cc2540连续工作时间长了，数据吞吐量会变小？

我的应用是每s传输3k字节的数据量

现象：丢包，经过反复测试发现刚开始几个小时是不丢包的，十个小时后开始丢包，而且是因为带宽不够丢的包。 

           硬件复位CC2540，又可以持续几个小时不丢包。

分析：初步怀疑里面有堆栈申请没有释放

处理： 

     将g_nData.pValue = (uint8 *)GATT_bm_alloc( 0, ATT_HANDLE_VALUE_NOTI, GATT_MAX_MTU, &len );改为

g_nData.pValue = (uint8 *)GATT_bm_alloc( 0, ATT_HANDLE_VALUE_NOTI, 20, &len );

  测试发现，没有作用

内存释放是这样的，应该没有问题，抄的TI的demo

if(GATT_Notification( 0, &g_nData, FALSE )!=SUCCESS)
{//发送失败

GATT_bm_free( (gattMsg_t *)&g_nData, ATT_HANDLE_VALUE_NOTI );

｝

协议栈用的是BLE-CC254x-1.4.2.2，不会是协议栈里面的bug搞出来的事吧

GATT_bm_alloc和GATT_bm_free为什么不是标准的成对出现？

发送出错才释放内存？

发送成功就不需要释放内存了？有或者在GATT_Notification函数里隐蔽地释放了？

可否用TI的吞吐量例程来测试一下： http://processors.wiki.ti.com/index.php/CC2540_Data_Throughput

wiki那个例程还是低版本协议栈的，不需要动态分配内存。

The stack will call GATT_bm_free so you do not need to. To get the highest throughput, you could just continuously call GATT_Notification in an infinite (or as long as possible if this is not simply a test) loop. You should also be using the smallest possible connection interval (7.5 ms). Of course doing this will likely cause bm_alloc to fail since you will run out of buffer space but you can simply retry in this case. You should also be checking the return value of GATT_notification.

You can refer below code:

static void SimpleBLEPeripheral_blastData()
{
  // Subtract the total packet overhead of ATT and L2CAP layer from notification payload
  uint16_t len = MAX_PDU_SIZE-TOTAL_PACKET_OVERHEAD;
  attHandleValueNoti_t noti;
  bStatus_t status;
  noti.handle = 0x1E;
  noti.len = len;

  // Store hte connection handle for future reference
  uint16_t connectionHandle;
  GAPRole_GetParameter(GAPROLE_CONNHANDLE, &connectionHandle);

  while(1)
  {
    // If RTOS queue is not empty, process app message.
    // We need to process the app message here in the case of a keypress
    while (!Queue_empty(appMsgQueue))
    {
      sbpEvt_t *pMsg = (sbpEvt_t *)Util_dequeueMsg(appMsgQueue);
      if (pMsg)
      {
        // Process message.
        SimpleBLEPeripheral_processAppMsg(pMsg);

        // Free the space from the message.
        ICall_free(pMsg);
      }
    }

    noti.pValue = (uint8 *)GATT_bm_alloc( connectionHandle, ATT_HANDLE_VALUE_NOTI, GATT_MAX_MTU, &len );

    if ( noti.pValue != NULL ) //if allocated
    {

      // Place index
      noti.pValue[0] = (msg_counter >> 24) & 0xFF;
      noti.pValue[1] = (msg_counter >> 16) & 0xFF;
      noti.pValue[2] = (msg_counter >> 8) & 0xFF;
      noti.pValue[3] = msg_counter & 0xFF;

      // Attempt to send the notification
      status = GATT_Notification( connectionHandle, &noti, GATT_NO_AUTHENTICATION);
      if ( status != SUCCESS ) //if noti not sent
      {
        PIN_setOutputValue(hSbpPins, Board_LED1 , Board_LED_ON);
        GATT_bm_free( (gattMsg_t *)&noti, ATT_HANDLE_VALUE_NOTI );
      }
      else
      {
        // Notification is successfully sent, increment counters
        PIN_setOutputValue(hSbpPins, Board_LED2 , Board_LED_ON);
        msg_counter++;
      }
    }
    else
    {
      // bleNoResources was returned
      asm(" NOP ");
    }

    // Reset debug pins
    PIN_setOutputValue(hSbpPins, Board_LED1 , Board_LED_OFF);
    PIN_setOutputValue(hSbpPins, Board_LED2 , Board_LED_OFF);
  }
}

https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/p/411466/1461483

我仔细核对了，就是那样写的。可能以前就参考的那个。

现在没法定位问题了。