[ICD] Stay in active mode when a reliable message context is awaiting an ack

src/app/icd/ICDEventManager.cpp

@@ -23,6 +23,7 @@ namespace chip {
 namespace app {
 
 uint8_t ICDEventManager::expectedMsgCount = 0;
+uint8_t ICDEventManager::awaitingAckCount = 0;
 static_assert(UINT8_MAX >= CHIP_CONFIG_MAX_EXCHANGE_CONTEXTS,
               "ICDEventManager::expectedMsgCount cannot hold count for the max exchange count");
 
@@ -97,7 +98,19 @@ void ICDEventManager::ICDEventHandler(const ChipDeviceEvent * event, intptr_t ar
         {
             icdManager->UpdateOperationState(ICDManager::OperationalState::ActiveMode);
         }
+        break;
+    case DeviceEventType::kICDMsgAckSyncEvent:
+        // When a Reliable Message Context is awaiting an ack, we keep the ICD in its active mode
+        if (event->AckSync.awaitingAck)
+        {
+            awaitingAckCount++;
+        }
+        else if (awaitingAckCount > 0)
+        {
+            awaitingAckCount--;
+        }
 
+        icdManager->SetKeepActiveModeRequirements(ICDManager::KeepActiveFlags::kAwaitingMsgAck, (awaitingAckCount != 0));
         break;
     case DeviceEventType::kAppWakeUpEvent:
         icdManager->UpdateOperationState(ICDManager::OperationalState::ActiveMode);

src/app/icd/ICDEventManager.h

@@ -48,6 +48,7 @@ class ICDEventManager
      */
     static void ICDEventHandler(const chip::DeviceLayer::ChipDeviceEvent * event, intptr_t arg);
     static uint8_t expectedMsgCount;
+    static uint8_t awaitingAckCount;
     ICDManager * mICDManager;
 };
 

src/app/icd/ICDManager.h

@@ -48,6 +48,7 @@ class ICDManager
         kCommissioningWindowOpen = 0x01,
         kFailSafeArmed           = 0x02,
         kExpectingMsgResponse    = 0x03,
+        kAwaitingMsgAck          = 0x04,
     };
 
     ICDManager() {}

src/include/platform/CHIPDeviceEvent.h

@@ -274,6 +274,16 @@ enum PublicEventTypes
      */
     kChipMsgRxEventHandled,
 
+    /**
+     * This event is used to sync the ICD with any Reliable Message exchange
+     * expecting an ack. The ICD shall stay in active Mode
+     * until the Reliable Message exchange post this event again
+     * informing the ICD that it is no longer awaiting the ack.
+     *
+     * This event contains an AckSync structure.
+     */
+    kICDMsgAckSyncEvent,
+
     /**
      * An application event occured that should wake up the system/device
      */
@@ -580,6 +590,15 @@ struct ChipDeviceEvent final
             bool wasReceived;
             bool clearsExpectedResponse;
         } RxEventContext;
+
+        struct
+        {
+            /*
+             * Set to true when a Reliable Message Context is awaiting for a ack to a message sent
+             * Set to false when the Reliable Message Context is no longer awaiting for a ack
+             */
+            bool awaitingAck;
+        } AckSync;
     };
 
     void Clear() { memset(this, 0, sizeof(*this)); }

src/messaging/ReliableMessageContext.cpp

@@ -33,9 +33,12 @@
 #include <messaging/ErrorCategory.h>
 #include <messaging/Flags.h>
 #include <messaging/ReliableMessageMgr.h>
+#include <platform/PlatformManager.h>
 #include <protocols/Protocols.h>
 #include <protocols/secure_channel/Constants.h>
 
+using namespace chip::DeviceLayer;
+
 namespace chip {
 namespace Messaging {
 
@@ -51,6 +54,22 @@ ReliableMessageMgr * ReliableMessageContext::GetReliableMessageMgr()
     return static_cast<ExchangeContext *>(this)->GetExchangeMgr()->GetReliableMessageMgr();
 }
 
+void ReliableMessageContext::SetMessageNotAcked(bool messageNotAcked)
+{
+    mFlags.Set(Flags::kFlagMessageNotAcked, messageNotAcked);
+
+#if CONFIG_DEVICE_LAYER
+    DeviceLayer::ChipDeviceEvent event;
+    event.Type                = DeviceLayer::DeviceEventType::kICDMsgAckSyncEvent;
+    event.AckSync.awaitingAck = messageNotAcked;
+    CHIP_ERROR status         = DeviceLayer::PlatformMgr().PostEvent(&event);
+    if (status != CHIP_NO_ERROR)
+    {
+        ChipLogError(DeviceLayer, "Failed to post AckSync event %" CHIP_ERROR_FORMAT, status.Format());
+    }
+#endif
+}
+
 CHIP_ERROR ReliableMessageContext::FlushAcks()
 {
     CHIP_ERROR err = CHIP_NO_ERROR;

src/messaging/ReliableMessageContext.h

@@ -241,11 +241,6 @@ inline void ReliableMessageContext::SetAckPending(bool inAckPending)
     mFlags.Set(Flags::kFlagAckPending, inAckPending);
 }
 
-inline void ReliableMessageContext::SetMessageNotAcked(bool messageNotAcked)
-{
-    mFlags.Set(Flags::kFlagMessageNotAcked, messageNotAcked);
-}
-
 inline void ReliableMessageContext::SetRequestingActiveMode(bool activeMode)
 {
     mFlags.Set(Flags::kFlagActiveMode, activeMode);