Update copyright lines for 2022.

[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 02d93cf..8a62eab 100644 (file)
--- a/src/smpi/internals/smpi_memory.cpp
+++ b/src/smpi/internals/smpi_memory.cpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2015-2021. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2015-2022. 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. */
@@ -28,9 +28,8 @@
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_memory, smpi, "Memory layout support for SMPI");
 
-int smpi_loaded_page      = -1;
 char* smpi_data_exe_start = nullptr;
-int smpi_data_exe_size    = 0;
+size_t smpi_data_exe_size = 0;
 SmpiPrivStrategies smpi_privatize_global_variables;
 static void* smpi_data_exe_copy;
 
@@ -176,15 +175,25 @@ void* smpi_temp_shm_mmap(int fd, size_t size)
 /** Map a given SMPI privatization segment (make an SMPI process active)
  *
  *  When doing a state restoration, the state of the restored variables  might not be consistent with the state of the
- *  virtual memory. In this case, we to change the data segment.
+ *  virtual memory. In this case, we have to change the data segment.
+ *
+ *  If 'addr' is not null, only switch if it's an address from the data segment.
+ *
+ *  Returns 'true' if the segment has to be switched (mmap privatization and 'addr' in data segment).
  */
-void smpi_switch_data_segment(simgrid::s4u::ActorPtr actor)
+bool smpi_switch_data_segment(simgrid::s4u::ActorPtr actor, const void* addr)
 {
-  if (smpi_loaded_page == actor->get_pid()) // no need to switch, we've already loaded the one we want
-    return;
+  if (smpi_cfg_privatization() != SmpiPrivStrategies::MMAP || smpi_data_exe_size == 0)
+    return false; // no need to switch
 
-  if (smpi_data_exe_size == 0) // no need to switch
-    return;
+  if (addr != nullptr &&
+      not(static_cast<const char*>(addr) >= smpi_data_exe_start &&
+          static_cast<const char*>(addr) < smpi_data_exe_start + smpi_data_exe_size))
+    return false; // no need to switch, addr is not concerned
+
+  static aid_t smpi_loaded_page = -1;
+  if (smpi_loaded_page == actor->get_pid()) // no need to switch, we've already loaded the one we want
+    return true;                            // return 'true' anyway
 
 #if HAVE_PRIVATIZATION
   // FIXME, cross-process support (mmap across process when necessary)
@@ -196,6 +205,8 @@ void smpi_switch_data_segment(simgrid::s4u::ActorPtr actor)
              "Couldn't map the new region (errno %d): %s", errno, strerror(errno));
   smpi_loaded_page = actor->get_pid();
 #endif
+
+  return true;
 }
 
 /**
@@ -210,7 +221,7 @@ void smpi_backup_global_memory_segment()
   initial_vm_map.clear();
   initial_vm_map.shrink_to_fit();
 
-  XBT_DEBUG("bss+data segment found : size %d starting at %p", smpi_data_exe_size, smpi_data_exe_start);
+  XBT_DEBUG("bss+data segment found : size %zu 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;