pthreads: add pthreads check mostly needed in downstream modules.

cmake/modules/CMakeLists.txt

@@ -3,6 +3,7 @@ set(modules
     CMakeLists.txt
     DuneAlugridMacros.cmake
     FindDLMalloc.cmake
+    FindPThreads.cmake
     FindSIONlib.cmake
     FindZOLTAN.cmake
 )

cmake/modules/DuneAlugridMacros.cmake

@@ -51,4 +51,5 @@ find_package(SIONlib)
 find_package(DLMalloc)
 find_package(ZOLTAN)
 
-message(AUTHOR_WARNING "TODO: Improve module test.")
+# check for phtreads
+include(FindPThreads)

cmake/modules/FindPThreads.cmake

+########################
+# pthreads....
+########################
+# we are using the cmake default implementation for threads at the moment
+include(FindThreads)
+set(HAVE_PTHREAD 0)
+set(USE_PTHREADS OFF CACHE BOOL "whether we are using pthreads.")
+if(CMAKE_USE_PTHREADS_INIT AND NOT HAVE_PTHREAD)
+  set(HAVE_PTHREAD 1)
+
+  set(CMAKE_THREAD_PREFER_PTHREAD 1)
+
+  include(CMakePushCheckState)
+  cmake_push_check_state()
+
+  #new settings
+  set(CMAKE_REQUIRED_LIBS "${CMAKE_REQUIRED_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT}" )
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${PTHREAD_CFLAGS}" )
+
+  if(USE_PTHREADS)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DUSE_PTHREADS=1")
+  endif(USE_PTHREADS)
+
+  check_cxx_source_compiles(
+                "include <pthread.h>
+                static const int maxThreads = 2 ;
+                static int& threadNumber () {
+                    static __thread int tn;
+                    return tn;
+                }
+                static int threadnumber[ maxThreads ];
+                pthread_barrier_t barrier;
+                static void* setThreadNumber(void *number) {
+                  const int num = *((int*) number);
+                  threadNumber () = num ;
+                  //sleep (1);
+                  threadnumber[ num ] = threadNumber ();
+                  pthread_barrier_wait( &barrier );
+                  return 0;
+                }
+                int main () {
+                  pthread_t thread[ maxThreads ];
+                  int num[ maxThreads ];
+                  for (int i=0; i<maxThreads; ++i )
+                  {
+                    num[ i ] = i;
+                    threadnumber[ i ] = -1;
+                  }
+                  pthread_barrier_init( &barrier, 0, maxThreads );
+                  for( int i=0; i<maxThreads; ++ i)
+                    pthread_create (&thread[ i ], 0, &setThreadNumber, (void *) &num[ i ]);
+
+                  for( int i=0; i<maxThreads; ++ i)
+                    pthread_join (thread[ i ], 0);
+                  int result = 0;
+                  for( int i=0; i<maxThreads; ++i )
+                    if( threadnumber[ i ] != i ) result = 1;
+                  return result;
+                }"
+                DUNE_CV_PTHREAD_TLS_COMPILES)
+
+  #message( "DUNE_CV_PTHREAD_TLS_COMPILES is set to ${DUNE_CV_PTHREAD_TLS_COMPILES}" )
+
+  if(DUNE_CV_PTHREAD_TLS_COMPILES)
+    set(HAVE_PTHREAD_TLS 1)
+  endif(DUNE_CV_PTHREAD_TLS_COMPILES)
+
+  cmake_pop_check_state()
+
+endif(CMAKE_USE_PTHREADS_INIT AND NOT HAVE_PTHREAD)