请问调用rt_thread_create（）创建线程，初始化定时器有何用处

choose521

调用rt_thread_create（）创建线程的时候，调用了下面的代码，作用是什么？
, s6 I/ `0 O) Q+ B0 W. o5 P3 v* |' q
/* initialize thread timer */
rt_timer_init(&(thread->thread_timer),thread->name,rt_thread_timeout,thread,0,RT_TIMER_FLAG_ONE_SHOT);
为什么要创建这个定时器？

. ]* {  c! w/ x) c. l在系统时钟中断回调函数里面，已经调用了下面的代码
  ^) q, ^+ W1 N" _2 s. p0 B
void rt_tick_increase(void)
{
struct rt_thread thread;
* Y# U4 @4 j2 V: w+ v/ increase the global tick /
8 R/ ~3 y2 S% Q  _6 E$ L++ rt_tick;
/ check time slice /
thread = rt_thread_self();
8 H+ Z9 I; i/ u* w. |7 A-- thread->remaining_tick;
if (thread->remaining_tick == 0)
{
+ Z, Q" i6 _+ T$ O" G6 |/ change to initialized tick /
7 t( s3 D- T2 t6 V- w8 mthread->remaining_tick = thread->init_tick;
/ yield /
9 a6 `. F- V7 ]8 M; L/ Srt_thread_yield();
* S  o% i. ]9 G. f8 w}
% p5 X1 k! m7 F/ v! s! X/ check timer */
rt_timer_check();
}
上面的代码已经会去判断remaining_tick，这个为0就执行让出cpu操作了。

opipo

用来控制挂起时间的。例如你主动调用delay或者阻塞于获取信号量等都会用到这个定时器。截取了一段信号量获取函数中的源码：
`
# R& X* B/ c6 g5 t$ J8 i! D' ~/ start /
* G( z; V1 I! m$ e( Q# Art_ipc_list_suspend(&(sem->parent.suspend_thread),
) l. G9 a! M& B7 fthread,
sem->parent.parent.flag);
# K/ {# Q4 d% b2 x, d
/* has waiting time, start thread timer */
if (time > 0)
{
( O4 m1 Z, q- m/ |RT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
5 ~; _) e! @6 gthread->name));
/* reset the timeout of thread timer and start it */
rt_timer_control(&(thread->thread_timer),
+ ~( l( S6 ?% Q1 s! ^! a; \RT_TIMER_CTRL_SET_TIME,
&time);
; Y' w% i4 e  T7 m  j3 s& ~rt_timer_start(&(thread->thread_timer));
7 M. R/ \! R6 m# w}
/* enable interrupt */
. v6 k* L+ ^/ a9 ?% Zrt_hw_interrupt_enable(temp);
/* do schedule */
8 W3 G3 Y+ w5 ^- s* Y' [rt_schedule(); rt_ipc_list_suspend(&(sem->parent.suspend_thread),
& z5 ~- q2 ~/ pthread,
sem->parent.parent.flag);
/* has waiting time, start thread timer */
7 J7 S8 S9 m$ a8 b  q+ \4 Kif (time > 0)
( p+ o" ]3 M/ F{
% P! M" ]# _2 n. I" \  ?) z9 rRT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
thread->name));
/* reset the timeout of thread timer and start it */
7 P: \% S* q/ R$ Z$ Urt_timer_control(&(thread->thread_timer),
3 m6 I5 j* K5 hRT_TIMER_CTRL_SET_TIME,
&time);
# ~; h9 I: I1 [- D7 W% |rt_timer_start(&(thread->thread_timer));
}
# {- Q. `' w& v+ t4 q1 d/ I( o/* enable interrupt */
; N. H7 E7 J8 w" j/ D8 X! N+ urt_hw_interrupt_enable(temp);
( D/ c) Z" h& o2 c4 [( D2 P/* do schedule */
rt_schedule();`
& W5 g& K) i; X7 k( y7 p

Blah

楼上说的很不错的
, f  }5 H) }2 z

land

可以试试一楼的方法