[RTT例程练习]2.2信号量之基本使用(动态/静态信号量)

#include 

static struct rt_semaphore static_sem;

static rt_sem_t dynamic_sem = RT_NULL;

static rt_uint8_t thread1_stack[1024];
struct rt_thread thread1;
static void rt_thread_entry1(void *parameter)
{
 rt_err_t result;
 rt_tick_t tick;

 /* static semaphore demo */
 tick = rt_tick_get();

 /* try to take the sem, wait 10 ticks */
 result = rt_sem_take(&static_sem, 10);

 if (result == -RT_ETIMEOUT)
 {
 if (rt_tick_get() - tick != 10)
 {
 rt_sem_detach(&static_sem);
 return ;
 }
 rt_kprintf("take semaphore timeout\n");
 } 
 else 
 {
 rt_kprintf("take a static semaphore, failed.\n");
 rt_sem_detach(&static_sem);
 return ;
 } 

 /* release the semaphore */ 
 rt_sem_release(&static_sem); 
 /* wait the semaphore forever */
 result = rt_sem_take(&static_sem, RT_WAITING_FOREVER);

 if (result != RT_EOK)
 {
 rt_kprintf("take a static semaphore, failed.\n");
 rt_sem_detach(&static_sem);
 return ;
 }

 rt_kprintf("take a static semaphore, done.\n");
 /* detach the semaphore object */
 rt_sem_detach(&static_sem);
//}

/* dynamic thread pointer */
//static void thread2_entry(void *parameter)
//{
// rt_err_t result;
// rt_tick_t tick;

 tick = rt_tick_get();

 /* try to take the semaphore, wait for 10 ticks */
 result = rt_sem_take(dynamic_sem, 10);
 if (result == -RT_ETIMEOUT)
 {
 if (rt_tick_get() - tick != 10)
 {
 rt_sem_delete(dynamic_sem);
 return ;
 } 
 rt_kprintf("take semaphore timeout\n");
 }
 else
 {
 rt_kprintf("take a dynamic semaphore, failed.\n");
 rt_sem_delete(dynamic_sem);
 return ;
 }

 /* release the dynamic semaphore */
 rt_sem_release(dynamic_sem);
 /* wait forever */
 result = rt_sem_take(dynamic_sem, RT_WAITING_FOREVER);

 if (result != RT_EOK)
 {
 rt_kprintf("take a dynamic semaphore, failed.\n");
 rt_sem_delete(dynamic_sem);
 return ;
 }

 rt_kprintf("take a dynamic semaphore, done.\n");
 /* delete the semaphore*/
 rt_sem_delete(dynamic_sem);
}
//static rt_thread_t tid = RT_NULL;
int rt_application_init()
{
 rt_err_t result;

 result = rt_sem_init(&static_sem,
 "ssem",
 0, RT_IPC_FLAG_FIFO);
 if (result != RT_EOK)
 {
 rt_kprintf("init static semaphore failed. \n");
 return -1;
 }

 dynamic_sem = rt_sem_create("dsem",
 0, RT_IPC_FLAG_FIFO);
 if (dynamic_sem == RT_NULL)
 {
 rt_kprintf("create dynamic semaphore failed. \n");
 return -1;
 }

 /* thread1 init */
 rt_thread_init(&thread1, 
 "t1", 
 rt_thread_entry1, RT_NULL,
 &thread1_stack[0], sizeof(thread1_stack),
 11, 5
 );
 rt_thread_startup(&thread1);

 return 0;
}

take semaphore timeout
take a staic semaphore, done.
take semaphore timeout
take a dynamic semaphore, done.