easy_thread_pooling

g++ easy_thread_pooling.cpp -o multi_thread -lboost_thread -lboost_system -lboost_chrono

easy_thread_pooling.cpp

#include <boost/thread.hpp>
#include <boost/chrono.hpp>
#include <iostream>

void simple_thread(int id){
    std::cout << id << std::endl;
}

void longrun_thread(int id){
    std::cout << "long run launched" << std::endl;
    int j;
    for(double i=0; i<100000000; i++){
	j += i; 
    }
    std::cout << "long run finished" << std::endl;
}

bool collectable(boost::thread* it){
    if(it->joinable()){
        if(it->try_join_for(boost::chrono::milliseconds(1))){
	    delete it;
	    return true;
	}
    }
    return false;
}


int main(){
    std::list<boost::thread*> thread_list;
    const size_t limit = 5;
    for(int i=0; i < 10; i++){
	while(thread_list.size() > limit){
	    thread_list.remove_if(collectable);
            std::cout << "resized to: " << thread_list.size() << std::endl;
	}
        thread_list.push_back(new boost::thread(&simple_thread, i));
	/*if(i == 0){
            thread_list.push_back(new boost::thread(&longrun_thread, i));
	}*/
    }
    while(thread_list.size() > 0) thread_list.remove_if(collectable);
    return 0;
}