ChangeLogTag:Fri Aug 24 21:52:37 UTC 2007 Steve Huston <shuston@riverace.com>

3 files changed, 31 insertions, 7 deletions

diff --git a/ACE/ChangeLog b/ACE/ChangeLog
index 0c28d0a59f3..59757a27eaf 100644
--- a/ACE/ChangeLog
+++ b/ACE/ChangeLog
@@ -1,6 +1,18 @@
 Fri Aug 24 21:52:37 UTC 2007  Steve Huston  <shuston@riverace.com>
 
-        * tests/Naming_Test.cpp: Correct logging formats.
+        * ace/MMAP_Memoy_Pool.cpp (map_file): Reverted the "always do
+          MAP_FIXED" flag on remapping a file from:
+          Wed Aug 22 18:10:09 UTC 2007  Steve Huston  <shuston@riverace.com>
+          That's an invalid thing to do, as it has the potential to remap
+          pages from things like the heap or the C library or ACE into the
+          mapped file - definitely not what we want. If the remap has to move
+          the area, it's best to fail it here.
+
+        * tests/Naming_Test.cpp: Correct logging formats and wedge in a base
+          address for the name space's mmaped region. This avoids having to
+          move the mapped area as it grows, which totally screws the name
+          space map. RHEL4 x64 seems to be the only platform this is tested
+          on regularly where this condition is hit.
 
 Fri Aug 24 16:15:59 UTC 2007  Phil Mesnier  <mesnier_p@ociweb.com>
 
diff --git a/ACE/ace/MMAP_Memory_Pool.cpp b/ACE/ace/MMAP_Memory_Pool.cpp
index 1a8c93079fd..1051b33d9ec 100644
--- a/ACE/ace/MMAP_Memory_Pool.cpp
+++ b/ACE/ace/MMAP_Memory_Pool.cpp
@@ -275,13 +275,13 @@ ACE_MMAP_Memory_Pool::map_file (size_t map_size)
     this->base_addr_ = 0;
 #endif /* ACE_HAS_POSITION_INDEPENDENT_POINTERS == 1 */
 
-  // Remap the file; try to stay at the same location as a previous mapping.
-  int flags = this->flags_;
-  if (this->base_addr_ != 0)
-    flags |= MAP_FIXED;
+  // Remap the file; try to stay at the same location as a previous mapping
+  // but do not force it with MAP_FIXED. Doing so will give the OS permission
+  // to map locations currently holding other things (such as the heap, or
+  // the C library) into the map file, producing very unexpected results.
   if (this->mmap_.map (map_size,
                        PROT_RDWR,
-                       flags,
+                       this->flags_,
                        this->base_addr_,
                        0,
                        this->sa_) == -1
diff --git a/ACE/tests/Naming_Test.cpp b/ACE/tests/Naming_Test.cpp
index 7ce62c3b424..f45bf86935d 100644
--- a/ACE/tests/Naming_Test.cpp
+++ b/ACE/tests/Naming_Test.cpp
@@ -198,7 +198,19 @@ run_main (int argc, ACE_TCHAR *argv[])
   ACE_Name_Options *name_options = ns_context->name_options ();
 
   name_options->parse_args (argc, argv);
-
+  /*
+  ** NOTE! This is an experimental value and is not magic in any way. It
+  ** works for me, on one system. It's needed because in the particular
+  ** case here where the underlying mmap will allocate a small area and
+  ** then try to grow it, it always moves it to a new location, which
+  ** totally screws things up. I once tried forcing the realloc to do
+  ** MAP_FIXED but that's not a good solution since it may overwrite other
+  ** mapped areas of memory, like the heap, or the C library, and get very
+  ** unexpected results.    (Steve Huston, 24-August-2007)
+  */
+# if defined (linux) && defined (__x86_64__)
+  name_options->base_address ((char*)0x3c00000000);
+#endif
   int unicode = 0;
 #if (defined (ACE_WIN32) && defined (ACE_USES_WCHAR))
   unicode = 1;