process.cpp

   1 #include <algorithm>
   2 #include <tr1/functional>
   3 #include <iterator>
   4 #include <numeric>
   5 #include <stdexcept>
   6 #include <sstream>
   7 #include <xbt/log.h>
   8 #include <xbt/time.h>
   9
  10 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(proc);
  11
  12 #include "misc.h"
  13 #include "options.h"
  14
  15 #include "process.h"
  16
  17 double process::total_load_init = 0.0;
  18 double process::total_load_exit = 0.0;
  19
  20 process::process(int argc, char* argv[])
  21 {
  22     if (argc < 2 || !(std::istringstream(argv[1]) >> load))
  23         throw std::invalid_argument("bad or missing initial load parameter");
  24
  25     neigh.assign(argv + 2, argv + argc);
  26
  27     pneigh.reserve(neigh.size());
  28     for (unsigned i = 0 ; i < neigh.size() ; i++) {
  29         neighbor* ptr = &neigh[i];
  30         m_host_t host = MSG_get_host_by_name(ptr->get_name());
  31         pneigh.push_back(ptr);
  32         rev_neigh.insert(std::make_pair(host, ptr));
  33     }
  34
  35     expected_load = load;
  36     total_load_init += load;
  37
  38     ctrl_close_pending = data_close_pending = neigh.size();
  39     if (neigh.size() == 1) {
  40         comm.next_close_on_ctrl_is_last();
  41         comm.next_close_on_data_is_last();
  42     }
  43     if (neigh.size() > 0)
  44         comm.listen();
  45
  46     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
  47     if (!LOG_ISENABLED(logp))
  48         return;
  49     std::ostringstream oss;
  50     oss << neigh.size() << " neighbor";
  51     if (!neigh.empty()) {
  52         oss << ESSE(neigh.size()) << ": ";
  53         std::transform(neigh.begin(), neigh.end() - 1,
  54                        std::ostream_iterator<const char*>(oss, ", "),
  55                        std::tr1::mem_fn(&neighbor::get_name));
  56         oss << neigh.back().get_name();
  57     }
  58     LOG1(logp, "Got %s.", oss.str().c_str());
  59     print_loads(true, logp);
  60 }
  61
  62 process::~process()
  63 {
  64     total_load_exit += load;
  65 }
  66
  67 int process::run()
  68 {
  69     INFO1("Initial load: %g", load);
  70     VERB0("Starting...");
  71     // first send() to inform neighbors about our load (force it)
  72     prev_load_broadcast = -1;
  73     iter = 0;
  74     bool one_more = true;
  75     do {
  76         ++iter;
  77
  78         if (opt::log_rate && iter % opt::log_rate == 0) {
  79             if (opt::bookkeeping)
  80                 INFO3("(%u) current load: %g ; expected: %g",
  81                       iter, load, expected_load);
  82             else
  83                 INFO2("(%u) current load: %g",
  84                       iter, load);
  85         }
  86         print_loads(true, xbt_log_priority_debug);
  87
  88         if (opt::bookkeeping)
  89             expected_load -= load_balance(expected_load);
  90         else
  91             load -= load_balance(load);
  92
  93         send();
  94         compute();
  95
  96 // NDS for Need To Send
  97 #define NDS ((opt::bookkeeping ? expected_load : load) != prev_load_broadcast)
  98         bool can_recv;
  99         do {
 100             // General idea: do not iterate if there is nothing to
 101             // compute, nor to send.
 102
 103             // fixme: review this chunk, and remove this NDS macro!
 104
 105             bool recv_wait = (load == 0 && !NDS);
 106             bool close_received = !receive(recv_wait? WAIT: NO_WAIT);
 107
 108             if (opt::exit_on_close && close_received)
 109                 one_more = false;
 110             else if (opt::maxiter && iter >= opt::maxiter)
 111                 one_more = false;
 112
 113             can_recv = (ctrl_close_pending || data_close_pending);
 114
 115         } while (one_more && can_recv && load == 0 && !NDS);
 116 #undef NDS
 117
 118     } while (one_more);
 119     VERB0("Going to finalize...");
 120     finalize();
 121
 122     /* Open Questions :
 123      * - definition of load on heterogeneous hosts ?
 124      * - how to detect convergence ?
 125      * - how to manage link failures ?
