关于vxworks轮转调度

chap1

关于vxworks轮转调度 [复制链接]

 下面是《vxworks与tornado》的例子：
#define PRIORITY 50
#define TIMESFLICE (float)sysClkRateGet()/100
void sched(void)
{
        int taskIdOne, taskIdTwo, taskIdThree;
       int i, j;

        if(kernelTimeSlice(TIMESLICE) == OK)
                printf("\n\n\n\n\t\t\tTIMESLICE = %f secondes\n\n\n", TIMESLICE/60);
        else
                printf("\n\n\n\n\t\t\tTIMESLICE SET ERROR!\n\n\n");

        if((taskIdOne =
                taskSpawn("task1", PRIORITY, 0x100, 2000, taskOne,
                   0,0,0,0,0,0,0,0,0,0)) == ERROR);
              printf("taskSpawn taskOne failed\n");
                  
        if((taskIdTwo =
                taskSpawn("task2", PRIORITY, 0x100, 2000, taskTwo,
                   0,0,0,0,0,0,0,0,0,0)) == ERROR);
              printf("taskSpawn taskTwo failed\n");

        if((taskIdThree =
                taskSpawn("task3", PRIORITY, 0x100, 2000, taskThree,
                   0,0,0,0,0,0,0,0,0,0)) == ERROR);
              printf("taskSpawn taskThree failed\n");


        for(i = 0;i < ITER1;i++)
        {
                for(j = 0; j < ITER2; j++)
                        logMsg("\n", 0, 0, 0, 0, 0, 0);
                for(j = 0; j < LONG_TIME; j++);
        }                  
}
sched的优先级为100,taskSpawn出来的任务的优先级都是50，实现轮转调度，发现放在sched代码后的循环语句还是在新建的三个任务前运行。
轮转调度不是先运行高优先级的任务吗？以为sched中的循环语句应该在所有新建任务完成后在执行的，请高手指教。

wo1301

有两个问题：
1.你怎么确定“放在sched代码后的循环语句还是在新建的三个任务前运行”？是在你创建的task里面加打印?

2.logMsg本身通过消息队列实现，也就是说对logMsg的调用本身就是通过向另外一个任务tLogTask发送消息，通过tLogTask输出到屏幕的。


有时侯看到的并不是真实的。

rto.wang

taskSpawn就是一个任务切换点，肯定是进行了切换。我也有同样的问题，task里面里面做什么了？

上面高手说的没错，logMsg为了保证在中断中可以调用，都是同一发给tLogTask任务来进行输出的。

最简单的方式，可以在内存中记录当前的cputick值看看。

kumelon

这个代码运行起来一直没有看到理论中的那种task1,task2,task3轮流运行一段时间的效果：

1. 
   
2. #include "vxWorks.h"
   
3. #include "taskLib.h"
   
4. #include "kernelLib.h"
   
5. #include "sysLib.h"
   
6. #include "logLib.h"
   
7. 
   
8. void taskOne(void);
   
9. void taskTwo(void);
   
10. void taskThree(void);
    
11. 
    
12. #define ITER1 5
    
13. #define ITER2 10
    
14. #define PRIORITY 50
    
15. #define TIMESLICE (float)sysClkRateGet()/100
    
16. #define LONG_TIME 1000000
    
17. 
    
18. void sched(void)
    
19. {
    
20.         int taskIdOne, taskIdTwo, taskIdThree;
    
21.        int i, j;
    
22. 
    
23.         if(kernelTimeSlice(TIMESLICE) == OK)
    
24.                 printf("\n\n\n\n\t\t\tTIMESLICE = %f secondes\n\n\n", TIMESLICE/60);
    
25.         else
    
26.                 printf("\n\n\n\n\t\t\tTIMESLICE SET ERROR!\n\n\n");
    
27. 
    
28.         if((taskIdOne =
    
29.                 taskSpawn("task1", PRIORITY, 0x100, 2000, taskOne,
    
30.                    0,0,0,0,0,0,0,0,0,0)) == ERROR);
    
31.               printf("taskSpawn taskOne failed\n");
    
32.                   
    
33.         if((taskIdTwo =
    
34.                 taskSpawn("task2", PRIORITY, 0x100, 2000, taskTwo,
    
35.                    0,0,0,0,0,0,0,0,0,0)) == ERROR);
    
36.               printf("taskSpawn taskTwo failed\n");
    
37. 
    
