diff --git a/trunk/paradiseo-peo/src/core/cooperative.h b/trunk/paradiseo-peo/src/core/cooperative.h
index efdcfebe4..65862d4b4 100644
--- a/trunk/paradiseo-peo/src/core/cooperative.h
+++ b/trunk/paradiseo-peo/src/core/cooperative.h
@@ -37,6 +37,7 @@
 #ifndef __cooperative_h
 #define __cooperative_h
 
+#include <vector>
 #include "communicable.h"
 #include "runner.h"
 
@@ -54,10 +55,20 @@ public :
 
   virtual void unpack () = 0;
 
-  void send (Cooperative * __coop); 
+  virtual void packSynchronizeReq () = 0;
+
+  void send (Cooperative * __coop);
+
+  void synchronizeCoopEx ();
 
   virtual void notifySending ();
 
+  virtual void notifyReceiving ();
+
+  virtual void notifySendingSyncReq ();
+
+  virtual void notifySynchronized ();
+
 private :
 
   Runner * owner;
diff --git a/trunk/paradiseo-peo/src/core/peo_init.cpp b/trunk/paradiseo-peo/src/core/peo_init.cpp
index 31af40b19..52c35bcf5 100644
--- a/trunk/paradiseo-peo/src/core/peo_init.cpp
+++ b/trunk/paradiseo-peo/src/core/peo_init.cpp
@@ -54,6 +54,7 @@ extern void initRunnersEnv ();
 extern void initWorkersEnv ();
 
 extern void initScheduler ();
+extern void initSynchron ();
 
 
 static void initExecutionEnv() {
@@ -61,6 +62,7 @@ static void initExecutionEnv() {
   initCommunicableEnv ();
   initBuffers ();
   initScheduler();
+  initSynchron ();
 
   initThreadsEnv ();
   initReactiveThreadsEnv ();
diff --git a/trunk/paradiseo-peo/src/core/runner.cpp b/trunk/paradiseo-peo/src/core/runner.cpp
index 624dd8578..4f421b32f 100644
--- a/trunk/paradiseo-peo/src/core/runner.cpp
+++ b/trunk/paradiseo-peo/src/core/runner.cpp
@@ -63,6 +63,8 @@ extern int getNodeRank ();
 
 extern int getNumberOfNodes ();
 
+extern void wakeUpCommunicator ();
+
 
 Runner :: Runner () {
 
@@ -188,6 +190,8 @@ void unpackTerminationOfRunner () {
     stopReactiveThreads ();
     printDebugMessage ("Reactive threads stopped!");
   }
+
+  wakeUpCommunicator ();
 }
 
 void initRunnersEnv () {
diff --git a/trunk/paradiseo-peo/src/core/topology.cpp b/trunk/paradiseo-peo/src/core/topology.cpp
index 6e6ed0779..465210b93 100644
--- a/trunk/paradiseo-peo/src/core/topology.cpp
+++ b/trunk/paradiseo-peo/src/core/topology.cpp
@@ -45,3 +45,8 @@ void Topology :: add (Cooperative & __mig) {
 
   mig.push_back (& __mig) ;
 }
+
+Topology :: operator std :: vector <Cooperative *>& () {
+
+  return mig;
+}
diff --git a/trunk/paradiseo-peo/src/core/topology.h b/trunk/paradiseo-peo/src/core/topology.h
index 1addbf842..8c818561f 100644
--- a/trunk/paradiseo-peo/src/core/topology.h
+++ b/trunk/paradiseo-peo/src/core/topology.h
@@ -53,9 +53,11 @@ public:
 				std :: vector <Cooperative *> & __from,
 				std :: vector <Cooperative *> & __to) = 0;
 
+	operator std :: vector <Cooperative *>& ();
+
 protected:
 
-	std :: vector <Cooperative *> mig ;  
+	std :: vector <Cooperative *> mig;
 };
 
 #endif
diff --git a/trunk/paradiseo-peo/src/peoAsyncIslandMig.h b/trunk/paradiseo-peo/src/peoAsyncIslandMig.h
index 266c32b0c..96a4db782 100644
--- a/trunk/paradiseo-peo/src/peoAsyncIslandMig.h
+++ b/trunk/paradiseo-peo/src/peoAsyncIslandMig.h
@@ -174,6 +174,8 @@ template< class EOT > class peoAsyncIslandMig : public Cooperative, public eoUpd
     void pack();
     //! Auxiliary function dealing with receiving immigrant individuals. There is no need to explicitly call the function.
     void unpack();
+    //! Auxiliary function dealing with the packing of synchronization requests - not the case.
+    void packSynchronizeReq();
 
 
   private:
@@ -243,6 +245,8 @@ template< class EOT > void peoAsyncIslandMig< EOT > :: unpack()
   unlock();
 }
 
+template< class EOT > void peoAsyncIslandMig< EOT > :: packSynchronizeReq() {
+}
 
 template< class EOT > void peoAsyncIslandMig< EOT > :: emigrate()
 {
diff --git a/trunk/paradiseo-peo/src/peoSyncIslandMig.h b/trunk/paradiseo-peo/src/peoSyncIslandMig.h
index 6cce0c2a5..149c28bf8 100644
--- a/trunk/paradiseo-peo/src/peoSyncIslandMig.h
+++ b/trunk/paradiseo-peo/src/peoSyncIslandMig.h
@@ -59,6 +59,8 @@
 #include "core/cooperative.h"
 #include "core/peo_debug.h"
 
+#include "rmc/mpi/synchron.h"
+
 
 //! Class providing the basis for the synchronous island migration model.
 
@@ -176,10 +178,21 @@ public:
   void pack();
   //! Auxiliary function dealing with receiving immigrant individuals. There is no need to explicitly call the function.
   void unpack();
+  //! Auxiliary function dealing with the packing of synchronization requests. There is no need to explicitly call the function.
+  void packSynchronizeReq();
 
   //! Auxiliary function dealing with migration notifications. There is no need to explicitly call the function.
   void notifySending();
 
+  //! Auxiliary function dealing with migration notifications. There is no need to explicitly call the function.
+  void notifyReceiving();
+
+  //! Auxiliary function dealing with synchronizing runners for migrations. There is no need to explicitly call the function.
+  void notifySendingSyncReq();
+
+  //! Auxiliary function for notifying the synchronization of the runners involved in migration.
+  void notifySynchronized();
+
 
 private:
 
@@ -205,6 +218,11 @@ private:
   std :: queue< Cooperative* > coop_em;
 
   sem_t sync;
+
+  bool explicitPassive;
+  bool standbyMigration;
+
+  std :: vector< Cooperative* > in, out, all;
 };
 
 
@@ -227,39 +245,28 @@ template< class EOT > peoSyncIslandMig< EOT > :: peoSyncIslandMig(
 
 template< class EOT > void peoSyncIslandMig< EOT > :: pack()
 {
-
-  lock ();
-
   ::pack( coop_em.front()->getKey() );
   ::pack( em.front() );
   coop_em.pop();
   em.pop();
-
-  unlock();
 }
 
-
 template< class EOT > void peoSyncIslandMig< EOT > :: unpack()
 {
-
-  lock ();
-
   eoPop< EOT > mig;
   ::unpack( mig );
   imm.push( mig );
-
-  unlock();
-
-  sem_post( &sync );
+  explicitPassive = true;
 }
 
+template< class EOT > void peoSyncIslandMig< EOT > :: packSynchronizeReq() {
+
+  packSynchronRequest( all );
+}
 
 template< class EOT > void peoSyncIslandMig< EOT > :: emigrate()
 {
 
-  std :: vector< Cooperative* > in, out;
-  topology.setNeighbors( this, in, out );
-
   for ( unsigned i = 0; i < out.size(); i ++ )
   {
 
@@ -272,57 +279,55 @@ template< class EOT > void peoSyncIslandMig< EOT > :: emigrate()
   }
 }
 
-
 template< class EOT > void peoSyncIslandMig< EOT > :: immigrate()
 {
-
-  lock ();
-  {
-
     assert( imm.size() );
     replace( destination, imm.front() ) ;
     imm.pop();
     printDebugMessage( "peoSyncIslandMig: receiving some immigrants." );
-  }
-  unlock();
 }
 
-
 template< class EOT > void peoSyncIslandMig< EOT > :: operator()()
 {
 
   if ( !cont( source ) )
   {
+    explicitPassive = standbyMigration = false;
+    topology.setNeighbors( this, in, out ); all = topology;
+
+    synchronizeCoopEx(); stop();
 
     // sending emigrants
     emigrate();
-    stop();
-
     // synchronizing
     sem_wait( &sync );
-    getOwner()->setActive();
-
     // receiving immigrants
     immigrate();
+
+    synchronizeCoopEx(); stop();
   }
 }
 
-
 template< class EOT > void peoSyncIslandMig< EOT > :: notifySending()
 {
-
-  lock ();
-  {
-
-    if ( imm.empty() )
-    {
-
-      printDebugMessage( "peoSyncIslandMig: entering pasive mode\n" );
-      getOwner()->setPassive();
-    }
+  if ( !explicitPassive ) getOwner()->setPassive();
 }
-unlock();
 
+template< class EOT > void peoSyncIslandMig< EOT > :: notifyReceiving()
+{
+  if ( standbyMigration ) getOwner()->setActive();
+  sem_post( &sync );
+}
+
+template< class EOT > void peoSyncIslandMig< EOT > :: notifySendingSyncReq () {
+
+  getOwner()->setPassive();
+}
+
+template< class EOT > void peoSyncIslandMig< EOT > :: notifySynchronized () {
+
+  standbyMigration = true;
+  getOwner()->setActive();
   resume();
 }
 
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/CMakeLists.txt b/trunk/paradiseo-peo/src/rmc/mpi/CMakeLists.txt
index cfdf54c78..5ab0ccd94 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/CMakeLists.txt
+++ b/trunk/paradiseo-peo/src/rmc/mpi/CMakeLists.txt
@@ -1,3 +1,9 @@
+SET(CMAKE_DEFAULT_BUILD_TYPE Debug CACHE STRING "Variable that stores the default CMake build type" FORCE)
+SET(CMAKE_CXX_FLAGS "-O0 -g")
+SET(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
+SET(CMAKE_CXX_FLAGS_RELEASE "-O0 -g")
+SET(CMAKE_CXX_FLAGS_MINSIZEREL "-O0 -g")
+SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O0 -g")
 
 ######################################################################################
 ### 0) Set the compiler
@@ -29,10 +35,11 @@ SET(LIBRARY_OUTPUT_PATH ${RMC_MPI_LIB_OUTPUT_PATH})
 SET (RMC_MPI_SOURCES node.cpp 
 					param.cpp 
 					comm.cpp 
-					coop.cpp 
+					cooperative.cpp 
 					mess.cpp 
 					rmc.cpp 
 					scheduler.cpp
+					synchron.cpp
 					worker.cpp 
 					send.cpp 
 					recv.cpp 
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/coop.cpp b/trunk/paradiseo-peo/src/rmc/mpi/coop.cpp
index 541677dd8..8d750f4aa 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/coop.cpp
+++ b/trunk/paradiseo-peo/src/rmc/mpi/coop.cpp
@@ -57,6 +57,10 @@ void Cooperative :: send (Cooperative * __coop) {
   //  stop ();
 }
 
+void Cooperative :: synchronizeCoopEx () {
+  :: send (this, my_node -> rk_sched, SYNCHRONIZE_REQ_TAG);
+}
+
 Cooperative * getCooperative (COOP_ID __key) {
 
   return dynamic_cast <Cooperative *> (getCommunicable (__key));
@@ -67,3 +71,12 @@ void Cooperative :: notifySending () {
   //getOwner -> setPassive ();
   //  resume ();
 }
+
+void Cooperative :: notifyReceiving () {
+}
+
+void Cooperative :: notifySendingSyncReq () {
+}
+
+void Cooperative :: notifySynchronized () {
+}
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/node.h b/trunk/paradiseo-peo/src/rmc/mpi/node.h
index 66610c91f..92d289bc1 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/node.h
+++ b/trunk/paradiseo-peo/src/rmc/mpi/node.h
@@ -40,8 +40,28 @@
 #include <string>
 #include <cassert>
 
+#include "../../core/runner.h"
+
+typedef int RANK_ID;
+
+struct Node {
+
+  RANK_ID rk; /* Rank */
+  std :: string name; /* Host name */
+  unsigned num_workers; /* Number of parallel workers */
+  int rk_sched; /* rank of the scheduler */
+  std :: vector <RUNNER_ID> id_run; /* List of runner def. IDs */
+  std :: vector <RUNNER_ID> execution_id_run; /* List of runtime execution runner IDs */
+};
+
+extern Node * my_node;
+
+extern bool isScheduleNode ();
+
 extern int getNodeRank (); /* It gives the rank of the calling process */
 
