1 /* Copyright (c) 2007-2018. 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. */
6 #include "SmpiHost.hpp"
9 #include "simgrid/s4u/Engine.hpp"
10 #include "simgrid/s4u/Host.hpp"
11 #include "simgrid/s4u/Mailbox.hpp"
12 #include "simgrid/s4u/forward.hpp"
13 #include "smpi_coll.hpp"
14 #include "smpi_comm.hpp"
15 #include "smpi_group.hpp"
16 #include "smpi_info.hpp"
17 #include "smpi_process.hpp"
18 #include "src/msg/msg_private.hpp"
19 #include "src/simix/smx_private.hpp"
20 #include "src/surf/surf_interface.hpp"
21 #include "xbt/config.hpp"
23 #include <cfloat> /* DBL_MAX */
30 #include <sys/sendfile.h>
33 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_kernel, smpi, "Logging specific to SMPI (kernel)");
34 #include <boost/tokenizer.hpp>
35 #include <boost/algorithm/string.hpp> /* trim_right / trim_left */
38 /* RTLD_DEEPBIND is a bad idea of GNU ld that obviously does not exist on other platforms
39 * See https://www.akkadia.org/drepper/dsohowto.pdf
40 * and https://lists.freebsd.org/pipermail/freebsd-current/2016-March/060284.html
42 #define RTLD_DEEPBIND 0
47 const char* papi_default_config_name = "default";
49 struct papi_process_data {
50 papi_counter_t counter_data;
55 using simgrid::s4u::Actor;
56 using simgrid::s4u::ActorPtr;
57 std::unordered_map<std::string, double> location2speedup;
59 static std::map</*process_id*/ ActorPtr, simgrid::smpi::Process*> process_data;
60 int process_count = 0;
61 static int smpi_exit_status = 0;
62 int smpi_universe_size = 0;
63 extern double smpi_total_benched_time;
64 xbt_os_timer_t global_timer;
66 * Setting MPI_COMM_WORLD to MPI_COMM_UNINITIALIZED (it's a variable)
67 * is important because the implementation of MPI_Comm checks
68 * "this == MPI_COMM_UNINITIALIZED"? If yes, it uses smpi_process()->comm_world()
70 * This is basically how we only have one global variable but all processes have
71 * different communicators (the one their SMPI instance uses).
73 * See smpi_comm.cpp and the functions therein for details.
75 MPI_Comm MPI_COMM_WORLD = MPI_COMM_UNINITIALIZED;
76 MPI_Errhandler *MPI_ERRORS_RETURN = nullptr;
77 MPI_Errhandler *MPI_ERRORS_ARE_FATAL = nullptr;
78 MPI_Errhandler *MPI_ERRHANDLER_NULL = nullptr;
79 // No instance gets manually created; check also the smpirun.in script as
80 // this default name is used there as well (when the <actor> tag is generated).
81 static const std::string smpi_default_instance_name("smpirun");
82 static simgrid::config::Flag<double> smpi_wtime_sleep(
83 "smpi/wtime", "Minimum time to inject inside a call to MPI_Wtime", 0.0);
84 static simgrid::config::Flag<double> smpi_init_sleep(
85 "smpi/init", "Time to inject inside a call to MPI_Init", 0.0);
87 void (*smpi_comm_copy_data_callback) (smx_activity_t, void*, size_t) = &smpi_comm_copy_buffer_callback;
89 int smpi_process_count()
94 simgrid::smpi::Process* smpi_process()
96 ActorPtr me = Actor::self();
97 if (me == nullptr) // This happens sometimes (eg, when linking against NS3 because it pulls openMPI...)
99 simgrid::msg::ActorExt* msgExt = static_cast<simgrid::msg::ActorExt*>(me->getImpl()->userdata);
100 return static_cast<simgrid::smpi::Process*>(msgExt->data);
103 simgrid::smpi::Process* smpi_process_remote(ActorPtr actor)
105 return process_data.at(actor);
108 MPI_Comm smpi_process_comm_self(){
109 return smpi_process()->comm_self();
112 void smpi_process_init(int *argc, char ***argv){
113 simgrid::smpi::Process::init(argc, argv);
116 int smpi_process_index(){
117 return simgrid::s4u::this_actor::getPid();
120 void * smpi_process_get_user_data(){
121 return smpi_process()->get_user_data();
124 void smpi_process_set_user_data(void *data){
125 return smpi_process()->set_user_data(data);
129 int smpi_global_size()
131 char *value = getenv("SMPI_GLOBAL_SIZE");
132 xbt_assert(value,"Please set env var SMPI_GLOBAL_SIZE to the expected number of processes.");
134 return xbt_str_parse_int(value, "SMPI_GLOBAL_SIZE contains a non-numerical value: %s");
137 void smpi_comm_set_copy_data_callback(void (*callback) (smx_activity_t, void*, size_t))
139 smpi_comm_copy_data_callback = callback;
142 static void print(std::vector<std::pair<size_t, size_t>> vec) {
143 std::fprintf(stderr, "{");
144 for (auto const& elt : vec) {
145 std::fprintf(stderr, "(0x%zx, 0x%zx),", elt.first, elt.second);
147 std::fprintf(stderr, "}\n");
149 static void memcpy_private(void* dest, const void* src, std::vector<std::pair<size_t, size_t>>& private_blocks)
151 for (auto const& block : private_blocks)
152 memcpy((uint8_t*)dest+block.first, (uint8_t*)src+block.first, block.second-block.first);
155 static void check_blocks(std::vector<std::pair<size_t, size_t>> &private_blocks, size_t buff_size) {
156 for (auto const& block : private_blocks)
157 xbt_assert(block.first <= block.second && block.second <= buff_size, "Oops, bug in shared malloc.");
160 void smpi_comm_copy_buffer_callback(smx_activity_t synchro, void *buff, size_t buff_size)
162 simgrid::kernel::activity::CommImplPtr comm =
163 boost::dynamic_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
166 size_t src_offset = 0;
167 size_t dst_offset = 0;
168 std::vector<std::pair<size_t, size_t>> src_private_blocks;
169 std::vector<std::pair<size_t, size_t>> dst_private_blocks;
170 XBT_DEBUG("Copy the data over");
171 if((src_shared=smpi_is_shared(buff, src_private_blocks, &src_offset))) {
172 XBT_DEBUG("Sender %p is shared. Let's ignore it.", buff);
173 src_private_blocks = shift_and_frame_private_blocks(src_private_blocks, src_offset, buff_size);
176 src_private_blocks.clear();
177 src_private_blocks.push_back(std::make_pair(0, buff_size));
179 if((dst_shared=smpi_is_shared((char*)comm->dst_buff, dst_private_blocks, &dst_offset))) {
180 XBT_DEBUG("Receiver %p is shared. Let's ignore it.", (char*)comm->dst_buff);
181 dst_private_blocks = shift_and_frame_private_blocks(dst_private_blocks, dst_offset, buff_size);
184 dst_private_blocks.clear();
185 dst_private_blocks.push_back(std::make_pair(0, buff_size));
187 check_blocks(src_private_blocks, buff_size);
188 check_blocks(dst_private_blocks, buff_size);
189 auto private_blocks = merge_private_blocks(src_private_blocks, dst_private_blocks);
190 check_blocks(private_blocks, buff_size);
192 if ((smpi_privatize_global_variables == SmpiPrivStrategies::Mmap) &&
193 (static_cast<char*>(buff) >= smpi_data_exe_start) &&
194 (static_cast<char*>(buff) < smpi_data_exe_start + smpi_data_exe_size)) {
195 XBT_DEBUG("Privatization : We are copying from a zone inside global memory... Saving data to temp buffer !");
196 smpi_switch_data_segment(comm->src_proc->iface());
197 tmpbuff = static_cast<void*>(xbt_malloc(buff_size));
198 memcpy_private(tmpbuff, buff, private_blocks);
201 if ((smpi_privatize_global_variables == SmpiPrivStrategies::Mmap) && ((char*)comm->dst_buff >= smpi_data_exe_start) &&
202 ((char*)comm->dst_buff < smpi_data_exe_start + smpi_data_exe_size)) {
203 XBT_DEBUG("Privatization : We are copying to a zone inside global memory - Switch data segment");
204 smpi_switch_data_segment(comm->dst_proc->iface());
206 XBT_DEBUG("Copying %zu bytes from %p to %p", buff_size, tmpbuff,comm->dst_buff);
207 memcpy_private(comm->dst_buff, tmpbuff, private_blocks);
209 if (comm->detached) {
210 // if this is a detached send, the source buffer was duplicated by SMPI
211 // sender to make the original buffer available to the application ASAP
213 //It seems that the request is used after the call there this should be free somewhere else but where???
