Avoid setting alarms with deadlines that have already elapsed

overlay.c

@@ -104,16 +104,14 @@ int overlayServerMode()
      of wifi latency anyway, so we'll live with it.  Larger values will affect voice transport,
      and smaller values would affect CPU and energy use, and make the simulation less realistic. */
 
-  time_ms_t now = gettime_ms();
-  
 #define SCHEDULE(X, Y, D) { \
 static struct profile_total _stats_##X={.name="" #X "",}; \
 static struct sched_ent _sched_##X={\
   .stats = &_stats_##X, \
   .function=X,\
 }; \
-_sched_##X.alarm=(now+Y);\
-_sched_##X.deadline=(now+Y+D);\
+_sched_##X.alarm=(gettime_ms()+Y);\
+_sched_##X.deadline=(gettime_ms()+Y+D);\
 schedule(&_sched_##X); }
   
   /* Periodically check for server shut down */

overlay_address.c

@@ -236,6 +236,12 @@ int overlay_address_append(struct decode_context *context, struct overlay_buffer
 
 static int add_explain_response(struct subscriber *subscriber, void *context){
   struct decode_context *response = context;
+  // only explain a SID once every half second.
+  time_ms_t now = gettime_ms();
+  if (now - subscriber->last_explained < 500)
+    return 0;
+  subscriber->last_explained = now;
+
   if (!response->please_explain){
     response->please_explain = calloc(sizeof(struct overlay_frame),1);
     response->please_explain->payload=ob_new();

overlay_address.h

@@ -85,6 +85,7 @@ struct subscriber{
   time_ms_t last_probe;
   time_ms_t last_probe_response;
   time_ms_t last_tx;
+  time_ms_t last_explained;
   
   // public signing key details for remote peers
   unsigned char sas_public[SAS_SIZE];

overlay_interface.c

@@ -611,7 +611,6 @@ static void interface_read_file(struct overlay_interface *interface)
   IN();
   /* Grab packets, unpackage and dispatch frames to consumers */
   struct file_packet packet;
-  time_ms_t now = gettime_ms();
   
   /* Read from interface file */
   long long length=lseek(interface->alarm.poll.fd,0,SEEK_END);
@@ -661,6 +660,7 @@ static void interface_read_file(struct overlay_interface *interface)
   /* if there's no input, while we want to check for more soon,
    we need to allow all other low priority alarms to fire first,
    otherwise we'll dominate the scheduler without accomplishing anything */
+  time_ms_t now = gettime_ms();
   if (interface->recv_offset>=length){
     if (interface->alarm.alarm == -1 || now + 5 < interface->alarm.alarm){
       interface->alarm.alarm = now + 5;
@@ -748,26 +748,29 @@ static void overlay_interface_poll(struct sched_ent *alarm)
   struct overlay_interface *interface = (overlay_interface *)alarm;
   
   if (alarm->poll.revents==0){
-    time_ms_t now = gettime_ms();
+    alarm->alarm=-1;
     
+    time_ms_t now = gettime_ms();
     if (interface->state==INTERFACE_STATE_UP && interface->tick_ms>0){
       if (now >= interface->last_tx+interface->tick_ms)
         overlay_send_tick_packet(interface);
       alarm->alarm=interface->last_tx+interface->tick_ms;
-    }else{
-      alarm->alarm=-1;
+      alarm->deadline=alarm->alarm+interface->tick_ms/2;
     }
-    alarm->deadline=alarm->alarm+interface->tick_ms/2;
-    
+
     switch(interface->socket_type){
       case SOCK_DGRAM:
       case SOCK_STREAM:
 	break;
       case SOCK_FILE:
 	interface_read_file(interface);
+        now = gettime_ms();
 	break;
     }
+
     if (alarm->alarm!=-1) {
+      if (alarm->alarm < now)
+        alarm->alarm = now;
       schedule(alarm);
     }
   }

serval.h

@@ -343,7 +343,7 @@ struct overlay_buffer;
 struct overlay_frame;
 struct broadcast;
 
-#define STRUCT_SCHED_ENT_UNUSED ((struct sched_ent){NULL, NULL, NULL, NULL, {-1, 0, 0}, 0LL, 0LL, NULL, -1})
+#define STRUCT_SCHED_ENT_UNUSED {.poll.fd=-1, ._poll_index=-1,}
 
 extern int overlayMode;