Java ReentrantLock toString() Method

by Online Tutorials Library July 22, 2022

Java ReentrantLock toString() Method

The toString() method of ReentrantLock Class returns a string identifying this lock and its lock state.

Syntax

Parameter

No parameter is passed.

Returns

A string identifying this lock, as well as its lock state

Throws

No Exception is thrown.

Example 1

  import java.util.concurrent.ExecutorService;   import java.util.concurrent.Executors;   import java.util.concurrent.locks.ReentrantLock;       class ToStringClass implements Runnable   {     String nm;     ReentrantLock relc;     public ToStringClass(ReentrantLock rl, String n)     {       relc = rl;       nm = n;     }     public void run()     {       boolean dn = false;       while (!dn)       {         try {        int c=0;        if(relc.tryLock())         {  int i; Thread t1=new Thread(); for( i =5 ; i <= 10 ; i++) System.out.println(t1.getName());  t1.checkAccess(); t1.countStackFrames(); c=c+1; if(i>7) { System.out.println(t1.getName()); break;        }               }       }       finally      {         //Outer lock release         System.out.println(“task name – ” + nm +                    ” releasing lock(outer lock)”);            relc.unlock();         System.out.println(“Lock Hold Count – ” +                      relc.getHoldCount());       }     }         }    }        public class ReentrantLoctoStringExample1  {     static final int MAX_Time = 2;     public static void main(String[] args)     {       ReentrantLock rel = new ReentrantLock();       ExecutorService pool = Executors.newFixedThreadPool(MAX_Time);       Runnable wrk1 = new ToStringClass(rel, “Job1″);       System.out.println(”  ” +wrk1.toString());           pool.execute(wrk1);       System.out.println(”  ” +pool.toString());      pool.shutdown();     }   }  

Test it Now

Output:

[email protected] Thread-0 Thread-0 Thread-0 Thread-0 Thread-0 Thread-0   [email protected][Running, pool size = 1,    active threads = 1, queued tasks = 0, completed tasks = 0] Thread-0 task name - Job1 releasing lock(outer lock) Lock Hold Count - 0

Example 2

  import java.util.concurrent.locks.ReentrantLock;    public class ReentrantLoctoStringExample2  {      public static void main(String[] args) {                ReentrantLock lock=new ReentrantLock();             System.out.println(”  ” +lock.toString());             ToStringClass2 myRnbl=new ToStringClass2(lock);             System.out.println(”  ” +myRnbl.toString());             new Thread(myRnbl,”Thread-1″).start();                               }  }       class ToStringClass2 implements Runnable{            ReentrantLock lock;      public ToStringClass2(ReentrantLock lock) {              this.lock=lock;      }            public void run(){                          System.out.println(Thread.currentThread().getName()                          +” is Waiting to get the lock”);                          try {                              int i=1;                 Thread t=new Thread();                   while(i<5) {                                      System.out.println(”     “+t.getThreadGroup());                   if(i==2)                     System.out.println(”     “+t.getThreadGroup());                   if(i==3)                     System.out.println(”     “+t.isInterrupted());                   if(i==4)                     System.out.println(”     “+t.getStackTrace());                                      i=i+1;                   }                                                                   assert !lock.isHeldByCurrentThread();                   lock.lock();                                                System.out.println(” after sleep(1500) Is held by Current Thread – ” + lock.isHeldByCurrentThread());                                    }                                    finally {                 lock.unlock();                 }             }  } 

Test it Now

Output:

[email protected][Unlocked]   [email protected] Thread-1 is Waiting to get the lock      java.lang.ThreadGroup[name=main,maxpri=10]      java.lang.ThreadGroup[name=main,maxpri=10]      java.lang.ThreadGroup[name=main,maxpri=10]      java.lang.ThreadGroup[name=main,maxpri=10]      false      java.lang.ThreadGroup[name=main,maxpri=10]      [Ljava.lang.StackTraceElement;@12a128ac  after sleep(1500) Is held by Current Thread - true

Next TopicJava ReentrantLock

Java ReentrantLock toString() Method

Java ReentrantLock toString() Method

Syntax

Parameter

Returns

Throws

Example 1

Example 2

Java Executors newWorkStealingPool() Method

Java Boolean Keyword

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