process.cpp

   1 #include <algorithm>
   2 #include <tr1/functional>
   3 #include <iterator>
   4 #include <stdexcept>
   5 #include <sstream>
   6 #include <xbt/log.h>
   7 #include <xbt/time.h>
   8 #include "misc.h"
   9 #include "options.h"
  10 #include "process.h"
  11
  12 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simu);
  13
  14 process::process(int argc, char* argv[])
  15 {
  16     if (argc < 2 || !(std::istringstream(argv[1]) >> load))
  17         throw std::invalid_argument("bad or missing initial load");
  18
  19     neigh.assign(argv + 2, argv + argc);
  20     expected_load = load;
  21
  22     ctrl_close_pending = data_close_pending = neigh.size();
  23     if (neigh.size() == 1) {
  24         comm.next_close_on_ctrl_is_last();
  25         comm.next_close_on_data_is_last();
  26     }
  27     if (neigh.size() > 0)
  28         comm.listen();
  29
  30     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
  31     if (!LOG_ISENABLED(logp))
  32         return;
  33     LOG1(logp, "My initial load is: %g", load);
  34     std::ostringstream oss;
  35     oss << neigh.size() << " neighbor";
  36     if (!neigh.empty()) {
  37         oss << ESSE(neigh.size()) << ": ";
  38         std::transform(neigh.begin(), neigh.end() - 1,
  39                        std::ostream_iterator<const char*>(oss, ", "),
  40                        std::tr1::mem_fn(&neighbor::get_name));
  41         oss << neigh.back().get_name();
  42     }
  43     LOG1(logp, "Got %s.", oss.str().c_str());
  44     print_loads(logp);
  45 }
  46
  47 int process::run()
  48 {
  49     bool one_more = true;
  50     unsigned iter = 0;
  51     VERB0("Starting...");
  52     while (one_more) {
  53         bool close_received;
  54
  55         if (opt::bookkeeping)
  56             INFO3("(%u) current load: %g ; expected: %g",
  57                   iter, load, expected_load);
  58         else
  59             INFO2("(%u) current load: %g",
  60                   iter, load);
  61
  62         compute();
  63         close_received = !receive(false);
  64
  65         /*
  66          *    compute load balancing;
  67          *    send tasks to neighbors;
  68          */
  69
  70         comm.flush(false);
  71         ++iter;
  72
  73         if (opt::exit_on_close && close_received)
  74             one_more = false;
  75         if (opt::maxiter && iter >= opt::maxiter)
  76             one_more = false;
  77     }
  78     VERB0("Going to finalize...");
  79     finalize();
  80
  81     /* Open Questions :
  82      * - definition of load on heterogeneous hosts ?
  83      * - how to detect convergence ?
  84      * - how to manage link failures ?
  85      */
  86
  87     VERB0("Done.");
  88     return 0;
  89 }
  90
  91 void process::compute()
  92 {
  93     // fixme: shall we do something special when duration is 0 ?
  94     double duration = opt::comp_cost(load);
  95     m_task_t task = MSG_task_create("computation", duration, 0.0, NULL);
  96     DEBUG2("compute %g flop%s.", duration, ESSE(duration));
  97     MSG_task_execute(task);
  98     MSG_task_destroy(task);
  99 }
 100
 101
 102 // Returns false if a CLOSE message was received.
 103 bool process::receive(bool wait_for_close)
 104 {
 105     bool result = true;
 106     message* msg;
 107     m_host_t from;
 108     while ((ctrl_close_pending ||
 109             data_close_pending) && comm.recv(msg, from, wait_for_close)) {
 110         DEBUG2("received %s from %s",
 111                msg->to_string().c_str(), MSG_host_get_name(from));
 112         switch (msg->get_type()) {
 113         case message::INFO:
 114             // fixme: update neighbor
 115             // need a map m_host_t -> neighbor&
 116             break;
 117         case message::CREDIT:
 118             expected_load += msg->get_amount();
 119             break;
 120         case message::LOAD:
 121             load += msg->get_amount();
 122             break;
 123         case message::CTRL_CLOSE:
 124             if (--ctrl_close_pending == 1)
 125                 comm.next_close_on_ctrl_is_last();
 126             DEBUG1("ctrl_close_pending = %d", ctrl_close_pending);
 127             result = false;
 128             break;
 129         case message::DATA_CLOSE:
 130             if (--data_close_pending == 1)
 131                 comm.next_close_on_data_is_last();
 132             DEBUG1("data_close_pending = %d", data_close_pending);
 133             result = false;
 134             break;
 135         }
 136         delete msg;
 137     }
 138     return result;
 139 }
 140
 141 void process::finalize()
 142 {
 143     DEBUG2("send CLOSE to %d neighbor%s.",
 144            (int )neigh.size(), ESSE(neigh.size()));
 145     std::vector<neighbor>::iterator n;
 146     for (n = neigh.begin() ; n != neigh.end() ; ++n) {
 147         comm.send(n->get_ctrl_mbox(), new message(message::CTRL_CLOSE, 0.0));
 148         comm.send(n->get_data_mbox(), new message(message::DATA_CLOSE, 0.0));
 149     }
 150
 151     DEBUG2("wait for CLOSE from %d neighbor%s.",
 152            (int )neigh.size(), ESSE(neigh.size()));
 153     receive(true);
 154
 155     comm.flush(true);
 156 }
 157
 158 void process::print_loads(e_xbt_log_priority_t logp)
 159 {
 160     if (!LOG_ISENABLED(logp))
 161         return;
 162
 163     std::ostringstream oss;
 164     if (neigh.empty()) {
 165         oss << "no neighbor!";
 166     } else {
 167         std::transform(neigh.begin(), neigh.end() - 1,
 168                        std::ostream_iterator<double>(oss, ", "),
 169                        std::tr1::mem_fn(&neighbor::get_load));
 170         oss << neigh.back().get_load();
 171     }
 172     LOG1(logp, "Neighbor loads: %s", oss.str().c_str());
 173 }
 174
 175 // Local variables:
 176 // mode: c++
 177 // End: