BUG: fixed issue InsightSoftwareConsortium#3032: fixed mutation from …

…several threads simultaneously The itkSingleLevelSetsv4DenseImage2DTest (and others) fail under TSan because an std::map was mutated from several threads at once. Fixed by using compare_exchange_strong() to create a thread safe way.
seanm · Jan 12, 2022 · d3bf262 · d3bf262
1 parent 38d385b
commit d3bf262
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Showing 2 changed files with 19 additions and 5 deletions.
diff --git a/Modules/Segmentation/LevelSetsv4/include/itkLevelSetEquationTermContainer.h b/Modules/Segmentation/LevelSetsv4/include/itkLevelSetEquationTermContainer.h
@@ -22,10 +22,10 @@
 #include "itkLevelSetEquationTermBase.h"
 #include "itkObject.h"
 
-#include <unordered_map>
-
+#include <atomic>
 #include <map>
 #include <string>
+#include <unordered_map>
 
 namespace itk
 {
@@ -320,7 +320,7 @@ class ITK_TEMPLATE_EXPORT LevelSetEquationTermContainer : public Object
 
   MapTermContainerType m_Container;
 
-  using MapCFLContainerType = std::map<TermIdType, LevelSetOutputRealType>;
+  using MapCFLContainerType = std::map<TermIdType, std::atomic<LevelSetOutputRealType>>;
   using MapCFLContainerIterator = typename MapCFLContainerType::iterator;
   using MapCFLContainerConstIterator = typename MapCFLContainerType::const_iterator;
 

diff --git a/Modules/Segmentation/LevelSetsv4/include/itkLevelSetEquationTermContainer.hxx b/Modules/Segmentation/LevelSetsv4/include/itkLevelSetEquationTermContainer.hxx
@@ -271,7 +271,14 @@ LevelSetEquationTermContainer<TInputImage, TLevelSetContainer>::Evaluate(const L
   {
     LevelSetOutputRealType temp_val = (term_it->second)->Evaluate(iP);
 
-    cfl_it->second = std::max(itk::Math::abs(temp_val), cfl_it->second);
+    LevelSetOutputRealType abs_temp_value = itk::Math::abs(temp_val);
+
+    // This is a thread-safe equivalent of:
+    // cfl_it->second = std::max(abs_temp_value, cfl_it->second);
+    LevelSetOutputRealType previous_value = cfl_it->second;
+    while ((abs_temp_value > previous_value) && !cfl_it->second.compare_exchange_strong(previous_value, abs_temp_value))
+    {
+    }
 
     oValue += temp_val;
     ++term_it;
@@ -298,7 +305,14 @@ LevelSetEquationTermContainer<TInputImage, TLevelSetContainer>::Evaluate(const L
   {
     LevelSetOutputRealType temp_val = (term_it->second)->Evaluate(iP, iData);
 
-    cfl_it->second = std::max(itk::Math::abs(temp_val), cfl_it->second);
+    LevelSetOutputRealType abs_temp_value = itk::Math::abs(temp_val);
+
+    // This is a thread-safe equivalent of:
+    // cfl_it->second = std::max(abs_temp_value, cfl_it->second);
+    LevelSetOutputRealType previous_value = cfl_it->second;
+    while ((abs_temp_value > previous_value) && !cfl_it->second.compare_exchange_strong(previous_value, abs_temp_value))
+    {
+    }
 
     oValue += temp_val;
     ++term_it;