pthread_cond_t简单例子 

 1 #include    <errno.h>
 2 #include    <math.h>  
 3 #include    <stdio.h> 
 4 #include    <stdlib.h>
 5 #include    <string.h>
 6 #include    <pthread.h>
 7 #include    <unistd.h>
 8 
 9 pthread_mutex_t mutex;
10 pthread_cond_t cond;
11 int x;
12 int y;
13 
14 
15 /* 
16  * ===  FUNCTION  ======================================================================
17  *         Name:  x_lt_y
18  *  Description:  
19  * =====================================================================================
20  */
21     void *
22 x_lt_y ( void *arg )
23 {
24     printf ( "FUNCTION %s: muetx lock\n" , __FUNCTION__ );
25     pthread_mutex_lock(&mutex);
26     if ( x <= y ) {
27         printf ( "FUNCTION %s: x is %d, y is %d\n", __FUNCTION__, x, y );
28         printf ( "FUNCTION %s: before cond_wait\n" , __FUNCTION__);
29         pthread_cond_wait( &cond, &mutex);
30         printf ( "FUNCTION %s: after cond_wait\n" , __FUNCTION__);
31     }
32     printf ( "FUNCTION %s: muetx unlock\n" , __FUNCTION__);
33     pthread_mutex_unlock(&mutex);
34     return  NULL;
35 }        /* -----  end of function decrement  ----- */
36 
37 /* 
38  * ===  FUNCTION  ======================================================================
39  *         Name:  x_gt_y
40  *  Description:  
41  * =====================================================================================
42  */
43     void *
44 x_gt_y ( void *arg )
45 {
46     printf ( "FUNCTION %s: muetx lock\n" , __FUNCTION__);
47     pthread_mutex_lock(&mutex);
48     x++;
49     y--;
50     if ( x > y ) {
51         printf ( "FUNCTION %s: x is %d, y is %d\n", __FUNCTION__, x, y );
52         printf ( "FUNCTION %s: before cond_signal\n" , __FUNCTION__);
53         pthread_cond_signal( &cond );
54         printf ( "FUNCTION %s: after cond_signal\n" , __FUNCTION__);
55     }
56     printf ( "FUNCTION %s: muetx unlock\n" , __FUNCTION__);
57     pthread_mutex_unlock(&mutex);
58     return NULL;
59 }        /* -----  end of function increment_count  ----- */
60 
61 /* 
62  * ===  FUNCTION  ======================================================================
63  *         Name:  main
64  *  Description:  main function
65  * =====================================================================================
66  */
67     int
68 main ( int argc, char *argv[] )
69 {
70     printf ("\nProgram %s\n\n", argv[0] );
71 
72     pthread_t tid1;
73     pthread_t tid2;
74 
75     pthread_mutex_init( &mutex, NULL );
76     pthread_cond_init( &cond, NULL );
77     x = 1;
78     y = 2;
79 
80     pthread_create( &tid1, NULL, x_lt_y, NULL );
81     sleep(2);
82     
83     pthread_create( &tid2, NULL, x_gt_y, NULL );
84     sleep(2);
85 
86     return EXIT_SUCCESS;
87 }        /* ----------  end of function main  ---------- */
posted @ 2012-07-08 10:18  kimiz  阅读(388)  评论(0)    收藏  举报