src/mc/mc_request.cpp

   1 /* Copyright (c) 2008-2020. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include "src/mc/mc_request.hpp"
   7 #include "src/include/mc/mc.h"
   8 #include "src/kernel/activity/CommImpl.hpp"
   9 #include "src/kernel/activity/MutexImpl.hpp"
  10 #include "src/mc/ModelChecker.hpp"
  11 #include "src/mc/checker/SimcallInspector.hpp"
  12 #include "src/mc/mc_smx.hpp"
  13 #include <array>
  14
  15 using simgrid::mc::remote;
  16 using simgrid::simix::Simcall;
  17
  18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_request, mc, "Logging specific to MC (request)");
  19
  20 static char *pointer_to_string(void *pointer);
  21 static char *buff_size_to_string(size_t size);
  22
  23 static inline simgrid::kernel::activity::CommImpl* MC_get_comm(smx_simcall_t r)
  24 {
  25   switch (r->call_) {
  26     case Simcall::COMM_WAIT:
  27       return simcall_comm_wait__getraw__comm(r);
  28     case Simcall::COMM_TEST:
  29       return simcall_comm_test__getraw__comm(r);
  30     default:
  31       return nullptr;
  32   }
  33 }
  34
  35 static inline
  36 smx_mailbox_t MC_get_mbox(smx_simcall_t r)
  37 {
  38   switch (r->call_) {
  39     case Simcall::COMM_ISEND:
  40       return simcall_comm_isend__get__mbox(r);
  41     case Simcall::COMM_IRECV:
  42       return simcall_comm_irecv__get__mbox(r);
  43     default:
  44       return nullptr;
  45   }
  46 }
  47
  48 namespace simgrid {
  49 namespace mc {
  50
  51 // Does half the job
  52 static inline
  53 bool request_depend_asymmetric(smx_simcall_t r1, smx_simcall_t r2)
  54 {
  55   if (r1->call_ == Simcall::COMM_ISEND && r2->call_ == Simcall::COMM_IRECV)
  56     return false;
  57
  58   if (r1->call_ == Simcall::COMM_IRECV && r2->call_ == Simcall::COMM_ISEND)
  59     return false;
  60
  61   // Those are internal requests, we do not need indirection because those objects are copies:
  62   const kernel::activity::CommImpl* synchro1 = MC_get_comm(r1);
  63   const kernel::activity::CommImpl* synchro2 = MC_get_comm(r2);
  64
  65   if ((r1->call_ == Simcall::COMM_ISEND || r1->call_ == Simcall::COMM_IRECV) && r2->call_ == Simcall::COMM_WAIT) {
  66     const kernel::activity::MailboxImpl* mbox = MC_get_mbox(r1);
  67
  68     if (mbox != synchro2->mbox_cpy
  69         && simcall_comm_wait__get__timeout(r2) <= 0)
  70       return false;
  71
  72     if ((r1->issuer_ != synchro2->src_actor_.get()) && (r1->issuer_ != synchro2->dst_actor_.get()) &&
  73         simcall_comm_wait__get__timeout(r2) <= 0)
  74       return false;
  75
  76     if ((r1->call_ == Simcall::COMM_ISEND) && (synchro2->type_ == kernel::activity::CommImpl::Type::SEND) &&
  77         (synchro2->src_buff_ != simcall_comm_isend__get__src_buff(r1)) && simcall_comm_wait__get__timeout(r2) <= 0)
  78       return false;
  79
  80     if ((r1->call_ == Simcall::COMM_IRECV) && (synchro2->type_ == kernel::activity::CommImpl::Type::RECEIVE) &&
  81         (synchro2->dst_buff_ != simcall_comm_irecv__get__dst_buff(r1)) && simcall_comm_wait__get__timeout(r2) <= 0)
  82       return false;
  83   }
  84
  85   /* FIXME: the following rule assumes that the result of the isend/irecv call is not stored in a buffer used in the
  86    * test call. */
  87 #if 0
  88   if((r1->call == Simcall::COMM_ISEND || r1->call == Simcall::COMM_IRECV)
  89       &&  r2->call == Simcall::COMM_TEST)
  90     return false;
  91 #endif
  92
  93   if (r1->call_ == Simcall::COMM_WAIT && (r2->call_ == Simcall::COMM_WAIT || r2->call_ == Simcall::COMM_TEST) &&
  94       (synchro1->src_actor_.get() == nullptr || synchro1->dst_actor_.get() == nullptr))
  95     return false;
  96
  97   if (r1->call_ == Simcall::COMM_TEST &&
  98       (simcall_comm_test__get__comm(r1) == nullptr || synchro1->src_buff_ == nullptr || synchro1->dst_buff_ == nullptr))
  99     return false;
 100
 101   if (r1->call_ == Simcall::COMM_TEST && r2->call_ == Simcall::COMM_WAIT &&
 102       synchro1->src_buff_ == synchro2->src_buff_ && synchro1->dst_buff_ == synchro2->dst_buff_)
 103     return false;
 104
 105   if (r1->call_ == Simcall::COMM_WAIT && r2->call_ == Simcall::COMM_TEST && synchro1->src_buff_ != nullptr &&
 106       synchro1->dst_buff_ != nullptr && synchro2->src_buff_ != nullptr && synchro2->dst_buff_ != nullptr &&
 107       synchro1->dst_buff_ != synchro2->src_buff_ && synchro1->dst_buff_ != synchro2->dst_buff_ &&
 108       synchro2->dst_buff_ != synchro1->src_buff_)
 109     return false;
 110
 111   return true;
 112 }
 113
 114 // Those are internal_req
 115 bool request_depend(smx_simcall_t req1, smx_simcall_t req2)
 116 {
 117   if (req1->issuer_ == req2->issuer_)
 118     return false;
 119
 120   /* Wait with timeout transitions are not considered by the independence theorem, thus we consider them as dependent with all other transitions */
 121   if ((req1->call_ == Simcall::COMM_WAIT && simcall_comm_wait__get__timeout(req1) > 0) ||
 122       (req2->call_ == Simcall::COMM_WAIT && simcall_comm_wait__get__timeout(req2) > 0))
 123     return true;
 124
 125   if (req1->call_ != req2->call_)
 126     return request_depend_asymmetric(req1, req2) && request_depend_asymmetric(req2, req1);
 127
 128   // Those are internal requests, we do not need indirection because those objects are copies:
 129   const kernel::activity::CommImpl* synchro1 = MC_get_comm(req1);
 130   const kernel::activity::CommImpl* synchro2 = MC_get_comm(req2);
 131
 132   switch (req1->call_) {
 133     case Simcall::COMM_ISEND:
 134       return simcall_comm_isend__get__mbox(req1) == simcall_comm_isend__get__mbox(req2);
 135     case Simcall::COMM_IRECV:
 136       return simcall_comm_irecv__get__mbox(req1) == simcall_comm_irecv__get__mbox(req2);
 137     case Simcall::COMM_WAIT:
 138       if (synchro1->src_buff_ == synchro2->src_buff_ && synchro1->dst_buff_ == synchro2->dst_buff_)
 139         return false;
 140       if (synchro1->src_buff_ != nullptr && synchro1->dst_buff_ != nullptr && synchro2->src_buff_ != nullptr &&
 141           synchro2->dst_buff_ != nullptr && synchro1->dst_buff_ != synchro2->src_buff_ &&
 142           synchro1->dst_buff_ != synchro2->dst_buff_ && synchro2->dst_buff_ != synchro1->src_buff_)
 143         return false;
 144       return true;
 145     default:
 146       return true;
 147   }
 148 }
 149
 150 } // namespace mc
 151 } // namespace simgrid
 152
 153 static char *pointer_to_string(void *pointer)
 154 {
 155   if (XBT_LOG_ISENABLED(mc_request, xbt_log_priority_verbose))
 156     return bprintf("%p", pointer);
 157
 158   return xbt_strdup("(verbose only)");
 159 }
 160
 161 static char *buff_size_to_string(size_t buff_size)
 162 {
 163   if (XBT_LOG_ISENABLED(mc_request, xbt_log_priority_verbose))
 164     return bprintf("%zu", buff_size);
 165
 166   return xbt_strdup("(verbose only)");
 167 }
 168
 169
 170 std::string simgrid::mc::request_to_string(smx_simcall_t req, int value, simgrid::mc::RequestType request_type)
 171 {
 172   xbt_assert(mc_model_checker != nullptr, "Must be called from MCer");
 173
 174   if (req->inspector_ != nullptr)
 175     return req->inspector_->to_string();
 176
 177   bool use_remote_comm = true;
 178   switch(request_type) {
 179   case simgrid::mc::RequestType::simix:
 180     use_remote_comm = true;
 181     break;
 182   case simgrid::mc::RequestType::executed:
 183   case simgrid::mc::RequestType::internal:
 184     use_remote_comm = false;
 185     break;
 186   default:
 187     THROW_IMPOSSIBLE;
 188   }
 189
 190   const char* type = nullptr;
 191   char *args = nullptr;
 192
 193   smx_actor_t issuer = MC_smx_simcall_get_issuer(req);
 194
 195   switch (req->call_) {
 196     case Simcall::COMM_ISEND: {
 197       type     = "iSend";
 198       char* p  = pointer_to_string(simcall_comm_isend__get__src_buff(req));
 199       char* bs = buff_size_to_string(simcall_comm_isend__get__src_buff_size(req));
 200       if (issuer->get_host())
 201         args = bprintf("src=(%ld)%s (%s), buff=%s, size=%s", issuer->get_pid(), MC_smx_actor_get_host_name(issuer),
 202                        MC_smx_actor_get_name(issuer), p, bs);
 203       else
 204         args = bprintf("src=(%ld)%s, buff=%s, size=%s", issuer->get_pid(), MC_smx_actor_get_name(issuer), p, bs);
 205       xbt_free(bs);
 206       xbt_free(p);
 207       break;
 208     }
 209
 210     case Simcall::COMM_IRECV: {
 211       size_t* remote_size = simcall_comm_irecv__get__dst_buff_size(req);
 212       size_t size         = 0;
 213       if (remote_size)
 214         mc_model_checker->get_remote_simulation().read_bytes(&size, sizeof(size), remote(remote_size));
 215
 216       type     = "iRecv";
 217       char* p  = pointer_to_string(simcall_comm_irecv__get__dst_buff(req));
 218       char* bs = buff_size_to_string(size);
 219       if (issuer->get_host())
 220         args = bprintf("dst=(%ld)%s (%s), buff=%s, size=%s", issuer->get_pid(), MC_smx_actor_get_host_name(issuer),
 221                        MC_smx_actor_get_name(issuer), p, bs);
 222       else
 223         args = bprintf("dst=(%ld)%s, buff=%s, size=%s", issuer->get_pid(), MC_smx_actor_get_name(issuer), p, bs);
 224       xbt_free(bs);
 225       xbt_free(p);
 226       break;
 227     }
 228
 229     case Simcall::COMM_WAIT: {
 230       simgrid::kernel::activity::CommImpl* remote_act = simcall_comm_wait__getraw__comm(req);
 231       char* p;
 232       if (value == -1) {
 233         type = "WaitTimeout";
 234         p    = pointer_to_string(remote_act);
 235         args = bprintf("comm=%s", p);
 236       } else {
 237         type = "Wait";
 238         p    = pointer_to_string(remote_act);
 239
 240         simgrid::mc::Remote<simgrid::kernel::activity::CommImpl> temp_synchro;
 241         const simgrid::kernel::activity::CommImpl* act;
 242         if (use_remote_comm) {
 243           mc_model_checker->get_remote_simulation().read(temp_synchro, remote(remote_act));
 244           act = temp_synchro.get_buffer();
 245         } else
 246           act = remote_act;
 247
 248         smx_actor_t src_proc =
 249             mc_model_checker->get_remote_simulation().resolve_actor(simgrid::mc::remote(act->src_actor_.get()));
 250         smx_actor_t dst_proc =
 251             mc_model_checker->get_remote_simulation().resolve_actor(simgrid::mc::remote(act->dst_actor_.get()));
 252         args                 = bprintf("comm=%s [(%ld)%s (%s)-> (%ld)%s (%s)]", p, src_proc ? src_proc->get_pid() : 0,
 253                        src_proc ? MC_smx_actor_get_host_name(src_proc) : "",
 254                        src_proc ? MC_smx_actor_get_name(src_proc) : "", dst_proc ? dst_proc->get_pid() : 0,
 255                        dst_proc ? MC_smx_actor_get_host_name(dst_proc) : "",
 256                        dst_proc ? MC_smx_actor_get_name(dst_proc) : "");
 257       }
 258       xbt_free(p);
 259       break;
 260     }
 261
 262     case Simcall::COMM_TEST: {
 263       simgrid::kernel::activity::CommImpl* remote_act = simcall_comm_test__getraw__comm(req);
 264       simgrid::mc::Remote<simgrid::kernel::activity::CommImpl> temp_synchro;
 265       const simgrid::kernel::activity::CommImpl* act;
 266       if (use_remote_comm) {
 267         mc_model_checker->get_remote_simulation().read(temp_synchro, remote(remote_act));
 268         act = temp_synchro.get_buffer();
 269       } else
 270         act = remote_act;
 271
 272       char* p;
 273       if (act->src_actor_.get() == nullptr || act->dst_actor_.get() == nullptr) {
 274         type = "Test FALSE";
 275         p    = pointer_to_string(remote_act);
 276         args = bprintf("comm=%s", p);
 277       } else {
 278         type = "Test TRUE";
 279         p    = pointer_to_string(remote_act);
 280
 281         smx_actor_t src_proc =
 282             mc_model_checker->get_remote_simulation().resolve_actor(simgrid::mc::remote(act->src_actor_.get()));
 283         smx_actor_t dst_proc =
 284             mc_model_checker->get_remote_simulation().resolve_actor(simgrid::mc::remote(act->dst_actor_.get()));
 285         args                 = bprintf("comm=%s [(%ld)%s (%s) -> (%ld)%s (%s)]", p, src_proc->get_pid(),
 286                        MC_smx_actor_get_name(src_proc), MC_smx_actor_get_host_name(src_proc), dst_proc->get_pid(),
 287                        MC_smx_actor_get_name(dst_proc), MC_smx_actor_get_host_name(dst_proc));
 288       }
 289       xbt_free(p);
 290       break;
 291     }
 292
 293     case Simcall::COMM_WAITANY: {
 294       type         = "WaitAny";
 295       size_t count = simcall_comm_waitany__get__count(req);
 296       if (count > 0) {
 297         simgrid::kernel::activity::CommImpl* remote_sync;
 298         remote_sync =
 299             mc_model_checker->get_remote_simulation().read(remote(simcall_comm_waitany__get__comms(req) + value));
 300         char* p     = pointer_to_string(remote_sync);
 301         args        = bprintf("comm=%s (%d of %zu)", p, value + 1, count);
 302         xbt_free(p);
 303       } else
 304         args = bprintf("comm at idx %d", value);
 305       break;
 306     }
 307
 308     case Simcall::COMM_TESTANY:
 309       if (value == -1) {
 310         type = "TestAny FALSE";
 311         args = xbt_strdup("-");
 312       } else {
 313         type = "TestAny";
 314         args = bprintf("(%d of %zu)", value + 1, simcall_comm_testany__get__count(req));
 315       }
 316       break;
 317
 318     case Simcall::MUTEX_TRYLOCK:
 319     case Simcall::MUTEX_LOCK: {
 320       if (req->call_ == Simcall::MUTEX_LOCK)
 321         type = "Mutex LOCK";
 322       else
 323         type = "Mutex TRYLOCK";
 324
 325       simgrid::mc::Remote<simgrid::kernel::activity::MutexImpl> mutex;
 326       mc_model_checker->get_remote_simulation().read_bytes(mutex.get_buffer(), sizeof(mutex),
 327                                                            remote(req->call_ == Simcall::MUTEX_LOCK
 328                                                                       ? simcall_mutex_lock__get__mutex(req)
 329                                                                       : simcall_mutex_trylock__get__mutex(req)));
 330       args = bprintf("locked = %d, owner = %d, sleeping = n/a", mutex.get_buffer()->is_locked(),
 331                      mutex.get_buffer()->get_owner() != nullptr
 332                          ? (int)mc_model_checker->get_remote_simulation()
 333                                .resolve_actor(simgrid::mc::remote(mutex.get_buffer()->get_owner()))
 334                                ->get_pid()
 335                          : -1);
 336       break;
 337     }
 338
 339     case Simcall::MC_RANDOM:
 340       type = "MC_RANDOM";
 341       args = bprintf("%d", value);
 342       break;
 343
 344     default:
 345       type = SIMIX_simcall_name(req->call_);
 346       args = bprintf("??");
 347       break;
 348   }
 349
 350   std::string str;
 351   if (args != nullptr)
 352     str = simgrid::xbt::string_printf("[(%ld)%s (%s)] %s(%s)", issuer->get_pid(), MC_smx_actor_get_host_name(issuer),
 353                                       MC_smx_actor_get_name(issuer), type, args);
 354   else
 355     str = simgrid::xbt::string_printf("[(%ld)%s (%s)] %s ", issuer->get_pid(), MC_smx_actor_get_host_name(issuer),
 356                                       MC_smx_actor_get_name(issuer), type);
 357   xbt_free(args);
 358   return str;
 359 }