 126      */
 127
 128     VERB0("Done.");
 129     INFO3("Final load after %d iteration%s: %g", iter, ESSE(iter), load);
 130     if (opt::bookkeeping)
 131         INFO1("Expected load: %g", expected_load);
 132     return 0;
 133 }
 134
 135 double process::sum_of_to_send() const
 136 {
 137     using namespace std::tr1;
 138     using namespace std::tr1::placeholders;
 139
 140     return std::accumulate(neigh.begin(), neigh.end(), 0.0,
 141                            bind(std::plus<double>(),
 142                                 _1, bind(&neighbor::get_to_send, _2)));
 143 }
 144
 145 double process::load_balance(double /*my_load*/)
 146 {
 147     if (iter == 1)
 148         WARN0("process::load_balance is a no-op!");
 149     return 0.0;
 150 }
 151
 152 void process::compute()
 153 {
 154     if (load > 0.0) {
 155         double duration = opt::comp_cost(load);
 156         m_task_t task = MSG_task_create("computation", duration, 0.0, NULL);
 157         DEBUG2("compute %g flop%s.", duration, ESSE(duration));
 158         MSG_task_execute(task);
 159         MSG_task_destroy(task);
 160     } else {
 161         DEBUG0("nothing to compute !");
 162     }
 163 }
 164
 165 void process::send1_no_bookkeeping(neighbor& nb)
 166 {
 167     if (load != prev_load_broadcast)
 168         comm.send(nb.get_ctrl_mbox(), new message(message::INFO, load));
 169     double load_to_send = nb.get_to_send();
 170     if (load_to_send > 0.0) {
 171         comm.send(nb.get_data_mbox(), new message(message::LOAD, load_to_send));
 172         nb.set_to_send(0.0);
 173     }
 174 }
 175
 176 void process::send1_bookkeeping(neighbor& nb)
 177 {
 178     if (expected_load != prev_load_broadcast)
 179         comm.send(nb.get_ctrl_mbox(),
 180                   new message(message::INFO, expected_load));
 181     double load_to_send;
 182     double new_debt;
 183     double debt_to_send = nb.get_to_send();
 184     if (debt_to_send > 0.0) {
 185         comm.send(nb.get_ctrl_mbox(),
 186                   new message(message::CREDIT, debt_to_send));
 187         nb.set_to_send(0.0);
 188         new_debt = nb.get_debt() + debt_to_send;
 189     } else {
 190         new_debt = nb.get_debt();
 191     }
 192     if (load <= new_debt) {
 193         load_to_send = load;
 194         nb.set_debt(new_debt - load_to_send);
 195         load = 0.0;
 196     } else {
 197         load_to_send = new_debt;
 198         nb.set_debt(0.0);
 199         load -= load_to_send;
 200     }
 201     if (load_to_send > 0.0)
 202         comm.send(nb.get_data_mbox(), new message(message::LOAD, load_to_send));
 203 }
 204
 205 void process::send()
 206 {
 207     using namespace std::tr1;
 208     using namespace std::tr1::placeholders;
 209
 210     if (opt::bookkeeping) {
 211         std::for_each(neigh.begin(), neigh.end(),
 212                       bind(&process::send1_bookkeeping, this, _1));
 213         prev_load_broadcast = expected_load;
 214     } else {
 215         std::for_each(neigh.begin(), neigh.end(),
 216                       bind(&process::send1_no_bookkeeping, this, _1));
 217         prev_load_broadcast = load;
 218     }
 219 }
 220
 221 bool process::receive(recv_wait_mode wait)
 222 {
 223     // DEBUG1("go for receive(%s)",
 224     //        "NO_WAIT\0WAIT\0\0\0\0WAIT_FOR_CLOSE" + 8 * wait);
 225     bool result = true;
 226     message* msg;
 227     m_host_t from;
 228     bool do_recv = ctrl_close_pending || data_close_pending;
 229     while (do_recv && comm.recv(msg, from, wait)) {
 230         switch (msg->get_type()) {
 231         case message::INFO: {
 232             neighbor* n = rev_neigh[from];
 233             n->set_load(msg->get_amount());
 234             break;
 235         }
 236         case message::CREDIT:
 237             expected_load += msg->get_amount();
 238             break;
 239         case message::LOAD:
 240             load += msg->get_amount();
 241             break;
 242         case message::CTRL_CLOSE:
 243             if (--ctrl_close_pending == 1)
 244                 comm.next_close_on_ctrl_is_last();
 245             DEBUG1("ctrl_close_pending = %d", ctrl_close_pending);
 246             result = false;
 247             break;
 248         case message::DATA_CLOSE:
 249             if (--data_close_pending == 1)
 250                 comm.next_close_on_data_is_last();
 251             DEBUG1("data_close_pending = %d", data_close_pending);
 252             result = false;
 253             break;
 254         }
 255         delete msg;
 256         do_recv = (wait == WAIT_FOR_CLOSE) &&
 257             (ctrl_close_pending || data_close_pending);
 258     }
 259     return result;
 260 }
 261
 262 void process::finalize1(neighbor& nb)
 263 {
 264     comm.send(nb.get_ctrl_mbox(), new message(message::CTRL_CLOSE, 0.0));
 265     comm.send(nb.get_data_mbox(), new message(message::DATA_CLOSE, 0.0));
 266 }
 267
 268 void process::finalize()
 269 {
 270     using namespace std::tr1;
 271     using namespace std::tr1::placeholders;
 272
 273     DEBUG2("send CLOSE to %d neighbor%s.",
 274            (int )neigh.size(), ESSE(neigh.size()));
 275     std::for_each(neigh.begin(), neigh.end(),
 276                   bind(&process::finalize1, this, _1));
 277
 278     DEBUG2("wait for CLOSE from %d neighbor%s.",
 279            (int )neigh.size(), ESSE(neigh.size()));
 280     receive(WAIT_FOR_CLOSE);
 281
 282     comm.flush(true);
 283 }
 284
 285 #define print_loads_generic(vec, verbose, logp, cat)                    \
 286     if (_XBT_LOG_ISENABLEDV((*cat), logp)) {                            \
 287         using namespace std::tr1;                                       \
 288         using namespace std::tr1::placeholders;                         \
 289         XCLOG0(cat, logp, "Neighbor loads:");                           \
 290         std::for_each(vec.begin(), vec.end(),                           \
 291                       bind(&neighbor::print, _1, verbose, logp, cat));  \
 292     } else ((void)0)
 293
 294 void process::print_loads(bool verbose,
 295                           e_xbt_log_priority_t logp,
 296                           xbt_log_category_t cat) const
 297 {
 298     print_loads_generic(neigh, verbose, logp, cat);
 299 }
 300
 301 void process::print_loads_p(bool verbose,
 302                             e_xbt_log_priority_t logp,
 303                             xbt_log_category_t cat) const
 304 {
 305     print_loads_generic(pneigh, verbose, logp, cat);
 306 }
 307
 308 #undef print_loads_generic
 309
 310 // Local variables:
 311 // mode: c++
 312 // End: