refactored throttle handling

mission/com/LiveTmTask.cpp

@@ -53,11 +53,14 @@ ReturnValue_t LiveTmTask::performOperation(uint8_t opCode) {
         }
       }
     }
-    if (channel.isBusy() and not signals::CFDP_CHANNEL_THROTTLE_SIGNAL) {
+    if (channel.isBusy() and !throttlePeriodOngoing) {
       // Throttle CFDP packet creator. It is by far the most relevant data creator, so throttling
-      // it is the easiest way to handle back pressure for now in a sensible way. It is cleared
-      // by the data creator.
-      signals::CFDP_CHANNEL_THROTTLE_SIGNAL = true;
+      // it is the easiest way to handle back pressure for now in a sensible way.
+      throttleCfdp();
+    } else if(!channel.isBusy() and throttlePeriodOngoing) {
+      if(minimumPeriodThrottleCd.hasTimedOut()) {
+        releaseCfdp();
+      }
     }
     if (!handledTm) {
       if (tmFunnelCd.hasTimedOut()) {
@@ -164,7 +167,7 @@ ReturnValue_t LiveTmTask::handleGenericTmQueue(MessageQueueIF& queue) {
     result = channel.write(data, size, partiallyWrittenSize);
     if (result == DirectTmSinkIF::PARTIALLY_WRITTEN) {
       // Already throttle CFDP.
-      signals::CFDP_CHANNEL_THROTTLE_SIGNAL = true;
+      throttleCfdp();
       result = channel.handleLastWriteSynchronously(data, size, partiallyWrittenSize, 200);
       if (result != returnvalue::OK) {
         // TODO: Event? Might lead to dangerous spam though..
@@ -180,6 +183,17 @@ ReturnValue_t LiveTmTask::handleGenericTmQueue(MessageQueueIF& queue) {
   return result;
 }
 
+void LiveTmTask::throttleCfdp() {
+  throttlePeriodOngoing = true;
+  minimumPeriodThrottleCd.resetTimer();
+  signals::CFDP_CHANNEL_THROTTLE_SIGNAL = true;
+}
+
+void LiveTmTask::releaseCfdp() {
+  throttlePeriodOngoing = false;
+  signals::CFDP_CHANNEL_THROTTLE_SIGNAL = false;
+}
+
 ModeTreeChildIF& LiveTmTask::getModeTreeChildIF() { return *this; }
 
 ReturnValue_t LiveTmTask::initialize() {

mission/com/LiveTmTask.h

@@ -39,6 +39,10 @@ class LiveTmTask : public SystemObject,
   CfdpTmFunnel& cfdpFunnel;
   VirtualChannel& channel;
   const std::atomic_bool& ptmeLocked;
+  // This countdown ensures that the CFDP is always throttled with a minimum period. Only after
+  // this period, the CFDP can be released if the channel is not busy.
+  Countdown minimumPeriodThrottleCd = Countdown(40);
+  bool throttlePeriodOngoing = false;
 
   void readCommandQueue(void);
 
@@ -56,6 +60,8 @@ class LiveTmTask : public SystemObject,
   void startTransition(Mode_t mode, Submode_t submode) override;
 
   void announceMode(bool recursive) override;
+  void throttleCfdp();
+  void releaseCfdp();
 
   object_id_t getObjectId() const override;
   const HasHealthIF* getOptHealthIF() const override;

mission/com/VirtualChannel.cpp

@@ -58,6 +58,7 @@ ReturnValue_t VirtualChannel::handleLastWriteSynchronously(const uint8_t* data,
       delayMs += 10;
       continue;
     }
+    sif::debug << "last write after" << delayMs << std::endl;
     return finishWrite(data, start, remLen);
   }
   return returnvalue::FAILED;