Linux下對信號量測試的一個簡單例子

Linux下對信號量測試的一個簡單例子：

1. #include <stdio.h>
2. #include <stdlib.h>
3. #include <pthread.h>
4. #include <semaphore.h>
6. #define MAXSTACK 100
7. int stack[MAXSTACK][2];
8. int size = 0;
9. sem_t sem;
11. void ReadData1(void)
12. {
13. FILE *fp = fopen("1.dat","r");
14. if(fp == NULL)
15. {
16. printf("Open file error\n");
17. return;
18. }
19. while(!feof(fp))
20. {
21. fscanf(fp,"%d %d",&stack[size][0],&stack[size][1]);
22. sem_post(&sem);
23. ++size;
24. }
25. if(fp != NULL)
26. fclose(fp);
27. }
29. void ReadData2(void)
30. {
31. FILE *fp = fopen("2.dat","r");
32. if(fp == NULL)
33. {
34. printf("Open file ERROR\n");
35. return;
36. }
37. while(!feof(fp))
38. {
39. fscanf(fp,"%d %d",&stack[size][0],&stack[size][1]);
40. sem_post(&sem);
41. ++size;
42. }
43. if(fp != NULL)
44. fclose(fp);
45. }
47. void HandleData1(void)
48. {
49. while(1)
50. {
51. sem_wait(&sem);
52. printf("Plus:%d+%d=%d\n",stack[size][0],stack[size][1],stack[size][0]+stack[size][1]);
53. --size;
54. }
55. }
57. void HandleData2(void)
58. {
59. while(1)
60. {
61. sem_wait(&sem);
62. printf("Multiply:%d*%d=%d\n",stack[size][0],stack[size][1],stack[size][0]*stack[size][1]);
63. --size;
64. }
65. }
68. int main(void)
69. {
70. pthread_t t1,t2,t3,t4;
71. sem_init(&sem,0,0);
72. pthread_create(&t1,NULL,(void *)HandleData1,NULL);
73. pthread_create(&t2,NULL,(void *)HandleData2,NULL);
74. pthread_create(&t3,NULL,(void *)ReadData1,NULL);
75. pthread_create(&t4,NULL,(void *)ReadData2,NULL);
76. pthread_join(t1,NULL);
77. }