+static void add_active_task(kernel::activity::ActivityImplPtr task)
+{
+ s4u::VirtualMachine* vm = get_vm_from_task(task);
+ if (vm != nullptr) {
+ VirtualMachineImpl *vm_impl = vm->get_impl();
+ vm_impl->active_tasks_ = vm_impl->active_tasks_ + 1;
+ vm_impl->update_action_weight();
+ }
+}
+
+static void remove_active_task(kernel::activity::ActivityImplPtr task)
+{
+ s4u::VirtualMachine* vm = get_vm_from_task(task);
+ if (vm != nullptr) {
+ VirtualMachineImpl *vm_impl = vm->get_impl();
+ vm_impl->active_tasks_ = vm_impl->active_tasks_ - 1;
+ vm_impl->update_action_weight();
+ }
+}
+
+VMModel::VMModel()
+{
+ all_existing_models.push_back(this);
+ s4u::Host::on_state_change.connect(host_state_change);
+ kernel::activity::ExecImpl::on_creation.connect(add_active_task);
+ kernel::activity::ExecImpl::on_completion.connect(remove_active_task);
+ kernel::activity::ActivityImpl::on_resumed.connect(add_active_task);
+ kernel::activity::ActivityImpl::on_suspended.connect(remove_active_task);
+}
+
+double VMModel::next_occuring_event(double now)