process.cpp

   1 #include "process.h"
   2
   3 #include <algorithm>
   4 #include <tr1/functional>
   5 #include <iterator>
   6 #include <stdexcept>
   7 #include <sstream>
   8 #include <xbt/log.h>
   9 #include <xbt/time.h>
  10 #include "misc.h"
  11 #include "options.h"
  12
  13 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simu);
  14
  15 process::process(int argc, char* argv[])
  16 {
  17     if (argc < 2 || !(std::istringstream(argv[1]) >> load))
  18         throw std::invalid_argument("bad or missing initial load");
  19
  20     neigh.assign(argv + 2, argv + argc);
  21
  22     std::for_each(neigh.begin(), neigh.end(),
  23                   std::tr1::bind(&process::insert_neighbor_in_map,
  24                                  this, std::tr1::placeholders::_1));
  25
  26     expected_load = load;
  27
  28     ctrl_close_pending = data_close_pending = neigh.size();
  29     if (neigh.size() == 1) {
  30         comm.next_close_on_ctrl_is_last();
  31         comm.next_close_on_data_is_last();
  32     }
  33     if (neigh.size() > 0)
  34         comm.listen();
  35
  36     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
  37     if (!LOG_ISENABLED(logp))
  38         return;
  39     std::ostringstream oss;
  40     oss << neigh.size() << " neighbor";
  41     if (!neigh.empty()) {
  42         oss << ESSE(neigh.size()) << ": ";
  43         std::transform(neigh.begin(), neigh.end() - 1,
  44                        std::ostream_iterator<const char*>(oss, ", "),
  45                        std::tr1::mem_fn(&neighbor::get_name));
  46         oss << neigh.back().get_name();
  47     }
  48     LOG1(logp, "Got %s.", oss.str().c_str());
  49     print_loads(logp);
  50 }
  51
  52 int process::run()
  53 {
  54     bool one_more = true;
  55
  56     INFO1("Initial load: %g", load);
  57     VERB0("Starting...");
  58     iter = 0;
  59     while (one_more) {
  60         ++iter;
  61
  62         if (opt::log_rate && iter % opt::log_rate == 0) {
  63             if (opt::bookkeeping)
  64                 INFO3("(%u) current load: %g ; expected: %g",
  65                       iter, load, expected_load);
  66             else
  67                 INFO2("(%u) current load: %g",
  68                       iter, load);
  69         }
  70
  71         compute();
  72
  73         bool close_received = !receive(false);
  74
  75         if (opt::bookkeeping)
  76             expected_load -= load_balance(expected_load);
  77         else
  78             load -= load_balance(load);
  79
  80         send();
  81         comm.flush(false);
  82
  83         if (opt::exit_on_close && close_received)
  84             one_more = false;
  85         if (opt::maxiter && iter >= opt::maxiter)
  86             one_more = false;
  87     }
  88     VERB0("Going to finalize...");
  89     finalize();
  90
  91     /* Open Questions :
  92      * - definition of load on heterogeneous hosts ?
  93      * - how to detect convergence ?
  94      * - how to manage link failures ?
  95      */
  96
  97     VERB0("Done.");
  98     if (opt::bookkeeping)
  99         INFO4("Final load after %d iteration%s: %g ; expected: %g",
 100               iter, ESSE(iter), load, expected_load);
 101     else
 102         INFO3("Final load after %d iteration%s: %g", iter, ESSE(iter), load);
 103     return 0;
 104 }
 105
 106 void process::compute()
 107 {
 108     // fixme: shall we do something special when duration is 0 ?
 109     double duration = opt::comp_cost(load);
 110     m_task_t task = MSG_task_create("computation", duration, 0.0, NULL);
 111     DEBUG2("compute %g flop%s.", duration, ESSE(duration));
 112     MSG_task_execute(task);
 113     MSG_task_destroy(task);
 114 }
 115
 116 double process::load_balance(double /*my_load*/)
 117 {
 118     return 0.0;
 119 }
 120
 121 void process::send1_no_bookkeeping(neighbor& nb)
 122 {
 123     comm.send(nb.get_ctrl_mbox(), new message(message::INFO, load));
 124     double load_to_send = nb.get_to_send();
 125     if (load_to_send > 0.0) {
 126         comm.send(nb.get_data_mbox(), new message(message::LOAD, load_to_send));
 127         nb.set_to_send(0.0);
 128     }
 129 }
 130
 131 void process::send1_bookkeeping(neighbor& nb)
 132 {
 133     comm.send(nb.get_ctrl_mbox(), new message(message::INFO, expected_load));
 134     double load_to_send;
 135     double new_debt;
 136     double debt_to_send = nb.get_to_send();
 137     if (debt_to_send > 0.0) {
 138         comm.send(nb.get_ctrl_mbox(),
 139                   new message(message::CREDIT, debt_to_send));
 140         nb.set_to_send(0.0);
 141         new_debt = nb.get_debt() + debt_to_send;
 142     } else {
 143         new_debt = nb.get_debt();
 144     }
 145     if (load <= new_debt) {
 146         load_to_send = load;
 147         nb.set_debt(new_debt - load_to_send);
 148         load = 0.0;
 149     } else {
 150         load_to_send = new_debt;
 151         nb.set_debt(0.0);
 152         load -= load_to_send;
 153     }
 154     if (load_to_send > 0.0)
 155         comm.send(nb.get_data_mbox(), new message(message::LOAD, load_to_send));
 156 }
 157
 158 void process::send()
 159 {
 160     // fixme: shall we send data at all iterations?
