- All policy-related errors should now be handled. I hope this is the last time I say this...

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@850 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/concrete_simulation.cc

@@ -155,11 +155,39 @@ ConcreteSimulation::get_history()
 }
 
 void
-ConcreteSimulation::set_policy(CPUPolicy* p)
+ConcreteSimulation::set_policy(CPUPolicy* p) throw(CPUPolicyException)
 {
-  _policy = p;
+  // NOTE: restoring of the previous policy is done here because I
+  // couldn't think of a clean way to do it
+  // inside activate_policy()
   
-  CPUPoliciesGatekeeper::get_instance().activate_policy(&_history, p);
+  try
+  {
+    CPUPoliciesGatekeeper::get_instance().activate_policy(&_history, p);
+    _policy = p;
+  }
+  catch(const CPUPolicyException& e1)
+  {
+    try
+    {
+      // this is a no-op if _policy is NULL
+      CPUPoliciesGatekeeper::get_instance().activate_policy(&_history, _policy);
+    }
+    catch(const CPUPolicyException& e2)
+    {
+      _policy = NULL;
+
+      string msg = _("unable to change policy and to restore the previous: ");
+      msg += e2.what();
+
+      throw CPUPolicyException(msg);
+    }
+
+    string msg = _("unable to change policy: ");
+    msg+= e1.what();
+    
+    throw CPUPolicyException(msg);
+  }
 }
 
 

src/backend/concrete_simulation.hh

@@ -49,7 +49,10 @@ namespace sgpem
 
     state get_state() const;
 
-    void set_policy(CPUPolicy*);
+    /**
+     \throw An instance of CPUPolicyException, \b not a derived class!!!
+     */
+    void set_policy(CPUPolicy*) throw(CPUPolicyException);
 
     ConcreteHistory& get_history();
 

src/backend/cpu_policies_gatekeeper.cc

@@ -90,46 +90,57 @@ CPUPoliciesGatekeeper::get_current_policy(History* history) throw(runtime_error)
 }
 
 void
-CPUPoliciesGatekeeper::activate_policy(History *history, CPUPolicy* policy)
+CPUPoliciesGatekeeper::activate_policy(History *history, CPUPolicy* policy) throw(UserInterruptException, MalformedPolicyException)
 {
   assert(history != NULL);
 
   ActiveIterator end = _active_policies.end();
   ActiveIterator pos = _active_policies.find(history);
 
-  if (pos != end && pos->second != policy)
-    _active_policies[history]->deactivate();
+  // deactivate the policy, if necessary
+  if (pos != end)
+  {
+    // nothing to do in this case
+    if(pos->second == policy)
+      return;
 
+    pos->second->deactivate();
+  }
+  
+  // if policy is NULL, simply erase the entry and return, since we are sure the policy is
+  // not active due to the previous lines
   if(policy == NULL)
   {
-    _active_policies.erase(pos);
+    // this is a no-op if history is not a key used in the map
+    _active_policies.erase(history);
     return;
   }
   
-  if (pos == end || pos->second != policy)
+  try
   {
-    try
-    {
-      // policy->activate() needs already an active policy, because:
-      //   * it calls the configure() method on the 
-      //     insert-your-favourite-scripting-language-here-policy
-      //   * which in turn calls the configure() method in the 
-      //     code written by the user
-      //   * which probably uses Simulation to get the _active_ C++ policy,
-      //     so it can get its policy_parameters()
-      //  ... so **DON'T** play Mr. Clever Dick and swap the following two
-      //    lines in an optimization frenzy! Or the user policy WILL fail.
-      _active_policies[history] = policy;
-      policy->activate();
-    }
-    catch(const CPUPolicyException& e)
-    {
-      std::cerr << e.what() << std::endl;
-      // See the comment above to understand why we do this
-      // in this way
-      _active_policies.erase(_active_policies.find(history));
-    }
+    // policy->activate() needs already an active policy, because:
+    //   * it calls the configure() method on the 
+    //     insert-your-favourite-scripting-language-here-policy
+    //   * which in turn calls the configure() method in the 
+    //     code written by the user
+    //   * which probably uses Simulation to get the _active_ C++ policy,
+    //     so it can get its policy_parameters()
+    //  ... so **DON'T** play Mr. Clever Dick and swap the following two
+    //    lines in an optimization frenzy! Or the user policy WILL fail.
+    _active_policies[history] = policy;
+    policy->activate();
   }
+  catch(const CPUPolicyException& e)
+  {
+    //std::cerr << e.what() << std::endl;
+    // See the comment above to understand why we do this
+    // in this way
+    _active_policies.erase(_active_policies.find(history));
+    
+    // the caller need to know if it failed
+    throw;
+  }
+  
 }
 
 CPUPoliciesGatekeeper::CPUPoliciesGatekeeper()

src/backend/cpu_policies_gatekeeper.hh

@@ -35,6 +35,8 @@ namespace sgpem
 #include <stdexcept>
 
 #include "singleton.hh"
+#include "malformed_policy_exception.hh"
+#include "user_interrupt_exception.hh"
 
 namespace sgpem
 {
@@ -58,7 +60,11 @@ namespace sgpem
 
     CPUPolicy*       get_current_policy(History* history) throw(std::runtime_error);
 
-    void       activate_policy(History* history, CPUPolicy* policy);
+    /**
+     Associates policy with history. If an exception is thrown, the current associated
+     policy with this history (if there are any), is \b no more active, \b nor associated 
+     */
+    void       activate_policy(History* history, CPUPolicy* policy) throw(UserInterruptException, MalformedPolicyException);
 
   private:
     CPUPoliciesGatekeeper();     //private constructor.

src/backend/scheduler.cc

@@ -640,7 +640,7 @@ try_to_run(unsigned int front, auto_ptr<ConcreteEnvironment>& next_snapshot)
 
 bool
 Scheduler::step_forward(ConcreteHistory& concrete_history, CPUPolicy& cpu_policy)
-	throw(UserInterruptException)
+	throw(UserInterruptException, MalformedPolicyException)
 {
 	// Preconditions:
 	assert (concrete_history.get_size() > 0);

src/backend/scheduler.hh

@@ -32,6 +32,7 @@ namespace sgpem
 #include "cpu_policy.hh"
 #include "ready_queue.hh"
 #include "user_interrupt_exception.hh"
+#include "malformed_policy_exception.hh"
 
 // Do not include full template definition here
 #include "singleton.hh"
@@ -78,7 +79,7 @@ namespace sgpem
        
         \return false If the simulation has ended, true otherwise
      */
-    bool       step_forward(ConcreteHistory& history, CPUPolicy& cpu_policy) throw(UserInterruptException);
+    bool       step_forward(ConcreteHistory& history, CPUPolicy& cpu_policy) throw(UserInterruptException, MalformedPolicyException);
 
     /**
        Returns the policy that will be used to generate the simulation at the next instant.

src/text_simulation.cc

@@ -374,7 +374,17 @@ TextSimulation::on_run(const Tokens& arguments)
     p_stderr(e.what());
     p_stderr(_("\nSimulation is now stopped, and "
                "the current policy will be deactivated\n"));
-    Simulation::get_instance().set_policy(NULL);
+    try
+    {
+      Simulation::get_instance().set_policy(NULL);
+    }
+    catch(const CPUPolicyException& f)
+    {
+      // should never happen
+      p_stderr(_("FATAL ERROR: unable to deactivate the policy: "));
+      p_stderr(f.what());
+      abort();
+    }
   }
   catch (const NullPolicyException& e)
   {
@@ -666,8 +676,8 @@ TextSimulation::on_set(const Tokens& arguments)
         vector<CPUPolicy*> policies = (*it)->get_avail_policies();
         for (CPUPolicyIt it = policies.begin(); it != policies.end(); ++it)
         {
-          if (policy == 0)
-            Simulation::get_instance().set_policy(*it);
+	  if (policy == 0)
+	    Simulation::get_instance().set_policy(*it);
 
           --policy;
         }
@@ -680,6 +690,13 @@ TextSimulation::on_set(const Tokens& arguments)
     {
       p_stderr(_("ERROR: invalid unsigned integer or not a valid policy index\n"));
     }
+    catch (const CPUPolicyException& e)
+    {
+      p_stderr(_("ERROR: "));
+      p_stderr(e.what());
+      p_stderr("\n");
+    }
+      
   }
   else if (attr == "CONTINUOUS")
   {