- Write some more of Scheduler::step_forward()

- Noted some design lackings, warning the designers


git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@706 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/dynamic_request.cc

@@ -83,7 +83,7 @@ DynamicRequest::get_instant() const
 }
 
 Request::state
-DynamicRequest::get_current_state() const
+DynamicRequest::get_state() const
 {
   return _state;
 }

src/backend/dynamic_request.hh

@@ -52,7 +52,7 @@ namespace sgpem
 
     unsigned int get_instant() const;
 
-    state get_current_state() const;
+    state get_state() const;
 
     void serialize(SerializeVisitor& translator) const;
 

src/backend/request.hh

@@ -45,7 +45,7 @@ namespace sgpem
 
     virtual std::vector<SubRequest*> get_subrequests() = 0;
     virtual unsigned int get_instant() const = 0;
-    virtual state get_current_state() const = 0;
+    virtual state get_state() const = 0;
 
     virtual void serialize(SerializeVisitor& translator) const = 0;
   };

src/backend/scheduler.cc

@@ -30,7 +30,7 @@
 // Do not include full template definition in the header file
 #include "singleton.tcc"
 
-#include <iostream>
+#include <memory>
 using namespace std;
 using namespace sgpem;
 
@@ -47,18 +47,31 @@ collect_threads(const std::vector<Process*>& procs,
 		std::vector<DynamicThread*>& collected_threads)
 {
   typedef std::vector<Process*> Processes;
-  typedef std::vector<Thread*>  Threads;
+  typedef std::vector<DynamicThread*>  Threads;
 
   collected_threads.clear();
   for(Processes::const_iterator it1 = procs.begin(); it1 != procs.end(); it1++)
     {
-      const Threads& ts = (*it1)->get_threads();
-      for(Threads::const_iterator it2 = ts.begin(); it2 != ts.end(); it2++) 
-	collected_threads.push_back((DynamicThread*) *it2);
+      const Threads& ts = ((DynamicProcess&) **it1).get_dynamic_threads();
+      collected_threads.insert(collected_threads.end(), ts.begin(), ts.end());
     }
 }
 
 
+static void
+free_all_resources_of(DynamicThread& ended_thread)
+{
+  typedef std::vector<DynamicRequest*>    Requests;
+  typedef std::vector<DynamicSubRequest*> SubRequests;
+  Requests& reqs = ended_thread.get_dynamic_requests();
+
+  for(Requests::iterator it = reqs.begin(); it != reqs.end(); it++)
+    {
+      // FIXME : write me
+      // Where is "state_fulfilled" or similar in Request::state?
+    }
+}
+
 // ---------------------------------------------------------
 
 
@@ -108,66 +121,106 @@ Scheduler::step_forward(History& history, Policy& cpu_policy) throw(UserInterrup
   bool simulation_ended = true; // Assume we've finished. Then prove me wrong.
 
   ConcreteHistory& concrete_history = (ConcreteHistory&) history;
-  ConcreteEnvironment* new_snapshot = new ConcreteEnvironment(concrete_history.get_last_environment());
   
-  typedef std::vector<DynamicProcess*> Processes;
-  typedef std::vector<DynamicThread*>  Threads;
+  // Use an auto_ptr since we've some exceptions in the coming...
+  auto_ptr<ConcreteEnvironment> new_snapshot(new ConcreteEnvironment(concrete_history.get_last_environment()));
+  
+  typedef std::vector<DynamicProcess*>    Processes;
+  typedef std::vector<DynamicRequest*>    Requests;
+  typedef std::vector<DynamicSubRequest*> SubRequests;
+  typedef std::vector<DynamicThread*>     Threads;
   
   Threads all_threads;
+  DynamicThread* running_thread = NULL;
 
   collect_threads(new_snapshot->get_processes(), all_threads);
 
   // designer + implementer (Matteo) comment follows:
-  // FIXME: decreasing the time elapsed of the running thread + process 
-  // should maybe be done here as the first thing, instead than 
-  // directly when selecting them
 
