From 163c54537f1a62d1c953851e6717032d7a833335 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hubert=20Mi=C5=9B?= <hubert.mis@nordicsemi.no>
Date: Mon, 20 Mar 2017 17:38:07 +0100
Subject: [PATCH] Add API function to check if MAC layer is during transmission
 operation. (#1447)

---
 include/openthread/link.h | 14 ++++++++++++++
 src/core/api/link_api.cpp |  4 ++++
 src/core/mac/mac.cpp      |  5 +++++
 src/core/mac/mac.hpp      | 10 ++++++++++
 4 files changed, 33 insertions(+)

diff --git a/include/openthread/link.h b/include/openthread/link.h
index de0f3b6ca..b49d8a1ae 100644
--- a/include/openthread/link.h
+++ b/include/openthread/link.h
@@ -136,6 +136,20 @@ OTAPI bool OTCALL otLinkIsEnergyScanInProgress(otInstance *aInstance);
  */
 OTAPI ThreadError OTCALL otLinkSendDataRequest(otInstance *aInstance);
 
+/**
+ * This function indicates whether or not an IEEE 802.15.4 MAC is in the transmit state.
+ *
+ * MAC module is in the transmit state during CSMA/CA procedure, CCA, Data, Beacon or Data Request frame transmission
+ * and receiving an ACK of a transmitted frame. MAC module is not in the transmit state during transmission of an ACK
+ * frame or a Beacon Request frame.
+ *
+ * @param[in] aInstance A pointer to an OpenThread instance.
+ *
+ * @returns true if an IEEE 802.15.4 MAC is in the transmit state, false otherwise.
+ *
+ */
+OTAPI bool OTCALL otLinkIsInTransmitState(otInstance *aInstance);
+
 /**
  * Get the IEEE 802.15.4 channel.
  *
diff --git a/src/core/api/link_api.cpp b/src/core/api/link_api.cpp
index acb132a60..8b0517abf 100644
--- a/src/core/api/link_api.cpp
+++ b/src/core/api/link_api.cpp
@@ -355,6 +355,10 @@ bool otLinkIsEnergyScanInProgress(otInstance *aInstance)
     return aInstance->mThreadNetif.GetMac().IsEnergyScanInProgress();
 }
 
+bool otLinkIsInTransmitState(otInstance *aInstance)
+{
+    return aInstance->mThreadNetif.GetMac().IsInTransmitState();
+}
 
 
 #ifdef __cplusplus
diff --git a/src/core/mac/mac.cpp b/src/core/mac/mac.cpp
index d39caa859..43edd78b7 100644
--- a/src/core/mac/mac.cpp
+++ b/src/core/mac/mac.cpp
@@ -257,6 +257,11 @@ bool Mac::IsEnergyScanInProgress(void)
     return (mState == kStateEnergyScan) || (mPendingScanRequest == kScanTypeEnergy);
 }
 
+bool Mac::IsInTransmitState(void)
+{
+    return (mState == kStateTransmitData) || (mState == kStateTransmitBeacon);
+}
+
 void Mac::StartEnergyScan(void)
 {
     mState = kStateEnergyScan;
diff --git a/src/core/mac/mac.hpp b/src/core/mac/mac.hpp
index deecebbaa..b195b3a66 100644
--- a/src/core/mac/mac.hpp
+++ b/src/core/mac/mac.hpp
@@ -502,6 +502,16 @@ public:
      */
     bool IsEnergyScanInProgress(void);
 
+    /**
+     * This method returns if the MAC layer is in transmit state.
+     *
+     * The MAC layer is in transmit state during CSMA/CA, CCA, transmission of Data, Beacon or Data Request frames and
+     * receiving of ACK frames. The MAC layer is not in transmit state during transmission of ACK frames or Beacon
+     * Requests.
+     *
+     */
+    bool IsInTransmitState(void);
+
     /**
      * This method registers a callback to provide received raw IEEE 802.15.4 frames.
      *