+
+ smpi_privatisation_regions = (smpi_privatisation_region_t) malloc(
+ smpi_process_count() * sizeof(struct s_smpi_privatisation_region));
+
+ for (i=0; i< SIMIX_process_count(); i++){
+ //create SIMIX_process_count() mappings of this size with the same data inside
+ void *address = NULL;
+ char path[] = "/dev/shm/my-buffer-XXXXXX";
+ int status;
+
+ int file_descriptor= mkstemp (path);
+ if (file_descriptor < 0) {
+ if (errno==EMFILE) {
+ xbt_die("Impossible to create temporary file for memory mapping: %s\n\
+The open() system call failed with the EMFILE error code (too many files). \n\n\
+This means that you reached the system limits concerning the amount of files per process. \
+This is not a surprise if you are trying to virtualize many processes on top of SMPI. \
+Don't panic -- you should simply increase your system limits and try again. \n\n\
+First, check what your limits are:\n\
+ cat /proc/sys/fs/file-max # Gives you the system-wide limit\n\
+ ulimit -Hn # Gives you the per process hard limit\n\
+ ulimit -Sn # Gives you the per process soft limit\n\
+ cat /proc/self/limits # Displays any per-process limitation (including the one given above)\n\n\
+If one of these values is less than the amount of MPI processes that you try to run, then you got the explanation of this error. \
+Ask the Internet about tutorials on how to increase the files limit such as: https://rtcamp.com/tutorials/linux/increase-open-files-limit/",
+ strerror(errno));
+ }
+ xbt_die("Impossible to create temporary file for memory mapping: %s",
+ strerror(errno));
+ }
+
+ status = unlink (path);
+ if (status)
+ xbt_die("Impossible to unlink temporary file for memory mapping");
+
+ status = ftruncate(file_descriptor, smpi_size_data_exe);
+ if(status)
+ xbt_die("Impossible to set the size of the temporary file for memory mapping");
+
+ /* Ask for a free region */
+ address = mmap (NULL, smpi_size_data_exe, PROT_READ | PROT_WRITE, MAP_SHARED, file_descriptor, 0);
+ if (address == MAP_FAILED)
+ xbt_die("Couldn't find a free region for memory mapping");
+
+ //initialize the values
+ memcpy(address, TOPAGE(smpi_start_data_exe), smpi_size_data_exe);
+
+ //store the address of the mapping for further switches
+ smpi_privatisation_regions[i].file_descriptor = file_descriptor;
+ smpi_privatisation_regions[i].address = address;
+ }
+
+#endif
+
+}
+
+void smpi_destroy_global_memory_segments(){
+ if (smpi_size_data_exe == 0)//no need to switch
+ return;
+#ifdef HAVE_MMAP
+ int i;
+ for (i=0; i< smpi_process_count(); i++){
+ if(munmap(smpi_privatisation_regions[i].address, smpi_size_data_exe) < 0) {
+ XBT_WARN("Unmapping of fd %d failed: %s",
+ smpi_privatisation_regions[i].file_descriptor, strerror(errno));
+ }
+ close(smpi_privatisation_regions[i].file_descriptor);