程序实验2：11-多线程编程-实验报告

1、嵌入式操作系统多线程 -实验报告（ 11-多线程编程）程序实验二： 11-多线程编程实验专业班级实验日期5.21姓名学号实验一（ p284： 11-thread.c）1、软件功能描述创建 3 个线程，让 3 个线程重用同一个执行函数，每个线程都有 5 次循环，可以看成 5 个小任务，每次循环之间会有随即等待时间 （ 1-10s）意义在于模拟每个任务到达的时间是随机的没有任何的特定规律。2、程序流程设计3部分程序代码注释 (关键函数或代码 )#include #include#include嵌入式操作系统多线程-实验报告（ 11-多线程编程）#defineT_NUMBER 3#defineP_N

2、UMBER 5#defineTIME 10.0void *thrd_func(void *arg )intthrd_num=( int )arg;intdelay_time =0;intcount =0;printf(Thread %d is staraingn,thrd_num);for (count=0;countP_NUMBER;count+)delay_time =(int )(rand()*TIME/(RAND_MAX)+1;sleep(delay_time);printf(tTH%d:job%d delay =%dn,thrd_num,count,delay_time);print

3、f(%d finishedn,thrd_num);pthread_exit(NULL);intmain()pthread_t threadT_NUMBER;intno=0,res;void * thrd_ret;srand(time(NULL);for (no=0;noT_NUMBER;no+)res=pthread_create(&threadno,NULL, thrd_func,(if (res!=0)void *)no);printf(Creay th %d faildn,no);exit(res);printf(successnwaitingn);for (no=0;noT_NUMBE

4、R;no+)res=pthread_join(threadno,&thrd_ret);if (!res)printf(t %d joinedn,no);嵌入式操作系统多线程 -实验报告（ 11-多线程编程）elseprintf(T %djoined faildn,no);return0;4编译、运行方法及结果(抓屏 )5结果分析由运行结果可以看出， 创建线程、 释放资源按照顺序， 而每个线程的运行和结束是独立与并行的。嵌入式操作系统多线程 -实验报告（ 11-多线程编程）嵌入式操作系统多线程 -实验报告（ 11-多线程编程）实验二（ p287: 11-thread_mutex.c）1、软件功能

5、描述在试验 1 的基础上通过互斥锁，使原本独立，无序的多个线程能够按顺序进行2、程序流程设计3部分程序代码注释 (关键函数或代码 )#include#include#include#define THREAD_NUMBER3/* 线程数 */#define REPEAT_NUMBER3/* 每个线程的小任务数 */#define DELAY_TIME_LEVELS10.0/* 小任务间的最大时间间隔 */pthread_mutex_t mutex;void *thrd_func(void *arg) /线程函数例程int thrd_num = (int)arg;int delay_time =

6、 0, count = 0;int res;/互斥锁上锁res = pthread_mutex_lock(&mutex);if(res)嵌入式操作系统多线程 -实验报告（ 11-多线程编程）printf(Thread %d is startingn, thrd_num);pthread_exit(NULL);printf(Thread %d is startingn, thrd_num);for(count = 0; count REPEA T_NUMBER; count+)delay_time = (int)(rand() * DELAY_TIME_LEVELS/(RAND_MAX) + 1

7、; sleep(delay_time);printf(tThread %d: job %d delay = %dn,thrd_num, count, delay_time);printf(Thread %d finishedn, thrd_num);pthread_exit(NULL);int main(void)pthread_t threadTHREAD_NUMBER;int no = 0, res;void * thrd_ret;srand(time(NULL);pthread_mutex_init(&mutex, NULL);for(no = 0; no THREAD_NUMBER;

8、no+ )res = pthread_create(&threadno, NULL, thrd_func, (void*)no); if(res != 0)printf(Create thread %d failedn, no );exit(res);printf(Create threads successn Waiting for threads to finish.n);/* 这里的问题很奇怪，按照书上程序敲打，出现的线程首先是2 而非 0，没有按照书上所说：与创建顺序相同，但是在这里体现了互斥性，由于后面的释放资源程序从为线程 2 占用资源，所以无法释放资源，导致程序卡死，最后修改为先

9、释放线程之后则可以依次显示*/for(no = 2; no THREAD_NUMBER; no-)0 开始，而一开始2 的资源，res = pthread_join(threadno,&thrd_ret);if(!res)printf(Thread %d joinedn, no);嵌入式操作系统多线程 -实验报告（ 11-多线程编程）elseprintf(Thread %d join failedn, no);pthread_mutex_unlock(&mutex);pthread_mutex_destroy(&mutex);return 0;4编译、运行方法及结果(抓屏 )5结果分析实验结果

10、体现了互斥性，3 个线程有序运行。嵌入式操作系统多线程 -实验报告（ 11-多线程编程）实验三（ P291： 11-thread_sem.c）1、软件功能描述该程序在实验1 的基础上，用信号量同步机制实现3 个线程的有序执行，利用pv 操作来控制执行顺序，达到执行的顺序和创建的顺序刚好相反。2、程序流程设计3部分程序代码注释 (关键函数或代码 )#include#include#include#include#define THREAD_NUMBER3#define REPEAT_NUMBER 3#define DELAY_TIME_LEVELS 10.0sem_t semTHREAD_NUM

11、BER;嵌入式操作系统多线程 -实验报告（ 11-多线程编程）void *thrd_func(void *arg)int thrd_num = (int)arg;int delay_time = 0;int count = 0;sem_wait(&semthrd_num);printf(Thread %d is startingn,thrd_num);for(count = 0; count REPEAT_NUMBER; count+)delay_time = (int)(rand() * DELAY_TIME_LEVELS/(RAND_MAX)+1; sleep(delay_time);pr

