Don't rely on random to generate temporary file names.

[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 d469b16..49e4ab1 100644 (file)
--- a/src/smpi/internals/smpi_memory.cpp
+++ b/src/smpi/internals/smpi_memory.cpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2015-2018. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2015-2019. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -24,7 +24,7 @@
 #include "src/xbt/memory_map.hpp"
 
 #include "private.hpp"
-#include "smpi_process.hpp"
+#include "src/smpi/include/smpi_actor.hpp"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_memory, smpi, "Memory layout support for SMPI");
 
@@ -88,7 +88,7 @@ static void smpi_get_executable_global_size()
 }
 #endif
 
-#if HAVE_SANITIZE_ADDRESS
+#if HAVE_SANITIZER_ADDRESS
 #include <sanitizer/asan_interface.h>
 static void* asan_safe_memcpy(void* dest, void* src, size_t n)
 {
@@ -133,7 +133,7 @@ void smpi_really_switch_data_segment(simgrid::s4u::ActorPtr actor)
 #if HAVE_PRIVATIZATION
   // FIXME, cross-process support (mmap across process when necessary)
   XBT_DEBUG("Switching data frame to the one of process %ld", actor->get_pid());
-  simgrid::smpi::Process* process = smpi_process_remote(actor);
+  simgrid::smpi::ActorExt* process = smpi_process_remote(actor);
   int current                     = process->privatized_region()->file_descriptor;
   void* tmp = mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_RW, MAP_FIXED | MAP_SHARED, current, 0);
   if (tmp != TOPAGE(smpi_data_exe_start))
@@ -155,7 +155,7 @@ int smpi_is_privatization_file(char* file)
  */
 void smpi_backup_global_memory_segment()
 {
-  xbt_assert(HAVE_PRIVATIZATION, "You are trying to use privatization on a system that does not support it. Don't.");
+#if HAVE_PRIVATIZATION
   smpi_get_executable_global_size();
   initial_vm_map.clear();
   initial_vm_map.shrink_to_fit();
@@ -163,7 +163,7 @@ void smpi_backup_global_memory_segment()
   XBT_DEBUG("bss+data segment found : size %d starting at %p", smpi_data_exe_size, smpi_data_exe_start);
 
   if (smpi_data_exe_size == 0) { // no need to do anything as global variables don't exist
-    smpi_privatize_global_variables = SmpiPrivStrategies::None;
+    smpi_privatize_global_variables = SmpiPrivStrategies::NONE;
     return;
   }
 
@@ -171,6 +171,9 @@ void smpi_backup_global_memory_segment()
   // Make a copy of the data segment. This clean copy is retained over the whole runtime
   // of the simulation and can be used to initialize a dynamically added, new process.
   asan_safe_memcpy(smpi_data_exe_copy, TOPAGE(smpi_data_exe_start), smpi_data_exe_size);
+#else /* ! HAVE_PRIVATIZATION */
+  xbt_die("You are trying to use privatization on a system that does not support it. Don't.");
+#endif
 }
 
 // Initializes the memory mapping for a single process and returns the privatization region
@@ -181,10 +184,16 @@ 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\