From f7c593e412f22ff7eeabb93ccaedbb22011982f5 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Thu, 27 Jun 2013 23:16:41 +0000
Subject: [PATCH] Re-enable the functionality previously reverted in 24748.
 This didn't work back then, and it's likely not going to work now, but I need
 a baseline of tests that fail.

git-svn-id: https://svn.dealii.org/trunk@29899 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/include/deal.II/base/work_stream.h | 27 ++++++++++------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/deal.II/include/deal.II/base/work_stream.h b/deal.II/include/deal.II/base/work_stream.h
index 3a98da2afa..8e2ade6d71 100644
--- a/deal.II/include/deal.II/base/work_stream.h
+++ b/deal.II/include/deal.II/base/work_stream.h
@@ -19,6 +19,7 @@
 #include <deal.II/base/template_constraints.h>
 #include <deal.II/base/std_cxx1x/function.h>
 #include <deal.II/base/std_cxx1x/bind.h>
+#include <deal.II/base/thread_local_storage.h>
 
 #ifdef DEAL_II_WITH_THREADS
 #  include <deal.II/base/thread_management.h>
@@ -156,8 +157,8 @@ namespace WorkStream
        */
       typedef
       std_cxx1x::tuple<std::vector<Iterator>,
-                ScratchData *,
-                std::vector<CopyData>,
+                Threads::ThreadLocalStorage<ScratchData>*,
+		std::vector<CopyData>,
                 unsigned int>
                 ItemType;
 
@@ -180,6 +181,7 @@ namespace WorkStream
         tbb::filter (/*is_serial=*/true),
         remaining_iterator_range (begin, end),
         ring_buffer (buffer_size),
+			thread_local_scratch(sample_scratch_data),
         n_emitted_items (0),
         chunk_size (chunk_size)
       {
@@ -194,20 +196,10 @@ namespace WorkStream
           tasks += Threads::new_task (&IteratorRangeToItemStream::init_buffer_elements,
                                       *this,
                                       i,
-                                      std_cxx1x::cref(sample_scratch_data),
                                       std_cxx1x::cref(sample_copy_data));
         tasks.join_all ();
       }
 
-      /**
-       * Destructor.
-       */
-      ~IteratorRangeToItemStream ()
-      {
-        for (unsigned int i=0; i<ring_buffer.size(); ++i)
-          delete std_cxx1x::get<1>(ring_buffer[i]);
-      }
-
       /**
        * Create a item and return a
        * pointer to it.
@@ -260,6 +252,12 @@ namespace WorkStream
       std::vector<ItemType>        ring_buffer;
 
       /**
+					  * Scratch data object. Each thread will
+					  * have its own local copy.
+					  */
+	Threads::ThreadLocalStorage<ScratchData> thread_local_scratch;
+
+					 /**
        * Counter for the number of emitted
        * items. Each item may consist of up
        * to chunk_size iterator elements.
@@ -286,7 +284,6 @@ namespace WorkStream
        * the ring buffer.
        */
       void init_buffer_elements (const unsigned int element,
-                                 const ScratchData &sample_scratch_data,
                                  const CopyData    &sample_copy_data)
       {
         Assert (std_cxx1x::get<1>(ring_buffer[element]) == 0,
@@ -295,7 +292,7 @@ namespace WorkStream
         std_cxx1x::get<0>(ring_buffer[element])
         .resize (chunk_size, remaining_iterator_range.second);
         std_cxx1x::get<1>(ring_buffer[element])
-          = new ScratchData(sample_scratch_data);
+	        = &thread_local_scratch;
         std_cxx1x::get<2>(ring_buffer[element])
         .resize (chunk_size, sample_copy_data);
       }
@@ -354,7 +351,7 @@ namespace WorkStream
 	    try
 	      {
 		worker (std_cxx1x::get<0>(*current_item)[i],
-			*std_cxx1x::get<1>(*current_item),
+		      std_cxx1x::get<1>(*current_item)->get(),
 			std_cxx1x::get<2>(*current_item)[i]);
 	      }
 	    catch (const std::exception &exc)
-- 
2.39.5