讀者寫者模型（概念&與生產消費者的區別￥讀寫優先順序問題）
阿新 • • 發佈：2019-02-09
1 #include<stdio.h>
2 #include<pthread.h>
3
4 int book=0;
5 pthread_rwlock_t rwlock;
6
7 void *myread(void *arg)
8 {
9 while(1)
10 {
11 ┊ if(pthread_rwlock_rdlock(&rwlock)!=0)
12 ┊ {
13 ┊ ┊ printf("writer is writing...\n");
14 ┊ }
15 ┊ else
16 ┊ {
17 ┊ printf("read book done:%d\n",book);
18 ┊ ┊ sleep(4);
19 ┊ }
20 }
21 }
22
23 void *mywrite(void *arg)
24 {
25 sleep(1);
26 while(1)
27 {
28 ┊ if(pthread_rwlock_wrlock(&rwlock)!=0)
29 ┊ {
30 ┊ ┊ printf("reader is reading...\n");
31 ┊ }
32 ┊ else
33 ┊ {
34 ┊ book++;
35 ┊ printf("write book done:%d\n",book);
36 ┊ sleep(5);
37 ┊ pthread_rwlock_unlock(&rwlock);
38 ┊ }
39 }
40 }
41
42 int main()
43 {
44 pthread_rwlock_init(&rwlock,NULL);
45 pthread_t r,w;
46 pthread_create(&r,NULL,myread ,NULL);
47 pthread_create(&w,NULL,mywrite,NULL);
48
49 pthread_join(r,NULL);
50 pthread_join(w,NULL);
51 pthread_rwlock_destroy(&rwlock);
52 return 0;
53 }
執行結果：