Parent keeps restoring children until success or timeout (#1581)

src/core/common/message.cpp

@@ -361,6 +361,7 @@ bool Message::IsSubTypeMle(void) const
     if (mInfo.mSubType == kSubTypeMleAnnounce ||
         mInfo.mSubType == kSubTypeMleDiscoverRequest ||
         mInfo.mSubType == kSubTypeMleDiscoverResponse ||
+        mInfo.mSubType == kSubTypeMleChildUpdateRequest ||
         mInfo.mSubType == kSubTypeMleGeneral)
     {
         rval = true;

src/core/common/message.hpp

@@ -110,7 +110,7 @@ struct MessageInfo
     };
 
     uint8_t          mType : 2;          ///< Identifies the type of message.
-    uint8_t          mSubType : 3;       ///< Identifies the message sub type.
+    uint8_t          mSubType : 4;       ///< Identifies the message sub type.
     bool             mDirectTx : 1;      ///< Used to indicate whether a direct transmission is required.
     bool             mLinkSecurity : 1;  ///< Indicates whether or not link security is enabled.
     uint8_t          mPriority : 2;      ///< Identifies the message priority level (lower value is higher priority).
@@ -218,6 +218,7 @@ public:
         kSubTypeMplRetransmission      = 5,  ///< MPL next retranmission message
         kSubTypeMleGeneral             = 6,  ///< General MLE
         kSubTypeJoinerFinalizeResponse = 7,  ///< Joiner Finalize Response
+        kSubTypeMleChildUpdateRequest  = 8,  ///< MLE Child Update Request
     };
 
     enum

src/core/thread/mle.cpp

@@ -1672,6 +1672,7 @@ ThreadError Mle::SendChildUpdateRequest(void)
     mChildUpdateAttempts++;
 
     VerifyOrExit((message = NewMleMessage()) != NULL);
+    message->SetSubType(Message::kSubTypeMleChildUpdateRequest);
     SuccessOrExit(error = AppendHeader(*message, Header::kCommandChildUpdateRequest));
     SuccessOrExit(error = AppendMode(*message, mDeviceMode));
 

src/core/thread/mle_constants.hpp

@@ -64,7 +64,6 @@ enum
     kUnicastRetransmissionDelay    = 1000,  ///< Base delay before retransmitting an MLE unicast.
     kMaxResponseDelay              = 1000,  ///< Maximum delay before responding to a multicast request
     kMaxChildIdRequestTimeout      = 5000,  ///< Maximum delay for receiving a Child ID Request
-    kChildUpdateRequestPeriod      = 100,   ///< The period for sending Child Update Request
     kMaxChildUpdateResponseTimeout = 2000,  ///< Maximum delay for receiving a Child Update Response
 };
 

src/core/thread/mle_router.cpp

@@ -56,7 +56,6 @@ MleRouter::MleRouter(ThreadNetif &aThreadNetif):
     Mle(aThreadNetif),
     mAdvertiseTimer(aThreadNetif.GetIp6().mTimerScheduler, &MleRouter::HandleAdvertiseTimer, NULL, this),
     mStateUpdateTimer(aThreadNetif.GetIp6().mTimerScheduler, &MleRouter::HandleStateUpdateTimer, this),
-    mChildUpdateRequestTimer(aThreadNetif.GetIp6().mTimerScheduler, &MleRouter::HandleChildUpdateRequestTimer, this),
     mAddressSolicit(OPENTHREAD_URI_ADDRESS_SOLICIT, &MleRouter::HandleAddressSolicit, this),
     mAddressRelease(OPENTHREAD_URI_ADDRESS_RELEASE, &MleRouter::HandleAddressRelease, this)
 {
@@ -74,6 +73,7 @@ MleRouter::MleRouter(ThreadNetif &aThreadNetif):
     mLeaderWeight = kLeaderWeight;
     mFixedLeaderPartitionId = 0;
     mMaxChildrenAllowed = kMaxChildren;
+    mIsRouterRestoringChildren = false;
 
     SetRouterId(kInvalidRouterId);
     mPreviousPartitionId = 0;
@@ -406,7 +406,7 @@ ThreadError MleRouter::SetStateRouter(uint16_t aRloc16)
     {
         if (mChildren[i].GetState() == Neighbor::kStateRestored)
         {
-            mChildUpdateRequestTimer.Start(kChildUpdateRequestPeriod);
+            mIsRouterRestoringChildren = true;
             break;
         }
     }
@@ -447,7 +447,7 @@ ThreadError MleRouter::SetStateLeader(uint16_t aRloc16)
     {
         if (mChildren[i].GetState() == Neighbor::kStateRestored)
         {
-            mChildUpdateRequestTimer.Start(kChildUpdateRequestPeriod);
+            mIsRouterRestoringChildren = true;
             break;
         }
     }
@@ -1766,6 +1766,26 @@ void MleRouter::HandleStateUpdateTimer(void)
         break;
     }
 
+    if (mIsRouterRestoringChildren)
+    {
+        bool hasRestoringChildren = false;
+
+        for (uint8_t i = 0; i < mMaxChildrenAllowed; i++)
+        {
+            if (mChildren[i].GetState() == Neighbor::kStateRestored)
+            {
+                SendChildUpdateRequest(&mChildren[i]);
+                hasRestoringChildren = true;
+            }
+        }
+
+        // no child to restore
+        if (!hasRestoringChildren)
+        {
+            mIsRouterRestoringChildren = false;
+        }
+    }
+
     // update children state
     for (int i = 0; i < mMaxChildrenAllowed; i++)
     {
@@ -1834,36 +1854,6 @@ exit:
     return;
 }
 
-void MleRouter::HandleChildUpdateRequestTimer(void *aContext)
-{
-    static_cast<MleRouter *>(aContext)->HandleChildUpdateRequestTimer();
-}
-
-void MleRouter::HandleChildUpdateRequestTimer(void)
-{
-    VerifyOrExit(GetDeviceState() == kDeviceStateRouter || GetDeviceState() == kDeviceStateLeader);
-
-    for (int i = 0; i < mMaxChildrenAllowed; i++)
-    {
-        if (mChildren[i].GetState() == Neighbor::kStateRestored)
-        {
-            SendChildUpdateRequest(&mChildren[i]);
-            mChildren[i].SetState(Neighbor::kStateChildUpdateRequest);
-
-            if (mChildren[i].IsRxOnWhenIdle())
-            {
-                mChildren[i].SetTimeout(Timer::MsecToSec(kMaxChildUpdateResponseTimeout));
-            }
-
-            mChildUpdateRequestTimer.Start(kChildUpdateRequestPeriod);
-            break;
-        }
-    }
-
-exit:
-    return;
-}
-
 ThreadError MleRouter::SendParentResponse(Child *aChild, const ChallengeTlv &challenge, bool aRoutersOnlyRequest)
 {
     ThreadError error = kThreadError_None;
@@ -2679,7 +2669,22 @@ ThreadError MleRouter::SendChildUpdateRequest(Child *aChild)
     Ip6::Address destination;
     Message *message;
 
+    if (!aChild->IsRxOnWhenIdle())
+    {
+        uint8_t childIndex = mNetif.GetMle().GetChildIndex(*aChild);
+
+        // No need to send "Child Update Request" to the sleepy child if there is one already queued for it.
+        for (message = mNetif.GetMeshForwarder().GetSendQueue().GetHead(); message; message = message->GetNext())
+        {
+            if (message->GetChildMask(childIndex) && message->GetSubType() == Message::kSubTypeMleChildUpdateRequest)
+            {
+                ExitNow();
+            }
+        }
+    }
+
     VerifyOrExit((message = NewMleMessage()) != NULL);
+    message->SetSubType(Message::kSubTypeMleChildUpdateRequest);
     SuccessOrExit(error = AppendHeader(*message, Header::kCommandChildUpdateRequest));
     SuccessOrExit(error = AppendSourceAddress(*message));
     SuccessOrExit(error = AppendLeaderData(*message));

src/core/thread/mle_router_ftd.hpp

@@ -718,12 +718,9 @@ private:
     bool HandleAdvertiseTimer(void);
     static void HandleStateUpdateTimer(void *aContext);
     void HandleStateUpdateTimer(void);
-    static void HandleChildUpdateRequestTimer(void *aContext);
-    void HandleChildUpdateRequestTimer(void);
 
     TrickleTimer mAdvertiseTimer;
     Timer mStateUpdateTimer;
-    Timer mChildUpdateRequestTimer;
 
     Coap::Resource mAddressSolicit;
     Coap::Resource mAddressRelease;
@@ -743,6 +740,7 @@ private:
     uint8_t mLeaderWeight;
     uint32_t mFixedLeaderPartitionId;  ///< only for certification testing
     bool mRouterRoleEnabled;
+    bool mIsRouterRestoringChildren;
 
     uint8_t mRouterId;
     uint8_t mPreviousRouterId;

src/core/thread/topology.hpp

@@ -93,7 +93,6 @@ public:
         switch (mState) {
         case kStateValid:
         case kStateRestored:
-        case kStateChildUpdateRequest:
             return true;
 
         default: