#include <iostream> #include <map> #include #include #include #include

namespace ba = boost::asio; namespace bp = boost::posix_time;

typedef std::map timer_map;

timer_map g_timers; boost::mutex g_timers_lock;

ba::io_service g_ios;

void on_timer(int id) {     {             boost::mutex::scoped_lock lock(g_timers_lock);             timer_map::iterator it = g_timers.find(id);             assert(it != g_timers.end());             g_timers.erase(id);     }

    // std::cout << "delete timer " << id << std::endl; }

int main(void) {     boost::thread trd(boost::bind(&ba::io_service::run, &g_ios));     trd.detach();

    int count = 0;     for (;;) {             for (int i = 0; i < 100; i++) {                     ba::deadline_timer* pt = new ba::deadline_timer(g_ios, bp::seconds(1));                     pt->async_wait(boost::bind(&on_timer, count));

                    boost::mutex::scoped_lock lock(g_timers_lock);                     g_timers.insert(std::make_pair(count++, pt));             }

            usleep(20000);     }

    return 0; }

================================== I know, I should lock the g_timers, but should I lock the g_ios? I mean these lines:

   ba::deadline_timer* pt = new ba::deadline_timer(g_ios, bp::seconds(1));    pt->async_wait(boost::bind(&on_timer, count));

Are thread safety? It reference the g_ios, and will it call g_ios.add_job(this_timer) ..etc.. ?

What is "add_job"? io_service doesn't have such a member function. Anyway, it's safe to access io_service from multiple threads, as documented: http://www.boost.org/doc/libs/1_49_0/doc/html/boost_asio/reference/io_servic... By the way, instead of locking "g_timers.insert" you can just post this function to io_service thread: g_ios.post([]() {...do anything here});