Don't delay the release of Lwip UDPEndPoint if there is no pending Lw…

…IPReceiveUDPMessage
project-chip · Aug 24, 2022 · 28485d5 · 28485d5
1 parent 0f9615d
commit 28485d5
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Showing 2 changed files with 22 additions and 7 deletions.
diff --git a/src/inet/UDPEndPointImplLwIP.cpp b/src/inet/UDPEndPointImplLwIP.cpp
@@ -252,17 +252,22 @@ void UDPEndPointImplLwIP::CloseImpl()
         mUDP              = nullptr;
         mLwIPEndPointType = LwIPEndPointType::Unknown;
 
-        // In case that there is a UDPEndPointImplLwIP::LwIPReceiveUDPMessage
+        // If there is a UDPEndPointImplLwIP::LwIPReceiveUDPMessage
         // event pending in the event queue (SystemLayer::ScheduleLambda), we
         // schedule a release call to the end of the queue, to ensure that the
         // queued pointer to UDPEndPointImplLwIP is not dangling.
-        Retain();
-        CHIP_ERROR err = GetSystemLayer().ScheduleLambda([this] { Release(); });
-        if (err != CHIP_NO_ERROR)
+        if (mDelayRelease == true)
         {
-            ChipLogError(Inet, "Unable scedule lambda: %" CHIP_ERROR_FORMAT, err.Format());
-            // There is nothing we can do here, accept the chance of racing
-            Release();
+            mDelayRelease = false;
+
+            Retain();
+            CHIP_ERROR err = GetSystemLayer().ScheduleLambda([this] { Release(); });
+            if (err != CHIP_NO_ERROR)
+            {
+                ChipLogError(Inet, "Unable scedule lambda: %" CHIP_ERROR_FORMAT, err.Format());
+                // There is nothing we can do here, accept the chance of racing
+                Release();
+            }
         }
     }
 
@@ -278,6 +283,9 @@ void UDPEndPointImplLwIP::Free()
 
 void UDPEndPointImplLwIP::HandleDataReceived(System::PacketBufferHandle && msg, IPPacketInfo * pktInfo)
 {
+    // Clear mDelayRelease flag so that we don't need to delay release of current UDPEndPoint.
+    mDelayRelease = false;
+
     if ((mState == State::kListening) && (OnMessageReceived != nullptr))
     {
         if (pktInfo != nullptr)
@@ -391,6 +399,10 @@ void UDPEndPointImplLwIP::LwIPReceiveUDPMessage(void * arg, struct udp_pcb * pcb
     pktInfo->SrcPort     = port;
     pktInfo->DestPort    = pcb->local_port;
 
+    // Set mDelayRelease flag to delay release of this UDP EndPoint until HandleDataReceived is
+    // called on this UDP EndPoint.
+    ep->mDelayRelease = true;
+
     CHIP_ERROR err = ep->GetSystemLayer().ScheduleLambda([ep, p = System::LwIPPacketBufferView::UnsafeGetLwIPpbuf(buf), pktInfo] {
         ep->HandleDataReceived(System::PacketBufferHandle::Adopt(p), pktInfo);
     });
@@ -402,6 +414,8 @@ void UDPEndPointImplLwIP::LwIPReceiveUDPMessage(void * arg, struct udp_pcb * pcb
     }
     else
     {
+        ep->mDelayRelease = false;
+
         // If ScheduleLambda() succeeded, `pktInfo` will be deleted in `HandleDataReceived`.
         // Otherwise we delete it here.
         Platform::Delete(pktInfo);

diff --git a/src/inet/UDPEndPointImplLwIP.h b/src/inet/UDPEndPointImplLwIP.h
@@ -61,6 +61,7 @@ class UDPEndPointImplLwIP : public UDPEndPoint, public EndPointStateLwIP
     static void LwIPReceiveUDPMessage(void * arg, struct udp_pcb * pcb, struct pbuf * p, const ip_addr_t * addr, u16_t port);
 
     udp_pcb * mUDP; // LwIP User datagram protocol (UDP) control block.
+    bool mDelayRelease = false;
 };
 
 using UDPEndPointImpl = UDPEndPointImplLwIP;