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

#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>

#define READ_TIME    20000
#define WRITE_TIME    30000

pthread_mutex_t g_Mutex;
int g_iX = 0;
int g_rwok = 0;

bool bExit = false;

void sig(int signal)
{
    bExit = true;
}

/* writer pthread, write per 30000 us */
void * writer(void * arg)
{
    while(1)
    {
        if(true == bExit)
        {
            g_rwok++;
            break;
        }
        if(EBUSY != pthread_mutex_trylock(&g_Mutex))
        {
            printf("33[0;32mwriter : lock, write begin33[0m
");
            g_iX = 1;
            usleep(WRITE_TIME);
            pthread_mutex_unlock(&g_Mutex);
            printf("33[0;32mwriter : write ok, unlock33[0m
");
        }
        else
        {
            printf("33[0;32mwriter : 33[0;31mbusy , can not write33[0m
");
        }
        usleep(WRITE_TIME);
    }

    return NULL;
}

/* reader pthread, read per 20000 us */
void * reader(void * arg)
{
    while(1)
    {
        if(true == bExit)
        {
            g_rwok++;
            break;
        }
        if(EBUSY != pthread_mutex_trylock(&g_Mutex))
        {
            printf("33[0;33mreader : lock33[0m
");
            g_iX = 0;
            usleep(READ_TIME);
            pthread_mutex_unlock(&g_Mutex);
            printf("33[0;33mreader : unlock , read ok33[0m
");
        }
        else
        {
            printf("33[0;33mreader : 33[0;31mbusy , can not read33[0m
");
        }
        usleep(READ_TIME);
    }

    return NULL;
}

int main(int argc, char *argv[])
{
    signal(SIGINT, sig);
    memset(&g_Mutex, sizeof(g_Mutex), 0);
    pthread_mutex_init(&g_Mutex, NULL);
    
    pthread_t preader, pwriter;
    pthread_create(&preader, NULL, reader, NULL);
    pthread_create(&pwriter, NULL, writer, NULL);
    while(1)
    {
        if(true == bExit && 2 == g_rwok)
        {
            break;
        }
        usleep(100000);
    }
    pthread_mutex_destroy(&g_Mutex);
    printf("33[0;33mdestroy mutex33[0m
");

    return 0;
}

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