214 //xbt_free(comm->comm.src_data);// inside SMPI the request is kept inside the user data and should be free
215 comm->src_buff = nullptr;
221 void smpi_comm_null_copy_buffer_callback(smx_activity_t comm, void *buff, size_t buff_size)
223 /* nothing done in this version */
226 static void smpi_check_options(){
227 //check correctness of MPI parameters
229 xbt_assert(xbt_cfg_get_int("smpi/async-small-thresh") <= xbt_cfg_get_int("smpi/send-is-detached-thresh"));
231 if (xbt_cfg_is_default_value("smpi/host-speed")) {
232 XBT_INFO("You did not set the power of the host running the simulation. "
233 "The timings will certainly not be accurate. "
234 "Use the option \"--cfg=smpi/host-speed:<flops>\" to set its value."
235 "Check http://simgrid.org/simgrid/latest/doc/options.html#options_smpi_bench for more information.");
238 xbt_assert(xbt_cfg_get_double("smpi/cpu-threshold") >=0,
239 "The 'smpi/cpu-threshold' option cannot have negative values [anymore]. If you want to discard "
240 "the simulation of any computation, please use 'smpi/simulate-computation:no' instead.");
244 return not process_data.empty();
247 void smpi_global_init()
249 if (not MC_is_active()) {
250 global_timer = xbt_os_timer_new();
251 xbt_os_walltimer_start(global_timer);
254 std::string filename = xbt_cfg_get_string("smpi/comp-adjustment-file");
255 if (not filename.empty()) {
256 std::ifstream fstream(filename);
257 if (not fstream.is_open()) {
258 xbt_die("Could not open file %s. Does it exist?", filename.c_str());
262 typedef boost::tokenizer< boost::escaped_list_separator<char>> Tokenizer;
263 std::getline(fstream, line); // Skip the header line
264 while (std::getline(fstream, line)) {
266 Tokenizer::iterator it = tok.begin();
267 Tokenizer::iterator end = std::next(tok.begin());
269 std::string location = *it;
270 boost::trim(location);
271 location2speedup.insert(std::pair<std::string, double>(location, std::stod(*end)));
276 // This map holds for each computation unit (such as "default" or "process1" etc.)
277 // the configuration as given by the user (counter data as a pair of (counter_name, counter_counter))
278 // and the (computed) event_set.
279 std::map</* computation unit name */ std::string, papi_process_data> units2papi_setup;
281 if (not xbt_cfg_get_string("smpi/papi-events").empty()) {
282 if (PAPI_library_init(PAPI_VER_CURRENT) != PAPI_VER_CURRENT)
283 XBT_ERROR("Could not initialize PAPI library; is it correctly installed and linked?"
284 " Expected version is %i",
287 typedef boost::tokenizer<boost::char_separator<char>> Tokenizer;
288 boost::char_separator<char> separator_units(";");
289 std::string str = xbt_cfg_get_string("smpi/papi-events");
290 Tokenizer tokens(str, separator_units);
292 // Iterate over all the computational units. This could be processes, hosts, threads, ranks... You name it.
293 // I'm not exactly sure what we will support eventually, so I'll leave it at the general term "units".
294 for (auto const& unit_it : tokens) {
295 boost::char_separator<char> separator_events(":");
296 Tokenizer event_tokens(unit_it, separator_events);
298 int event_set = PAPI_NULL;
299 if (PAPI_create_eventset(&event_set) != PAPI_OK) {
300 // TODO: Should this let the whole simulation die?
301 XBT_CRITICAL("Could not create PAPI event set during init.");
304 // NOTE: We cannot use a map here, as we must obey the order of the counters
305 // This is important for PAPI: We need to map the values of counters back
306 // to the event_names (so, when PAPI_read() has finished)!
307 papi_counter_t counters2values;
309 // Iterate over all counters that were specified for this specific
311 // Note that we need to remove the name of the unit
312 // (that could also be the "default" value), which always comes first.
313 // Hence, we start at ++(events.begin())!