+extern RANK_ID getRankOfRunner (RUNNER_ID __key);
+
 extern int getNumberOfNodes (); /* It gives the size of the environment (Total number of nodes) */
 
 extern void collectiveCountOfRunners ( unsigned int* num_local_exec_runners, unsigned int* num_exec_runners );
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/recv.cpp b/trunk/paradiseo-peo/src/rmc/mpi/recv.cpp
index 9ea9cf7fd..4562cd8dd 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/recv.cpp
+++ b/trunk/paradiseo-peo/src/rmc/mpi/recv.cpp
@@ -38,13 +38,13 @@
 #include "tags.h"
 #include "worker.h"
 #include "scheduler.h"
+#include "synchron.h"
 #include "mess.h"
 #include "node.h"
 #include "../../core/runner.h"
 #include "../../core/cooperative.h"
 #include "../../core/peo_debug.h"
 
-
 void receiveMessages () {
 
   cleanBuffers ();
@@ -66,14 +66,30 @@ void receiveMessages () {
       switch (tag) {
 
       case RUNNER_STOP_TAG:
-        unpackTerminationOfRunner ();	
-        wakeUpCommunicator ();
+        unpackTerminationOfRunner ();
         break;
 
+      case SYNCHRONIZE_REQ_TAG:
+        unpackSynchronRequest ();
+        break;
+
+      case SYNCHRONIZED_TAG:
+        {
+          RUNNER_ID runner_id;
+          unpack (runner_id);
+
+          COOP_ID coop_id;
+          unpack (coop_id);
+
+          getCooperative (coop_id) -> notifySynchronized ();
+          break;
+        }
+
       case COOP_TAG:
         COOP_ID coop_id;
         unpack (coop_id);
         getCooperative (coop_id) -> unpack ();
+        getCooperative (coop_id) -> notifyReceiving ();
         break;
 
       case SCHED_REQUEST_TAG:	
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/schema.h b/trunk/paradiseo-peo/src/rmc/mpi/schema.h
index 0381bd5cd..30e061c2c 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/schema.h
+++ b/trunk/paradiseo-peo/src/rmc/mpi/schema.h
@@ -41,29 +41,18 @@
 #include <vector>
 #include <cassert>
 
+#include "node.h"
 #include "../../core/runner.h"
 
 
-typedef int RANK_ID;
-
-struct Node {
-
-  RANK_ID rk; /* Rank */
-  std :: string name; /* Host name */
-  unsigned num_workers; /* Number of parallel workers */
-  int rk_sched; /* rank of the scheduler */
-  std :: vector <RUNNER_ID> id_run; /* List of runner def. IDs */
-  std :: vector <RUNNER_ID> execution_id_run; /* List of runtime execution runner IDs */
-};
-
-extern std :: vector <Node> the_schema;
-
 extern Node * my_node;
 
-extern void loadSchema (const char * __filename);
-
-extern RANK_ID getRankOfRunner (RUNNER_ID __key);
-
 extern bool isScheduleNode ();
 
+extern RANK_ID getRankOfRunner (RUNNER_ID __key);
+
+extern std :: vector <Node> the_schema;
+
+extern void loadSchema (const char * __filename);
+
 #endif
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/send.cpp b/trunk/paradiseo-peo/src/rmc/mpi/send.cpp
index d36dc0d88..cf10b9b6e 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/send.cpp
+++ b/trunk/paradiseo-peo/src/rmc/mpi/send.cpp
@@ -131,6 +131,11 @@ void sendMessages () {
       dynamic_cast <Cooperative *> (comm) -> notifySending ();
       break;
 
+    case SYNCHRONIZE_REQ_TAG:
+      dynamic_cast <Cooperative *> (comm) -> packSynchronizeReq ();
+      dynamic_cast <Cooperative *> (comm) -> notifySendingSyncReq ();
+      break;
+
     case SCHED_REQUEST_TAG:
       dynamic_cast <Service *> (comm) -> packResourceRequest ();
       dynamic_cast <Service *> (comm) -> notifySendingResourceRequest ();
@@ -155,6 +160,7 @@ void sendMessages () {
       sendMessageToAll (req.tag);
     else
       sendMessage (req.to, req.tag);
+
     mess.pop ();
   }
 
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/synchron.cpp b/trunk/paradiseo-peo/src/rmc/mpi/synchron.cpp
new file mode 100644
index 000000000..12468c226
--- /dev/null
+++ b/trunk/paradiseo-peo/src/rmc/mpi/synchron.cpp
@@ -0,0 +1,123 @@
+/* 
+* <scheduler.cpp>
+* Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2006-2007
+* (C) OPAC Team, LIFL, 2002-2007
+*
+* Sebastien Cahon, Alexandru-Adrian Tantar
+*
+* This software is governed by the CeCILL license under French law and
+* abiding by the rules of distribution of free software.  You can  use,
+* modify and/ or redistribute the software under the terms of the CeCILL
+* license as circulated by CEA, CNRS and INRIA at the following URL
+* "http://www.cecill.info".
+*
+* As a counterpart to the access to the source code and  rights to copy,
+* modify and redistribute granted by the license, users are provided only
+* with a limited warranty  and the software's author,  the holder of the
+* economic rights,  and the successive licensors  have only  limited liability.
+*
+* In this respect, the user's attention is drawn to the risks associated
+* with loading,  using,  modifying and/or developing or reproducing the
+* software by the user in light of its specific status of free software,
+* that may mean  that it is complicated to manipulate,  and  that  also
+* therefore means  that it is reserved for developers  and  experienced
+* professionals having in-depth computer knowledge. Users are therefore
+* encouraged to load and test the software's suitability as regards their
+* requirements in conditions enabling the security of their systems and/or
+* data to be ensured and,  more generally, to use and operate it in the
+* same conditions as regards security.
+* The fact that you are presently reading this means that you have had
+* knowledge of the CeCILL license and that you accept its terms.
+*
+* ParadisEO WebSite : http://paradiseo.gforge.inria.fr
+* Contact: paradiseo-help@lists.gforge.inria.fr
+*
+*/
+
+#include <queue>
+#include "synchron.h"
+#include "../../core/messaging.h"
+#include "node.h"
+#include "tags.h"
+#include "mess.h"
+
+
+
+static SYNC syncRunners; /* Runners to be synchronized */
+
+extern void wakeUpCommunicator();
+
+extern RANK_ID getRankOfRunner (RUNNER_ID __key);
+
+/* Initializing the list of runners to be synchronized */
+void initSynchron () {
+
+  syncRunners = SYNC();
+}
+
+/* packing a synchronization request from a service */
+void packSynchronRequest ( const std :: vector <Cooperative *>& coops ) {
+
+  /* Number of coops to synchronize */
+  pack( (unsigned)( coops.size() ) );
+
+  /* Coops to synchronize */
+  for (unsigned i = 0; i < coops.size(); i ++) {
+    pack( coops[ i ]->getOwner()->getDefinitionID() );
+    pack( coops[ i ]->getKey() );
+  }
+}
+
+/* Processing a synchronization request from a service */
+void unpackSynchronRequest () {
+
+  unsigned req_num_entries;
+  unpack (req_num_entries);
+
+  /* Creating a sync vector + adding the created entry */
+  std::pair< SYNC_RUNNERS, unsigned > req_sync;
+
+  /* Adding entries for each of the runners to be synchronized */
+  SyncEntry req_entry;
+  for (unsigned i = 0; i < req_num_entries; i ++) {
+
+    unpack (req_entry.runner);
+    unpack (req_entry.coop);
+
+    req_sync.first.push_back (req_entry);
+  }
+
+  /* Looking for the sync vector */
+  SYNC::iterator sync_it = syncRunners.find (req_sync);
+
+  /* The vector does not exist - insert a new sync */
+  if (sync_it == syncRunners.end ()) {
+    req_sync.second = 1;
+    syncRunners.insert (req_sync);
+  }
+  else {
+
+    /* The vector exists - updating the entry */
+    std::pair< SYNC_RUNNERS, unsigned >& sync_req_entry = const_cast< std::pair< SYNC_RUNNERS, unsigned >& > (*sync_it);
+    sync_req_entry.second ++;
+
+    /* All the runners to be synchronized sent the SYNC_REQUEST signal */
+    if (sync_req_entry.second == sync_req_entry.first.size()) {
+
+      /* Remove the entry */
+      syncRunners.erase (sync_it); 
+
+      /* Send SYNCHRONIZED signals to all the coop objects */
+      for (unsigned i = 0; i < req_sync.first.size(); i ++) {
+
+        initMessage ();
+
+        pack (req_sync.first [i].runner);
+        pack (req_sync.first [i].coop);
+
+        RANK_ID dest_rank = getRankOfRunner (req_sync.first [i].runner);
+        sendMessage (dest_rank, SYNCHRONIZED_TAG);
+      }
+    }
+  }
+}
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/synchron.h b/trunk/paradiseo-peo/src/rmc/mpi/synchron.h
new file mode 100644
index 000000000..b9ac7e6b7
--- /dev/null
+++ b/trunk/paradiseo-peo/src/rmc/mpi/synchron.h
@@ -0,0 +1,85 @@
+/* 
+* <synchron.h>
+* Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2006-2007
+* (C) OPAC Team, LIFL, 2002-2007
+*
+* Sebastien Cahon, Alexandru-Adrian Tantar
+*
+* This software is governed by the CeCILL license under French law and
+* abiding by the rules of distribution of free software.  You can  use,
+* modify and/ or redistribute the software under the terms of the CeCILL
+* license as circulated by CEA, CNRS and INRIA at the following URL
+* "http://www.cecill.info".
+*
+* As a counterpart to the access to the source code and  rights to copy,
+* modify and redistribute granted by the license, users are provided only
+* with a limited warranty  and the software's author,  the holder of the
+* economic rights,  and the successive licensors  have only  limited liability.
+*
+* In this respect, the user's attention is drawn to the risks associated
+* with loading,  using,  modifying and/or developing or reproducing the
+* software by the user in light of its specific status of free software,
+* that may mean  that it is complicated to manipulate,  and  that  also
+* therefore means  that it is reserved for developers  and  experienced
+* professionals having in-depth computer knowledge. Users are therefore
+* encouraged to load and test the software's suitability as regards their
+* requirements in conditions enabling the security of their systems and/or
+* data to be ensured and,  more generally, to use and operate it in the
+* same conditions as regards security.
+* The fact that you are presently reading this means that you have had
+* knowledge of the CeCILL license and that you accept its terms.
+*
+* ParadisEO WebSite : http://paradiseo.gforge.inria.fr
+* Contact: paradiseo-help@lists.gforge.inria.fr
+*
+*/
+
+#ifndef __synchron_h
+#define __synchron_h
+
+#include <set>
+#include <vector>
+#include <utility>
+
+#include "../../core/runner.h"
+#include "../../core/cooperative.h"
+
+struct SyncEntry {
+
+  RUNNER_ID runner;
+  COOP_ID coop;
+};
+
+struct SyncCompare {
+
+  bool operator()( const std::pair< std::vector< SyncEntry >, unsigned >& A, const std::pair< std::vector< SyncEntry >, unsigned >& B ) {
+
+    const std::vector< SyncEntry >& syncA = A.first;
+    const std::vector< SyncEntry >& syncB = B.first;
+
+    if ( syncA.size() == syncB.size() ) {
+      std::vector< SyncEntry >::const_iterator itA = syncA.begin();
+      std::vector< SyncEntry >::const_iterator itB = syncB.begin();
+
+      while ( (*itA).runner < (*itB).runner && itA != syncA.end() ) { itA++; itB++; }
+
+      return itA == syncA.end();
+    }
+
+    return syncA.size() < syncB.size();
+  }
+};
+
+typedef std::vector< SyncEntry > SYNC_RUNNERS;
+typedef std::set< std::pair< SYNC_RUNNERS, unsigned >, SyncCompare > SYNC;
+
+/* Initializing the list of runners to be synchronized */
+extern void initSynchron ();
+
+/* packing a synchronization request from a service */
+extern void packSynchronRequest ( const std :: vector <Cooperative *>& coops );
+
+/* Processing a synchronization request from a service */
+extern void unpackSynchronRequest ();
+
+#endif
diff --git a/trunk/paradiseo-peo/src/rmc/mpi/tags.h b/trunk/paradiseo-peo/src/rmc/mpi/tags.h
index 8fb7f8a84..67a7a71be 100644
--- a/trunk/paradiseo-peo/src/rmc/mpi/tags.h
+++ b/trunk/paradiseo-peo/src/rmc/mpi/tags.h
@@ -48,4 +48,7 @@
 #define TASK_RESULT_TAG 19
 #define TASK_DONE_TAG 20
 
+#define SYNCHRONIZE_REQ_TAG 1000
+#define SYNCHRONIZED_TAG 1001
+
 #endif