38.         if((taskIdThree =
    
39.                 taskSpawn("task3", PRIORITY, 0x100, 2000, taskThree,
    
40.                    0,0,0,0,0,0,0,0,0,0)) == ERROR);
    
41.               printf("taskSpawn taskThree failed\n");
    
42. 
    
43.           
    
44. }
    
45. 
    
46. void taskOne(void)
    
47. {
    
48.         int i, j;
    
49.         for(i = 0;i < ITER1;i++)
    
50.         {
    
51.                 for(j = 0; j < ITER2; j++)
    
52.                         logMsg("\n", 0, 0, 0, 0, 0, 0);
    
53.                 for(j = 0; j < LONG_TIME; j++);
    
54.         }
    
55. }
    
56. 
    
57. void taskTwo(void)
    
58. {
    
59.         int i, j;
    
60.         for(i = 0;i < ITER1;i++)
    
61.         {
    
62.                 for(j = 0; j < ITER2; j++)
    
63.                         logMsg("\n", 0, 0, 0, 0, 0, 0);
    
64.                 for(j = 0; j < LONG_TIME; j++);
    
65.         }
    
66. }
    
67. 
    
68. void taskThree(void)
    
69. {
    
70.         int i, j;
    
71.         for(i = 0;i < ITER1;i++)
    
72.         {
    
73.                 for(j = 0; j < ITER2; j++)
    
74.                         logMsg("\n", 0, 0, 0, 0, 0, 0);
    
75.                 for(j = 0; j < LONG_TIME; j++);
    
76.         }
    
77. }
    

复制代码

运行结果如下：

1. 
   
2. 
   
3. 
   
4. 
   
5. 
   
6. 
   
7.                         TIMESLICE = 0.010000 secondes
   
8. 
   
9. 
   
10. taskSpawn taskOne failed
    
11. taskSpawn taskTwo failed
    
12. taskSpawn taskThree failed
    
13. 0x3868de8 (task1):
    
14. 0x3868de8 (task1):
    
15. 0x3868de8 (task1):
    
16. 0x3868de8 (task1):
    
17. 0x3868de8 (task1):
    
18. 0x3868de8 (task1):
    
19. 0x3868de8 (task1):
    
20. 0x3868de8 (task1):
    
21. 0x3868de8 (task1):
    
22. 0x3868de8 (task1):
    
23. 0x3868de8 (task1):
    
24. 0x3868de8 (task1):
    
25. 0x3868de8 (task1):
    
26. 0x3868de8 (task1):
    
27. 0x3868de8 (task1):
    
28. 0x3868de8 (task1):
    
29. 0x3868de8 (task1):
    
30. 0x3868de8 (task1):
    
31. 0x3868de8 (task1):
    
32. 0x3868de8 (task1):
    
33. 0x3868de8 (task1):
    
34. 0x3868de8 (task1):
    
35. 0x3868de8 (task1):
    
36. 0x3868de8 (task1):
    
37. 0x3868de8 (task1):
    
38. 0x3868de8 (task1):
    
39. 0x3868de8 (task1):
    
40. 0x3868de8 (task1):
    
41. 0x3868de8 (task1):
    
42. 0x3868de8 (task1):
    
43. 0x3868de8 (task1):
    
44. 0x3868de8 (task1):
    
45. 0x3868de8 (task1):
    
46. 0x3868de8 (task1):
    
47. 0x3868de8 (task1):
    
48. 0x3868de8 (task1):
    
49. 0x3868de8 (task1):
    
50. 0x3868de8 (task1):
    
51. 0x3868de8 (task1):
    
52. 0x3868de8 (task1):
    
53. 0x3868de8 (task1):
    
54. 0x3868de8 (task1):
    
55. 0x3868de8 (task1):
    
56. 0x3868de8 (task1):
    
57. 0x3868de8 (task1):
    
58. 0x3868de8 (task1):
    
59. 0x3868de8 (task1):
    
60. 0x3868de8 (task1):
    
61. 0x3868de8 (task1):
    
62. 0x3868de8 (task1):
    
63. 0x3865268 (task2):
    
64. 0x3865268 (task2):
    
65. 0x3865268 (task2):
    
