Jira 795 Make read / write calls to be blocking, git issue arduino#383

1. Add the parameter of read to support block/unblock call.
2. Changed file list
    libraries/CurieBLE/src/BLECharacteristic.cpp
    libraries/CurieBLE/src/BLECharacteristic.h
    libraries/CurieBLE/src/internal/BLECallbacks.cpp
    libraries/CurieBLE/src/internal/BLECharacteristicImp.cpp
    libraries/CurieBLE/src/internal/BLECharacteristicImp.h

Author: sgbihu

libraries/CurieBLE/src/BLECharacteristic.cpp

@@ -367,14 +367,14 @@ bool BLECharacteristic::canUnsubscribe()
     return retVar;
 }
 
-bool BLECharacteristic::read()
+bool BLECharacteristic::read(bool blocked)
 {
     bool retVar = false;
     BLECharacteristicImp *characteristicImp = getImplementation();
 
     if (NULL != characteristicImp)
     {
-        retVar = characteristicImp->read();
+        retVar = characteristicImp->read(blocked);
     }
     return retVar;
 }

libraries/CurieBLE/src/BLECharacteristic.h

@@ -321,7 +321,7 @@ class BLECharacteristic: public BLEAttributeWithValue
      *
      * @note  Only for GATT client. Schedule read request to the GATT server
      */
-    virtual bool read();
+    virtual bool read(bool blocked = false);
 
     /**
      * @brief   Write the charcteristic value

libraries/CurieBLE/src/internal/BLECallbacks.cpp

@@ -145,7 +145,7 @@ uint8_t profile_read_rsp_process(bt_conn_t *conn,
                                  const void *data, 
                                  uint16_t length)
 {
-    if (NULL == data)
+    if (NULL == data && 0 != length)
     {
         return BT_GATT_ITER_STOP;
     }

libraries/CurieBLE/src/internal/BLECharacteristicImp.cpp

@@ -593,9 +593,10 @@ bt_uuid_t* BLECharacteristicImp::getClientCharacteristicConfigUuid(void)
     return (bt_uuid_t*) &_gatt_ccc_uuid;
 }
 
-bool BLECharacteristicImp::read()
+bool BLECharacteristicImp::read(bool blocked)
 {
     int retval = 0;
+    bool ret_bool;
     bt_conn_t* conn = NULL;
 
     if (true == BLEUtils::isLocalBLE(_ble_device))
@@ -633,8 +634,18 @@ bool BLECharacteristicImp::read()
     if (0 == retval)
     {
         _reading = true;
+        ret_bool = true;
+        
+        // Block the call
+        if (blocked == true)
+        {
+            while (_reading == true )
+            {
+                delay(5);
+            }
+        }
     }
-    return _reading;
+    return ret_bool;
 }
 
 bool BLECharacteristicImp::write(const unsigned char value[], 

libraries/CurieBLE/src/internal/BLECharacteristicImp.h

@@ -146,18 +146,18 @@ class BLECharacteristicImp: public BLEAttribute{
     /**
      * @brief   Schedule the read request to read the characteristic in peripheral
      *
-     * @param[in]   none
+     * @param[in]   blocked    Flag the call is blocked or un-blocked
      *
      * @return  bool    Indicate the success or error
      *
-     * @note  Only for central device
+     * @note  Only for GATT client
+     *        Default it is un-block call
      */
-    bool read();
+    bool read(bool blocked = false);
 
     /**
      * @brief   Schedule the write request to update the characteristic in peripheral
      *
-     * @param[in]   peripheral   The peripheral device that want to be updated
      * @param[in]   value       New value to set, as a byte array.  Data is stored in internal copy.
      * @param[in]   length      Length, in bytes, of valid data in the array to write.
      *                      Must not exceed maxLength set for this characteristic.
@@ -324,7 +324,7 @@ class BLECharacteristicImp: public BLEAttribute{
     bt_gatt_subscribe_params_t _sub_params;
     bool        _subscribed;
 
-    bool _reading;
+    volatile bool _reading;
     bt_gatt_read_params_t _read_params; // GATT read parameter
 
     typedef LinkNode<BLEDescriptorImp *>  BLEDescriptorLinkNodeHeader;