CC2530 事件轮询流程

CC2530芯片中的操作系统抽象层(OSAL)是一个多任务操作系统，在开发时首先需要将任务静态添加至系统进行编译，当任务执行后会产生对应的事件，当系统初始化时，需要初始化新添加的任务：

void osalInitTasks( void )
{
uint8 taskID = 0;//这里可以看出系统最多有256个任务

tasksEvents = (uint16 *)osal_mem_alloc( sizeof( uint16 ) * tasksCnt);//每项任务对应事件数组中的每一项
osal_memset( tasksEvents, 0, (sizeof( uint16 ) * tasksCnt));
//初始化系统默认任务
………..
GenericApp_Init( taskID );//这里就初始化新添加的任务
}添加任务处理函数:
// The order in this table must be identical to the task initialization calls below in osalInitTask.
typedef unsigned short (*pTaskEventHandlerFn)( unsigned char task_id, unsigned short event );
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 //添加任务处理函数
};系统运行后开始轮询所有任务的事件：
void osal_run_system( void )
{
uint8 idx = 0;

osalTimeUpdate();
Hal_ProcessPoll(); //轮询获取事件
//出现系统事件就直接调用前面注册的事件处理函数
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);
}
}事件分为两种：系统事件和自定义事件，系统事件如：
#define ZDO_NEW_DSTADDR 0xD0 // ZDO has received a new DstAddr for this app
#define ZDO_STATE_CHANGE 0xD1 // ZDO has changed the device's network state
#define ZDO_MATCH_DESC_RSP_SENT 0xD2 // ZDO match descriptor response was sent
#define ZDO_CB_MSG 0xD3 // ZDO incoming message callback
#define ZDO_NETWORK_REPORT 0xD4 // ZDO received a Network Report message
#define ZDO_NETWORK_UPDATE 0xD5 // ZDO received a Network Update message
#define ZDO_ADDR_CHANGE_IND 0xD6 // ZDO was informed of device address change而自定义事件后，任务就需要通过osal_set_event函数将对应目的任务设置事件，事件和数据被封装成消息，任务最终通过osal_msg_send函数发送对应的消息。
uint8 osal_msg_send( uint8 destination_task, uint8 *msg_ptr )消息定义如下:
typedef struct
{
void *next;
uint16 len;
uint8 dest_id;
} osal_msg_hdr_t;

typedef struct
{
uint8 event;
uint8 status;
} osal_event_hdr_t;而上面消息只是头部，在消息分配函数中，消息内容默认放在消息头部后面:
uint8 * osal_msg_allocate( uint16 len )
{
osal_msg_hdr_t *hdr;

if ( len == 0 )
return ( NULL );

hdr = (osal_msg_hdr_t *) osal_mem_alloc( (short)(len + sizeof( osal_msg_hdr_t )) );
if ( hdr )
{
hdr->next = NULL;
hdr->len = len;
hdr->dest_id = TASK_NO_TASK;
return ( (uint8 *) (hdr + 1) );
}
else
return ( NULL );
}
而消息接受函数返回除头部以外的数据部分：

uint8 *osal_msg_receive( uint8 task_id );

这个过程下来，事件流程就清晰了，轮询产生事件，事件调用处理函数，函数中获取消息，处理数据，整个事件驱动流程完成。