-  // 1. mark future threads as ready, if appropriate
-  // 2. mark ended threads as terminated
   for(Threads::iterator it = all_threads.begin(); it != all_threads.end(); it++)
     {
-      if((*it)->get_state() == Schedulable::state_future)
+      DynamicThread& current = **it; 
+     
+      // 1. mark future threads as ready, if appropriate
+      if(current.get_state() == Schedulable::state_future)
 	{
-	  Process& parent = (*it)->get_process();
-	  if(parent.get_elapsed_time() == (*it)->get_arrival_time())
-	    (*it)->set_state(Schedulable::state_ready);
+	  Process& parent = current.get_process();
+	  if(parent.get_elapsed_time() == current.get_arrival_time())
+	    current.set_state(Schedulable::state_ready);
 	}
-      
-      if((*it)->get_total_cpu_time() - (*it)->get_elapsed_time() == 0)
-	(*it)->set_state(Schedulable::state_terminated);
-      
-      // 3. check for simulation termination (we can directly use threads)
-      // for this check, since processes' state is based upon theirs)
+            
+      // Save the current running thread for future usage, if it hasn't ended
+      // its allotted time
+      if(current.get_state() == Schedulable::state_running)
+	{
+	  running_thread = &current; // Even if we change its state to terminated
+	  // 2. mark threads that used all their allotted time as terminated
+	  if(current.get_total_cpu_time() - current.get_elapsed_time() == 0)
+	    current.set_state(Schedulable::state_terminated);
+	} 
+
+      // 3. check for simulation termination (we can directly use threads
+      // for this check, since processes' state is based upon threads' one)
       if(simulation_ended && 
 	 ((*it)->get_state() & (Schedulable::state_blocked | 
 				Schedulable::state_terminated)) == 0)
 	simulation_ended = false;
     }
 
+  // FIXME: increasing the time elapsed of the running thread + process 
+  // should maybe be done here as the first thing, instead than 
+  // directly when selecting them
+  if(running_thread != NULL)
+    {
+      running_thread->decrease_remaining_time();
+      running_thread->get_process().decrease_remaining_time();
+    }
+  
+  // 4a. Requests for the running thread exhausted
+  if(running_thread != NULL) {
+    Requests& reqs = running_thread->get_dynamic_requests();
+    
+    // FIXME we lack a way to tell and/or remember for how 
+    // much a subrequest has been being fulfilled
+    // THIS MEANS this part is NOT complete
+    // We should check if a request has been fulfilled
+
+    // FIXME If a request was being fulfilled to the running thread,
+    // we should decrease the request remaining time here.
+
+    // This is why we kept a ref to the old running thread,
+    // even if it was terminated
+    if(running_thread->get_state() == Schedulable::state_terminated)
+      free_all_resources_of(*running_thread); // this function isn't complete
+    
+  }
+  
 
   //                    /
   //                  /
   //                /
   // (I'M HERE)   < * * * * * * * * * * *  
-  //		    \
+  //                \
   //                  \
   //                    \
   //
   // (is it visible enough for you?)
 
+  
+  ReadyQueue& ready_queue = new_snapshot->get_sorted_queue();
+  prepare_ready_queue(ready_queue);
   try
   {
-    // call the policy to sort the queue
-    // ...
+    // ?. Use the policy to sort the queue
+
+    // FIXME: how does it get the queue?
+    cpu_policy.sort_queue();
   }
-  catch( UserInterruptException e )
+  catch(UserInterruptException& e)
   {
     _policy_manager.init();
-
-    //TODO Do we need to perform some other cleanup operation here?
-    delete new_snapshot;
-
-    // Do we need to update something?
+    //              ^^^^^ 
+    //  Do we need to update something else?
 
     // Going up unwinding the stack, tell:
     //    - the user that the policy sucks
@@ -175,5 +228,7 @@ Scheduler::step_forward(History& history, Policy& cpu_policy) throw(UserInterrup
     throw;
   }
   
-  concrete_history.append_new_environment(new_snapshot);
+  // append the new snapshot...
+  // ...and remember to release the auto_ptr!
+  concrete_history.append_new_environment(new_snapshot.release());
 }

src/backend/scheduler.hh

@@ -91,9 +91,11 @@ namespace sgpem
     Policy&      get_policy();
 
   private:
+    void prepare_ready_queue(ReadyQueue& queue);
+    
     Scheduler();     //private constructor.
        
-    ReadyQueue  _ready_queue;
+    ReadyQueue       _ready_queue;
     PolicyManager&   _policy_manager;
   };