实现一个计程车的流程，打车，taxi，上车，到达

#include <stdio.h>  
#include <stdlib.h>  
#include <unistd.h>  
#include <pthread.h>  //定义头文件

pthread_cond_t taxicond = PTHREAD_COND_INITIALIZER; 
  /*初始化条件变量*/
pthread_mutex_t taximutex = PTHREAD_MUTEX_INITIALIZER;
/*初始化互斥锁*/  

先写main函数；创建线程

int main (int argc, char **argv)  
{  
    char *name;  
    pthread_t thread;  //线程号

    pthread_attr_t threadattr; /*线程属性*/ 
    pthread_attr_init(&threadattr);/*对线程属性变量进行初始化*/  
    
    name = "Susan";  
    pthread_create(&thread, &threadattr, traveler_arrive, name); 
/*创建一个thread进程，与traveler_arrive函数捆绑在一起，name为Susan*/
  sleep(1);  
  
    name = "Jack";  
    pthread_create(&thread,&threadattr,taxi_arrive,name);/*创建进程thread，taxi_arrive函数捆绑在一起name为Jack*/  
    sleep(1);  
    
    name = "Mike";  
    pthread_create(&thread,&threadattr,taxi_arrive,name); /*创建进程thread，taxi_arrive函数捆绑在一起name为Mike*/  
    sleep(1);  
  
    return 0;  
} 

创建了一个name=Susan的用traveler_arrive函数
创建了一个Jack用taxi_arrive函数
创建了一个Mike用taxi_arrive函数

注：上面已经初始化互斥锁和条件变量
不用写int函数了

下面实现函数

void *traveler_arrive(void *name)  
{  

    char *p = (char *)name;  

    printf ("Travelr: %s need a taxi now!\n", p);  
    pthread_mutex_lock(&taximutex); /*拿到互斥锁，锁住互斥量*/ 
    pthread_cond_wait(&taxicond, &taximutex);/*令进程等待在条件变量上修改条件*/  
    pthread_mutex_unlock(&taximutex);/*释放互斥锁*/  

    printf ("traveler: %s now got a taxi!\n", p);  
    pthread_exit(NULL);/*退出*/  
} 

传入void* name 给转换为char* 给 *p

输出谁需要taxi

上锁 锁住互斥量，令进程等待在条件变量上修改条件，解锁

输出谁got a taxi

上面的函数是乘车的人的函数

下面是taxi的人的函数

void *taxi_arrive(void *name)  
{  
    char *p = (char *)name;  
    printf ("Taxi: %s arrives.\n", p);  
    pthread_cond_signal(&taxicond); /*条件改变，发送信号，通知进程thread*/ 
    pthread_exit(NULL);  /*退出*/
}  

转换为char *
输出taxi 谁 到达
发送信号，通知乘车人进程 进程thread

总代码：

#include <stdio.h>  
#include <stdlib.h>  
#include <unistd.h>  
#include <pthread.h>  //定义头文件

pthread_cond_t taxicond = PTHREAD_COND_INITIALIZER; 
  /*初始化条件变量*/
pthread_mutex_t taximutex = PTHREAD_MUTEX_INITIALIZER;
/*初始化互斥锁*/  

void *traveler_arrive(void *name)  
{  

    char *p = (char *)name;  

    printf ("Travelr: %s need a taxi now!\n", p);  
    pthread_mutex_lock(&taximutex); /*拿到互斥锁，锁住互斥量*/ 
    pthread_cond_wait(&taxicond, &taximutex);/*令进程等待在条件变量上修改条件*/  
    pthread_mutex_unlock(&taximutex);/*释放互斥锁*/  

    printf ("traveler: %s now got a taxi!\n", p);  
    pthread_exit(NULL);/*退出*/  
}  
  
void *taxi_arrive(void *name)  
{  
    char *p = (char *)name;  
    printf ("Taxi: %s arrives.\n", p);  
    pthread_cond_signal(&taxicond); /*条件改变，发送信号，通知进程thread*/ 
    pthread_exit(NULL);  /*退出*/
}  

  
int main (int argc, char **argv)  
{  
    char *name;  
    pthread_t thread;  //线程号

    pthread_attr_t threadattr; /*线程属性*/ 
    pthread_attr_init(&threadattr);/*对线程属性变量进行初始化*/  
    
    name = "Susan";  
    pthread_create(&thread, &threadattr, traveler_arrive, name); 
/*创建一个thread进程，与traveler_arrive函数捆绑在一起，name为Susan*/
    sleep(1);  
    
    name = "Jack";  
    pthread_create(&thread,&threadattr,taxi_arrive,name);/*创建进程thread，taxi_arrive函数捆绑在一起name为Jack*/  
    sleep(1);  
    
    name = "Mike";  
    pthread_create(&thread,&threadattr,taxi_arrive,name); /*创建进程thread，taxi_arrive函数捆绑在一起name为Mike*/ 
    sleep(1);  
  
    return 0;  
}