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
   9 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(proc);
  10
  11 #include "misc.h"
  12 #include "options.h"
  13 #include "tracing.h"
  14
  15 #include "process.h"
  16
  17 double process::total_load_init = 0.0;
  18 double process::total_load_running = 0.0;
  19 double process::total_load_exit = 0.0;
  20
  21 namespace {
  22
  23     void sleep_until_date(double& date, double duration = 0.0)
  24     {
  25         double sleep_duration = date - MSG_get_clock();
  26         if (sleep_duration > 0.0)
  27             MSG_process_sleep(sleep_duration);
  28         date = MSG_get_clock() + duration;
  29     }
  30
  31 }
  32
  33 process::process(int argc, char* argv[])
  34 {
  35     if (argc < 2 || !(std::istringstream(argv[1]) >> real_load))
  36         throw std::invalid_argument("bad or missing initial load parameter");
  37
  38     neigh.assign(argv + 2, argv + argc);
  39
  40     pneigh.reserve(neigh.size());
  41     for (unsigned i = 0 ; i < neigh.size() ; i++) {
  42         neighbor* ptr = &neigh[i];
  43         m_host_t host = MSG_get_host_by_name(ptr->get_name());
  44         pneigh.push_back(ptr);
  45         rev_neigh.insert(std::make_pair(host, ptr));
  46     }
  47
  48     comp = 0.0;
  49
  50     prev_load_broadcast = -1;   // force sending of load on first send_all()
  51     expected_load = real_load;
  52     total_load_running += real_load;
  53     total_load_init += real_load;
  54
  55     ctrl_close_pending = data_close_pending = neigh.size();
  56     close_received = false;
  57     finalizing = false;
  58
  59     comp_iter = lb_iter = 0;
  60
  61     lb_thread = new_msg_thread("loba",
  62                                std::tr1::bind(&process::load_balance_loop,
  63                                               this));
  64
  65     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
  66     if (!LOG_ISENABLED(logp))
  67         return;
  68     std::ostringstream oss;
  69     oss << neigh.size() << " neighbor";
  70     if (!neigh.empty()) {
  71         oss << ESSE(neigh.size()) << ": ";
  72         std::transform(neigh.begin(), neigh.end() - 1,
  73                        std::ostream_iterator<const char*>(oss, ", "),
  74                        std::tr1::mem_fn(&neighbor::get_name));
  75         oss << neigh.back().get_name();
  76     }
  77     XBT_LOG(logp, "Got %s.", oss.str().c_str());
  78     print_loads(false, logp);
  79 }
  80
  81 process::~process()
  82 {
  83     delete lb_thread;
  84     total_load_exit += real_load;
  85     if (opt::log_rate < 0)
  86         return;
  87     if (opt::bookkeeping) {
  88         XBT_INFO("Final load after %d:%d iterations: %g ; expected: %g",
  89                  lb_iter, comp_iter, real_load, expected_load);
  90     } else {
  91         XBT_INFO("Final load after %d:%d iterations: %g",
  92                  lb_iter, comp_iter, real_load);
  93     }
  94     XBT_VERB("Total computation for this process: %g", comp);
  95 }
  96
  97 int process::run()
  98 {
  99     if (opt::log_rate >= 0)
 100         XBT_INFO("Initial load: %g", real_load);
 101     XBT_VERB("Starting...");
 102     mutex.acquire();
 103     lb_thread->start();
 104     while (lb_iter <= opt::comp_iter_delay)
 105         cond.wait(mutex);
 106     mutex.release();
 107     double sleep_duration = opt::comp_time_delay - MSG_get_clock();
 108     if (sleep_duration > 0.0)
 109         MSG_process_sleep(sleep_duration);
 110     compute_loop();
 111     lb_thread->wait();
 112     XBT_VERB("Done.");
 113     return 0;
 114 }
 115
 116 void process::load_balance_loop()
 117 {
 118     using std::tr1::bind;
 119     using std::tr1::placeholders::_1;
 120
 121     double next_iter_after_date = MSG_get_clock() + opt::min_lb_iter_duration;
 122     while (still_running()) {
 123         if (lb_iter == opt::comp_iter_delay) {
 124             mutex.acquire();
 125             ++lb_iter;
 126             cond.signal();
 127             mutex.release();
 128         } else {
 129             ++lb_iter;
 130         }
 131
 132         if (opt::log_rate && lb_iter % opt::log_rate == 0) {
 133             if (opt::bookkeeping)
 134                 XBT_INFO("(%u:%u) current load: %g ; expected: %g",
 135                          lb_iter, comp_iter, real_load, expected_load);
 136             else
