core: propagate parallel_for() exceptions

modules/core/src/parallel.cpp

@@ -129,6 +129,28 @@
 
 #include "parallel_impl.hpp"
 
+
+#ifndef CV__EXCEPTION_PTR
+#  ifdef CV_CXX11
+#    define CV__EXCEPTION_PTR 1
+#  elif defined(CV_ICC)
+#    define CV__EXCEPTION_PTR 1
+#  elif defined(_MSC_VER)
+#    define CV__EXCEPTION_PTR (_MSC_VER >= 1600)
+#  elif defined(__clang__)
+#    define CV__EXCEPTION_PTR 0  // C++11 only (see above)
+#  elif defined(__GNUC__) && defined(__GXX_EXPERIMENTAL_CXX0X__)
+#    define CV__EXCEPTION_PTR (__GXX_EXPERIMENTAL_CXX0X__ > 0)
+#  endif
+#endif
+#ifndef CV__EXCEPTION_PTR
+#  define CV__EXCEPTION_PTR 0
+#else
+#  include <exception>  // std::exception_ptr
+#endif
+
+
+
 using namespace cv;
 
 namespace cv
@@ -169,7 +191,7 @@ namespace
     {
     public:
         ParallelLoopBodyWrapperContext(const cv::ParallelLoopBody& _body, const cv::Range& _r, double _nstripes) :
-            is_rng_used(false)
+            is_rng_used(false), hasException(false)
         {
 
             body = &_body;
@@ -189,7 +211,7 @@ namespace
             pThreadRoot = cv::instr::getInstrumentTLSStruct().pCurrentNode;
 #endif
         }
-        ~ParallelLoopBodyWrapperContext()
+        void finalize()
         {
 #ifdef ENABLE_INSTRUMENTATION
             for(size_t i = 0; i < pThreadRoot->m_childs.size(); i++)
@@ -209,7 +231,17 @@ namespace
             if (traceRootRegion)
                 CV_TRACE_NS::details::parallelForFinalize(*traceRootRegion);
 #endif
+
+            if (hasException)
+            {
+#if CV__EXCEPTION_PTR
+                std::rethrow_exception(pException);
+#else
+                CV_ErrorNoReturn(Error::StsError, "Exception in parallel_for() body: " + exception_message);
+#endif
+            }
         }
+        ~ParallelLoopBodyWrapperContext() {}
 
         const cv::ParallelLoopBody* body;
         cv::Range wholeRange;
@@ -223,6 +255,32 @@ namespace
 #ifdef ENABLE_INSTRUMENTATION
         cv::instr::InstrNode *pThreadRoot;
 #endif
+        bool hasException;
+#if CV__EXCEPTION_PTR
+        std::exception_ptr pException;
+#else
+        cv::String exception_message;
+#endif
+#if CV__EXCEPTION_PTR
+        void recordException()
+#else
+        void recordException(const cv::String& msg)
+#endif
+        {
+            if (!hasException)
+            {
+                cv::AutoLock lock(cv::getInitializationMutex());
+                if (!hasException)
+                {
+                    hasException = true;
+#if CV__EXCEPTION_PTR
+                    pException = std::current_exception();
+#else
+                    exception_message = msg;
+#endif
+                }
+            }
+        }
     private:
         ParallelLoopBodyWrapperContext(const ParallelLoopBodyWrapperContext&); // disabled
         ParallelLoopBodyWrapperContext& operator=(const ParallelLoopBodyWrapperContext&); // disabled
@@ -273,7 +331,29 @@ namespace
             CV_TRACE_ARG_VALUE(range_end, "range.end", (int64)r.end);
 #endif
 
-            (*ctx.body)(r);
+            try
+            {
+                (*ctx.body)(r);
+            }
+#if CV__EXCEPTION_PTR
+            catch (...)
+            {
+                ctx.recordException();
+            }
+#else
+            catch (const cv::Exception& e)
+            {
+                ctx.recordException(e.what());
+            }
+            catch (const std::exception& e)
+            {
+                ctx.recordException(e.what());
+            }
+            catch (...)
+            {
+                ctx.recordException("Unknown exception");
+            }
+#endif
 
             if (!ctx.is_rng_used && !(cv::theRNG() == ctx.rng))
                 ctx.is_rng_used = true;
@@ -486,6 +566,8 @@ static void parallel_for_impl(const cv::Range& range, const cv::ParallelLoopBody
 #error You have hacked and compiling with unsupported parallel framework
 
 #endif
+
+        ctx.finalize();  // propagate exceptions if exists
     }
     else
     {