314 for (Tokenizer::iterator events_it = ++(event_tokens.begin()); events_it != event_tokens.end(); ++events_it) {
316 int event_code = PAPI_NULL;
317 char* event_name = const_cast<char*>((*events_it).c_str());
318 if (PAPI_event_name_to_code(event_name, &event_code) == PAPI_OK) {
319 if (PAPI_add_event(event_set, event_code) != PAPI_OK) {
320 XBT_ERROR("Could not add PAPI event '%s'. Skipping.", event_name);
323 XBT_DEBUG("Successfully added PAPI event '%s' to the event set.", event_name);
326 XBT_CRITICAL("Could not find PAPI event '%s'. Skipping.", event_name);
330 counters2values.push_back(
331 // We cannot just pass *events_it, as this is of type const basic_string
332 std::make_pair<std::string, long long>(std::string(*events_it), 0));
335 std::string unit_name = *(event_tokens.begin());
336 papi_process_data config = {.counter_data = std::move(counters2values), .event_set = event_set};
338 units2papi_setup.insert(std::make_pair(unit_name, std::move(config)));
344 void smpi_global_destroy()
346 smpi_bench_destroy();
347 smpi_shared_destroy();
348 smpi_deployment_cleanup_instances();
350 if (simgrid::smpi::Colls::smpi_coll_cleanup_callback != nullptr)
351 simgrid::smpi::Colls::smpi_coll_cleanup_callback();
353 MPI_COMM_WORLD = MPI_COMM_NULL;
355 if (not MC_is_active()) {
356 xbt_os_timer_free(global_timer);
359 if (smpi_privatize_global_variables == SmpiPrivStrategies::Mmap)
360 smpi_destroy_global_memory_segments();
364 static void smpi_init_options(){
365 // return if already called
366 if (smpi_cpu_threshold > -1)
368 simgrid::smpi::Colls::set_collectives();
369 simgrid::smpi::Colls::smpi_coll_cleanup_callback = nullptr;
370 smpi_cpu_threshold = xbt_cfg_get_double("smpi/cpu-threshold");
371 smpi_host_speed = xbt_cfg_get_double("smpi/host-speed");
372 xbt_assert(smpi_host_speed >= 0, "You're trying to set the host_speed to a negative value (%f)", smpi_host_speed);
373 std::string smpi_privatize_option = xbt_cfg_get_string("smpi/privatization");
374 if (smpi_privatize_option == "no" || smpi_privatize_option == "0")
375 smpi_privatize_global_variables = SmpiPrivStrategies::None;
376 else if (smpi_privatize_option == "yes" || smpi_privatize_option == "1")
377 smpi_privatize_global_variables = SmpiPrivStrategies::Default;
378 else if (smpi_privatize_option == "mmap")
379 smpi_privatize_global_variables = SmpiPrivStrategies::Mmap;
380 else if (smpi_privatize_option == "dlopen")
381 smpi_privatize_global_variables = SmpiPrivStrategies::Dlopen;
383 xbt_die("Invalid value for smpi/privatization: '%s'", smpi_privatize_option.c_str());
385 if (not SMPI_switch_data_segment) {
386 XBT_DEBUG("Running without smpi_main(); disable smpi/privatization.");
387 smpi_privatize_global_variables = SmpiPrivStrategies::None;
389 #if defined(__FreeBSD__)
390 if (smpi_privatize_global_variables == SmpiPrivStrategies::Mmap) {
391 XBT_INFO("mmap privatization is broken on FreeBSD, switching to dlopen privatization instead.");
392 smpi_privatize_global_variables = SmpiPrivStrategies::Dlopen;
396 if (smpi_cpu_threshold < 0)
397 smpi_cpu_threshold = DBL_MAX;
399 std::string val = xbt_cfg_get_string("smpi/shared-malloc");
400 if ((val == "yes") || (val == "1") || (val == "on") || (val == "global")) {
401 smpi_cfg_shared_malloc = shmalloc_global;
402 } else if (val == "local") {
403 smpi_cfg_shared_malloc = shmalloc_local;
404 } else if ((val == "no") || (val == "0") || (val == "off")) {
405 smpi_cfg_shared_malloc = shmalloc_none;
407 xbt_die("Invalid value '%s' for option smpi/shared-malloc. Possible values: 'on' or 'global', 'local', 'off'",
412 typedef std::function<int(int argc, char *argv[])> smpi_entry_point_type;
413 typedef int (* smpi_c_entry_point_type)(int argc, char **argv);
414 typedef void (*smpi_fortran_entry_point_type)();
416 static int smpi_run_entry_point(smpi_entry_point_type entry_point, std::vector<std::string> args)
418 char noarg[] = {'\0'};
419 const int argc = args.size();
420 std::unique_ptr<char*[]> argv(new char*[argc + 1]);
421 for (int i = 0; i != argc; ++i)
422 argv[i] = args[i].empty() ? noarg : &args[i].front();
423 argv[argc] = nullptr;
425 int res = entry_point(argc, argv.get());
427 XBT_WARN("SMPI process did not return 0. Return value : %d", res);
428 if (smpi_exit_status == 0)
429 smpi_exit_status = res;
434 // TODO, remove the number of functions involved here
435 static smpi_entry_point_type smpi_resolve_function(void* handle)
437 smpi_fortran_entry_point_type entry_point_fortran = (smpi_fortran_entry_point_type)dlsym(handle, "user_main_");
438 if (entry_point_fortran != nullptr) {
439 return [entry_point_fortran](int argc, char** argv) {
440 smpi_process_init(&argc, &argv);
441 entry_point_fortran();
446 smpi_c_entry_point_type entry_point = (smpi_c_entry_point_type)dlsym(handle, "main");
447 if (entry_point != nullptr) {
451 return smpi_entry_point_type();
454 int smpi_main(const char* executable, int argc, char *argv[])
456 srand(SMPI_RAND_SEED);
458 if (getenv("SMPI_PRETEND_CC") != nullptr) {
459 /* Hack to ensure that smpicc can pretend to be a simple compiler. Particularly handy to pass it to the
460 * configuration tools */
466 SIMIX_global_init(&argc, argv);
467 MSG_init(&argc,argv);
469 SMPI_switch_data_segment = &smpi_switch_data_segment;
471 // TODO This will not be executed in the case where smpi_main is not called,
472 // e.g., not for smpi_msg_masterslave. This should be moved to another location
473 // that is always called -- maybe close to Actor::onCreation?
474 simgrid::s4u::Host::onCreation.connect([](simgrid::s4u::Host& host) {
475 host.extension_set(new simgrid::smpi::SmpiHost(&host));
478 // parse the platform file: get the host list
479 SIMIX_create_environment(argv[1]);
480 SIMIX_comm_set_copy_data_callback(smpi_comm_copy_buffer_callback);
483 if (smpi_privatize_global_variables == SmpiPrivStrategies::Dlopen) {
485 std::string executable_copy = executable;
487 // Prepare the copy of the binary (get its size)
488 struct stat fdin_stat;
489 stat(executable_copy.c_str(), &fdin_stat);
490 off_t fdin_size = fdin_stat.st_size;
491 static std::size_t rank = 0;
493 simix_global->default_function = [executable_copy, fdin_size](std::vector<std::string> args) {
494 return std::function<void()>([executable_copy, fdin_size, args] {
496 // Copy the dynamic library:
497 std::string target_executable = executable_copy
498 + "_" + std::to_string(getpid())
499 + "_" + std::to_string(rank++) + ".so";
501 int fdin = open(executable_copy.c_str(), O_RDONLY);
502 xbt_assert(fdin >= 0, "Cannot read from %s. Please make sure that the file exists and is executable.",
503 executable_copy.c_str());
504 int fdout = open(target_executable.c_str(), O_CREAT | O_RDWR, S_IRWXU);
505 xbt_assert(fdout >= 0, "Cannot write into %s", target_executable.c_str());
507 XBT_DEBUG("Copy %ld bytes into %s", static_cast<long>(fdin_size), target_executable.c_str());
509 ssize_t sent_size = sendfile(fdout, fdin, NULL, fdin_size);
510 xbt_assert(sent_size == fdin_size,
511 "Error while copying %s: only %zd bytes copied instead of %ld (errno: %d -- %s)",
512 target_executable.c_str(), sent_size, fdin_size, errno, strerror(errno));
514 const int bufsize = 1024 * 1024 * 4;
516 while (int got = read(fdin, buf, bufsize)) {
518 xbt_assert(errno == EINTR, "Cannot read from %s", executable_copy.c_str());
522 while (int done = write(fdout, p, todo)) {
524 xbt_assert(errno == EINTR, "Cannot write into %s", target_executable.c_str());
536 // Load the copy and resolve the entry point:
537 void* handle = dlopen(target_executable.c_str(), RTLD_LAZY | RTLD_LOCAL | RTLD_DEEPBIND);
538 int saved_errno = errno;
539 if (xbt_cfg_get_boolean("smpi/keep-temps") == false)
540 unlink(target_executable.c_str());
541 if (handle == nullptr)
542 xbt_die("dlopen failed: %s (errno: %d -- %s)", dlerror(), saved_errno, strerror(saved_errno));
543 smpi_entry_point_type entry_point = smpi_resolve_function(handle);
545 xbt_die("Could not resolve entry point");
547 smpi_run_entry_point(entry_point, args);
552 // Load the dynamic library and resolve the entry point:
553 void* handle = dlopen(executable, RTLD_LAZY | RTLD_LOCAL);
554 if (handle == nullptr)
555 xbt_die("dlopen failed for %s: %s (errno: %d -- %s)", executable, dlerror(), errno, strerror(errno));
556 smpi_entry_point_type entry_point = smpi_resolve_function(handle);
558 xbt_die("main not found in %s", executable);
559 // TODO, register the executable for SMPI privatization
561 // Execute the same entry point for each simulated process:
562 simix_global->default_function = [entry_point](std::vector<std::string> args) {
563 return std::function<void()>([entry_point, args] {
564 smpi_run_entry_point(entry_point, args);
570 SIMIX_launch_application(argv[2]);
571 SMPI_app_instance_register(smpi_default_instance_name.c_str(), nullptr,
572 process_data.size()); // This call has a side effect on process_count...
573 MPI_COMM_WORLD = *smpi_deployment_comm_world(smpi_default_instance_name);
574 smpi_universe_size = process_count;
577 /* Clean IO before the run */
581 if (MC_is_active()) {
587 xbt_os_walltimer_stop(global_timer);
588 if (xbt_cfg_get_boolean("smpi/display-timing")){
589 double global_time = xbt_os_timer_elapsed(global_timer);
590 XBT_INFO("Simulated time: %g seconds. \n\n"
591 "The simulation took %g seconds (after parsing and platform setup)\n"
592 "%g seconds were actual computation of the application",
593 SIMIX_get_clock(), global_time , smpi_total_benched_time);
595 if (smpi_total_benched_time/global_time>=0.75)
596 XBT_INFO("More than 75%% of the time was spent inside the application code.\n"
597 "You may want to use sampling functions or trace replay to reduce this.");
600 smpi_global_destroy();
604 return smpi_exit_status;
607 // Called either directly from the user code, or from the code called by smpirun
609 simgrid::s4u::Actor::onCreation.connect([](simgrid::s4u::ActorPtr actor) {
610 if (not actor->isDaemon()) {
611 process_data.insert({actor, new simgrid::smpi::Process(actor, nullptr)});
614 simgrid::s4u::Actor::onDestruction.connect([](simgrid::s4u::ActorPtr actor) {
615 auto it = process_data.find(actor);
616 if (it != process_data.end()) {
618 process_data.erase(it);
624 smpi_check_options();
626 simgrid::s4u::onSimulationEnd.connect(TRACE_smpi_release);
627 if (smpi_privatize_global_variables == SmpiPrivStrategies::Mmap)
628 smpi_backup_global_memory_segment();
631 void SMPI_finalize(){
632 smpi_global_destroy();
635 void smpi_mpi_init() {
636 if(smpi_init_sleep > 0)
637 simcall_process_sleep(smpi_init_sleep);
640 double smpi_mpi_wtime(){
642 if (smpi_process()->initialized() != 0 && smpi_process()->finalized() == 0 && smpi_process()->sampling() == 0) {
644 time = SIMIX_get_clock();
645 // to avoid deadlocks if used as a break condition, such as
646 // while (MPI_Wtime(...) < time_limit) {
649 // because the time will not normally advance when only calls to MPI_Wtime
650 // are made -> deadlock (MPI_Wtime never reaches the time limit)
651 if(smpi_wtime_sleep > 0)
652 simcall_process_sleep(smpi_wtime_sleep);
655 time = SIMIX_get_clock();