+static void smpi_copy_file(std::string src, std::string target, off_t fdin_size)
+{
+ int fdin = open(src.c_str(), O_RDONLY);
+ xbt_assert(fdin >= 0, "Cannot read from %s. Please make sure that the file exists and is executable.", src.c_str());
+ int fdout = open(target.c_str(), O_CREAT | O_RDWR, S_IRWXU);
+ xbt_assert(fdout >= 0, "Cannot write into %s", target.c_str());
+
+ XBT_DEBUG("Copy %" PRIdMAX " bytes into %s", static_cast<intmax_t>(fdin_size), target.c_str());
+ bool slow_copy = true;
+#if HAVE_SENDFILE
+ ssize_t sent_size = sendfile(fdout, fdin, NULL, fdin_size);
+ if (sent_size == fdin_size)
+ slow_copy = false;
+ else if (sent_size != -1 || errno != ENOSYS)
+ xbt_die("Error while copying %s: only %zd bytes copied instead of %" PRIdMAX " (errno: %d -- %s)", target.c_str(),
+ sent_size, static_cast<intmax_t>(fdin_size), errno, strerror(errno));
+#endif
+ if (slow_copy) {
+ const int bufsize = 1024 * 1024 * 4;
+ char buf[bufsize];
+ while (int got = read(fdin, buf, bufsize)) {
+ if (got == -1) {
+ xbt_assert(errno == EINTR, "Cannot read from %s", src.c_str());
+ } else {
+ char* p = buf;
+ int todo = got;
+ while (int done = write(fdout, p, todo)) {
+ if (done == -1) {
+ xbt_assert(errno == EINTR, "Cannot write into %s", target.c_str());
+ } else {
+ p += done;
+ todo -= done;
+ }
+ }
+ }
+ }
+ }
+ close(fdin);
+ close(fdout);
+}
+
+#if not defined(__APPLE__)
+static int visit_libs(struct dl_phdr_info* info, size_t, void* data)
+{
+ char* libname = (char*)(data);
+ const char *path = info->dlpi_name;
+ if(strstr(path, libname)){
+ strncpy(libname, path, 512);
+ return 1;
+ }
+
+ return 0;
+}
+#endif
+
+static void smpi_init_privatization_dlopen(std::string executable)
+{
+ // Prepare the copy of the binary (get its size)
+ struct stat fdin_stat;
+ stat(executable.c_str(), &fdin_stat);
+ off_t fdin_size = fdin_stat.st_size;
+ static std::size_t rank = 0;
+
+ std::string libnames = simgrid::config::get_value<std::string>("smpi/privatize-libs");
+ if (not libnames.empty()) {
+ // split option
+ std::vector<std::string> privatize_libs;
+ boost::split(privatize_libs, libnames, boost::is_any_of(";"));
+
+ for (auto const& libname : privatize_libs) {
+ // load the library once to add it to the local libs, to get the absolute path
+ void* libhandle = dlopen(libname.c_str(), RTLD_LAZY);
+ // get library name from path
+ char fullpath[512] = {'\0'};
+ strcpy(fullpath, libname.c_str());
+#if not defined(__APPLE__)
+ int ret = dl_iterate_phdr(visit_libs, fullpath);
+ if (ret == 0)
+ xbt_die("Can't find a linked %s - check the setting you gave to smpi/privatize-libs", fullpath);
+ else
+ XBT_DEBUG("Extra lib to privatize found : %s", fullpath);
+#else
+ xbt_die("smpi/privatize-libs is not (yet) compatible with OSX");
+#endif
+ privatize_libs_paths.push_back(fullpath);
+ dlclose(libhandle);
+ }
+ }
+
+ simix_global->default_function = [executable, fdin_size](std::vector<std::string> args) {
+ return std::function<void()>([executable, fdin_size, args] {
+
+ // Copy the dynamic library:
+ std::string target_executable =
+ executable + "_" + std::to_string(getpid()) + "_" + std::to_string(rank) + ".so";
+
+ smpi_copy_file(executable, target_executable, fdin_size);
+ // if smpi/privatize-libs is set, duplicate pointed lib and link each executable copy to a different one.
+ std::vector<std::string> target_libs;
+ for (auto const& libpath : privatize_libs_paths) {
+ // if we were given a full path, strip it
+ size_t index = libpath.find_last_of("/\\");
+ std::string libname;
+ if (index != std::string::npos)
+ libname = libpath.substr(index + 1);
+
+ if (not libname.empty()) {
+ // load the library to add it to the local libs, to get the absolute path
+ struct stat fdin_stat2;
+ stat(libpath.c_str(), &fdin_stat2);
+ off_t fdin_size2 = fdin_stat2.st_size;
+
+ // Copy the dynamic library, the new name must be the same length as the old one
+ // just replace the name with 7 digits for the rank and the rest of the name.
+ unsigned int pad = 7;
+ if (libname.length() < pad)
+ pad = libname.length();
+ std::string target_lib =
+ std::string(pad - std::to_string(rank).length(), '0') + std::to_string(rank) + libname.substr(pad);
+ target_libs.push_back(target_lib);
+ XBT_DEBUG("copy lib %s to %s, with size %lld", libpath.c_str(), target_lib.c_str(), (long long)fdin_size2);
+ smpi_copy_file(libpath, target_lib, fdin_size2);
+
+ std::string sedcommand = "sed -i -e 's/" + libname + "/" + target_lib + "/g' " + target_executable;
+ int ret = system(sedcommand.c_str());
+ if (ret != 0)
+ xbt_die("error while applying sed command %s \n", sedcommand.c_str());
+ }
+ }
+
+ rank++;
+ // Load the copy and resolve the entry point:
+ void* handle = dlopen(target_executable.c_str(), RTLD_LAZY | RTLD_LOCAL | WANT_RTLD_DEEPBIND);
+ int saved_errno = errno;
+ if (simgrid::config::get_value<bool>("smpi/keep-temps") == false) {
+ unlink(target_executable.c_str());
+ for (const std::string& target_lib : target_libs)
+ unlink(target_lib.c_str());
+ }
+ if (handle == nullptr)
+ xbt_die("dlopen failed: %s (errno: %d -- %s)", dlerror(), saved_errno, strerror(saved_errno));
+ smpi_entry_point_type entry_point = smpi_resolve_function(handle);
+ if (not entry_point)
+ xbt_die("Could not resolve entry point");
+ smpi_run_entry_point(entry_point, args);
+ });
+ };
+}
+
+static void smpi_init_privatization_no_dlopen(std::string executable)
+{
+ if (smpi_privatize_global_variables == SmpiPrivStrategies::MMAP)
+ smpi_prepare_global_memory_segment();
+ // Load the dynamic library and resolve the entry point:
+ void* handle = dlopen(executable.c_str(), RTLD_LAZY | RTLD_LOCAL);
+ if (handle == nullptr)
+ xbt_die("dlopen failed for %s: %s (errno: %d -- %s)", executable.c_str(), dlerror(), errno, strerror(errno));
+ smpi_entry_point_type entry_point = smpi_resolve_function(handle);
+ if (not entry_point)
+ xbt_die("main not found in %s", executable.c_str());
+ if (smpi_privatize_global_variables == SmpiPrivStrategies::MMAP)
+ smpi_backup_global_memory_segment();
+
+ // Execute the same entry point for each simulated process:
+ simix_global->default_function = [entry_point](std::vector<std::string> args) {
+ return std::function<void()>([entry_point, args] { smpi_run_entry_point(entry_point, args); });
+ };
+}
+
+int smpi_main(const char* executable, int argc, char* argv[])