tqt507 pthread 多线程测试 atomic 原子操作

// tqt057 测试结果  find /opt -name *atomic.h*
// aarch64-linux-gnu-gcc demoatomic.c -o demoatomic -pthread -I/opt/EmbedSky/TQT507/CoreA/longan/kernel/linux-4.9/tools/include
// cp ./demoatomic /home/book/nfs_rootfs

#include <linux/atomic.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>

/* 定义一个原子变量 */
static atomic_t count = ATOMIC_INIT(0);

#define pthidall 20

pthread_t pthid[pthidall];
int count_total=20000;
static void *pthread_test(void *arg)
{
    for (int i = 0; i < count_total; i++) { 
        atomic_inc(&count);
    }
}

/* 在函数中使用原子操作 */
int main(void) {
    int val = 0;
    
    for (int i = 0; i < pthidall; i++) { 
        pthread_create(&pthid[i],NULL,pthread_test, NULL);
    }
    for (int i = 0; i < pthidall; i++) { 
        if ( pthread_join ( pthid[i], NULL ) ) {
            printf("error join thread->%d \n",pthid[i]);
        }
     }
    

    /* 原子自增 */
    //atomic_inc(&count);
    //atomic_set(atomic_t * v, int i);

    /* 读取原子变量值 */
    val = atomic_read(&count);
    printf("pthread test atomic_inc->%d\n",val);//pthidall*count_total
    
    /* 设置原子变量值 */ 
    atomic_set(&count, 5);
    val = atomic_read(&count); printf("atomic_set->%d\n",val);
    
     
    //生下的几个报错没有此函数
    /* 原子比较并交换：如果原子变量值为 5，则将其设置为 7。 */
    //val = atomic_read(&count); printf("atomic_read->%d\n",val);
    //atomic_cmpxchg(&count, 5, 7);
    //val = atomic_read(&count); printf("atomic_cmpxchg 5->7 ->%d\n",val);
    //val = atomic_read(&count); printf("atomic_read->%d\n",val);
    //atomic_cmpxchg(&count, 0, 1);
    //val = atomic_read(&count); printf("atomic_cmpxchg 0->1 ->%d\n",val);

    /* 原子自减 */
    //val = atomic_read(&count); printf("atomic_read->%d\n",val);
    //atomic_dec(&count);
    //val = atomic_read(&count); printf("atomic_dec->%d\n",val);

    /* 原子加操作 */
    //val = atomic_read(&count); printf("atomic_read->%d\n",val);
    //atomic_add(2, &count);
    //val = atomic_read(&count); printf("atomic_add->%d\n",val);

    /* 原子减操作 */
    //val = atomic_read(&count); printf("atomic_read->%d\n",val);
    //atomic_sub(1, &count);
    //val = atomic_read(&count); printf("atomic_sub->%d\n",val);

    return 0;
}