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/Host.hpp"
10 #include "simgrid/s4u/Mailbox.hpp"
11 #include "simgrid/s4u/forward.hpp"
12 #include "smpi_coll.hpp"
13 #include "smpi_comm.hpp"
14 #include "smpi_group.hpp"
15 #include "smpi_info.hpp"
16 #include "smpi_process.hpp"
17 #include "src/msg/msg_private.hpp"
18 #include "src/simix/smx_private.hpp"
19 #include "src/surf/surf_interface.hpp"
20 #include "xbt/config.hpp"
22 #include <cfloat> /* DBL_MAX */
29 #include <sys/sendfile.h>
32 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_kernel, smpi, "Logging specific to SMPI (kernel)");
33 #include <boost/tokenizer.hpp>
34 #include <boost/algorithm/string.hpp> /* trim_right / trim_left */
37 /* RTLD_DEEPBIND is a bad idea of GNU ld that obviously does not exist on other platforms
38 * See https://www.akkadia.org/drepper/dsohowto.pdf
39 * and https://lists.freebsd.org/pipermail/freebsd-current/2016-March/060284.html
41 #define RTLD_DEEPBIND 0
46 const char* papi_default_config_name = "default";
48 struct papi_process_data {
49 papi_counter_t counter_data;
54 using simgrid::s4u::Actor;
55 using simgrid::s4u::ActorPtr;
56 std::unordered_map<std::string, double> location2speedup;
58 static std::map</*process_id*/ ActorPtr, simgrid::smpi::Process*> process_data;
59 int process_count = 0;
60 int smpi_universe_size = 0;
61 extern double smpi_total_benched_time;
62 xbt_os_timer_t global_timer;
64 * Setting MPI_COMM_WORLD to MPI_COMM_UNINITIALIZED (it's a variable)
65 * is important because the implementation of MPI_Comm checks
66 * "this == MPI_COMM_UNINITIALIZED"? If yes, it uses smpi_process()->comm_world()
68 * This is basically how we only have one global variable but all processes have
69 * different communicators (the one their SMPI instance uses).
71 * See smpi_comm.cpp and the functions therein for details.
73 MPI_Comm MPI_COMM_WORLD = MPI_COMM_UNINITIALIZED;
74 MPI_Errhandler *MPI_ERRORS_RETURN = nullptr;
75 MPI_Errhandler *MPI_ERRORS_ARE_FATAL = nullptr;
76 MPI_Errhandler *MPI_ERRHANDLER_NULL = nullptr;
77 // No instance gets manually created; check also the smpirun.in script as
78 // this default name is used there as well (when the <actor> tag is generated).
79 static const char* smpi_default_instance_name = "smpirun";
80 static simgrid::config::Flag<double> smpi_wtime_sleep(
81 "smpi/wtime", "Minimum time to inject inside a call to MPI_Wtime", 0.0);
82 static simgrid::config::Flag<double> smpi_init_sleep(
83 "smpi/init", "Time to inject inside a call to MPI_Init", 0.0);
85 void (*smpi_comm_copy_data_callback) (smx_activity_t, void*, size_t) = &smpi_comm_copy_buffer_callback;
87 int smpi_process_count()
92 simgrid::smpi::Process* smpi_process()
94 ActorPtr me = Actor::self();
95 if (me == nullptr) // This happens sometimes (eg, when linking against NS3 because it pulls openMPI...)
