[MOAB-dev] r3431 - MOAB/trunk

[kraftche at cae.wisc.edu]

Author: kraftche
Date: 2010-01-18 11:52:33 -0600 (Mon, 18 Jan 2010)
New Revision: 3431

Modified:
   MOAB/trunk/Tqdcfr.cpp
   MOAB/trunk/Tqdcfr.hpp
Log:
Fix memory corruption in tqdcfr test (two redundant fixes for the same problem).

The problem:

Tqdcfr.cpp contains both the implementation of MOAB's cub file reader and 
some test code.  The test code is wrapped within a #ifdef TEST_TQDCFR 
block.  When the test is compiled and linked to libmoab.so the resulting
executable ends up with two copies of the Tqdcfr implementation: one from
MOAB and one from the test .o file.  When libmoab is a static library this
isn't a problem.  The linker will never pull in MOAB's Tqdcfr.o from the
static library because it doesn't require it to resolve any symbols (all
symbols already defined in the test .o.)  This is not the case for a shared
library, where the .so is either used entirely or not at all.  The duplicate
code isn't really an issue in that case either as long as both copies are
the same.  However, Tqdcfr also declares some static instances of std::string.
That's where things go wrong.  The resulting test executable ends up with
two instances of the static string with the same symbol name and two registered
exit handlers to clean up the statics (one form the .so and one from the
main.)  These both end up trying to free the same instance of the static
string, resulting in memory corruption.

The 1st implemented solution:  Use const char* defined in .cpp file rather
than std::string for string constants so no exit-time cleanup is required.

The 2nd implemented solution:  Wrap main body of Tqdcfr.cpp in 
#ifndef TEST_TQDCFR to avoid object code duplication.

The best solution (not implemented) is probably to just put the test code in 
its own .cpp file.



Modified: MOAB/trunk/Tqdcfr.cpp
===================================================================
--- MOAB/trunk/Tqdcfr.cpp	2010-01-16 00:07:47 UTC (rev 3430)
+++ MOAB/trunk/Tqdcfr.cpp	2010-01-18 17:52:33 UTC (rev 3431)
@@ -16,12 +16,16 @@
 #include "Tqdcfr.hpp"
 #include "MBCore.hpp"
 #include "MBRange.hpp"
+#include "FileOptions.hpp"
+#include <iostream>
+
+#ifndef TEST_TQDCFR
+
 #include "MBReadUtilIface.hpp"
 #include "GeomTopoTool.hpp"
 #include "MBTagConventions.hpp"
 #include "MBCN.hpp"
 #include "MBInternals.hpp"
-#include "FileOptions.hpp"
 #include "HigherOrderFactory.hpp"
 #include "exodus_order.h"
 
@@ -29,7 +33,6 @@
 #include "MBmpi.h"
 #endif
 
-#include <iostream>
 #include <sstream>
 #include <assert.h>
 
@@ -91,8 +94,8 @@
 // moab_conn[ cub_hex27_order[i] ] = cubit_conn[ i ];
 const int* const* const* const cub_elem_order_map = exodus_elem_order_map;
 
-std::string Tqdcfr::BLOCK_NODESET_OFFSET_TAG_NAME = "BLOCK_NODESET_OFFSET";
-std::string Tqdcfr::BLOCK_SIDESET_OFFSET_TAG_NAME = "BLOCK_SIDESET_OFFSET";
+const char *const BLOCK_NODESET_OFFSET_TAG_NAME = "BLOCK_NODESET_OFFSET";
+const char *const BLOCK_SIDESET_OFFSET_TAG_NAME = "BLOCK_SIDESET_OFFSET";
 
 #define RR if (MB_SUCCESS != result) return result
 
@@ -400,7 +403,7 @@
     // set, we don't need to convert
   unsigned int nodeset_offset, sideset_offset;
   MBTag tmp_tag;
-  MBErrorCode result = mdbImpl->tag_get_handle(BLOCK_NODESET_OFFSET_TAG_NAME.c_str(),
+  MBErrorCode result = mdbImpl->tag_get_handle(BLOCK_NODESET_OFFSET_TAG_NAME,
                                                tmp_tag);
   if (MB_SUCCESS != result) nodeset_offset = 0;
   else {
@@ -408,7 +411,7 @@
     if (MB_SUCCESS != result) return result;
   }
 
-  result = mdbImpl->tag_get_handle(BLOCK_SIDESET_OFFSET_TAG_NAME.c_str(),
+  result = mdbImpl->tag_get_handle(BLOCK_SIDESET_OFFSET_TAG_NAME,
                                    tmp_tag);
   if (MB_SUCCESS != result) sideset_offset = 0;
   else {
@@ -2571,7 +2574,8 @@
   return mdbImpl->create_meshset( flags, h );
 }
 
-#ifdef TEST_TQDCFR
+// #ifdef TEST_TQDCFR
+#else
 #include "MBCore.hpp"
 #include "testdir.h"
 

Modified: MOAB/trunk/Tqdcfr.hpp
===================================================================
--- MOAB/trunk/Tqdcfr.hpp	2010-01-16 00:07:47 UTC (rev 3430)
+++ MOAB/trunk/Tqdcfr.hpp	2010-01-18 17:52:33 UTC (rev 3431)
@@ -336,9 +336,6 @@
 
   Tqdcfr(MBInterface *impl);
 
-  static std::string BLOCK_NODESET_OFFSET_TAG_NAME;
-  static std::string BLOCK_SIDESET_OFFSET_TAG_NAME;
-  
   MBErrorCode create_set( MBEntityHandle& h, unsigned int flags = MESHSET_SET );
 
 private: