哪位大侠帮我解释一下,OSTaskCreateExt(void (*task)(void *pd)reentrant, .............

OSTaskCreateExt(void  (*task)(void *pd)reentrant, 
                            void   *dataptr, 
                            OS_STK *ptos, 
                            INT8U   prio,
                            INT16U  id,
                            OS_STK *pbos,
                            INT32U  stk_size,
                            void   *pext,
                            INT16U  opt)reentrant;这个 "void  (*task)(void *pd)reentrant"是什么意思啊?