97 simgrid::msg::ActorExt* msgExt = static_cast<simgrid::msg::ActorExt*>(me->getImpl()->userdata);
98 return static_cast<simgrid::smpi::Process*>(msgExt->data);
101 simgrid::smpi::Process* smpi_process_remote(ActorPtr actor)
103 return process_data.at(actor);
106 MPI_Comm smpi_process_comm_self(){
107 return smpi_process()->comm_self();
110 void smpi_process_init(int *argc, char ***argv){
111 simgrid::smpi::Process::init(argc, argv);
114 int smpi_process_index(){
115 return simgrid::s4u::Actor::self()->getPid();
118 void * smpi_process_get_user_data(){
119 return smpi_process()->get_user_data();
122 void smpi_process_set_user_data(void *data){
123 return smpi_process()->set_user_data(data);
127 int smpi_global_size()
129 char *value = getenv("SMPI_GLOBAL_SIZE");
130 xbt_assert(value,"Please set env var SMPI_GLOBAL_SIZE to the expected number of processes.");
132 return xbt_str_parse_int(value, "SMPI_GLOBAL_SIZE contains a non-numerical value: %s");
135 void smpi_comm_set_copy_data_callback(void (*callback) (smx_activity_t, void*, size_t))
137 smpi_comm_copy_data_callback = callback;
140 static void print(std::vector<std::pair<size_t, size_t>> vec) {
141 std::fprintf(stderr, "{");
142 for (auto const& elt : vec) {
143 std::fprintf(stderr, "(0x%zx, 0x%zx),", elt.first, elt.second);
145 std::fprintf(stderr, "}\n");
147 static void memcpy_private(void* dest, const void* src, std::vector<std::pair<size_t, size_t>>& private_blocks)
149 for (auto const& block : private_blocks)
150 memcpy((uint8_t*)dest+block.first, (uint8_t*)src+block.first, block.second-block.first);
153 static void check_blocks(std::vector<std::pair<size_t, size_t>> &private_blocks, size_t buff_size) {
154 for (auto const& block : private_blocks)
155 xbt_assert(block.first <= block.second && block.second <= buff_size, "Oops, bug in shared malloc.");
158 void smpi_comm_copy_buffer_callback(smx_activity_t synchro, void *buff, size_t buff_size)
160 simgrid::kernel::activity::CommImplPtr comm =
161 boost::dynamic_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
164 size_t src_offset = 0;
165 size_t dst_offset = 0;
166 std::vector<std::pair<size_t, size_t>> src_private_blocks;
167 std::vector<std::pair<size_t, size_t>> dst_private_blocks;
168 XBT_DEBUG("Copy the data over");
169 if((src_shared=smpi_is_shared(buff, src_private_blocks, &src_offset))) {
170 XBT_DEBUG("Sender %p is shared. Let's ignore it.", buff);
171 src_private_blocks = shift_and_frame_private_blocks(src_private_blocks, src_offset, buff_size);
174 src_private_blocks.clear();
175 src_private_blocks.push_back(std::make_pair(0, buff_size));
177 if((dst_shared=smpi_is_shared((char*)comm->dst_buff, dst_private_blocks, &dst_offset))) {
178 XBT_DEBUG("Receiver %p is shared. Let's ignore it.", (char*)comm->dst_buff);
179 dst_private_blocks = shift_and_frame_private_blocks(dst_private_blocks, dst_offset, buff_size);
182 dst_private_blocks.clear();
183 dst_private_blocks.push_back(std::make_pair(0, buff_size));
185 check_blocks(src_private_blocks, buff_size);
186 check_blocks(dst_private_blocks, buff_size);
187 auto private_blocks = merge_private_blocks(src_private_blocks, dst_private_blocks);
188 check_blocks(private_blocks, buff_size);
190 if ((smpi_privatize_global_variables == SMPI_PRIVATIZE_MMAP) && (static_cast<char*>(buff) >= smpi_data_exe_start) &&
191 (static_cast<char*>(buff) < smpi_data_exe_start + smpi_data_exe_size)) {
192 XBT_DEBUG("Privatization : We are copying from a zone inside global memory... Saving data to temp buffer !");
194 smpi_switch_data_segment(Actor::self()->getPid());
195 tmpbuff = static_cast<void*>(xbt_malloc(buff_size));
196 memcpy_private(tmpbuff, buff, private_blocks);
199 if ((smpi_privatize_global_variables == SMPI_PRIVATIZE_MMAP) && ((char*)comm->dst_buff >= smpi_data_exe_start) &&
200 ((char*)comm->dst_buff < smpi_data_exe_start + smpi_data_exe_size)) {
201 XBT_DEBUG("Privatization : We are copying to a zone inside global memory - Switch data segment");
202 smpi_switch_data_segment(Actor::self()->getPid());
204 XBT_DEBUG("Copying %zu bytes from %p to %p", buff_size, tmpbuff,comm->dst_buff);
205 memcpy_private(comm->dst_buff, tmpbuff, private_blocks);
207 if (comm->detached) {
208 // if this is a detached send, the source buffer was duplicated by SMPI
209 // sender to make the original buffer available to the application ASAP
211 //It seems that the request is used after the call there this should be free somewhere else but where???
