1 /* Copyright (c) 2007-2019. The SimGrid Team. All rights reserved. */
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. */
7 #include "simgrid/s4u/Engine.hpp"
8 #include "simgrid/s4u/Host.hpp"
9 #include "src/smpi/include/smpi_actor.hpp"
11 #include "simgrid/sg_config.hpp"
12 #include "src/kernel/activity/ExecImpl.hpp"
13 #include "src/kernel/activity/IoImpl.hpp"
14 #include "src/kernel/activity/MailboxImpl.hpp"
15 #include "src/kernel/activity/SleepImpl.hpp"
16 #include "src/kernel/activity/SynchroRaw.hpp"
17 #include "src/mc/mc_record.hpp"
18 #include "src/mc/mc_replay.hpp"
19 #include "src/simix/smx_host_private.hpp"
20 #include "src/simix/smx_private.hpp"
21 #include "src/surf/StorageImpl.hpp"
22 #include "src/surf/xml/platf.hpp"
25 #include "src/mc/remote/Client.hpp"
28 #include <boost/heap/fibonacci_heap.hpp>
30 XBT_LOG_NEW_CATEGORY(simix, "All SIMIX categories");
31 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_kernel, simix, "Logging specific to SIMIX (kernel)");
33 std::unique_ptr<simgrid::simix::Global> simix_global;
36 typedef std::pair<double, smx_timer_t> TimerQelt;
37 boost::heap::fibonacci_heap<TimerQelt, boost::heap::compare<simgrid::xbt::HeapComparator<TimerQelt>>> simix_timers;
40 /** @brief Timer datatype */
45 decltype(simix_timers)::handle_type handle_;
46 simgrid::xbt::Task<void()> callback;
47 double getDate() { return date; }
48 s_smx_timer_t(double date, simgrid::xbt::Task<void()> callback) : date(date), callback(std::move(callback)) {}
51 void (*SMPI_switch_data_segment)(simgrid::s4u::ActorPtr) = nullptr;
53 bool _sg_do_verbose_exit = true;
54 static void inthandler(int)
56 if ( _sg_do_verbose_exit ) {
57 XBT_INFO("CTRL-C pressed. The current status will be displayed before exit (disable that behavior with option 'verbose-exit').");
58 SIMIX_display_process_status();
61 XBT_INFO("CTRL-C pressed, exiting. Hiding the current process status since 'verbose-exit' is set to false.");
67 static void segvhandler(int signum, siginfo_t* siginfo, void* /*context*/)
69 if (siginfo->si_signo == SIGSEGV && siginfo->si_code == SEGV_ACCERR) {
70 fprintf(stderr, "Access violation detected.\n"
71 "This probably comes from a programming error in your code, or from a stack\n"
72 "overflow. If you are certain of your code, try increasing the stack size\n"
73 " --cfg=contexts/stack-size=XXX (current size is %u KiB).\n"
75 "If it does not help, this may have one of the following causes:\n"
76 "a bug in SimGrid, a bug in the OS or a bug in a third-party libraries.\n"
77 "Failing hardware can sometimes generate such errors too.\n"
79 "If you think you've found a bug in SimGrid, please report it along with a\n"
80 "Minimal Working Example (MWE) reproducing your problem and a full backtrace\n"
81 "of the fault captured with gdb or valgrind.\n",
82 smx_context_stack_size / 1024);
83 } else if (siginfo->si_signo == SIGSEGV) {
84 fprintf(stderr, "Segmentation fault.\n");
86 if (smpi_enabled() && smpi_privatize_global_variables == SmpiPrivStrategies::NONE) {
87 #if HAVE_PRIVATIZATION
88 fprintf(stderr, "Try to enable SMPI variable privatization with --cfg=smpi/privatization:yes.\n");
90 fprintf(stderr, "Sadly, your system does not support --cfg=smpi/privatization:yes (yet).\n");
91 #endif /* HAVE_PRIVATIZATION */
93 #endif /* HAVE_SMPI */
98 char sigsegv_stack[SIGSTKSZ]; /* alternate stack for SIGSEGV handler */
101 * Install signal handler for SIGSEGV. Check that nobody has already installed
102 * its own handler. For example, the Java VM does this.
104 static void install_segvhandler()
108 stack.ss_sp = sigsegv_stack;
109 stack.ss_size = sizeof sigsegv_stack;
112 if (sigaltstack(&stack, &old_stack) == -1) {
113 XBT_WARN("Failed to register alternate signal stack: %s", strerror(errno));
116 if (not(old_stack.ss_flags & SS_DISABLE)) {
117 XBT_DEBUG("An alternate stack was already installed (sp=%p, size=%zu, flags=%x). Restore it.", old_stack.ss_sp,
118 old_stack.ss_size, (unsigned)old_stack.ss_flags);
119 sigaltstack(&old_stack, nullptr);
122 struct sigaction action;
123 struct sigaction old_action;
124 action.sa_sigaction = &segvhandler;
125 action.sa_flags = SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
126 sigemptyset(&action.sa_mask);
128 if (sigaction(SIGSEGV, &action, &old_action) == -1) {
129 XBT_WARN("Failed to register signal handler for SIGSEGV: %s", strerror(errno));
132 if ((old_action.sa_flags & SA_SIGINFO) || old_action.sa_handler != SIG_DFL) {
133 XBT_DEBUG("A signal handler was already installed for SIGSEGV (%p). Restore it.",
134 (old_action.sa_flags & SA_SIGINFO) ? (void*)old_action.sa_sigaction : (void*)old_action.sa_handler);
135 sigaction(SIGSEGV, &old_action, nullptr);
141 /********************************* SIMIX **************************************/
142 double SIMIX_timer_next()
144 return simix_timers.empty() ? -1.0 : simix_timers.top().first;
150 void Global::empty_trash()
152 while (not actors_to_destroy.empty()) {
153 smx_actor_t actor = &actors_to_destroy.front();
154 actors_to_destroy.pop_front();
155 XBT_DEBUG("Getting rid of %p", actor);
156 intrusive_ptr_release(actor);
159 xbt_dynar_reset(simix_global->dead_actors_vector);
163 * @brief Executes the actors in simix_global->actors_to_run.
165 * The actors in simix_global->actors_to_run are run (in parallel if possible). On exit, simix_global->actors_to_run
166 * is empty, and simix_global->actors_that_ran contains the list of actors that just ran.
167 * The two lists are swapped so, be careful when using them before and after a call to this function.
169 void Global::run_all_actors()
171 SIMIX_context_runall();
173 simix_global->actors_to_run.swap(simix_global->actors_that_ran);
174 simix_global->actors_to_run.clear();
177 simgrid::config::Flag<double> breakpoint{"simix/breakpoint",
178 "When non-negative, raise a SIGTRAP after given (simulated) time", -1.0};
182 static simgrid::simix::ActorCode maestro_code;
183 void SIMIX_set_maestro(void (*code)(void*), void* data)
186 XBT_INFO("WARNING, SIMIX_set_maestro is believed to not work on windows. Please help us investigating this issue if you need that feature");
188 maestro_code = std::bind(code, data);
193 * @brief Initialize SIMIX internal data.
195 void SIMIX_global_init(int *argc, char **argv)
198 // The communication initialization is done ASAP.
199 // We need to communicate initialization of the different layers to the model-checker.
200 simgrid::mc::Client::initialize();
203 if (simix_global == nullptr) {
204 simix_global = std::unique_ptr<simgrid::simix::Global>(new simgrid::simix::Global());
205 simix_global->maestro_process = nullptr;
207 surf_init(argc, argv); /* Initialize SURF structures */
208 SIMIX_context_mod_init();
210 // Either create a new context with maestro or create
211 // a context object with the current context mestro):
212 simgrid::kernel::actor::create_maestro(maestro_code);
214 /* Prepare to display some more info when dying on Ctrl-C pressing */
215 std::signal(SIGINT, inthandler);
218 install_segvhandler();
220 /* register a function to be called by SURF after the environment creation */
222 simgrid::s4u::on_platform_created.connect(surf_presolve);
224 simgrid::s4u::Storage::on_creation.connect([](simgrid::s4u::Storage& storage) {
225 sg_storage_t s = simgrid::s4u::Storage::by_name(storage.get_name());
226 xbt_assert(s != nullptr, "Storage not found for name %s", storage.get_cname());
230 if (simgrid::config::get_value<bool>("clean-atexit"))
233 if (_sg_cfg_exit_asap)
240 * @brief Clean the SIMIX simulation
242 * This functions remove the memory used by SIMIX
247 return; // to avoid double cleaning by java and C
250 XBT_DEBUG("SIMIX_clean called. Simulation's over.");
251 if (not simix_global->actors_to_run.empty() && SIMIX_get_clock() <= 0.0) {
253 XBT_CRITICAL("The time is still 0, and you still have processes ready to run.");
254 XBT_CRITICAL("It seems that you forgot to run the simulation that you setup.");
