linux下使用线程锁互斥访问资源

linux使用线程锁访问互斥资源：

1、线程锁的创建 

pthread_mutex_t g_Mutex;

 

2、完整代码如下

  1 #include <stdio.h>

  2 #include <string.h>

  3 #include <pthread.h>

  4 #include <stdlib.h>

  5 #include <unistd.h>

  6 #include <errno.h>

  7 #include <signal.h>

  8 

  9 #define READ_TIME    20000

 10 #define WRITE_TIME    30000

 11 

 12 pthread_mutex_t g_Mutex;

 13 int g_iX = 0;

 14 int g_rwok = 0;

 15 

 16 bool bExit = false;

 17 

 18 void sig(int signal)

 19 {

 20     bExit = true;

 21 }

 22 

 23 /* writer pthread, write per 30000 us */

 24 void * writer(void * arg)

 25 {

 26     while(1)

 27     {

 28         if(true == bExit)

 29         {

 30             g_rwok++;

 31             break;

 32         }

 33         if(EBUSY != pthread_mutex_trylock(&g_Mutex))

 34         {

 35             printf("\033[0;32mwriter : lock, write begin\033[0m\n");

 36             g_iX = 1;

 37             usleep(WRITE_TIME);

 38             pthread_mutex_unlock(&g_Mutex);

 39             printf("\033[0;32mwriter : write ok, unlock\033[0m\n");

 40         }

 41         else

 42         {

 43             printf("\033[0;32mwriter : \033[0;31mbusy , can not write\033[0m\n");

 44         }

 45         usleep(WRITE_TIME);

 46     }

 47 

 48     return NULL;

 49 }

 50 

 51 /* reader pthread, read per 20000 us */

 52 void * reader(void * arg)

 53 {

 54     while(1)

 55     {

 56         if(true == bExit)

 57         {

 58             g_rwok++;

 59             break;

 60         }

 61         if(EBUSY != pthread_mutex_trylock(&g_Mutex))

 62         {

 63             printf("\033[0;33mreader : lock\033[0m\n");

 64             g_iX = 0;

 65             usleep(READ_TIME);

 66             pthread_mutex_unlock(&g_Mutex);

 67             printf("\033[0;33mreader : unlock , read ok\033[0m\n");

 68         }

 69         else

 70         {

 71             printf("\033[0;33mreader : \033[0;31mbusy , can not read\033[0m\n");

 72         }

 73         usleep(READ_TIME);

 74     }

 75 

 76     return NULL;

 77 }

 78 

 79 int main(int argc, char *argv[])

 80 {

 81     signal(SIGINT, sig);

 82     memset(&g_Mutex, sizeof(g_Mutex), 0);

 83     pthread_mutex_init(&g_Mutex, NULL);

 84     

 85     pthread_t preader, pwriter;

 86     pthread_create(&preader, NULL, reader, NULL);

 87     pthread_create(&pwriter, NULL, writer, NULL);

 88     while(1)

 89     {

 90         if(true == bExit && 2 == g_rwok)

 91         {

 92             break;

 93         }

 94         usleep(100000);

 95     }

 96     pthread_mutex_destroy(&g_Mutex);

 97     printf("\033[0;33mdestroy mutex\033[0m\n");

 98 

 99     return 0;

100 }

3、运行结果如下

reader : lock

writer : busy , can not write

reader : unlock , read ok

writer : lock, write begin

reader : busy , can not read

writer : write ok, unlock

reader : lock

reader : unlock , read ok

writer : lock, write begin

reader : busy , can not read

writer : write ok, unlock