#include <iostream>
#include <unistd.h>
#include <sys/wait.h>
#include <cstdlib>
#include <ctime>

void random_task(int id) {
	srand(time(0));
	int delay=1+rand()%3;
	std::cout<< "PID:" <<getpid() << "task " <<id 
	<< "delay: " << delay << "s\n"; 
	sleep(delay);
	
}
int main() {
	int total_tasks=10;
	int k=4;
	int pipefd[2];
	pipe(pipefd);

	pid_t rootpid=getpid();


	//---create workers---
	for(int w=0;w<k;w++)
		fork();
	//---workers assigned tasks
	if (getpid()!=rootpid)
	{
		close(pipefd[1]);
		int task;
		while (read(pipefd[0], &task, sizeof(task))>0)
		{
			random_task(task);
		}
		close(pipefd[0]);
		_exit(0);
	
	}
	//--root pid
	close(pipefd[0]);
	for(int t=0;t<total_tasks;t++) {
		write(pipefd[1],&t,sizeof(t));
	}
	close(pipefd[1]);
	while(wait(0)>0) ;
	std::cout << "All tasks completed\n";
	return 0;
}