Preserve on_exit funcions between restarts.

[simgrid.git] / src / smpi / internals / smpi_memory.cpp

diff --git a/src/smpi/internals/smpi_memory.cpp b/src/smpi/internals/smpi_memory.cpp
index 14214de4a444f07ed0ede3f3770a95f19fb3f8dc..04a59d607cc0f72cfdc4326dfdaca308fe4e7bcf 100644 (file)
--- a/src/smpi/internals/smpi_memory.cpp
+++ b/src/smpi/internals/smpi_memory.cpp
@@ -75,11 +75,12 @@ static void smpi_get_executable_global_size()
       ++i;
       if (i != map.end() && i->pathname.empty() && (i->prot & PROT_RWX) == PROT_RW &&
           (char*)i->start_addr == smpi_data_exe_start + smpi_data_exe_size) {
-        // Only count this region if it was not already present in the initial map.
-        auto found = std::find_if(begin(initial_vm_map), end(initial_vm_map),
-                                  [&i](const simgrid::xbt::VmMap& m) { return m.start_addr == i->start_addr; });
-        if (found == end(initial_vm_map))
-          smpi_data_exe_size = (char*)i->end_addr - smpi_data_exe_start;
+        // Only count the portion of this region not present in the initial map.
+        auto found = std::find_if(initial_vm_map.begin(), initial_vm_map.end(), [&i](const simgrid::xbt::VmMap& m) {
+          return i->start_addr <= m.start_addr && m.start_addr < i->end_addr;
+        });
+        auto end_addr      = (found == initial_vm_map.end() ? i->end_addr : found->start_addr);
+        smpi_data_exe_size = (char*)end_addr - smpi_data_exe_start;
       }
       return;
     }
@@ -184,10 +185,16 @@ smpi_privatization_region_t smpi_init_global_memory_segment_process()
   char path[24];
   int status;
 
-  do {
-    snprintf(path, sizeof(path), "/smpi-buffer-%06x", rand() % 0xffffffU);
+  constexpr unsigned VAL_MASK = 0xffffffU;
+  static unsigned prev_val    = VAL_MASK;
+  for (unsigned i = (prev_val + 1) & VAL_MASK; i != prev_val; i = (i + 1) & VAL_MASK) {
+    snprintf(path, sizeof(path), "/smpi-buffer-%06x", i);
     file_descriptor = shm_open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-  } while (file_descriptor == -1 && errno == EEXIST);
+    if (file_descriptor != -1 || errno != EEXIST) {
+      prev_val = i;
+      break;
+    }
+  }
   if (file_descriptor < 0) {
     if (errno == EMFILE) {
       xbt_die("Impossible to create temporary file for memory mapping: %s\n\