212 //xbt_free(comm->comm.src_data);// inside SMPI the request is kept inside the user data and should be free
213 comm->src_buff = nullptr;
219 void smpi_comm_null_copy_buffer_callback(smx_activity_t comm, void *buff, size_t buff_size)
221 /* nothing done in this version */
224 static void smpi_check_options(){
225 //check correctness of MPI parameters
227 xbt_assert(xbt_cfg_get_int("smpi/async-small-thresh") <= xbt_cfg_get_int("smpi/send-is-detached-thresh"));
229 if (xbt_cfg_is_default_value("smpi/host-speed")) {
230 XBT_INFO("You did not set the power of the host running the simulation. "
231 "The timings will certainly not be accurate. "
232 "Use the option \"--cfg=smpi/host-speed:<flops>\" to set its value."
233 "Check http://simgrid.org/simgrid/latest/doc/options.html#options_smpi_bench for more information.");
236 xbt_assert(xbt_cfg_get_double("smpi/cpu-threshold") >=0,
237 "The 'smpi/cpu-threshold' option cannot have negative values [anymore]. If you want to discard "
238 "the simulation of any computation, please use 'smpi/simulate-computation:no' instead.");
242 return not process_data.empty();
245 void smpi_global_init()
247 if (not MC_is_active()) {
248 global_timer = xbt_os_timer_new();
249 xbt_os_walltimer_start(global_timer);
252 std::string filename = xbt_cfg_get_string("smpi/comp-adjustment-file");
253 if (not filename.empty()) {
254 std::ifstream fstream(filename);
255 if (not fstream.is_open()) {
256 xbt_die("Could not open file %s. Does it exist?", filename.c_str());
260 typedef boost::tokenizer< boost::escaped_list_separator<char>> Tokenizer;
261 std::getline(fstream, line); // Skip the header line
262 while (std::getline(fstream, line)) {
264 Tokenizer::iterator it = tok.begin();
265 Tokenizer::iterator end = std::next(tok.begin());
267 std::string location = *it;
268 boost::trim(location);
269 location2speedup.insert(std::pair<std::string, double>(location, std::stod(*end)));
274 // This map holds for each computation unit (such as "default" or "process1" etc.)
275 // the configuration as given by the user (counter data as a pair of (counter_name, counter_counter))
276 // and the (computed) event_set.
277 std::map</* computation unit name */ std::string, papi_process_data> units2papi_setup;
279 if (not xbt_cfg_get_string("smpi/papi-events").empty()) {
280 if (PAPI_library_init(PAPI_VER_CURRENT) != PAPI_VER_CURRENT)
281 XBT_ERROR("Could not initialize PAPI library; is it correctly installed and linked?"
282 " Expected version is %i",
285 typedef boost::tokenizer<boost::char_separator<char>> Tokenizer;
286 boost::char_separator<char> separator_units(";");
287 std::string str = xbt_cfg_get_string("smpi/papi-events");
288 Tokenizer tokens(str, separator_units);
290 // Iterate over all the computational units. This could be processes, hosts, threads, ranks... You name it.
291 // I'm not exactly sure what we will support eventually, so I'll leave it at the general term "units".
292 for (auto const& unit_it : tokens) {
293 boost::char_separator<char> separator_events(":");
294 Tokenizer event_tokens(unit_it, separator_events);
296 int event_set = PAPI_NULL;
297 if (PAPI_create_eventset(&event_set) != PAPI_OK) {
298 // TODO: Should this let the whole simulation die?
299 XBT_CRITICAL("Could not create PAPI event set during init.");
302 // NOTE: We cannot use a map here, as we must obey the order of the counters
303 // This is important for PAPI: We need to map the values of counters back
304 // to the event_names (so, when PAPI_read() has finished)!
305 papi_counter_t counters2values;
307 // Iterate over all counters that were specified for this specific
309 // Note that we need to remove the name of the unit
310 // (that could also be the "default" value), which always comes first.
311 // Hence, we start at ++(events.begin())!
312 for (Tokenizer::iterator events_it = ++(event_tokens.begin()); events_it != event_tokens.end(); ++events_it) {
314 int event_code = PAPI_NULL;
315 char* event_name = const_cast<char*>((*events_it).c_str());
316 if (PAPI_event_name_to_code(event_name, &event_code) == PAPI_OK) {
317 if (PAPI_add_event(event_set, event_code) != PAPI_OK) {
318 XBT_ERROR("Could not add PAPI event '%s'. Skipping.", event_name);
321 XBT_DEBUG("Successfully added PAPI event '%s' to the event set.", event_name);
324 XBT_CRITICAL("Could not find PAPI event '%s'. Skipping.", event_name);
328 counters2values.push_back(
329 // We cannot just pass *events_it, as this is of type const basic_string
330 std::make_pair<std::string, long long>(std::string(*events_it), 0));
333 std::string unit_name = *(event_tokens.begin());
334 papi_process_data config = {.counter_data = std::move(counters2values), .event_set = event_set};
336 units2papi_setup.insert(std::make_pair(unit_name, std::move(config)));
342 void smpi_global_destroy()
344 smpi_bench_destroy();
345 smpi_shared_destroy();
346 smpi_deployment_cleanup_instances();
347 for (auto& pair : process_data) {
348 auto& process = pair.second;
349 if (process->comm_self() != MPI_COMM_NULL) {
350 simgrid::smpi::Comm::destroy(process->comm_self());
352 if (process->comm_intra() != MPI_COMM_NULL) {
353 simgrid::smpi::Comm::destroy(process->comm_intra());
355 xbt_os_timer_free(process->timer());
356 xbt_mutex_destroy(process->mailboxes_mutex());
358 process_data.clear();
360 if (simgrid::smpi::Colls::smpi_coll_cleanup_callback != nullptr)
361 simgrid::smpi::Colls::smpi_coll_cleanup_callback();
363 MPI_COMM_WORLD = MPI_COMM_NULL;
365 if (not MC_is_active()) {
366 xbt_os_timer_free(global_timer);
369 if(smpi_privatize_global_variables == SMPI_PRIVATIZE_MMAP)
370 smpi_destroy_global_memory_segments();
374 static void smpi_init_options(){
375 // return if already called
376 if (smpi_cpu_threshold > -1)
378 simgrid::smpi::Colls::set_collectives();
379 simgrid::smpi::Colls::smpi_coll_cleanup_callback = nullptr;
380 smpi_cpu_threshold = xbt_cfg_get_double("smpi/cpu-threshold");
381 smpi_host_speed = xbt_cfg_get_double("smpi/host-speed");
382 std::string smpi_privatize_option = xbt_cfg_get_string("smpi/privatization");
383 if (smpi_privatize_option == "no" || smpi_privatize_option == "0")
384 smpi_privatize_global_variables = SMPI_PRIVATIZE_NONE;
385 else if (smpi_privatize_option == "yes" || smpi_privatize_option == "1")
386 smpi_privatize_global_variables = SMPI_PRIVATIZE_DEFAULT;
387 else if (smpi_privatize_option == "mmap")
388 smpi_privatize_global_variables = SMPI_PRIVATIZE_MMAP;
389 else if (smpi_privatize_option == "dlopen")
390 smpi_privatize_global_variables = SMPI_PRIVATIZE_DLOPEN;
392 xbt_die("Invalid value for smpi/privatization: '%s'", smpi_privatize_option.c_str());
394 #if defined(__FreeBSD__)
395 if (smpi_privatize_global_variables == SMPI_PRIVATIZE_MMAP) {
396 XBT_INFO("Mixing mmap privatization is broken on FreeBSD, switching to dlopen privatization instead.");
397 smpi_privatize_global_variables = SMPI_PRIVATIZE_DLOPEN;
401 if (smpi_cpu_threshold < 0)
402 smpi_cpu_threshold = DBL_MAX;
404 std::string val = xbt_cfg_get_string("smpi/shared-malloc");
405 if ((val == "yes") || (val == "1") || (val == "on") || (val == "global")) {
406 smpi_cfg_shared_malloc = shmalloc_global;
407 } else if (val == "local") {
408 smpi_cfg_shared_malloc = shmalloc_local;
409 } else if ((val == "no") || (val == "0") || (val == "off")) {
410 smpi_cfg_shared_malloc = shmalloc_none;
412 xbt_die("Invalid value '%s' for option smpi/shared-malloc. Possible values: 'on' or 'global', 'local', 'off'",
417 typedef std::function<int(int argc, char *argv[])> smpi_entry_point_type;