66. 0x3865268 (task2):
    
67. 0x3865268 (task2):
    
68. 0x3865268 (task2):
    
69. 0x3865268 (task2):
    
70. 0x3865268 (task2):
    
71. 0x3865268 (task2):
    
72. 0x3865268 (task2):
    
73. 0x3865268 (task2):
    
74. 0x3865268 (task2):
    
75. 0x3865268 (task2):
    
76. 0x3865268 (task2):
    
77. 0x3865268 (task2):
    
78. 0x3865268 (task2):
    
79. 0x3865268 (task2):
    
80. 0x3865268 (task2):
    
81. 0x3865268 (task2):
    
82. 0x3865268 (task2):
    
83. 0x3865268 (task2):
    
84. 0x3865268 (task2):
    
85. 0x3865268 (task2):
    
86. 0x3865268 (task2):
    
87. 0x3865268 (task2):
    
88. 0x3865268 (task2):
    
89. 0x3865268 (task2):
    
90. 0x3865268 (task2):
    
91. 0x3865268 (task2):
    
92. 0x3865268 (task2):
    
93. 0x3865268 (task2):
    
94. 0x3865268 (task2):
    
95. 0x3865268 (task2):
    
96. 0x3865268 (task2):
    
97. 0x3865268 (task2):
    
98. 0x3865268 (task2):
    
99. 0x3865268 (task2):
    
100. 0x3865268 (task2):
     
101. 0x3865268 (task2):
     
102. 0x3865268 (task2):
     
103. 0x3865268 (task2):
     
104. 0x3865268 (task2):
     
105. 0x3865268 (task2):
     
106. 0x3865268 (task2):
     
107. 0x3865268 (task2):
     
108. 0x3865268 (task2):
     
109. 0x3865268 (task2):
     
110. 0x3865268 (task2):
     
111. 0x3865268 (task2):
     
112. 0x3865268 (task2):
     
113. 0x38616e8 (task3):
     
114. 0x38616e8 (task3):
     
115. 0x38616e8 (task3):
     
116. 0x38616e8 (task3):
     
117. 0x38616e8 (task3):
     
118. 0x38616e8 (task3):
     
119. 0x38616e8 (task3):
     
120. 0x38616e8 (task3):
     
121. 0x38616e8 (task3):
     
122. 0x38616e8 (task3):
     
123. 0x38616e8 (task3):
     
124. 0x38616e8 (task3):
     
125. 0x38616e8 (task3):
     
126. 0x38616e8 (task3):
     
127. 0x38616e8 (task3):
     
128. 0x38616e8 (task3):
     
129. 0x38616e8 (task3):
     
130. 0x38616e8 (task3):
     
131. 0x38616e8 (task3):
     
132. 0x38616e8 (task3):
     
133. 0x38616e8 (task3):
     
134. 0x38616e8 (task3):
     
135. 0x38616e8 (task3):
     
136. 0x38616e8 (task3):
     
137. 0x38616e8 (task3):
     
138. 0x38616e8 (task3):
     
139. 0x38616e8 (task3):
     
140. 0x38616e8 (task3):
     
141. 0x38616e8 (task3):
     
142. 0x38616e8 (task3):
     
143. 0x38616e8 (task3):
     
144. 0x38616e8 (task3):
     
145. 0x38616e8 (task3):
     
146. 0x38616e8 (task3):
     
147. 0x38616e8 (task3):
     
148. 0x38616e8 (task3):
     
149. 0x38616e8 (task3):
     
150. 0x38616e8 (task3):
     
151. 0x38616e8 (task3):
     
152. 0x38616e8 (task3):
     
153. 0x38616e8 (task3):
     
154. 0x38616e8 (task3):
     
155. 0x38616e8 (task3):
     
156. 0x38616e8 (task3):
     
157. 0x38616e8 (task3):
     
158. 0x38616e8 (task3):
     
159. 0x38616e8 (task3):
     
160. 0x38616e8 (task3):
     
161. 0x38616e8 (task3):
     
162. 0x38616e8 (task3):
     

复制代码

而且sched在执行taskspawn的时候，还出现了taskspawn failed错误，既然taskspawn错误了，为何最终3个还是生成了、执行了？

change_p

顶贴，学习中，愿高手指点迷津。