255 xbt_die("Bailing out to avoid that stop-before-start madness. Please fix your code.");
259 if (SIMIX_process_count()>0){
260 if(smpi_process()->initialized()){
261 xbt_die("Process exited without calling MPI_Finalize - Killing simulation");
263 XBT_WARN("Process called exit when leaving - Skipping cleanups");
269 /* Kill all processes (but maestro) */
270 simix_global->maestro_process->kill_all();
271 SIMIX_context_runall();
272 simix_global->empty_trash();
274 /* Exit the SIMIX network module */
275 SIMIX_mailbox_exit();
277 while (not simix_timers.empty()) {
278 delete simix_timers.top().second;
281 /* Free the remaining data structures */
282 simix_global->actors_to_run.clear();
283 simix_global->actors_that_ran.clear();
284 simix_global->actors_to_destroy.clear();
285 simix_global->process_list.clear();
288 xbt_dynar_free(&simix_global->actors_vector);
289 xbt_dynar_free(&simix_global->dead_actors_vector);
292 /* Let's free maestro now */
293 delete simix_global->maestro_process->context_;
294 simix_global->maestro_process->context_ = nullptr;
295 delete simix_global->maestro_process;
296 simix_global->maestro_process = nullptr;
298 /* Finish context module and SURF */
299 SIMIX_context_mod_exit();
303 simix_global = nullptr;
308 * @brief A clock (in second).
310 * @return Return the clock.
312 double SIMIX_get_clock()
314 if(MC_is_active() || MC_record_replay_is_active()){
315 return MC_process_clock_get(SIMIX_process_self());
317 return surf_get_clock();
321 /** Wake up all processes waiting for a Surf action to finish */
322 static void SIMIX_wake_processes()
324 for (auto const& model : all_existing_models) {
325 simgrid::kernel::resource::Action* action;
327 XBT_DEBUG("Handling the processes whose action failed (if any)");
328 while ((action = model->extract_failed_action())) {
329 XBT_DEBUG(" Handling Action %p",action);
330 SIMIX_simcall_exit(static_cast<simgrid::kernel::activity::ActivityImpl*>(action->get_data()));
332 XBT_DEBUG("Handling the processes whose action terminated normally (if any)");
333 while ((action = model->extract_done_action())) {
334 XBT_DEBUG(" Handling Action %p",action);
335 if (action->get_data() == nullptr)
336 XBT_DEBUG("probably vcpu's action %p, skip", action);
338 SIMIX_simcall_exit(static_cast<simgrid::kernel::activity::ActivityImpl*>(action->get_data()));
343 /** Handle any pending timer */
344 static bool SIMIX_execute_timers()
347 while (not simix_timers.empty() && SIMIX_get_clock() >= simix_timers.top().first) {
349 // FIXME: make the timers being real callbacks (i.e. provide dispatchers that read and expand the args)
350 smx_timer_t timer = simix_timers.top().second;
355 xbt_die("Exception thrown ouf of timer callback");
362 /** Execute all the tasks that are queued
364 * e.g. `.then()` callbacks of futures.
366 static bool SIMIX_execute_tasks()
368 xbt_assert(simix_global->tasksTemp.empty());
370 if (simix_global->tasks.empty())
375 // We don't want the callbacks to modify the vector we are iterating over:
376 swap(simix_global->tasks, simix_global->tasksTemp);
378 // Execute all the queued tasks:
379 for (auto& task : simix_global->tasksTemp)
382 simix_global->tasksTemp.clear();
383 } while (not simix_global->tasks.empty());
390 * @brief Run the main simulation loop.
394 if (not MC_record_path.empty()) {
395 simgrid::mc::replay(MC_record_path);
402 XBT_DEBUG("New Schedule Round; size(queue)=%zu", simix_global->actors_to_run.size());
404 if (simgrid::simix::breakpoint >= 0.0 && surf_get_clock() >= simgrid::simix::breakpoint) {
405 XBT_DEBUG("Breakpoint reached (%g)", simgrid::simix::breakpoint.get());
406 simgrid::simix::breakpoint = -1.0;
414 SIMIX_execute_tasks();
416 while (not simix_global->actors_to_run.empty()) {
417 XBT_DEBUG("New Sub-Schedule Round; size(queue)=%zu", simix_global->actors_to_run.size());
419 /* Run all processes that are ready to run, possibly in parallel */
420 simix_global->run_all_actors();
422 /* answer sequentially and in a fixed arbitrary order all the simcalls that were issued during that sub-round */
424 /* WARNING, the order *must* be fixed or you'll jeopardize the simulation reproducibility (see RR-7653) */
426 /* Here, the order is ok because:
428 * Short proof: only maestro adds stuff to the actors_to_run array, so the execution order of user contexts do
429 * not impact its order.
