Documentation of MPI examples.

eo/test/mpi/t-mpi-wrapper.cpp

@@ -1,3 +1,34 @@
+/*
+(c) Thales group, 2012
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation;
+    version 2 of the License.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+Contact: http://eodev.sourceforge.net
+
+Authors:
+    Benjamin Bouvier <benjamin.bouvier@gmail.com>
+*/
+
+/*
+ * This file shows an example of how to wrap a handler of a job store. Here, the wrapped handler is the "IsFinished"
+ * one. The only function that has been added is that the wrapper prints a message on standard output, indicating what
+ * the wrapped function returns as a result.
+ *
+ * This test is performed on a parallel apply job, the same as in parallelApply. The main difference is when
+ * instanciating the store.
+ */
+
 # include <mpi/eoMpi.h>
 # include <mpi/eoParallelApply.h>
 # include <mpi/eoTerminateJob.h>
@@ -9,6 +40,7 @@ using namespace std;
 
 using namespace eo::mpi;
 
+// Job functor.
 struct plusOne : public eoUF< int&, void >
 {
     void operator() ( int & x )
@@ -17,6 +49,10 @@ struct plusOne : public eoUF< int&, void >
     }
 };
 
+/*
+ * Shows the wrapped result of IsFinished, prints a message and returns the wrapped value.
+ * times is an integer counting how many time the wrapper (hence the wrapped too) has been called.
+ */
 template< class EOT >
 struct ShowWrappedResult : public IsFinishedParallelApply<EOT>
 {
@@ -39,7 +75,6 @@ struct ShowWrappedResult : public IsFinishedParallelApply<EOT>
     int times;
 };
 
-// These tests require at least 3 processes to be launched.
 int main(int argc, char** argv)
 {
     // eo::log << eo::setlevel( eo::debug );
@@ -63,7 +98,11 @@ int main(int argc, char** argv)
 
     ParallelApplyStore< int > store( plusOneInstance, eo::mpi::DEFAULT_MASTER, 1 );
     store.data( v );
-    store.wrapIsFinished( new ShowWrappedResult<int> );
+    // This is the only thing which changes: we wrap the IsFinished function.
+    // According to RAII, we'll delete the invokated wrapper at the end of the main ; the store won't delete it
+    // automatically.
+    IsFinishedParallelApply* wrapper = new ShowWrappedResult<int>;
+    store.wrapIsFinished( wrapper );
 
     ParallelApply<int> job( assign, eo::mpi::DEFAULT_MASTER, store );
     // Equivalent to:
@@ -86,6 +125,8 @@ int main(int argc, char** argv)
         cout << endl;
     }
 
+    delete wrapper;
+
     return 0;
 }