (add); Thread T2=NewThread (add); Thread T3=NewThread (sub); Thread T4=NewThread (sub);        T1.start ();        T2.start ();        T3.start ();    T4.start (); }}

Results:

Thread-2 ..... 0thread-1 ..... 1thread-3 ..... 0thread-0 ..... 1thread-2 ..... 0thread-1 ..... 1thread-3 ..... 0thread-0 ..... 1thread-2 ..... 0

do not use synchronized

 PackageCom.pb.thread.demo4;Importjava.util.concurrent.locks.Condition;ImportJava.util.concurrent.locks.Lock;ImportJava.util.concurrent.locks.ReentrantLock;/*** One thread plus one operation, one thread doing subtraction, multiple threads running alternately *@authorDenny **/ Public classCount {Private intnum = 0; Private Booleanflag=false;//IdentificationLock lock =NewReentrantlock ();//LockCondition add = Lock.newcondition ();//addition LockCondition sub = lock.newcondition ();//Subtraction Lock     Public voidAdd () {lock.lock ();//Lock        Try {             while(flag) {//Cycle Judgmentadd.await (); }             This. num++; System.out.println (Thread.CurrentThread (). GetName ()+ "........" + This. Num);  This. Flag =true;//Set IdentitySub.signal ();//Wake the specified thread}Catch(interruptedexception e) {e.printstacktrace (); }finally{lock.unlock (); }            }     Public voidSub () {Lock.lock ();//Lock        Try {             while(!flag) {//Cycle Judgmentsub.await (); }             This. num--; System.out.println (Thread.CurrentThread (). GetName ()+ "........" + This. Num);  This. Flag =false;//Set IdentityAdd.signal ();//Wake the specified thread}Catch(interruptedexception e) {e.printstacktrace (); }finally{lock.unlock (); }            }}

 Package Com.pb.thread.demo4;  Public class Implements Runnable {    private  count count;      Public Add (count count) {        this.count=Count;    }     @Override    publicvoid  run () {        while (true  ) {            count.add ();     }}}

 Package Com.pb.thread.demo4;  Public class Implements Runnable {    private  count count;      Public Sub (count count) {        this.count=Count;    }     @Override    publicvoid  run () {        while (true  ) {            count.sub ();     }}}

 PackageCom.pb.thread.demo4; Public classCounttest { Public Static voidMain (string[] args) {Count C=NewCount (); Add Add=NewAdd (c); Sub Sub=NewSub (c); Thread T1=NewThread (add); Thread T2=NewThread (add); Thread T3=NewThread (sub); Thread T4=NewThread (sub);        T1.start ();        T2.start ();        T3.start ();    T4.start (); }}

Results:

Thread-1 ..... 1thread-3 ..... 0thread-0 ..... 1thread-2 ..... 0thread-1 ..... 1thread-3 ..... 0thread-0 ..... 1thread-2 ..... 0

One thread adds one operation, one thread does minus one operation, and multiple threads alternately run--synchronized