[mesh-forwarder] introduce FinalizeAndRemoveMessage() (#10830)

This commit adds a new helper method, `FinalizeAndRemoveMessage()`,
which finalizes all direct and indirect transmissions of a message
before removing it from the send queue. This helper is used by
`EvictMessage()` and `RemoveDataResponseMessages()`, simplifying
the code.

src/core/thread/mesh_forwarder.cpp

@@ -184,32 +184,6 @@ void MeshForwarder::PrepareEmptyFrame(Mac::TxFrame &aFrame, const Mac::Address &
     aFrame.SetPayloadLength(0);
 }
 
-void MeshForwarder::EvictMessage(Message &aMessage)
-{
-    PriorityQueue *queue = aMessage.GetPriorityQueue();
-
-    OT_ASSERT(queue != nullptr);
-
-    LogMessage(kMessageEvict, aMessage, kErrorNoBufs);
-
-    if (queue == &mSendQueue)
-    {
-#if OPENTHREAD_FTD
-        for (Child &child : Get<ChildTable>().Iterate(Child::kInStateAnyExceptInvalid))
-        {
-            IgnoreError(mIndirectSender.RemoveMessageFromSleepyChild(aMessage, child));
-        }
-#endif
-
-        FinalizeMessageDirectTx(aMessage, kErrorNoBufs);
-        RemoveMessageIfNoPendingTx(aMessage);
-    }
-    else
-    {
-        queue->DequeueAndFree(aMessage);
-    }
-}
-
 void MeshForwarder::ResumeMessageTransmissions(void)
 {
     if (mTxPaused)
@@ -1361,6 +1335,18 @@ exit:
     return;
 }
 
+void MeshForwarder::FinalizeAndRemoveMessage(Message &aMessage, Error aError, MessageAction aAction)
+{
+    LogMessage(aAction, aMessage, aError);
+
+#if OPENTHREAD_FTD
+    FinalizeMessageIndirectTxs(aMessage);
+#endif
+
+    FinalizeMessageDirectTx(aMessage, aError);
+    RemoveMessageIfNoPendingTx(aMessage);
+}
+
 bool MeshForwarder::RemoveMessageIfNoPendingTx(Message &aMessage)
 {
     bool didRemove = false;

src/core/thread/mesh_forwarder.hpp

@@ -530,7 +530,6 @@ private:
                                  Message::Priority       aPriority);
     Error HandleDatagram(Message &aMessage, const Mac::Address &aMacSource);
     void  ClearReassemblyList(void);
-    void  EvictMessage(Message &aMessage);
     void  HandleDiscoverComplete(void);
 
     void          HandleReceivedFrame(Mac::RxFrame &aFrame);
@@ -543,6 +542,7 @@ private:
     void HandleSentFrame(Mac::TxFrame &aFrame, Error aError);
     void UpdateSendMessage(Error aFrameTxError, Mac::Address &aMacDest, Neighbor *aNeighbor);
     void FinalizeMessageDirectTx(Message &aMessage, Error aError);
+    void FinalizeAndRemoveMessage(Message &aMessage, Error aError, MessageAction aAction);
     bool RemoveMessageIfNoPendingTx(Message &aMessage);
 
     void HandleTimeTick(void);
@@ -551,6 +551,7 @@ private:
     Error GetFramePriority(RxInfo &aRxInfo, Message::Priority &aPriority);
 
 #if OPENTHREAD_FTD
+    void          FinalizeMessageIndirectTxs(Message &aMessage);
     FwdFrameInfo *FindFwdFrameInfoEntry(uint16_t aSrcRloc16, uint16_t aDatagramTag);
     bool          UpdateFwdFrameInfoArrayOnTimeTick(void);
 
@@ -558,6 +559,7 @@ private:
                               uint16_t                aSrcRloc16,
                               Message::Priority      &aPriority);
     void  GetForwardFramePriority(RxInfo &aRxInfo, Message::Priority &aPriority);
+
 #endif
 
     void PauseMessageTransmissions(void) { mTxPaused = true; }

src/core/thread/mesh_forwarder_ftd.cpp

@@ -255,7 +255,7 @@ Error MeshForwarder::EvictMessage(Message::Priority aPriority)
 exit:
     if ((error == kErrorNone) && (evict != nullptr))
     {
-        EvictMessage(*evict);
+        FinalizeAndRemoveMessage(*evict, kErrorNoBufs, kMessageEvict);
     }
 
     return error;
@@ -299,30 +299,28 @@ void MeshForwarder::RemoveMessagesForChild(Child &aChild, MessageChecker &aMessa
     }
 }
 
+void MeshForwarder::FinalizeMessageIndirectTxs(Message &aMessage)
+{
+    VerifyOrExit(!aMessage.GetIndirectTxChildMask().IsEmpty());
+
+    for (Child &child : Get<ChildTable>().Iterate(Child::kInStateAnyExceptInvalid))
+    {
+        IgnoreError(mIndirectSender.RemoveMessageFromSleepyChild(aMessage, child));
+        VerifyOrExit(!aMessage.GetIndirectTxChildMask().IsEmpty());
+    }
+
+exit:
+    return;
+}
+
 void MeshForwarder::RemoveDataResponseMessages(void)
 {
-    Ip6::Header ip6Header;
-
     for (Message &message : mSendQueue)
     {
-        if (!message.IsMleCommand(Mle::kCommandDataResponse))
+        if (message.IsMleCommand(Mle::kCommandDataResponse))
         {
-            continue;
+            FinalizeAndRemoveMessage(message, kErrorDrop, kMessageDrop);
         }
-
-        IgnoreError(message.Read(0, ip6Header));
-
-        if (!(ip6Header.GetDestination().IsMulticast()))
-        {
-            for (Child &child : Get<ChildTable>().Iterate(Child::kInStateAnyExceptInvalid))
-            {
-                IgnoreError(mIndirectSender.RemoveMessageFromSleepyChild(message, child));
-            }
-        }
-
-        LogMessage(kMessageDrop, message);
-        FinalizeMessageDirectTx(message, kErrorDrop);
-        RemoveMessageIfNoPendingTx(message);
     }
 }
 

src/core/thread/mesh_forwarder_mtd.cpp

@@ -68,7 +68,7 @@ Error MeshForwarder::EvictMessage(Message::Priority aPriority)
 
     if (message->GetPriority() < static_cast<uint8_t>(aPriority))
     {
-        EvictMessage(*message);
+        FinalizeAndRemoveMessage(*message, kErrorNoBufs, kMessageEvict);
         ExitNow(error = kErrorNone);
     }