zigbee 2：OSAL概要

2015-02-03 星期二 9:55:20

这几天看了先板子的资料和OSAL，主要记录下OSAL。

1、OSAL

• 概要
  

看了代码，OSAL确实只能称之为操作系统抽象层，就是选择执行函数指针数组tasksArr[]里的pfunc，并没有切入到硬件SP中去操作(push/pop)。

const  pTaskEventHandlerFn tasksArr[] = {
  macEventLoop,
  nwk_event_loop,
  Hal_ProcessEvent,
#if defined( MT_TASK )
  MT_ProcessEvent,
#endif
  APS_event_loop,
#if defined ( ZIGBEE_FRAGMENTATION )
  APSF_ProcessEvent,
#endif
  ZDApp_event_loop,
#if defined ( ZIGBEE_FREQ_AGILITY ) || defined ( ZIGBEE_PANID_CONFLICT )
  ZDNwkMgr_event_loop,
#endif
  GenericApp_ProcessEvent
};

在osal_run_system()中调用tasksArr[]

void  osal_run_system(  void  )
{
  ......
  do  {
    if  (tasksEvents[idx])   // Task is highest priority that is ready.
    {
      break ;
    }
  }  while  (++idx < tasksCnt);
  if  (idx < tasksCnt)
  {
    uint16 events;
    halIntState_t intState;

    HAL_ENTER_CRITICAL_SECTION(intState);
    events = tasksEvents[idx];
    tasksEvents[idx] = 0;   // Clear the Events for this task.
    HAL_EXIT_CRITICAL_SECTION(intState);

    activeTaskID = idx;
    events = (tasksArr[idx])( idx, events );
    activeTaskID = TASK_NO_TASK;

    HAL_ENTER_CRITICAL_SECTION(intState);
    tasksEvents[idx] |= events;   // Add back unprocessed events to the current task.
    HAL_EXIT_CRITICAL_SECTION(intState);
  }
  ......
}

• 事件触发

  对tasksEvents[]赋值。

  uint8 osal_set_event( uint8 task_id, uint16 event_flag )
  {
    if  ( task_id < tasksCnt )
    {
      halIntState_t   intState;
      HAL_ENTER_CRITICAL_SECTION(intState);     // Hold off interrupts
      tasksEvents[task_id] |= event_flag;   // Stuff the event bit(s)
      HAL_EXIT_CRITICAL_SECTION(intState);      // Release interrupts
      return  ( SUCCESS );
    }
     else
    {
      return  ( INVALID_TASK );
    }
  }

• MSG

  uint8 OnBoard_SendKeys( uint8 keys, uint8 state )
  {
    keyChange_t *msgPtr;
  
    if  ( registeredKeysTaskID != NO_TASK_ID )
    {
      // Send the address to the task
      msgPtr = (keyChange_t *)osal_msg_allocate(  sizeof (keyChange_t) );
      if  ( msgPtr )
      {
        msgPtr->hdr.event = KEY_CHANGE;
        msgPtr->state = state;
        msgPtr->keys = keys;
  
        osal_msg_send( registeredKeysTaskID, (uint8 *)msgPtr );
      }
      return  ( ZSuccess );
    }
    else
      return  ( ZFailure );
  }

  

osal_msg_allocate()返回的内存地址(return ( (uint8 *) (hdr + 1) )) 为addr_key，所以msgPtr指向addr_key。

对msgPtr赋值后，再传递给osal_msg_send(),最终把指向addr_key的内存挂在msg queue的尾部。

uint8 osal_msg_send( uint8 destination_task, uint8 *msg_ptr )
{
  if  ( msg_ptr == NULL )
    return  ( INVALID_MSG_POINTER );

  if  ( destination_task >= tasksCnt )
  {
    osal_msg_deallocate( msg_ptr );
    return  ( INVALID_TASK );
  }

  // Check the message header
  if  ( OSAL_MSG_NEXT( msg_ptr ) != NULL ||
       OSAL_MSG_ID( msg_ptr ) != TASK_NO_TASK )
  {
    osal_msg_deallocate( msg_ptr );
    return  ( INVALID_MSG_POINTER );
  }

  OSAL_MSG_ID( msg_ptr ) = destination_task;

  // queue message
  osal_msg_enqueue( &osal_qHead, msg_ptr );

  // Signal the task that a message is waiting
  osal_set_event( destination_task, SYS_EVENT_MSG );

  return  ( SUCCESS );
}

在osal_msg_send()中，OSAL_MSG_ID( msg_ptr ) = destination_task; 先将msg_ptr(指向addr_key)偏移到addr_msg后再赋值。

在osal_msg_enqueue()中，挂在msg queue的尾部是指向addr_key的内存。

在osal_msg_receive()中，读取对应的msg(指向addr_key)后再和​osal_msg_send()一样偏移后操作。