 137                 XBT_INFO("(%u:%u) current load: %g",
 138                          lb_iter, comp_iter, real_load);
 139         }
 140
 141         if (get_load() > 0.0)
 142             load_balance();
 143
 144         print_loads(true, xbt_log_priority_debug);
 145
 146         // send
 147         std::for_each(neigh.begin(), neigh.end(),
 148                       bind(&process::ctrl_send, this, _1));
 149         prev_load_broadcast = get_load();
 150
 151         sleep_until_date(next_iter_after_date, opt::min_lb_iter_duration);
 152         ctrl_receive(0.0);
 153
 154         comm.ctrl_flush(false);
 155     }
 156
 157     XBT_VERB("Going to finalize for %s...", __func__);
 158     XBT_DEBUG("send CTRL_CLOSE to %zu neighbor%s",
 159               neigh.size(), ESSE(neigh.size()));
 160     std::for_each(neigh.begin(), neigh.end(),
 161                   bind(&process::ctrl_close, this, _1));
 162     while (ctrl_close_pending) {
 163         comm.ctrl_flush(false);
 164         XBT_DEBUG("waiting for %d CTRL CLOSE", ctrl_close_pending);
 165         ctrl_receive(-1.0);
 166     }
 167     comm.ctrl_flush(true);
 168 }
 169
 170 void process::compute_loop()
 171 {
 172     using std::tr1::bind;
 173     using std::tr1::placeholders::_1;
 174
 175     double next_iter_after_date = MSG_get_clock() + opt::min_comp_iter_duration;
 176     while (still_running()) {
 177         // receive
 178         if (real_load > 0.0)
 179             data_receive(0.0);
 180         else
 181             data_receive(opt::min_comp_iter_duration);
 182
 183         comm.data_flush(false);
 184
 185         if (real_load == 0.0)
 186             continue;
 187
 188         // send
 189         std::for_each(neigh.begin(), neigh.end(),
 190                       bind(&process::data_send, this, _1));
 191
 192         // compute
 193         ++comp_iter;
 194         double flops = opt::comp_cost(real_load);
 195         m_task_t task = MSG_task_create("computation", flops, 0.0, NULL);
 196         TRACE_msg_set_task_category(task, TRACE_CAT_COMP);
 197         XBT_DEBUG("compute %g flop%s", flops, ESSE(flops));
 198         MSG_task_execute(task);
 199         comp += flops;
 200         MSG_task_destroy(task);
 201
 202         sleep_until_date(next_iter_after_date, opt::min_comp_iter_duration);
 203     }
 204
 205     XBT_VERB("Going to finalize for %s...", __func__);
 206     // last send, for not losing load scheduled to be sent
 207     std::for_each(neigh.begin(), neigh.end(),
 208                   bind(&process::data_send, this, _1));
 209     finalizing = true;
 210     total_load_running -= real_load;
 211     XBT_DEBUG("send DATA_CLOSE to %zu neighbor%s",
 212               neigh.size(), ESSE(neigh.size()));
 213     std::for_each(neigh.begin(), neigh.end(),
 214                   bind(&process::data_close, this, _1));
 215     while (data_close_pending) {
 216         comm.data_flush(false);
 217         XBT_DEBUG("waiting for %d DATA CLOSE", data_close_pending);
 218         data_receive(-1.0);
 219     }
 220     comm.data_flush(true);
 221 }
 222
 223 bool process::still_running()
 224 {
 225     static bool last_status = true;
 226
 227     if (!last_status) {
 228         /* nop */
 229
 230     } else if (opt::time_limit && MSG_get_clock() >= opt::time_limit) {
 231         XBT_VERB("Reached time limit: %g/%g", MSG_get_clock(), opt::time_limit);
 232         last_status = false;
 233
 234     } else if (opt::lb_maxiter && lb_iter >= opt::lb_maxiter) {
 235         XBT_VERB("Reached lb_maxiter: %d/%d", lb_iter, opt::lb_maxiter);
 236         last_status = false;
 237
 238     } else if (opt::comp_maxiter && comp_iter >= opt::comp_maxiter) {
 239         XBT_VERB("Reached comp_maxiter: %d/%d", comp_iter, opt::comp_maxiter);
 240         last_status = false;
 241
 242     } else if (opt::exit_on_close && close_received) {
 243         XBT_VERB("Close received");
 244         last_status = false;
 245
 246     } else if (real_load == 0.0 && !data_close_pending) {
 247         XBT_VERB("I'm a poor lonesome process, and I have no load...");
 248         last_status = false;
 249
 250     } else if (100.0 * total_load_running / total_load_init <=
 251                opt::load_ratio_threshold) {
 252         // fixme: this check should be implemented with a distributed
 253         // algorithm, and not a shared global variable!