 161     if (opt::bookkeeping) {
 162         std::for_each(neigh.begin(), neigh.end(),
 163                       std::tr1::bind(&process::send1_bookkeeping,
 164                                      this, std::tr1::placeholders::_1));
 165     } else {
 166         std::for_each(neigh.begin(), neigh.end(),
 167                       std::tr1::bind(&process::send1_no_bookkeeping,
 168                                      this, std::tr1::placeholders::_1));
 169     }
 170 }
 171
 172 // Returns false if a CLOSE message was received.
 173 bool process::receive(bool wait_for_close)
 174 {
 175     bool result = true;
 176     message* msg;
 177     m_host_t from;
 178     while ((ctrl_close_pending ||
 179             data_close_pending) && comm.recv(msg, from, wait_for_close)) {
 180         DEBUG2("received %s from %s",
 181                msg->to_string().c_str(), MSG_host_get_name(from));
 182         switch (msg->get_type()) {
 183         case message::INFO: {
 184             neighbor* n = rev_neigh[from];
 185             n->set_load(msg->get_amount());
 186             break;
 187         }
 188         case message::CREDIT:
 189             expected_load += msg->get_amount();
 190             break;
 191         case message::LOAD:
 192             load += msg->get_amount();
 193             break;
 194         case message::CTRL_CLOSE:
 195             if (--ctrl_close_pending == 1)
 196                 comm.next_close_on_ctrl_is_last();
 197             DEBUG1("ctrl_close_pending = %d", ctrl_close_pending);
 198             result = false;
 199             break;
 200         case message::DATA_CLOSE:
 201             if (--data_close_pending == 1)
 202                 comm.next_close_on_data_is_last();
 203             DEBUG1("data_close_pending = %d", data_close_pending);
 204             result = false;
 205             break;
 206         }
 207         delete msg;
 208     }
 209     return result;
 210 }
 211
 212 void process::finalize1(neighbor& nb)
 213 {
 214     comm.send(nb.get_ctrl_mbox(), new message(message::CTRL_CLOSE, 0.0));
 215     comm.send(nb.get_data_mbox(), new message(message::DATA_CLOSE, 0.0));
 216 }
 217
 218 void process::finalize()
 219 {
 220     DEBUG2("send CLOSE to %d neighbor%s.",
 221            (int )neigh.size(), ESSE(neigh.size()));
 222     std::for_each(neigh.begin(), neigh.end(),
 223                   std::tr1::bind(&process::finalize1,
 224                                  this, std::tr1::placeholders::_1));
 225
 226     DEBUG2("wait for CLOSE from %d neighbor%s.",
 227            (int )neigh.size(), ESSE(neigh.size()));
 228     receive(true);
 229
 230     comm.flush(true);
 231 }
 232
 233 void process::print_loads(e_xbt_log_priority_t logp)
 234 {
 235     if (!LOG_ISENABLED(logp))
 236         return;
 237
 238     std::ostringstream oss;
 239     if (neigh.empty()) {
 240         oss << "no neighbor!";
 241     } else {
 242         std::transform(neigh.begin(), neigh.end() - 1,
 243                        std::ostream_iterator<double>(oss, ", "),
 244                        std::tr1::mem_fn(&neighbor::get_load));
 245         oss << neigh.back().get_load();
 246     }
 247     LOG1(logp, "Neighbor loads: %s", oss.str().c_str());
 248 }
 249
 250 void process::insert_neighbor_in_map(neighbor& nb)
 251 {
 252     neighbor* nbp = &nb;
 253     m_host_t host = MSG_get_host_by_name(nb.get_name());
 254     rev_neigh.insert(std::make_pair(host, nbp));
 255 }
 256
 257 // Local variables:
 258 // mode: c++
 259 // End: