Return n_lost_pulses in sync from receiver

In order to have proper statistics we need to return the
number of lost pulses from the receiver. We cannot just count
the gap in pulse_id as the beam might be operated at
different frequencies.

sf-stream/include/ZmqPulseSyncReceiver.hpp

@@ -8,6 +8,11 @@
 
 #include "formats.hpp"
 
+struct PulseAndSync {
+    const uint64_t pulse_id;
+    const uint32_t n_lost_pulses;
+};
+
 class ZmqPulseSyncReceiver {
 
     void* ctx_;
@@ -22,7 +27,7 @@ public:
             const int n_modules);
     ~ZmqPulseSyncReceiver();
 
-    uint64_t get_next_pulse_id() const;
+    PulseAndSync get_next_pulse_id() const;
 };
 
 

sf-stream/src/ZmqPulseSyncReceiver.cpp

@@ -38,7 +38,7 @@ ZmqPulseSyncReceiver::~ZmqPulseSyncReceiver()
     }
 }
 
-uint64_t ZmqPulseSyncReceiver::get_next_pulse_id() const
+PulseAndSync ZmqPulseSyncReceiver::get_next_pulse_id() const
 {
     uint64_t pulses[n_modules_];
 
@@ -52,12 +52,12 @@ uint64_t ZmqPulseSyncReceiver::get_next_pulse_id() const
     }
 
     if (modules_in_sync) {
-        return pulses[0];
+        return {pulses[0], 0};
     }
 
+    // How many pulses we lost in total to get the next pulse_id.
+    uint32_t n_lost_pulses = 0;
     for (int i_sync=0; i_sync < SYNC_RETRY_LIMIT; i_sync++) {
-        cout << "Sync attempt " << i_sync << endl;
-
         uint64_t min_pulse_id = numeric_limits<uint64_t>::max();;
         uint64_t max_pulse_id = 0;
 
@@ -83,18 +83,26 @@ uint64_t ZmqPulseSyncReceiver::get_next_pulse_id() const
         }
 
         modules_in_sync = true;
+        // Max pulses we lost in this sync attempt.
+        uint32_t i_sync_lost_pulses = 0;
         for (int i = 0; i < n_modules_; i++) {
+            // How many pulses we lost for this specific module.
+            uint32_t i_module_lost_pulses = 0;
             while (pulses[i] < max_pulse_id) {
                 zmq_recv(sockets_[i], &pulses[i], sizeof(uint64_t), 0);
+                i_module_lost_pulses++;
             }
 
+            i_sync_lost_pulses = max(i_sync_lost_pulses, i_module_lost_pulses);
+
             if (pulses[i] != max_pulse_id) {
                 modules_in_sync = false;
             }
         }
+        n_lost_pulses += i_sync_lost_pulses;
 
         if (modules_in_sync) {
-            return pulses[0];
+            return {pulses[0], n_lost_pulses};
         }
     }