#include <iostream>
#include <thread>
#include <mutex>
#include <condition_variable>


using namespace std ;
mutex mutexObj1 ;
mutex mutexObj2 ;

mutex mutexObj3 ;
condition_variable cv;

mutex mutexG ;
bool var1 = false ;
bool var2 = false ;

void function3()
{

	for( int i1= 0 ; i1 < 10 ; i1 += 2 )
	  {
              unique_lock lk( mutexObj3 )  ;
              var1 = false ;
			  cout << "i1:" << i1 << endl ;

        	   var2 = true ;
			   cv.notify_one();
			   cv.wait(lk, []{ return var1; });
	  } //for
     cout << "Out of the for loop for function 3." << endl ;
     var2 = true ;
     cv.notify_one();

}

void function4()
{

	for( int i2= 1 ; i2 < 10 ; i2 += 2 )
	  {
		  unique_lock lk( mutexObj3 );
		  var2 = false ;
		  cout << "i2--:" <<  i2 << endl ;

		   var1 = true ;
           cv.notify_one();
		   cv.wait(lk, []{ return var2; });
           this_thread::sleep_for( chrono::microseconds(1) );
	  } //for
	   var1 = true ;
       cv.notify_one();

   cout << "Out of the for loop for function 4." << endl ;
}




void function1()
{

	for( int i1= 0 ; i1 < 10 ; i1 += 2 )
	  {
		  mutexObj1.lock() ;

          mutexG.lock() ;
		  cout << "i1:" << i1 << endl ;
		  mutexG.unlock() ;

		  mutexObj1.unlock() ;

	  }

}

void function2()
{

	for( int i2= 1 ; i2 < 10 ; i2 += 2 )
	  {
		  mutexObj1.lock() ;

		  mutexG.lock() ;
		  cout << "i2:" <<  i2 << endl ;
		  mutexG.unlock() ;


		  mutexObj1.unlock() ;
          //this_thread::sleep_for( chrono::microseconds(1) );
	  } //for



}



int main()
{
   //mutexObj2.lock() ;
   //this_thread::sleep_for( chrono::seconds(2) );
   thread th1 ( function1 ) ;
   thread th2 ( function2 ) ;

 //  thread th1 ( function3 ) ;
 //  thread th2 ( function4 ) ;

   //this_thread::sleep_for( chrono::seconds(5) );
   //mutexObj1.unlock() ; mutexObj2.unlock() ;
   th1.join() ;  th2.join() ;


  return 0 ;
}