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？
* w% |$ J; h. K& u
" h* y; O+ n# u8 A/* initialize thread timer */
, ^; s' I7 n. N+ Wrt_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？

在系统时钟中断回调函数里面，已经调用了下面的代码
9 g; {  L# K/ a" ]8 P! F& m% ?( q
void rt_tick_increase(void)
9 y& K  X7 `6 X$ _) P; R8 p4 U{
" k  z  i; V. [& a9 j7 E' estruct rt_thread thread;
' h$ e6 q/ w- c9 s8 S/ increase the global tick /
1 n% i- |/ U4 _- ]7 B8 u  G++ rt_tick;
0 t1 X( E- u! t5 a. x/ check time slice /
thread = rt_thread_self();
-- thread->remaining_tick;
6 X8 B& I( I/ z/ l7 `$ `if (thread->remaining_tick == 0)
- ]2 l/ P  O6 n$ e. b$ t& H6 p, L( c{
/ change to initialized tick /
thread->remaining_tick = thread->init_tick;
. k6 b* M% s/ T# t. f  `/ yield /
rt_thread_yield();
5 L% X- {  a2 H- u( N, v6 `}
6 t2 L. \5 R: x* f$ P8 B4 t/ check timer */
rt_timer_check();
7 b& c, h- S- \9 _/ m' M: l}
1 _! L( K# F- j% `' y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。
6 D3 i: N- P+ m6 s& h' k9 ~

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：
`
% F/ g5 r# A, M( q( ^; x/ start /
4 K* D# n) l4 z  c/ Q- A! lrt_ipc_list_suspend(&(sem->parent.suspend_thread),
thread,
9 K" |* F. g, o) U3 R4 r% usem->parent.parent.flag);

5 e! C! h! W% _1 z2 E- P/* has waiting time, start thread timer */
2 t" u! k3 Z6 Vif (time > 0)
{
RT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
thread->name));
' K# X7 f1 j; o7 c. ]9 O/* reset the timeout of thread timer and start it */
rt_timer_control(&(thread->thread_timer),
1 K# c* L" j1 ~  K% X) G9 k" j+ FRT_TIMER_CTRL_SET_TIME,
&time);
$ N1 @; d/ ]' x2 A7 ?4 d; hrt_timer_start(&(thread->thread_timer));
* K/ K2 ]$ k( ~}
/* enable interrupt */
1 z& u% {8 `6 art_hw_interrupt_enable(temp);
/* do schedule */
! A; {5 X' R+ {+ ]' l% Grt_schedule(); rt_ipc_list_suspend(&(sem->parent.suspend_thread),
thread,
sem->parent.parent.flag);
/* has waiting time, start thread timer */
+ B) Q$ B7 M4 s2 F2 yif (time > 0)
) X7 {* t+ P; i4 i+ u+ h2 R, D{
! Y0 M: q+ Y5 S% S  y) f# IRT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
thread->name));
& N! T6 V7 B/ E0 r/* reset the timeout of thread timer and start it */
: y# @. N3 M& b( lrt_timer_control(&(thread->thread_timer),
' U. X6 B. G7 ?; VRT_TIMER_CTRL_SET_TIME,
&time);
$ n& l1 \) D1 T4 m/ k& ~/ H' rrt_timer_start(&(thread->thread_timer));
}
/* enable interrupt */
2 B' K7 h" e6 i, M1 Trt_hw_interrupt_enable(temp);
/* do schedule */
rt_schedule();`
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Blah

楼上说的很不错的

land

可以试试一楼的方法