From 21d73e5386bfb3144dba7905e8f5127d014e31df Mon Sep 17 00:00:00 2001
From: rongli <rongli@nestlabs.com>
Date: Thu, 4 May 2017 14:03:13 +0800
Subject: [PATCH] Update child's keep-alive period (#1676)

* Update child's keep-alive period

* Python Cert: correct sed1 index

* update for comments
---
 src/core/thread/data_poll_manager.cpp                  | 2 +-
 src/core/thread/mle.cpp                                | 8 ++++----
 src/core/thread/mle_constants.hpp                      | 1 +
 tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py | 2 +-
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/core/thread/data_poll_manager.cpp b/src/core/thread/data_poll_manager.cpp
index 612672925..5223cdc30 100644
--- a/src/core/thread/data_poll_manager.cpp
+++ b/src/core/thread/data_poll_manager.cpp
@@ -388,7 +388,7 @@ uint32_t DataPollManager::CalculatePollPeriod(void) const
 
     if (period == 0)
     {
-        period = Timer::SecToMsec(mMeshForwarder.GetNetif().GetMle().GetTimeout() / Mle::kMaxChildKeepAliveAttempts);
+        period = Timer::SecToMsec(mMeshForwarder.GetNetif().GetMle().GetTimeout()) -  kRetxPollPeriod * kMaxPollRetxAttempts;
 
         if (period == 0)
         {
diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index dc5d67346..5bfad985f 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -588,7 +588,7 @@ ThreadError Mle::SetStateChild(uint16_t aRloc16)
 
     if ((mDeviceMode & ModeTlv::kModeRxOnWhenIdle) != 0)
     {
-        mParentRequestTimer.Start(Timer::SecToMsec(mTimeout / kMaxChildKeepAliveAttempts));
+        mParentRequestTimer.Start(Timer::SecToMsec(mTimeout) - kUnicastRetransmissionDelay * kMaxChildKeepAliveAttempts);
     }
 
     if ((mDeviceMode & ModeTlv::kModeFFD) != 0)
@@ -616,9 +616,9 @@ ThreadError Mle::SetTimeout(uint32_t aTimeout)
 {
     VerifyOrExit(mTimeout != aTimeout);
 
-    if (aTimeout < 4)
+    if (aTimeout < kMinTimeout)
     {
-        aTimeout = 4;
+        aTimeout = kMinTimeout;
     }
 
     mTimeout = aTimeout;
@@ -2968,7 +2968,7 @@ ThreadError Mle::HandleChildUpdateResponse(const Message &aMessage, const Ip6::M
         }
         else
         {
-            mParentRequestTimer.Start(Timer::SecToMsec(mTimeout / kMaxChildKeepAliveAttempts));
+            mParentRequestTimer.Start(Timer::SecToMsec(mTimeout) - kUnicastRetransmissionDelay * kMaxChildKeepAliveAttempts);
             mNetif.GetMeshForwarder().SetRxOnWhenIdle(true);
         }
 
diff --git a/src/core/thread/mle_constants.hpp b/src/core/thread/mle_constants.hpp
index 94f66d32f..8934a1d64 100644
--- a/src/core/thread/mle_constants.hpp
+++ b/src/core/thread/mle_constants.hpp
@@ -65,6 +65,7 @@ enum
     kMaxResponseDelay              = 1000,  ///< Maximum delay before responding to a multicast request
     kMaxChildIdRequestTimeout      = 5000,  ///< Maximum delay for receiving a Child ID Request
     kMaxChildUpdateResponseTimeout = 2000,  ///< Maximum delay for receiving a Child Update Response
+    kMinTimeout                    = (((kMaxChildKeepAliveAttempts + 1) * kUnicastRetransmissionDelay) / 1000),  ///< Minimum timeout(s)
 };
 
 enum
diff --git a/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py b/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py
index ed4cb915b..146094b76 100755
--- a/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py
+++ b/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py
@@ -34,7 +34,7 @@ import node
 
 LEADER = 1
 ROUTER = 2
-SED1 = 6
+SED1 = 7
 
 class Cert_5_1_07_MaxChildCount(unittest.TestCase):
     def setUp(self):