Support zero-delay cycles

core/CMakeLists.txt

@@ -181,7 +181,6 @@ define(SCHEDULER)
 define(LF_SOURCE_DIRECTORY)
 define(LF_SOURCE_GEN_DIRECTORY)
 define(LF_PACKAGE_DIRECTORY)
-define(LF_FEDERATES_BIN_DIRECTORY)
 define(LF_FILE_SEPARATOR)
 define(WORKERS_NEEDED_FOR_FEDERATE)
 define(LF_ENCLAVES)

core/federated/RTI/main.c

@@ -122,7 +122,7 @@ void usage(int argc, const char* argv[]) {
   lf_print("  -n, --number_of_federates <n>");
   lf_print("   The number of federates in the federation that this RTI will control.\n");
   lf_print("  -nt, --number_of_transient_federates <n>");
-  lf_print("   The number of federates that are transient; this must be strictly less than the number of federates.\n");
+  lf_print("   The number of transient federates in the federation that this RTI will control.\n");
   lf_print("  -p, --port <n>");
   lf_print("   The port number to use for the RTI. Must be larger than 0 and smaller than %d. Default is %d.\n",
            UINT16_MAX, DEFAULT_PORT);
@@ -242,7 +242,7 @@ int process_args(int argc, const char* argv[]) {
       }
       i++;
       long num_transient_federates = strtol(argv[i], NULL, 10);
-      if (num_transient_federates < 0L || num_transient_federates == LONG_MAX || num_transient_federates == LONG_MIN) {
+      if (num_transient_federates == LONG_MAX || num_transient_federates == LONG_MIN) {
         lf_print_error("--number_of_transient_federates needs a valid positive or null integer argument.");
         usage(argc, argv);
         return 0;
@@ -294,8 +294,8 @@ int process_args(int argc, const char* argv[]) {
     usage(argc, argv);
     return 0;
   }
-  if (rti.number_of_transient_federates >= rti.base.number_of_scheduling_nodes) {
-    lf_print_error("--number_of_transient_federates cannot be higher or equal to the number of federates.");
+  if (rti.number_of_transient_federates > rti.base.number_of_scheduling_nodes) {
+    lf_print_error("--number_of_transient_federates cannot be higher than the number of federates.");
     usage(argc, argv);
     return 0;
   }

core/federated/RTI/rti_common.c

@@ -94,6 +94,8 @@ tag_t earliest_future_incoming_message_tag(scheduling_node_t* e) {
   for (int i = 0; i < e->num_min_delays; i++) {
     // Node e->min_delays[i].id is upstream of e with min delay e->min_delays[i].min_delay.
     scheduling_node_t* upstream = rti_common->scheduling_nodes[e->min_delays[i].id];
+    if (upstream->state == NOT_CONNECTED)
+      continue;
     // If we haven't heard from the upstream node, then assume it can send an event at the start time.
     if (lf_tag_compare(upstream->next_event, NEVER_TAG) == 0) {
       tag_t start_tag = {.time = start_time, .microstep = 0};

core/federated/RTI/rti_remote.h

@@ -82,7 +82,11 @@ typedef enum clock_sync_stat { clock_sync_off, clock_sync_init, clock_sync_on }
 /**
  * The federation life cycle phases.
  */
-typedef enum federation_life_cycle_phase { startup_phase, execution_phase, shutdown_phase } federation_life_cycle_phase;
+typedef enum federation_life_cycle_phase {
+  startup_phase,   // Not all persistent federates have joined.
+  execution_phase, // All persistent federates have joined.
+  shutdown_phase   // Federation is shutting down.
+} federation_life_cycle_phase;
 
 /**
  * @brief The type for an element in a delayed grants priority queue that is sorted by tag.
@@ -390,15 +394,15 @@ void* federate_info_thread_TCP(void* fed);
  * @param socket_id Pointer to the socket ID.
  * @param error_code An error code.
  */
-void send_reject(int* socket_id, unsigned char error_code);
+void send_reject(int* socket_id, rejection_code_t error_code);
 
 /**
  * Wait for one incoming connection request from each (persistent) federate,
  * and upon receiving it, create a thread to communicate with that federate.
  * Return when all persistent federates have connected.
  * @param socket_descriptor The socket on which to accept connections.
  */
-void lf_connect_to_persistent_federates(int socket_descriptor);
+void* lf_connect_to_persistent_transient_federates_thread(int socket_descriptor);
 
 /**
  * Thread to wait for incoming connection request from transient federates.
@@ -408,11 +412,6 @@ void lf_connect_to_persistent_federates(int socket_descriptor);
  */
 void* lf_connect_to_transient_federates_thread(void* nothing);
 
-/**
- * Thread that manages the delayed grants using a priprity queue.
- */
-void* lf_delayed_grants_thread(void* nothing);
-
 /**
  * Thread to respond to new connections, which could be federates of other
  * federations who are attempting to join the wrong federation.