prefer passing const ref to EventSlot when dumping in PrecedenceSvc

GaudiHive/src/IPrecedenceSvc.h

@@ -57,9 +57,9 @@ public:
   virtual const std::string printState( EventSlot& ) const = 0;
 
   /// Dump precedence rules
-  virtual void dumpPrecedenceRules( EventSlot& ) = 0;
+  virtual void dumpPrecedenceRules( const EventSlot& ) = 0;
   /// Dump precedence trace
-  virtual void dumpPrecedenceTrace( EventSlot& ) = 0;
+  virtual void dumpPrecedenceTrace( const EventSlot& ) = 0;
 };
 
 #endif /* GAUDIHIVE_IPRECEDENCESVC_H_ */

GaudiHive/src/PrecedenceSvc.cpp

@@ -8,11 +8,11 @@
 * granted to it by virtue of its status as an Intergovernmental Organization        *
 * or submit itself to any jurisdiction.                                             *
 \***********************************************************************************/
-#include "PrecedenceSvc.h"
 #include "EventSlot.h"
 #include "PRGraph/Visitors/Promoters.h"
 #include "PRGraph/Visitors/Rankers.h"
 #include "PRGraph/Visitors/Validators.h"
+#include "PrecedenceSvc.h"
 
 #include <Gaudi/Algorithm.h>
 #include <Gaudi/Sequence.h>
@@ -307,7 +307,7 @@ const std::string PrecedenceSvc::printState( EventSlot& slot ) const {
 }
 
 // ============================================================================
-void PrecedenceSvc::dumpPrecedenceRules( EventSlot& slot ) {
+void PrecedenceSvc::dumpPrecedenceRules( const EventSlot& slot ) {
 
   if ( !m_dumpPrecRules ) {
     warning() << "To trace temporal and topological aspects of execution flow, "
@@ -333,7 +333,7 @@ void PrecedenceSvc::dumpPrecedenceRules( EventSlot& slot ) {
 }
 
 // ============================================================================
-void PrecedenceSvc::dumpPrecedenceTrace( EventSlot& slot ) {
+void PrecedenceSvc::dumpPrecedenceTrace( const EventSlot& slot ) {
 
   if ( !m_dumpPrecTrace ) {
     warning() << "To trace task precedence patterns, set DumpPrecedenceTrace "

GaudiHive/src/PrecedenceSvc.h

@@ -64,10 +64,10 @@ public:
 
   /// Dump precedence rules (available only in DEBUG mode, and must be enabled
   /// with the corresponding service property)
-  void dumpPrecedenceRules( EventSlot& ) override;
+  void dumpPrecedenceRules( const EventSlot& ) override;
   /// Dump precedence trace (available only in DEBUG mode, and must be enabled
   /// with the corresponding service property)
-  void dumpPrecedenceTrace( EventSlot& ) override;
+  void dumpPrecedenceTrace( const EventSlot& ) override;
 
   /// Precedence rules accessor
   const concurrency::PrecedenceRulesGraph* getRules() const { return &m_PRGraph; };