12、intf(tThread %d: job %d delay = %dn,thrd_num, count, delay_time); printf(Thread %d finishedn, thrd_num);pthread_exit(NULL);int main(void)pthread_t threadTHREAD_NUMBER;int no = 0,res;void * thrd_ret;srand(time(NULL);for(no = 0; no = 0; no-)res = pthread_join(threadno, &thrd_ret);if(!res)printf(Thread

13、 %d joinedn, no);嵌入式操作系统多线程 -实验报告（ 11-多线程编程）elseprintf(Thread %d join failedn, no);sem_post(&sem(no + THREAD_NUMBER-1)%THREAD_NUMBER);for(no = 0; no THREAD_NUMBER; no+)sem_destroy(&semno);return 0;4编译、运行方法及结果(抓屏 )5结果分析嵌入式操作系统多线程 -实验报告（ 11-多线程编程）程序运行、结束都是按照顺序进行的，只是顺序和创建的顺序刚好相反。嵌入式操作系统多线程 -实验报告（ 11-多线

14、程编程）实验四（ p295: 11-thread_attr.c）1、软件功能描述创建一个线程，具有绑定和分离属性，主线程通过 finish flag 标志变量来获得线程结束的消息，不调用 pthread_join 函数2、程序流程设计3部分程序代码注释 (关键函数或代码 )#include#include#include#define REPEAT_NUMBER 3#define DELAY_TIME_LEVELS10.0int finish_flag = 0;void *thrd_func(void *arg)嵌入式操作系统多线程 -实验报告（ 11-多线程编程）int delay_time

15、 = 0;int count = 0;printf(Th is startingn);for(count=0; count REPEA T_NUMBER; count+)delay_time = (int)(rand()*DELAY_TIME_LEVELS/(RAND_MAX) + 1); sleep(delay_time);printf(tTh : job %d delay = %dn,count,delay_time);printf(Th finishedn);finish_flag = 1;pthread_exit(NULL);int main(void)pthread_t thread

16、;pthread_attr_t attr;int no = 0,res;void * thrd_ret;srand(time(NULL);res = pthread_attr_init(&attr);if(res != 0)printf(Create attribute failedn);exit(res);res = pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);res += pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); if(res!=0)printf(Set

17、ting attribute failedn);exit(res);res = pthread_create(&th, &attr, thrd_func, NULL);if(res!=0)printf(Create th failedn);exit(res);pthread_attr_destroy(&attr);printf(Create th successn);while(!finish_flag)嵌入式操作系统多线程 -实验报告（ 11-多线程编程）printf(Waiting for th to finish.n);sleep(2);return 0;4编译、运行方法及结果(抓屏 )

18、5结果分析由结果可以看出，这个创建的线程具有绑定好而分离属性，而且主线程通过一个 finish_glag 标志变量赖获得线程结束的消息，但是线程在运行结束之后似乎没有收回系统资源，因为程序运行前和程序运行后使用“ free”命令查看内存使用情况，发现使用的内存并不一致。嵌入式操作系统多线程 -实验报告（ 11-多线程编程）实验五（ p298: 11-producer-customer.c）1、软件功能描述信号量的意义， 在程序生产中和消费过程中是随机进行的， 而且生产者的速度比消费者的速度平均快两倍。 生产者一次生产一个单元产品， 消费者一次消费一个单元的产品 。2、程序流程设计3部分程序代码

19、注释 (关键函数或代码 )#include#include#include嵌入式操作系统多线程 -实验报告（ 11-多线程编程）#include#include#include#include#include#define MYFIFO myfifo#defineBUFFER_SIZE3#defineUNIT_SIZE5#defineRUN_TIME30#defineDELAY_TIME_LEVELS5.0int fd;time_t end_time;sem_t mutex,full,avail;void *producer(void *arg)int real_write;int delay

20、_time=0;while(time(NULL)end_time)delay_time=(int)(rand()*DELAY_TIME_LEVELS/(RAND_MAX)/2.0)+1;sleep(delay_time);sem_wait(&avail);sem_wait(&mutex);printf(nProducer: delay = %dn, delay_time);if(real_write=write(fd,hello,UNIT_SIZE)=-1)if(errno=EAGAIN)printf(The FIFO has not been read yet.Please try latt

21、ern);elseprintf(Write %d to the FIFOn, real_write);sem_post(&full);sem_post(&mutex);pthread_exit(NULL);void *customer(void *arg)嵌入式操作系统多线程 -实验报告（ 11-多线程编程）unsigned char read_bufferUNIT_SIZE;int real_read;int delay_time;while(time(NULL)end_time)delay_time=(int)(rand()*DELAY_TIME_LEVELS/(RAND_MAX)+1;

22、sleep(delay_time);sem_wait(&full);sem_wait(&mutex);memset(read_buffer,0,UNIT_SIZE);printf(nCustomer: delay = %dn,delay_time);if(real_read = read(fd,read_buffer,UNIT_SIZE)=-1)if(errno=EAGAIN)printf(No data yetn);printf(Read %s from FIFOn,read_buffer);sem_post(&avail);sem_post(&mutex);pthread_exit(NULL);int main()pthread_t thrd_prd_id,thrd_cst_id;pthread_t mon_th_id;int ret;srand(time(NULL);end_time=time(NULL)+RUN_TIME;if(mkfifo(MYFIFO,O_CREAT|O_EX