431 * Long proof: processes remain sorted through an arbitrary (implicit, complex but fixed) order in all cases.
433 * - if there is no kill during the simulation, processes remain sorted according by their PID.
434 * Rationale: This can be proved inductively.
435 * Assume that actors_to_run is sorted at a beginning of one round (it is at round 0: the deployment file
436 * is parsed linearly).
437 * Let's show that it is still so at the end of this round.
438 * - if a process is added when being created, that's from maestro. It can be either at startup
439 * time (and then in PID order), or in response to a process_create simcall. Since simcalls are handled
440 * in arbitrary order (inductive hypothesis), we are fine.
441 * - If a process is added because it's getting killed, its subsequent actions shouldn't matter
442 * - If a process gets added to actors_to_run because one of their blocking action constituting the meat
443 * of a simcall terminates, we're still good. Proof:
444 * - You are added from SIMIX_simcall_answer() only. When this function is called depends on the resource
445 * kind (network, cpu, disk, whatever), but the same arguments hold. Let's take communications as an
447 * - For communications, this function is called from SIMIX_comm_finish().
448 * This function itself don't mess with the order since simcalls are handled in FIFO order.
449 * The function is called:
450 * - before the comm starts (invalid parameters, or resource already dead or whatever).
451 * The order then trivial holds since maestro didn't interrupt its handling of the simcall yet
452 * - because the communication failed or were canceled after startup. In this case, it's called from
453 * the function we are in, by the chunk:
454 * set = model->states.failed_action_set;
455 * while ((synchro = extract(set)))
456 * SIMIX_simcall_post((smx_synchro_t) synchro->data);
457 * This order is also fixed because it depends of the order in which the surf actions were
458 * added to the system, and only maestro can add stuff this way, through simcalls.
459 * We thus use the inductive hypothesis once again to conclude that the order in which synchros are
460 * poped out of the set does not depend on the user code's execution order.
461 * - because the communication terminated. In this case, synchros are served in the order given by
462 * set = model->states.done_action_set;
463 * while ((synchro = extract(set)))
464 * SIMIX_simcall_post((smx_synchro_t) synchro->data);
465 * and the argument is very similar to the previous one.
466 * So, in any case, the orders of calls to SIMIX_comm_finish() do not depend on the order in which user
467 * processes are executed.
468 * So, in any cases, the orders of processes within actors_to_run do not depend on the order in which
469 * user processes were executed previously.
470 * So, if there is no killing in the simulation, the simulation reproducibility is not jeopardized.
471 * - If there is some process killings, the order is changed by this decision that comes from user-land
472 * But this decision may not have been motivated by a situation that were different because the simulation is
474 * So, even the order change induced by the process killing is perfectly reproducible.
476 * So science works, bitches [http://xkcd.com/54/].
478 * We could sort the actors_that_ran array completely so that we can describe the order in which simcalls are
479 * handled (like "according to the PID of issuer"), but it's not mandatory (order is fixed already even if
481 * That would thus be a pure waste of time.
484 for (smx_actor_t const& process : simix_global->actors_that_ran) {
485 if (process->simcall.call != SIMCALL_NONE) {
486 SIMIX_simcall_handle(&process->simcall, 0);
490 SIMIX_execute_tasks();
492 SIMIX_wake_processes();
493 } while (SIMIX_execute_tasks());
495 /* If only daemon processes remain, cancel their actions, mark them to die and reschedule them */
496 if (simix_global->process_list.size() == simix_global->daemons.size())
497 for (auto const& dmon : simix_global->daemons) {
498 XBT_DEBUG("Kill %s", dmon->get_cname());
499 simix_global->maestro_process->kill(dmon);
503 time = SIMIX_timer_next();
504 if (time > -1.0 || not simix_global->process_list.empty()) {
505 XBT_DEBUG("Calling surf_solve");
506 time = surf_solve(time);
507 XBT_DEBUG("Moving time ahead : %g", time);
510 /* Notify all the hosts that have failed */
511 /* FIXME: iterate through the list of failed host and mark each of them */
512 /* as failed. On each host, signal all the running processes with host_fail */
514 // Execute timers and tasks until there isn't anything to be done:
517 again = SIMIX_execute_timers();
518 if (SIMIX_execute_tasks())
520 SIMIX_wake_processes();
523 /* Clean actors to destroy */
524 simix_global->empty_trash();
526 XBT_DEBUG("### time %f, #processes %zu, #to_run %zu", time, simix_global->process_list.size(),
527 simix_global->actors_to_run.size());
529 } while (time > -1.0 || not simix_global->actors_to_run.empty());
531 if (not simix_global->process_list.empty()) {
533 if (simix_global->process_list.size() <= simix_global->daemons.size()) {
534 XBT_CRITICAL("Oops! Daemon actors cannot do any blocking activity (communications, synchronization, etc) "
535 "once the simulation is over. Please fix your on_exit() functions.");
537 XBT_CRITICAL("Oops! Deadlock or code not perfectly clean.");
539 SIMIX_display_process_status();
540 simgrid::s4u::on_deadlock();
543 simgrid::s4u::on_simulation_end();
547 * @brief Set the date to execute a function
549 * Set the date to execute the function on the surf.
550 * @param date Date to execute function
551 * @param callback Function to be executed
552 * @param arg Parameters of the function
555 smx_timer_t SIMIX_timer_set(double date, void (*callback)(void*), void *arg)
557 smx_timer_t timer = new s_smx_timer_t(date, simgrid::xbt::make_task([callback, arg]() { callback(arg); }));
558 timer->handle_ = simix_timers.emplace(std::make_pair(date, timer));
562 smx_timer_t SIMIX_timer_set(double date, simgrid::xbt::Task<void()> callback)
564 smx_timer_t timer = new s_smx_timer_t(date, std::move(callback));
565 timer->handle_ = simix_timers.emplace(std::make_pair(date, timer));
569 /** @brief cancels a timer that was added earlier */
570 void SIMIX_timer_remove(smx_timer_t timer) {
571 simix_timers.erase(timer->handle_);
575 /** @brief Returns the date at which the timer will trigger (or 0 if nullptr timer) */
576 double SIMIX_timer_get_date(smx_timer_t timer) {
577 return timer ? timer->getDate() : 0;
580 void SIMIX_display_process_status()
582 int nbprocess = simix_global->process_list.size();
584 XBT_INFO("%d processes are still running, waiting for something.", nbprocess);
585 /* List the process and their state */
586 XBT_INFO("Legend of the following listing: \"Process <pid> (<name>@<host>): <status>\"");
587 for (auto const& kv : simix_global->process_list) {
588 smx_actor_t process = kv.second;
590 if (process->waiting_synchro) {
592 const char* synchro_description = "unknown";
594 if (boost::dynamic_pointer_cast<simgrid::kernel::activity::ExecImpl>(process->waiting_synchro) != nullptr)
595 synchro_description = "execution";
597 if (boost::dynamic_pointer_cast<simgrid::kernel::activity::CommImpl>(process->waiting_synchro) != nullptr)
598 synchro_description = "communication";
600 if (boost::dynamic_pointer_cast<simgrid::kernel::activity::SleepImpl>(process->waiting_synchro) != nullptr)
601 synchro_description = "sleeping";
603 if (boost::dynamic_pointer_cast<simgrid::kernel::activity::RawImpl>(process->waiting_synchro) != nullptr)
604 synchro_description = "synchronization";
606 if (boost::dynamic_pointer_cast<simgrid::kernel::activity::IoImpl>(process->waiting_synchro) != nullptr)
607 synchro_description = "I/O";
609 XBT_INFO("Process %ld (%s@%s): waiting for %s synchro %p (%s) in state %d to finish", process->get_pid(),
610 process->get_cname(), process->get_host()->get_cname(), synchro_description,
611 process->waiting_synchro.get(), process->waiting_synchro->get_cname(),
612 (int)process->waiting_synchro->state_);
615 XBT_INFO("Process %ld (%s@%s)", process->get_pid(), process->get_cname(), process->get_host()->get_cname());
620 int SIMIX_is_maestro()
622 smx_actor_t self = SIMIX_process_self();
623 return simix_global == nullptr /*SimDag*/ || self == nullptr || self == simix_global->maestro_process;