418 typedef int (* smpi_c_entry_point_type)(int argc, char **argv);
419 typedef void (*smpi_fortran_entry_point_type)();
421 static int smpi_run_entry_point(smpi_entry_point_type entry_point, std::vector<std::string> args)
423 char noarg[] = {'\0'};
424 const int argc = args.size();
425 std::unique_ptr<char*[]> argv(new char*[argc + 1]);
426 for (int i = 0; i != argc; ++i)
427 argv[i] = args[i].empty() ? noarg : &args[i].front();
428 argv[argc] = nullptr;
430 int res = entry_point(argc, argv.get());
432 XBT_WARN("SMPI process did not return 0. Return value : %d", res);
433 smpi_process()->set_return_value(res);
438 // TODO, remove the number of functions involved here
439 static smpi_entry_point_type smpi_resolve_function(void* handle)
441 smpi_fortran_entry_point_type entry_point_fortran = (smpi_fortran_entry_point_type)dlsym(handle, "user_main_");
442 if (entry_point_fortran != nullptr) {
443 return [entry_point_fortran](int argc, char** argv) {
444 smpi_process_init(&argc, &argv);
445 entry_point_fortran();
450 smpi_c_entry_point_type entry_point = (smpi_c_entry_point_type)dlsym(handle, "main");
451 if (entry_point != nullptr) {
455 return smpi_entry_point_type();
458 int smpi_main(const char* executable, int argc, char *argv[])
460 srand(SMPI_RAND_SEED);
462 if (getenv("SMPI_PRETEND_CC") != nullptr) {
463 /* Hack to ensure that smpicc can pretend to be a simple compiler. Particularly handy to pass it to the
464 * configuration tools */
470 SIMIX_global_init(&argc, argv);
471 MSG_init(&argc,argv);
473 SMPI_switch_data_segment = &smpi_switch_data_segment;
475 // TODO This will not be executed in the case where smpi_main is not called,
476 // e.g., not for smpi_msg_masterslave. This should be moved to another location
477 // that is always called -- maybe close to Actor::onCreation?
478 simgrid::s4u::Host::onCreation.connect([](simgrid::s4u::Host& host) {
479 host.extension_set(new simgrid::smpi::SmpiHost(&host));
482 // parse the platform file: get the host list
483 SIMIX_create_environment(argv[1]);
484 SIMIX_comm_set_copy_data_callback(smpi_comm_copy_buffer_callback);
487 if (smpi_privatize_global_variables == SMPI_PRIVATIZE_DLOPEN) {
489 std::string executable_copy = executable;
491 // Prepare the copy of the binary (get its size)
492 struct stat fdin_stat;
493 stat(executable_copy.c_str(), &fdin_stat);
494 off_t fdin_size = fdin_stat.st_size;
495 static std::size_t rank = 0;
497 simix_global->default_function = [executable_copy, fdin_size](std::vector<std::string> args) {
498 return std::function<void()>([executable_copy, fdin_size, args] {
500 // Copy the dynamic library:
501 std::string target_executable = executable_copy
502 + "_" + std::to_string(getpid())
503 + "_" + std::to_string(rank++) + ".so";
505 int fdin = open(executable_copy.c_str(), O_RDONLY);
506 xbt_assert(fdin >= 0, "Cannot read from %s", executable_copy.c_str());
507 int fdout = open(target_executable.c_str(), O_CREAT | O_RDWR, S_IRWXU);
508 xbt_assert(fdout >= 0, "Cannot write into %s", target_executable.c_str());
511 ssize_t sent_size = sendfile(fdout, fdin, NULL, fdin_size);
512 xbt_assert(sent_size == fdin_size,
513 "Error while copying %s: only %zd bytes copied instead of %ld (errno: %d -- %s)",
514 target_executable.c_str(), sent_size, fdin_size, errno, strerror(errno));
516 XBT_VERB("Copy %d bytes into %s", static_cast<int>(fdin_size), target_executable.c_str());
517 const int bufsize = 1024 * 1024 * 4;
519 while (int got = read(fdin, buf, bufsize)) {
521 xbt_assert(errno == EINTR, "Cannot read from %s", executable_copy.c_str());
525 while (int done = write(fdout, p, todo)) {
527 xbt_assert(errno == EINTR, "Cannot write into %s", target_executable.c_str());
539 // Load the copy and resolve the entry point:
540 void* handle = dlopen(target_executable.c_str(), RTLD_LAZY | RTLD_LOCAL | RTLD_DEEPBIND);
541 int saved_errno = errno;
542 if (xbt_cfg_get_boolean("smpi/keep-temps") == false)
543 unlink(target_executable.c_str());
544 if (handle == nullptr)
545 xbt_die("dlopen failed: %s (errno: %d -- %s)", dlerror(), saved_errno, strerror(saved_errno));
546 smpi_entry_point_type entry_point = smpi_resolve_function(handle);
548 xbt_die("Could not resolve entry point");
550 smpi_run_entry_point(entry_point, args);
557 // Load the dynamic library and resolve the entry point:
558 void* handle = dlopen(executable, RTLD_LAZY | RTLD_LOCAL | RTLD_DEEPBIND);
559 if (handle == nullptr)
560 xbt_die("dlopen failed for %s: %s (errno: %d -- %s)", executable, dlerror(), errno, strerror(errno));
561 smpi_entry_point_type entry_point = smpi_resolve_function(handle);
563 xbt_die("main not found in %s", executable);
564 // TODO, register the executable for SMPI privatization
566 // Execute the same entry point for each simulated process:
567 simix_global->default_function = [entry_point](std::vector<std::string> args) {
568 return std::function<void()>([entry_point, args] {
569 smpi_run_entry_point(entry_point, args);
576 SIMIX_launch_application(argv[2]);
577 SMPI_app_instance_register(smpi_default_instance_name, nullptr,
578 SIMIX_process_count()); // This call has a side effect on process_count...
579 MPI_COMM_WORLD = *smpi_deployment_comm_world(smpi_default_instance_name);
580 smpi_universe_size = process_count;
583 /* Clean IO before the run */
587 if (MC_is_active()) {
593 xbt_os_walltimer_stop(global_timer);
594 if (xbt_cfg_get_boolean("smpi/display-timing")){
595 double global_time = xbt_os_timer_elapsed(global_timer);
596 XBT_INFO("Simulated time: %g seconds. \n\n"
597 "The simulation took %g seconds (after parsing and platform setup)\n"
598 "%g seconds were actual computation of the application",
599 SIMIX_get_clock(), global_time , smpi_total_benched_time);
601 if (smpi_total_benched_time/global_time>=0.75)
602 XBT_INFO("More than 75%% of the time was spent inside the application code.\n"
603 "You may want to use sampling functions or trace replay to reduce this.");
607 for (auto& pair : process_data) {
608 auto& smpi_process = pair.second;
609 if (smpi_process->return_value() != 0) {
610 ret = smpi_process->return_value(); // return first non 0 value
614 smpi_global_destroy();
621 // Called either directly from the user code, or from the code called by smpirun
623 simgrid::s4u::Actor::onCreation.connect([](simgrid::s4u::ActorPtr actor) {
624 process_data.insert({actor, new simgrid::smpi::Process(actor, nullptr)});
626 simgrid::s4u::Actor::onDestruction.connect([](simgrid::s4u::ActorPtr actor) {
627 if (process_data.find(actor) != process_data.end()) {
628 delete process_data.at(actor);
629 process_data.erase(actor);
635 smpi_check_options();
637 simgrid::surf::surfExitCallbacks.connect(TRACE_smpi_release);
638 if(smpi_privatize_global_variables == SMPI_PRIVATIZE_MMAP)
639 smpi_backup_global_memory_segment();
642 void SMPI_finalize(){
643 smpi_global_destroy();
646 void smpi_mpi_init() {
647 if(smpi_init_sleep > 0)
648 simcall_process_sleep(smpi_init_sleep);
651 double smpi_mpi_wtime(){
653 if (smpi_process()->initialized() != 0 && smpi_process()->finalized() == 0 && smpi_process()->sampling() == 0) {
655 time = SIMIX_get_clock();
656 // to avoid deadlocks if used as a break condition, such as
657 // while (MPI_Wtime(...) < time_limit) {
660 // because the time will not normally advance when only calls to MPI_Wtime
661 // are made -> deadlock (MPI_Wtime never reaches the time limit)
662 if(smpi_wtime_sleep > 0)
663 simcall_process_sleep(smpi_wtime_sleep);
666 time = SIMIX_get_clock();