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？

! b$ F: J) P1 n. |! a/* initialize thread timer */
rt_timer_init(&(thread->thread_timer),thread->name,rt_thread_timeout,thread,0,RT_TIMER_FLAG_ONE_SHOT);
; g/ e( ^& |2 k& b& H5 U为什么要创建这个定时器？
+ L! p9 g5 U  P5 b- Y
) X* A5 e6 ~1 p- l在系统时钟中断回调函数里面，已经调用了下面的代码
8 }+ P3 B+ N( G$ N- D
void rt_tick_increase(void)
{
struct rt_thread thread;
( q5 K- {# q1 E- m/ increase the global tick /
1 S5 n( [$ g% w" `: Z++ rt_tick;
2 u2 w" u% L4 ^0 x/ check time slice /
5 g: V/ s* w8 v2 \* [) Xthread = rt_thread_self();
-- thread->remaining_tick;
if (thread->remaining_tick == 0)
{
/ change to initialized tick /
# W; c9 F" P& c' ]1 ~. S0 E; uthread->remaining_tick = thread->init_tick;
/ yield /
$ P# R7 t3 P2 u' ]- R( x" Q+ Vrt_thread_yield();
}
: ^5 ~9 ]" Y: _" K5 _. O) d/ 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。
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land

可以试试一楼的方法

Blah

楼上说的很不错的

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：
`
/ start /
rt_ipc_list_suspend(&(sem->parent.suspend_thread),
. L+ S" [" r* L( Z$ j: rthread,
sem->parent.parent.flag);
3 y/ K: g% U' ~7 _- ~0 |+ J
6 W1 h" s0 k5 B6 I! J/* has waiting time, start thread timer */
& n+ R9 u* x, s% ?& R. K' Dif (time > 0)
1 s3 x, R6 J9 P3 ^" k, N2 ?{
  r7 |; G1 d0 D; J. @RT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
thread->name));
. |# W9 R  e8 m: M, g' i. b' w; m) q/* reset the timeout of thread timer and start it */
rt_timer_control(&(thread->thread_timer),
RT_TIMER_CTRL_SET_TIME,
) r- K; |; m* n& r9 A9 J&time);
rt_timer_start(&(thread->thread_timer));
}
: a0 g% _) y/ d& j8 K' V# C/* enable interrupt */
  B3 N1 `9 S; y: w$ Rrt_hw_interrupt_enable(temp);
! O! B' e) m& X8 O3 ~/* do schedule */
% a3 T/ X! _4 B6 k" Yrt_schedule(); rt_ipc_list_suspend(&(sem->parent.suspend_thread),
thread,
sem->parent.parent.flag);
/* has waiting time, start thread timer */
  y3 W0 a5 b6 d% [if (time > 0)
+ l0 i; q3 l2 B' Q, i  [/ p7 ?8 Q{
8 F0 b2 T$ E; k- L+ ?% F4 ^RT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
thread->name));
1 R# I5 d4 q. M$ u* y5 t  |/* reset the timeout of thread timer and start it */
, `, k3 e# a8 z; Srt_timer_control(&(thread->thread_timer),
RT_TIMER_CTRL_SET_TIME,
7 A9 N0 @* _: K; j  K$ g6 C&time);
rt_timer_start(&(thread->thread_timer));
}
/* enable interrupt */
rt_hw_interrupt_enable(temp);
/* do schedule */
. e" B) e$ }2 f) mrt_schedule();`