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     prev_load_broadcast = -1;   // force sending of load on first send()
  36     expected_load = load;
  37     total_load_init += load;
  38
  39     ctrl_close_pending = data_close_pending = neigh.size();
  40     if (neigh.size() == 1) {
  41         comm.next_close_on_ctrl_is_last();
  42         comm.next_close_on_data_is_last();
  43     }
  44     close_received = false;
  45     may_receive =  (neigh.size() > 0); // the same as (ctrl_close_pending ||
  46                                        //              data_close_pending)
  47     if (may_receive)
  48         comm.listen();
  49
  50     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
  51     if (!LOG_ISENABLED(logp))
  52         return;
  53     std::ostringstream oss;
  54     oss << neigh.size() << " neighbor";
  55     if (!neigh.empty()) {
  56         oss << ESSE(neigh.size()) << ": ";
  57         std::transform(neigh.begin(), neigh.end() - 1,
  58                        std::ostream_iterator<const char*>(oss, ", "),
  59                        std::tr1::mem_fn(&neighbor::get_name));
  60         oss << neigh.back().get_name();
  61     }
  62     LOG1(logp, "Got %s.", oss.str().c_str());
  63     print_loads(true, logp);
  64 }
  65
  66 process::~process()
  67 {
  68     total_load_exit += load;
  69 }
  70
  71 int process::run()
  72 {
  73     INFO1("Initial load: %g", load);
  74     VERB0("Starting...");
  75     iter = 0;
  76     bool one_more = true;
  77     do {
  78         ++iter;
  79
  80         if (opt::log_rate && iter % opt::log_rate == 0) {
  81             if (opt::bookkeeping)
  82                 INFO3("(%u) current load: %g ; expected: %g",
  83                       iter, load, expected_load);
  84             else
  85                 INFO2("(%u) current load: %g",
  86                       iter, load);
  87         }
  88         print_loads(true, xbt_log_priority_debug);
  89
  90         if (opt::bookkeeping)
  91             expected_load -= load_balance(expected_load);
  92         else
  93             load -= load_balance(load);
  94
  95         send();
  96         compute();
  97
  98 // NDS for Need To Send
  99 #define NDS ((opt::bookkeeping ? expected_load : load) != prev_load_broadcast)
 100         do {
 101             // General idea: block on receiving unless there is
 102             // something to compute, or to send, or we must exit.
 103
 104             // fixme: review this chunk, and remove this NDS macro!
 105
 106             // FIXME: HAD A DEADLOCK HERE...
 107
 108             bool recv_wait = (load == 0 && !NDS);
 109             DEBUG1("CALL RECEIVE(%s)", recv_wait? "WAIT": "NO_WAIT");
 110             receive(recv_wait? WAIT: NO_WAIT);
 111
 112             if (opt::exit_on_close && close_received)
 113                 one_more = false;
 114             else if (opt::maxiter && iter >= opt::maxiter)
 115                 one_more = false;
 116
 117         } while (one_more && may_receive && load == 0 && !NDS);
 118         DEBUG0("RECEIVE LOOP ENDED");
 119 #undef NDS
 120
 121     } while (one_more);
 122     VERB0("Going to finalize...");
 123     finalize();
 124
 125     /* Open Questions :
 126      * - definition of load on heterogeneous hosts ?
 127      * - how to detect convergence ?
 128      * - how to manage link failures ?
 129      */
 130
 131     VERB0("Done.");
 132     INFO3("Final load after %d iteration%s: %g", iter, ESSE(iter), load);
 133     if (opt::bookkeeping)
 134         INFO1("Expected load: %g", expected_load);
 135     return 0;
 136 }
 137
 138 double process::sum_of_to_send() const
 139 {
 140     using namespace std::tr1;
 141     using namespace std::tr1::placeholders;
 142
 143     return std::accumulate(neigh.begin(), neigh.end(), 0.0,
 144                            bind(std::plus<double>(),
 145                                 _1, bind(&neighbor::get_to_send, _2)));
 146 }
 147
 148 double process::load_balance(double /*my_load*/)
 149 {
 150     if (iter == 1)
 151         WARN0("process::load_balance is a no-op!");
 152     return 0.0;
 153 }
 154
 155 void process::compute()
 156 {
 157     if (load > 0.0) {
 158         double duration = opt::comp_cost(load);
 159         m_task_t task = MSG_task_create("computation", duration, 0.0, NULL);
 160         DEBUG2("compute %g flop%s.", duration, ESSE(duration));
 161         MSG_task_execute(task);
 162         MSG_task_destroy(task);
 163     } else {
 164         DEBUG0("nothing to compute !");
 165     }
 166 }
 167
 168 void process::send1_no_bookkeeping(neighbor& nb)
 169 {
 170     if (load != prev_load_broadcast)
 171         comm.send(nb.get_ctrl_mbox(), new message(message::INFO, load));
 172     double load_to_send = nb.get_to_send();
 173     if (load_to_send > 0.0) {
 174         comm.send(nb.get_data_mbox(), new message(message::LOAD, load_to_send));
 175         nb.set_to_send(0.0);
 176     }
 177 }
 178
 179 void process::send1_bookkeeping(neighbor& nb)
 180 {
 181     if (expected_load != prev_load_broadcast)
 182         comm.send(nb.get_ctrl_mbox(),
 183                   new message(message::INFO, expected_load));
 184     double load_to_send;
 185     double new_debt;
 186     double debt_to_send = nb.get_to_send();
 187     if (debt_to_send > 0.0) {
 188         comm.send(nb.get_ctrl_mbox(),
 189                   new message(message::CREDIT, debt_to_send));
 190         nb.set_to_send(0.0);
 191         new_debt = nb.get_debt() + debt_to_send;
 192     } else {
 193         new_debt = nb.get_debt();
 194     }
 195     if (load <= new_debt) {
 196         load_to_send = load;
 197         nb.set_debt(new_debt - load_to_send);
 198         load = 0.0;
 199     } else {
 200         load_to_send = new_debt;
 201         nb.set_debt(0.0);
 202         load -= load_to_send;
 203     }
 204     if (load_to_send > 0.0)
 205         comm.send(nb.get_data_mbox(), new message(message::LOAD, load_to_send));
 206 }
 207
 208 void process::send()
 209 {
 210     using namespace std::tr1;
 211     using namespace std::tr1::placeholders;
 212
 213     if (opt::bookkeeping) {
 214         std::for_each(neigh.begin(), neigh.end(),
 215                       bind(&process::send1_bookkeeping, this, _1));
 216         prev_load_broadcast = expected_load;
 217     } else {
 218         std::for_each(neigh.begin(), neigh.end(),
 219                       bind(&process::send1_no_bookkeeping, this, _1));
 220         prev_load_broadcast = load;
 221     }
 222 }
 223
 224 void process::receive(recv_wait_mode wait)
 225 {
 226     // DEBUG1("go for receive(%s)",
 227     //        "NO_WAIT\0WAIT\0\0\0\0WAIT_FOR_CLOSE" + 8 * wait);
 228     message* msg;
 229     m_host_t from;
 230     bool do_loop = may_receive;
 231     while (do_loop && comm.recv(msg, from, wait)) {
 232         switch (msg->get_type()) {
 233         case message::INFO: {
 234             neighbor* n = rev_neigh[from];
 235             n->set_load(msg->get_amount());
 236             break;
 237         }
 238         case message::CREDIT:
 239             expected_load += msg->get_amount();
 240             break;
 241         case message::LOAD:
 242             load += msg->get_amount();
 243             break;
 244         case message::CTRL_CLOSE:
 245             if (--ctrl_close_pending == 1)
 246                 comm.next_close_on_ctrl_is_last();
 247             // DEBUG1("ctrl_close_pending = %d", ctrl_close_pending);
 248             close_received = true;
 249             break;
 250         case message::DATA_CLOSE:
 251             if (--data_close_pending == 1)
 252                 comm.next_close_on_data_is_last();
 253             // DEBUG1("data_close_pending = %d", data_close_pending);
 254             close_received = true;
 255             break;
 256         }
 257         delete msg;
 258         may_receive = (ctrl_close_pending || data_close_pending);
 259         do_loop = (wait == WAIT_FOR_CLOSE) && may_receive;
 260     }
 261 }
 262
 263 void process::finalize1(neighbor& nb)
 264 {
 265     comm.send(nb.get_ctrl_mbox(), new message(message::CTRL_CLOSE, 0.0));
 266     comm.send(nb.get_data_mbox(), new message(message::DATA_CLOSE, 0.0));
 267 }
 268
 269 void process::finalize()
 270 {
 271     using namespace std::tr1;
 272     using namespace std::tr1::placeholders;
 273
 274     DEBUG2("send CLOSE to %d neighbor%s.",
 275            (int )neigh.size(), ESSE(neigh.size()));
 276     std::for_each(neigh.begin(), neigh.end(),
 277                   bind(&process::finalize1, this, _1));
 278
 279     DEBUG2("wait for CLOSE from %d neighbor%s.",
 280            (int )neigh.size(), ESSE(neigh.size()));
 281     receive(WAIT_FOR_CLOSE);
 282
 283     comm.flush(true);
 284 }
 285
 286 #define print_loads_generic(vec, verbose, logp, cat)                    \
 287     if (_XBT_LOG_ISENABLEDV((*cat), logp)) {                            \
 288         using namespace std::tr1;                                       \
 289         using namespace std::tr1::placeholders;                         \
 290         XCLOG0(cat, logp, "Neighbor loads:");                           \
 291         std::for_each(vec.begin(), vec.end(),                           \
 292                       bind(&neighbor::print, _1, verbose, logp, cat));  \
 293     } else ((void)0)
 294
 295 void process::print_loads(bool verbose,
 296                           e_xbt_log_priority_t logp,
 297                           xbt_log_category_t cat) const
 298 {
 299     print_loads_generic(neigh, verbose, logp, cat);
 300 }
 301
 302 void process::print_loads_p(bool verbose,
 303                             e_xbt_log_priority_t logp,
 304                             xbt_log_category_t cat) const
 305 {
 306     print_loads_generic(pneigh, verbose, logp, cat);
 307 }
 308
 309 #undef print_loads_generic
 310
 311 // Local variables:
 312 // mode: c++
 313 // End: