- Add unified Singleton support

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@643 3ecf2c5c-341e-0410-92b4-d18e462d057c

Makefile.am

@@ -48,6 +48,7 @@ bin_PROGRAMS =
 plugin_LTLIBRARIES =
 noinst_HEADERS =
 pkglib_LTLIBRARIES =
+pkginclude_HEADERS =
 EXTRA_DIST =
 MAINTAINERCLEANFILES =
 MOSTLYCLEANFILES =
@@ -127,6 +128,7 @@ pkglib_LTLIBRARIES += src/backend/libbackend.la
 
 src_backend_libbackend_la_CPPFLAGS = \
 		-I@top_srcdir@ \
+		-I@top_srcdir@/src/templates \
 		-DPOLDIR="\"$(policiesdir)\"" \
 		-DPLUGDIR="\"$(plugindir)\"" \
 		-DLOCALEDIR="\"$(localedir)\"" \
@@ -163,7 +165,7 @@ src_backend_libbackend_la_SOURCES = \
 		src/backend/thread.cc \
 		src/backend/user_interrupt_exception.cc
 
-pkginclude_HEADERS = \
+pkginclude_HEADERS += \
 		config.h \
 		src/backend/dynamic_process.hh \
 		src/backend/dynamic_schedulable.hh \
@@ -198,6 +200,7 @@ bin_PROGRAMS += sgpemv2
 
 sgpemv2_CPPFLAGS = \
 		-I@top_srcdir@ \
+		-I@top_srcdir@/src/templates \
 		-DLOCALEDIR="\"$(localedir)\"" \
 		$(CAIRO_CFLAGS) \
 		$(GTKMM_CFLAGS) \
@@ -242,10 +245,12 @@ noinst_HEADERS += \
 #
 # ############################################################
 
-noinst_HEADERS += \
+pkginclude_HEADERS += \
 	src/templates/parameter.tcc \
-	src/templates/smartp.tcc \
+	src/templates/singleton.hh \
-	src/templates/smartp.hh
+	src/templates/singleton.tcc \
+	src/templates/smartp.hh \
+	src/templates/smartp.tcc
 
 # ############################################################
 #
@@ -266,6 +271,7 @@ noinst_PROGRAMS = \
 
 src_testsuite_test_history_CPPFLAGS = \
 		-I@top_srcdir@/src \
+		-I@top_srcdir@/src/templates \
 		$(GLIBMM_CFLAGS)
 src_testsuite_test_history_LDFLAGS = \
 		src/backend/libbackend.la \
@@ -277,6 +283,7 @@ src_testsuite_test_history_SOURCES = \
 
 #src_testsuite_test_parse_command_CPPFLAGS = \
 #		-I@top_srcdir@/src \
+#		-I@top_srcdir@/src/templates \
 #		$(GLIBMM_CFLAGS)
 #src_testsuite_test_parse_command_LDFLAGS = \
 #		src/backend/libbackend.la \
@@ -288,6 +295,7 @@ src_testsuite_test_history_SOURCES = \
 # advice: get dummy_policy from the somewhere in the repository, and compile it in.
 #src_testsuite_test_stepforward_CPPFLAGS = \
 #		-I@top_srcdir@/src \
+#		-I@top_srcdir@/src/templates \
 #		$(GLIBMM_CFLAGS)
 #src_testsuite_test_stepforward_LDFLAGS = \
 #		src/backend/libbackend.la \

config/sgpemv2-uninstalled.pc.in

@@ -14,4 +14,4 @@ URL: http://www.math.unipd.it/
 Requires: glibmm-2.4 >= 2.8  gthread-2.0 >= 2.8
 Libs: -L${libdir}/src/backend -lbackend
 Libs.private: -lglibmm-2.4 -lgthread-2.0
-Cflags: -I${includedir}/backend
+Cflags: -I${includedir}/backend -I${includedir}/templates

plugins/pyloader/src/python_policy_manager.cc

@@ -107,10 +107,11 @@ PythonPolicyManager::init()
   // environment variables. 
   // FIXME: find better way to achieve this.
   
+  GlobalPreferences& prefs = GlobalPreferences::get_instance();
   Glib::ustring importdirs = "import sys\n" 
       "sys.path[:0] = [ ";
-  for_each(GlobalPreferences::instance().policies_dir_begin(),
+  for_each(prefs.policies_dir_begin(),
-	   GlobalPreferences::instance().policies_dir_end(),
+	   prefs.policies_dir_end(),
 	   pol_dirs_concat(importdirs));
   importdirs += " '" SHAREDIR "' ]\n";
 
@@ -131,8 +132,9 @@ PythonPolicyManager::get_avail_policies()
 void
 PythonPolicyManager::collect_policies()
 {
-  GlobalPreferences::dir_iterator dir_it = GlobalPreferences::instance().policies_dir_begin();
+  GlobalPreferences& prefs = GlobalPreferences::get_instance();
-  GlobalPreferences::dir_iterator dir_end = GlobalPreferences::instance().policies_dir_end();
+  GlobalPreferences::dir_iterator dir_it = prefs.policies_dir_begin();
+  GlobalPreferences::dir_iterator dir_end = prefs.policies_dir_end();
 
   for(; dir_it != dir_end; ++dir_it)
   {

plugins/pyloader/src/testsuite/test-python_loader.cc

@@ -67,7 +67,7 @@ main(int argc, char** argv) {
     }
     else 
       // Add argv[1] as the directory to search for uninstalled policies
-      sgpem::GlobalPreferences::instance().add_policies_dir(argv[1]);
+      sgpem::GlobalPreferences::get_instance().add_policies_dir(argv[1]);
 
     // Self-register itself to Scheduler, however we don't care about it
     TestPythonPolicyManager polman;

src/backend/global_preferences.cc

@@ -23,17 +23,6 @@
 
 using namespace sgpem;
 
-GlobalPreferences* GlobalPreferences::_instance = 0;
-
-GlobalPreferences& 
-GlobalPreferences::instance()
-{
-    if(!_instance)
-	_instance = new GlobalPreferences();
-    return *_instance;
-}
-
-
 GlobalPreferences::GlobalPreferences()
     : _mod_dirs(1, PLUGDIR), _pol_dirs(1, POLDIR)
 {}

src/backend/global_preferences.hh

@@ -26,6 +26,8 @@
 #include <glibmm/ustring.h>
 #include <vector>
 
+#include "singleton.hh"
+
 namespace sgpem {
     class GlobalPreferences;
 }
@@ -33,11 +35,12 @@ namespace sgpem {
 #include "config.h"
 
 namespace sgpem {
-    class SG_DLLEXPORT GlobalPreferences {
+  class SG_DLLEXPORT GlobalPreferences : public Singleton<GlobalPreferences>
-    public:
+  {
-	typedef std::vector<Glib::ustring>::const_iterator dir_iterator;
+    friend class Singleton<GlobalPreferences>;
 
-	static GlobalPreferences& instance();
+  public:
+	typedef std::vector<Glib::ustring>::const_iterator dir_iterator;
 
 	dir_iterator modules_dir_begin() const;
 	dir_iterator modules_dir_end() const;
@@ -53,7 +56,6 @@ namespace sgpem {
 	GlobalPreferences(const GlobalPreferences&);
 	GlobalPreferences& operator=(const GlobalPreferences&);
 	
-	static GlobalPreferences* _instance;
 	std::vector<Glib::ustring> _mod_dirs;
 	std::vector<Glib::ustring> _pol_dirs;
     };

src/backend/history.cc

@@ -23,27 +23,15 @@ using namespace std;
 using namespace sgpem;
 using namespace memory;
 
-//History::instance;			//static object
-History* History::_instance = 0;
-
 /**
 	The constructor sets _total_time_elapsed to -1: this permits to insert the INITIAL STATUS
 	of the simulation which must begin at instant -1 and live for 1 instant.
 */
-History::History()			//private constructor. The parameter is discarded
+History::History()			//private constructor. 
   :_total_time_elapsed(-1)
 {}
 		
 
-History&
-History::get_instance()
-{
-    if(!_instance)
-	_instance = new History();
-    return *_instance;
-}
-		
-
 /**
   Returns a pointer to a copy of the DynamicSchedulable object relative to this instant.
   It can be NULL if time is out of range or if there are no running entities in the associated

src/backend/history.hh

@@ -32,6 +32,8 @@
 #include "dynamic_schedulable.hh"
 #include "../templates/smartp.hh"
 
+#include "singleton.hh"
+
 namespace sgpem
 {
 
@@ -47,8 +49,10 @@ namespace sgpem
   */
   class History;
 	
-  class SG_DLLEXPORT History : public ObservedSubject 
+  class SG_DLLEXPORT History : public Singleton<History>, public ObservedSubject 
   {
+    friend class Singleton<History>;
+
   public:
 	/**
 	 Gets the \ref Schedulable object running at the specified time.
@@ -83,15 +87,8 @@ namespace sgpem
 	virtual void	truncate_at(int instant);
 	
 		
-	/**
-	 Gets the only instance of History.
-	 \return The Singleton instance of this object.
-	 */	
-	static History&	get_instance();
-			
   protected:
-	History();			//private constructor. The parameter is discarded
+	History();			//private constructor.
-	static History*  _instance;
 
   private:
 	int             _total_time_elapsed;

src/backend/policies_gatekeeper.cc

@@ -34,16 +34,6 @@ using namespace sgpem;
 typedef vector<PolicyManager*>::iterator ManagerIterator;
 typedef map<History*, Policy*>::iterator ActiveIterator;
 
-PoliciesGatekeeper* PoliciesGatekeeper::_instance = NULL;
-
-PoliciesGatekeeper&
-PoliciesGatekeeper::get_instance()
-{
-  if(!_instance)
-    _instance = new PoliciesGatekeeper();
-  return *_instance;
-}
-
 vector<PolicyManager*>
 PoliciesGatekeeper::get_registered() const
 {

src/backend/policies_gatekeeper.hh

@@ -34,6 +34,8 @@ namespace sgpem
 #include <map>
 #include <stdexcept>
 
+#include "singleton.hh"
+
 namespace sgpem
 {
   class PoliciesGatekeeper;
@@ -43,15 +45,11 @@ namespace sgpem
 
    */
 
-  class SG_DLLEXPORT PoliciesGatekeeper
+  class SG_DLLEXPORT PoliciesGatekeeper : public Singleton<PoliciesGatekeeper>
   {
-  public:
+    friend class Singleton<PoliciesGatekeeper>;
-    /** \brief Returns the unique instance of this class, conforming to the Singleton pattern.
-     * 
-     * \return the unique instance of this class, conforming to the Singleton pattern.
-     */
-    static PoliciesGatekeeper&	    get_instance();
 
+  public:
     std::vector<PolicyManager*>	    get_registered() const;
 
     void			    register_manager(PolicyManager* manager);
@@ -68,7 +66,6 @@ namespace sgpem
     // Deactivates active policies managed by the specified manager.
     void			    deactivate_policies(PolicyManager* manager);
     
-    static PoliciesGatekeeper*      _instance;
     std::vector<PolicyManager*>	    _registered;
     std::map<History*, Policy*>	    _active_policies;
   };

src/backend/scheduler.cc

@@ -29,9 +29,6 @@ using namespace std;
 using namespace sgpem;
 using namespace memory;
 
-Scheduler* 
-Scheduler::_instance = 0;
-
 //private constructor. The parameter is discarded
 Scheduler::Scheduler()
   : _policy_manager(PolicyManager::get_registered_manager())
@@ -39,14 +36,6 @@ Scheduler::Scheduler()
   _policy_manager.init();
 }
 
-Scheduler&
-Scheduler::get_instance()
-{
-  if(!_instance)
-    _instance = new Scheduler();
-  return *_instance;
-}
-
 SchedulableQueue*			
 Scheduler::get_ready_queue()
 {

src/backend/scheduler.hh

@@ -37,11 +37,13 @@ namespace sgpem
 #include "schedulable_queue.hh"
 #include "user_interrupt_exception.hh"
 
+#include "singleton.hh"
+
 namespace sgpem
 {
-	class Scheduler;
+  class Scheduler;
 
-	/**	\brief Manages the DynamicSchedulable objects, implementing a given policy.
+  /**	\brief Manages the DynamicSchedulable objects, implementing a given policy.
 	
 	Class Scheduler manages the schedulable entities which are ready to run, 
 	ordering them in a queue; it also checks that the current scheduling policy 
@@ -50,61 +52,49 @@ namespace sgpem
 	the DynamicSchedulable objects (for further details about this, check 
 	class DynamicSchedulable).
 	
-	*/
+  */
 
-	class SG_DLLEXPORT Scheduler
+  class SG_DLLEXPORT Scheduler : public Singleton<Scheduler>
-	{
+  {
-	public:
+    friend class Singleton<Scheduler>;
-		/** \brief Returns the unique instance of this class, conforming to the Singleton pattern.
+  public:
-		 * 
+    /**
-		 * If Scheduler isn't initialized, creates it. Should be called at least once before
+       Returns a pointer to the queue containing all the ready 
-		 * starting the Simulation.
+       schedulable objects (for the policy to sort it). 
-		 * \return the unique instance of this class, conforming to the Singleton pattern.
+       \return a pointer to the queue containing all the ready 
-		*/
+       schedulable objects (for the policy to sort it). 
-		static Scheduler&  			get_instance();
+    */
-		/**
+    SchedulableQueue*			get_ready_queue();
-		Returns a pointer to the queue containing all the ready 
+    /**
-		schedulable objects (for the policy to sort it). 
+       Resets the simulation to the initial state.
-		\return a pointer to the queue containing all the ready 
+    */
-		schedulable objects (for the policy to sort it). 
+    void 						reset_status();
-		*/
+    /**
-		SchedulableQueue*			get_ready_queue();
+       Generates a new SchedulableQueue representing the status of the processes
-		/**
+       at the simulation instant next to the current one, and extends the History by
-		Resets the simulation to the initial state.
+       one instant with it.
-		*/
+    */
-		void 						reset_status();
+    void 						step_forward() throw(UserInterruptException);
-		/**
+    /**
-		Generates a new SchedulableQueue representing the status of the processes
+       Sets the policy that will be used to generate the simulation at the next instant.
-		at the simulation instant next to the current one, and extends the History by
+       \param policy the policy that will be used to generate the simulation at the next instant.
-		one instant with it.
+    */
-		*/
+    /* DISABLED until we don't have PolicyManager::set_policy()
-		void 						step_forward() throw(UserInterruptException);
+       void						set_policy(Policy* policy);
-		/**
+    */
-		Sets the policy that will be used to generate the simulation at the next instant.
+    /**
-		\param policy the policy that will be used to generate the simulation at the next instant.
+       Returns the policy that will be used to generate the simulation at the next instant.
-		*/
+       \return the policy that will be used to generate the simulation at the next instant.
-		/* DISABLED until we don't have PolicyManager::set_policy()
+    */
-		void						set_policy(Policy* policy);
+    Policy& 					get_policy();
-		*/
-		/**
-		Returns the policy that will be used to generate the simulation at the next instant.
-		\return the policy that will be used to generate the simulation at the next instant.
-		*/
-		Policy& 					get_policy();
 				
 		
-	private:
+  private:
-		Scheduler();					//private constructor.
+    Scheduler();					//private constructor.
-		static Scheduler*       _instance;
+    SchedulableQueue		_ready_queue;
-		SchedulableQueue		_ready_queue;
+    PolicyManager& 		_policy_manager;
-		PolicyManager& 		_policy_manager;
+  };
-	};
 
 }//~ namespace sgpem
 
 #endif //SCHEDULER_HH
-
-
-
-
-

src/main.cc

@@ -63,8 +63,9 @@ static void load_pyloader_plugin() {
     // Leaks willingly:
     Module* pyloader = 0;
 
-    GlobalPreferences::dir_iterator it = GlobalPreferences::instance().modules_dir_begin();
+    GlobalPreferences& prefs = GlobalPreferences::get_instance();
-    while(it != GlobalPreferences::instance().modules_dir_end()) {
+    GlobalPreferences::dir_iterator it = prefs.modules_dir_begin();
+    while(it != prefs.modules_dir_end()) {
 	std::string pyloader_path = Module::build_path(*it, "pyloader");
 	pyloader = new Module(pyloader_path);
 	if(*pyloader) break;

src/parse_opts.cc

@@ -80,10 +80,10 @@ parse_options(int& argc, char**& argv)
 								// FIXME : to be written!
 								break;
 						case 'P':
-								GlobalPreferences::instance().add_policies_dir(optarg);
+								GlobalPreferences::get_instance().add_policies_dir(optarg);
 								break;
 						case 'M':
-								GlobalPreferences::instance().add_modules_dir(optarg);
+								GlobalPreferences::get_instance().add_modules_dir(optarg);
 								break;
 						case ':':
 								printf(_("[EE] Wrong number of parameters. Please see \n"

src/templates/parameter.tcc

@@ -1,4 +1,4 @@
-// Src/templates/parameter.tcc - Copyright 2005, 2006, University
+// src/templates/parameter.tcc - Copyright 2005, 2006, University
 //               of Padova, dept. of Pure and Applied
 //               Mathematics
 //

src/templates/singleton.hh

@@ -0,0 +1,59 @@
+// singleton.hh - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+#ifndef SINGLETON_HH
+#define SINGLETON_HH 1
+
+#include <glibmm/thread.h>
+#include "config.h"
+
+namespace sgpem 
+{
+  
+  /** \brief An abstract implementation of the Singleton design pattern. 
+   * 
+   * Singleton implementers constuctor will have to declare friendliness 
+   * to Singleton::get_instance(). This also attempts to achieve 
+   * thread-safeness.
+   */
+  template<typename Instantiated_class>
+  class SG_DLLEXPORT Singleton 
+  {
+  public:
+  
+    /** \brief Ensures thread safety is respected, and returns the instantiated object 
+     *
+     * This is done by locking _instance via a mutex, before intantiating the 
+     * Instantiated_class attribute (if not done before).
+     *
+     * \return The instantiated object
+     */
+    static Instantiated_class& get_instance();
+
+  private:
+    static Instantiated_class* _instance;
+    static Glib::StaticMutex   _mutex;
+  }; //~ class Singleton
+
+} //~ namespace sgpem
+
+
+#include "singleton.tcc"
+
+#endif //~ SINGLETON_HH
+

src/templates/singleton.tcc

@@ -0,0 +1,45 @@
+// singleton.tcc - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+#ifndef SINGLETON_TCC
+#define SINGLETON_TCC 1
+
+#include "singleton.hh"
+
+template<typename Instantiated_class>
+Instantiated_class*
+sgpem::Singleton<Instantiated_class>::_instance = NULL;
+
+template<typename Instantiated_class>
+Glib::StaticMutex
+sgpem::Singleton<Instantiated_class>::_mutex = GLIBMM_STATIC_MUTEX_INIT;
+
+
+template<typename Instantiated_class>
+Instantiated_class&
+sgpem::Singleton<Instantiated_class>::get_instance()
+{
+  Glib::Mutex::Lock lock(_mutex);
+  if(_instance == NULL)
+    _instance = new Instantiated_class();
+  return *_instance;
+}
+
+
+#endif //~ SINGLETON_TCC
+