Return the signal_set when setting signal handler

include/fc/interprocess/signals.hpp

@@ -1,8 +1,11 @@
 #pragma once
 #include <functional>
+#include <boost/asio/signal_set.hpp>
 
 namespace fc 
 {
-  /// handler will be called from ASIO thread
+   /// Set a handler to process an IPC (inter process communication) signal.
-  void set_signal_handler( std::function<void(int)> handler, int signal_num ); 
+   /// Handler will be called from ASIO thread.
+   /// @return shared pointer to the signal_set that holds the handler
+   std::shared_ptr<boost::asio::signal_set> set_signal_handler( std::function<void(int)> handler, int signal_num );
 }

src/interprocess/signals.cpp

@@ -3,15 +3,16 @@
 
 namespace fc
 {
-  void set_signal_handler( std::function<void(int)> handler, int signal_num )
+   std::shared_ptr<boost::asio::signal_set> set_signal_handler( std::function<void(int)> handler, int signal_num )
-  {
+   {
-      std::shared_ptr<boost::asio::signal_set> sig_set(new boost::asio::signal_set(fc::asio::default_io_service(), signal_num));
+      std::shared_ptr<boost::asio::signal_set> sig_set( new boost::asio::signal_set( fc::asio::default_io_service(),
-      sig_set->async_wait( 
+                                                                                     signal_num) );
-            [sig_set,handler]( const boost::system::error_code& err, int num ) 
+      sig_set->async_wait( [sig_set,handler]( const boost::system::error_code& err, int num )
-            {
+      {
-                handler( num );     
+         if( err != boost::asio::error::operation_aborted )
-                sig_set->cancel();
+            handler( num );
-             //   set_signal_handler( handler, signal_num );
+         sig_set->cancel();
-            } );
+      } );
-  }
+      return sig_set;
+   }
 }