 360
 361 namespace simgrid {
 362 namespace mc {
 363
 364 bool request_is_enabled_by_idx(smx_simcall_t req, unsigned int idx)
 365 {
 366   kernel::activity::CommImpl* remote_act = nullptr;
 367   switch (req->call_) {
 368     case Simcall::COMM_WAIT:
 369       /* FIXME: check also that src and dst processes are not suspended */
 370       remote_act = simcall_comm_wait__getraw__comm(req);
 371       break;
 372
 373     case Simcall::COMM_WAITANY:
 374       remote_act = mc_model_checker->get_remote_simulation().read(remote(simcall_comm_testany__get__comms(req) + idx));
 375       break;
 376
 377     case Simcall::COMM_TESTANY:
 378       remote_act = mc_model_checker->get_remote_simulation().read(remote(simcall_comm_testany__get__comms(req) + idx));
 379       break;
 380
 381     default:
 382       return true;
 383   }
 384
 385   Remote<kernel::activity::CommImpl> temp_comm;
 386   mc_model_checker->get_remote_simulation().read(temp_comm, remote(remote_act));
 387   const kernel::activity::CommImpl* comm = temp_comm.get_buffer();
 388   return comm->src_actor_.get() && comm->dst_actor_.get();
 389 }
 390
 391 static inline const char* get_color(int id)
 392 {
 393   static constexpr std::array<const char*, 13> colors{{"blue", "red", "green3", "goldenrod", "brown", "purple",
 394                                                        "magenta", "turquoise4", "gray25", "forestgreen", "hotpink",
 395                                                        "lightblue", "tan"}};
 396   return colors[id % colors.size()];
 397 }
 398
 399 std::string request_get_dot_output(smx_simcall_t req, int value)
 400 {
 401   const smx_actor_t issuer = MC_smx_simcall_get_issuer(req);
 402   const char* color        = get_color(issuer->get_pid() - 1);
 403
 404   if (req->inspector_ != nullptr)
 405     return simgrid::xbt::string_printf("label = \"%s\", color = %s, fontcolor = %s",
 406                                        req->inspector_->dot_label().c_str(), color, color);
 407
 408   std::string label;
 409
 410   switch (req->call_) {
 411     case Simcall::COMM_ISEND:
 412       if (issuer->get_host())
 413         label = xbt::string_printf("[(%ld)%s] iSend", issuer->get_pid(), MC_smx_actor_get_host_name(issuer));
 414       else
 415         label = bprintf("[(%ld)] iSend", issuer->get_pid());
 416       break;
 417
 418     case Simcall::COMM_IRECV:
 419       if (issuer->get_host())
 420         label = xbt::string_printf("[(%ld)%s] iRecv", issuer->get_pid(), MC_smx_actor_get_host_name(issuer));
 421       else
 422         label = xbt::string_printf("[(%ld)] iRecv", issuer->get_pid());
 423       break;
 424
 425     case Simcall::COMM_WAIT:
 426       if (value == -1) {
 427         if (issuer->get_host())
 428           label = xbt::string_printf("[(%ld)%s] WaitTimeout", issuer->get_pid(), MC_smx_actor_get_host_name(issuer));
 429         else
 430           label = xbt::string_printf("[(%ld)] WaitTimeout", issuer->get_pid());
 431       } else {
 432         kernel::activity::ActivityImpl* remote_act = simcall_comm_wait__getraw__comm(req);
 433         Remote<kernel::activity::CommImpl> temp_comm;
 434         mc_model_checker->get_remote_simulation().read(temp_comm,
 435                                                        remote(static_cast<kernel::activity::CommImpl*>(remote_act)));
 436         const kernel::activity::CommImpl* comm = temp_comm.get_buffer();
 437
 438         const kernel::actor::ActorImpl* src_proc =
 439             mc_model_checker->get_remote_simulation().resolve_actor(mc::remote(comm->src_actor_.get()));
 440         const kernel::actor::ActorImpl* dst_proc =
 441             mc_model_checker->get_remote_simulation().resolve_actor(mc::remote(comm->dst_actor_.get()));
 442         if (issuer->get_host())
 443           label =
 444               xbt::string_printf("[(%ld)%s] Wait [(%ld)->(%ld)]", issuer->get_pid(), MC_smx_actor_get_host_name(issuer),
 445                                  src_proc ? src_proc->get_pid() : 0, dst_proc ? dst_proc->get_pid() : 0);
 446         else
 447           label = xbt::string_printf("[(%ld)] Wait [(%ld)->(%ld)]", issuer->get_pid(),
 448                                      src_proc ? src_proc->get_pid() : 0, dst_proc ? dst_proc->get_pid() : 0);
 449       }
 450       break;
 451
 452     case Simcall::COMM_TEST: {
 453       kernel::activity::ActivityImpl* remote_act = simcall_comm_test__getraw__comm(req);
 454       Remote<simgrid::kernel::activity::CommImpl> temp_comm;
 455       mc_model_checker->get_remote_simulation().read(temp_comm,
 456                                                      remote(static_cast<kernel::activity::CommImpl*>(remote_act)));
 457       const kernel::activity::CommImpl* comm = temp_comm.get_buffer();
 458       if (comm->src_actor_.get() == nullptr || comm->dst_actor_.get() == nullptr) {
 459         if (issuer->get_host())
 460           label = xbt::string_printf("[(%ld)%s] Test FALSE", issuer->get_pid(), MC_smx_actor_get_host_name(issuer));
 461         else
 462           label = bprintf("[(%ld)] Test FALSE", issuer->get_pid());
 463       } else {
 464         if (issuer->get_host())
 465           label = xbt::string_printf("[(%ld)%s] Test TRUE", issuer->get_pid(), MC_smx_actor_get_host_name(issuer));
 466         else
 467           label = xbt::string_printf("[(%ld)] Test TRUE", issuer->get_pid());
 468       }
 469       break;
 470     }
 471
 472     case Simcall::COMM_WAITANY: {
 473       size_t comms_size = simcall_comm_waitany__get__count(req);
 474       if (issuer->get_host())
 475         label = xbt::string_printf("[(%ld)%s] WaitAny [%d of %zu]", issuer->get_pid(),
 476                                    MC_smx_actor_get_host_name(issuer), value + 1, comms_size);
 477       else
 478         label = xbt::string_printf("[(%ld)] WaitAny [%d of %zu]", issuer->get_pid(), value + 1, comms_size);
 479       break;
 480     }
 481
 482     case Simcall::COMM_TESTANY:
 483       if (value == -1) {
 484         if (issuer->get_host())
 485           label = xbt::string_printf("[(%ld)%s] TestAny FALSE", issuer->get_pid(), MC_smx_actor_get_host_name(issuer));
 486         else
 487           label = xbt::string_printf("[(%ld)] TestAny FALSE", issuer->get_pid());
 488       } else {
 489         if (issuer->get_host())
 490           label =
 491               xbt::string_printf("[(%ld)%s] TestAny TRUE [%d of %lu]", issuer->get_pid(),
 492                                  MC_smx_actor_get_host_name(issuer), value + 1, simcall_comm_testany__get__count(req));
 493         else
 494           label = xbt::string_printf("[(%ld)] TestAny TRUE [%d of %lu]", issuer->get_pid(), value + 1,
 495                                      simcall_comm_testany__get__count(req));
 496       }
 497       break;
 498
 499     case Simcall::MUTEX_TRYLOCK:
 500       label = xbt::string_printf("[(%ld)] Mutex TRYLOCK", issuer->get_pid());
 501       break;
 502
 503     case Simcall::MUTEX_LOCK:
 504       label = xbt::string_printf("[(%ld)] Mutex LOCK", issuer->get_pid());
 505       break;
 506
 507     case Simcall::MC_RANDOM:
 508       if (issuer->get_host())
 509         label = xbt::string_printf("[(%ld)%s] MC_RANDOM (%d)", issuer->get_pid(), MC_smx_actor_get_host_name(issuer),
 510                                    value);
 511       else
 512         label = xbt::string_printf("[(%ld)] MC_RANDOM (%d)", issuer->get_pid(), value);
 513       break;
 514
 515     default:
 516       THROW_UNIMPLEMENTED;
 517   }
 518
 519   return xbt::string_printf("label = \"%s\", color = %s, fontcolor = %s", label.c_str(), color, color);
 520 }
 521
 522 } // namespace mc
 523 } // namespace simgrid