From 1490099ddd10dffebcd6d9020b3a4f3c0624b69c Mon Sep 17 00:00:00 2001
From: Carl Poirier <carl.poirier.2@gmail.com>
Date: Fri, 31 Jan 2014 18:27:06 +0100
Subject: [PATCH] Parallelized the RN_DATA::Recalculate() function.

---
 CMakeLists.txt           |  7 +++++++
 pcbnew/CMakeLists.txt    |  2 ++
 pcbnew/ratsnest_data.cpp | 28 +++++++++++++++++++++++-----
 3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d72d54d6de..c3fc56208b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -125,6 +125,13 @@ if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
         set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility-inlines-hidden" )
     endif()
 
+    find_package( OpenMP QUIET )
+    if( OPENMP_FOUND )
+        set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}" )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}" )
+        add_definitions( -DUSE_OPENMP )
+    endif()
+
     if( MINGW )
         set( CMAKE_EXE_LINKER_FLAGS_RELEASE "-s" )
 
diff --git a/pcbnew/CMakeLists.txt b/pcbnew/CMakeLists.txt
index 11663c684f..86e8dd296d 100644
--- a/pcbnew/CMakeLists.txt
+++ b/pcbnew/CMakeLists.txt
@@ -1,6 +1,8 @@
 
 set( MAKE_LINK_MAPS false )
 
+set( CMAKE_CXX_FLAGS "-fopenmp" )
+
 add_definitions( -DPCBNEW )
 add_subdirectory(router)
 
diff --git a/pcbnew/ratsnest_data.cpp b/pcbnew/ratsnest_data.cpp
index af5f6932fd..977e3bcc9e 100644
--- a/pcbnew/ratsnest_data.cpp
+++ b/pcbnew/ratsnest_data.cpp
@@ -27,6 +27,10 @@
  * @brief Class that computes missing connections on a PCB.
  */
 
+#ifdef USE_OPENMP
+#include <omp.h>
+#endif /* USE_OPENMP */
+
 #include <ratsnest_data.h>
 
 #include <class_board.h>
@@ -829,12 +833,25 @@ void RN_DATA::Recalculate( int aNet )
 {
     if( aNet < 0 )              // Recompute everything
     {
-        // Start with net number 1, as 0 stand for not connected
-        for( unsigned int i = 1; i < m_board->GetNetCount(); ++i )
+        unsigned int tid, i, chunk, netCount;
+        netCount = m_board->GetNetCount();
+        chunk = 1;
+
+#ifdef USE_OPENMP
+        #pragma omp parallel shared(chunk, netCount) private(i, tid)
         {
-            if( m_nets[i].IsDirty() )
-                updateNet( i );
-        }
+            tid = omp_get_thread_num();
+            #pragma omp for schedule(guided, chunk)
+#else /* USE_OPENMP */
+        {
+#endif
+            // Start with net number 1, as 0 stand for not connected
+            for( i = 1; i < netCount; ++i )
+            {
+                if( m_nets[i].IsDirty() )
+                    updateNet( i );
+            }
+       }  /* end of parallel section */
     }
     else if( aNet > 0 )         // Recompute only specific net
     {
@@ -848,3 +865,4 @@ void RN_DATA::ClearSimple()
     BOOST_FOREACH( RN_NET& net, m_nets )
         net.ClearSimple();
 }
+