engine: Add loop event

Author: cassava

engine/src/simulation.cpp

@@ -387,6 +387,7 @@ StateId SimulationMachine::Connect::impl(SimulationContext& ctx) {
     ctx.coordinator->enroll(r);
 
     // Events:
+    ctx.callback_loop = r.register_event<events::LoopFactory>();
     ctx.callback_start = r.register_event<events::StartFactory>();
     ctx.callback_stop = r.register_event<events::StopFactory>();
     ctx.callback_success = r.register_event<events::SuccessFactory>();
@@ -808,6 +809,7 @@ StateId SimulationMachine::StepBegin::impl(SimulationContext& ctx) {
   ctx.server->refresh_buffer();
 
   // Run time-based triggers
+  ctx.callback_loop->trigger(ctx.sync);
   ctx.callback_time->trigger(ctx.sync);
 
   // Determine whether to continue simulating or stop
@@ -1040,6 +1042,7 @@ StateId SimulationMachine::Pause::impl(SimulationContext& ctx) {
   // TODO(ben): Process triggers that come in so we can also conclude.
   // What kind of triggers do we want to allow? Should we also be processing
   // NEXT trigger events? How after pausing do we resume?
+  ctx.callback_loop->trigger(ctx.sync);
   ctx.callback_pause->trigger(ctx.sync);
   std::this_thread::sleep_for(ctx.config.engine.polling_interval);
 

engine/src/simulation_context.hpp

@@ -322,6 +322,7 @@ DEFINE_NIL_EVENT(Failure, "failure", "simulation failure")
 DEFINE_NIL_EVENT(Reset, "reset", "reset of simulation")
 DEFINE_NIL_EVENT(Pause, "pause", "pausation of simulation")
 DEFINE_NIL_EVENT(Resume, "resume", "resumption of simulation after pause")
+DEFINE_NIL_EVENT(Loop, "loop", "begin of inner simulation loop each cycle")
 
 }  // namespace events
 
@@ -355,6 +356,7 @@ struct SimulationContext {
   bool pause_execution{false};
 
   // Events
+  std::shared_ptr<events::LoopCallback> callback_loop;
   std::shared_ptr<events::PauseCallback> callback_pause;
   std::shared_ptr<events::ResumeCallback> callback_resume;
   std::shared_ptr<events::StartCallback> callback_start;