produces infinite loop in for loop in php code example

Example 1: php infinite loop

$interval=60; //minutes
  set_time_limit( 0 );
  $sleep = $interval*60-(time());

  while ( 1 ){
     if(time() != $sleep) {
       // the looping will pause on the specific time it was set to sleep
       // it will loop again once it finish sleeping.
       time_sleep_until($sleep); 
     }
     #do the routine job, trigger a php function and what not.
   }

Example 2: infinite loop php

//this infinte loop never stops until the if condition became true 
while(1){
			if(/*condition to exit from while*/);break;}
			ob_flush();	
			flush();
			sleep(2);
        	}