 254         XBT_VERB("No more load to balance in system.");
 255         last_status = false;
 256     }
 257
 258     return last_status;
 259 }
 260
 261 void process::load_balance()
 262 {
 263     if (lb_iter == 1)           // warn only once
 264         XBT_WARN("process::load_balance() is a no-op!");
 265 }
 266
 267 void process::send(neighbor& nb, double amount)
 268 {
 269     set_load(get_load() - amount);
 270     nb.set_to_send(nb.get_to_send() + amount);
 271     nb.set_load(nb.get_load() + amount);
 272 }
 273
 274 #define print_loads_generic(vec, verbose, logp, cat)                    \
 275     if (_XBT_LOG_ISENABLEDV((*cat), logp)) {                            \
 276         using std::tr1::bind;                                           \
 277         using std::tr1::placeholders::_1;                               \
 278         XBT_XCLOG(cat, logp, "Neighbor loads:");                        \
 279         std::for_each(vec.begin(), vec.end(),                           \
 280                       bind(&neighbor::print, _1, verbose, logp, cat));  \
 281     } else ((void)0)
 282
 283 void process::print_loads(bool verbose,
 284                           e_xbt_log_priority_t logp,
 285                           xbt_log_category_t cat) const
 286 {
 287     print_loads_generic(neigh, verbose, logp, cat);
 288 }
 289
 290 void process::print_loads_p(bool verbose,
 291                             e_xbt_log_priority_t logp,
 292                             xbt_log_category_t cat) const
 293 {
 294     print_loads_generic(pneigh, verbose, logp, cat);
 295 }
 296
 297 #undef print_loads_generic
 298
 299 void process::ctrl_send(neighbor& nb)
 300 {
 301     double info_to_send = get_load();
 302     if (info_to_send != prev_load_broadcast)
 303         comm.ctrl_send(nb.get_ctrl_mbox(),
 304                        new message(message::INFO, info_to_send));
 305     if (opt::bookkeeping) {
 306         double debt_to_send = nb.get_to_send();
 307         if (debt_to_send > 0.0) {
 308             nb.set_to_send(0.0);
 309             nb.set_debt(nb.get_debt() + debt_to_send);
 310             comm.ctrl_send(nb.get_ctrl_mbox(),
 311                            new message(message::CREDIT, debt_to_send));
 312         }
 313     }
 314 }
 315
 316 void process::data_send(neighbor& nb)
 317 {
 318     double load_to_send;
 319     if (opt::bookkeeping) {
 320         if (real_load <= nb.get_debt()) {
 321             load_to_send = real_load;
 322             nb.set_debt(nb.get_debt() - load_to_send);
 323             real_load = 0.0;
 324         } else {
 325             load_to_send = nb.get_debt();
 326             nb.set_debt(0.0);
 327             real_load -= load_to_send;
 328         }
 329     } else {
 330         load_to_send = nb.get_to_send();
 331         nb.set_to_send(0.0);
 332         // do not update real_load here
 333     }
 334     if (load_to_send > 0.0)
 335         comm.data_send(nb.get_data_mbox(),
 336                        new message(message::LOAD, load_to_send));
 337 }
 338
 339 void process::ctrl_close(neighbor& nb)
 340 {
 341     comm.ctrl_send(nb.get_ctrl_mbox(), new message(message::CTRL_CLOSE, 0.0));
 342 }
 343
 344 void process::data_close(neighbor& nb)
 345 {
 346     comm.data_send(nb.get_data_mbox(), new message(message::DATA_CLOSE, 0.0));
 347 }
 348
 349 void process::ctrl_receive(double timeout)
 350 {
 351     message* msg;
 352     m_host_t from;
 353
 354     XBT_DEBUG("%sblocking receive on ctrl (%g)", "\0non-" + !timeout, timeout);
 355     while (ctrl_close_pending && comm.ctrl_recv(msg, from, timeout)) {
 356         handle_message(msg, from);
 357         timeout = 0.0;
 358     }
 359 }
 360
 361 void process::data_receive(double timeout)
 362 {
 363     message* msg;
 364     m_host_t from;
 365
 366     XBT_DEBUG("%sblocking receive on data (%g)", "\0non-" + !timeout, timeout);
 367     while (data_close_pending && comm.data_recv(msg, from, timeout)) {
 368         handle_message(msg, from);
 369         timeout = 0.0;
 370     }
 371 }
 372
 373 void process::handle_message(message* msg, m_host_t from)
 374 {
 375     switch (msg->get_type()) {
 376     case message::INFO: {
 377         neighbor* n = rev_neigh[from];
 378         n->set_load(msg->get_amount());
 379         break;
 380     }
 381     case message::CREDIT:
 382         expected_load += msg->get_amount();
 383         break;
 384     case message::LOAD: {
 385         double ld = msg->get_amount();
 386         real_load += ld;
 387         if (finalizing)
 388             total_load_running -= ld;
 389         break;
 390     }
 391     case message::CTRL_CLOSE:
 392         ctrl_close_pending--;
 393         close_received = true;
 394         break;
 395     case message::DATA_CLOSE:
 396         data_close_pending--;
 397         close_received = true;
 398         break;
 399     }
 400     delete msg;
 401 }
 402
 403 // Local variables:
 404 // mode: c++
 405 // End: