/*三个窗口卖一百张票
*/#include<stdio.h>
#include<unistd.h>
#include<pthread.h>
#include<string.h>
int tickets = 0;
void * sellticket(void * arg) {//卖票usleep(7000);while(tickets <= 100) {printf("%ld 正在卖第 %d 张票\n", pthread_self(), tickets);tickets++;}return NULL;
}int main() {//创建子线程pthread_t tid1, tid2, tid3;pthread_create(&tid1, NULL, sellticket, NULL);pthread_create(&tid2, NULL, sellticket, NULL);pthread_create(&tid3, NULL, sellticket, NULL);pthread_detach(tid1);pthread_detach(tid2);pthread_detach(tid3);pthread_exit(NULL);return 0;
}

当多线程对共享的资源同时进行处理时，可能出现三个线程同时使用一个变量，会出现三个线程都输出正在卖第一百张票的情况

 

/*互斥量的类型 pthread_mutex_tint pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr);初始化互斥量参数：-mutex 需要初始化的变量-attr 互斥量相关的属性 一般使用默认 传入NULL- restrict C语言的修饰符，被修饰的指针不能由另外的指针进行操作int pthread_mutex_destory(pthread_mutex_t *mutex)-释放互斥量的资源int pthread_mutex_lock(pthread_mutex_t *mutex)-加锁 （阻塞）int pthread_mutex_trylock(pthread_mutex_t *mutex)-加锁，尝试加锁，如果加锁失败，不会阻塞，直接返回int pthread_mutex_unlock(pthread_mutex_t *mutex);-解锁
*/#include<stdio.h>
#include<unistd.h>
#include<pthread.h>
#include<string.h>int tickets = 0;pthread_mutex_t mutex;void * sellticket(void * arg) {//卖票while(1) {pthread_mutex_lock(&mutex);if(tickets <= 1000) {usleep(600);printf("%ld 正在卖第 %d 张票\n", pthread_self(), tickets);tickets++;}else {pthread_mutex_unlock(&mutex);break;}//解锁pthread_mutex_unlock(&mutex);}  return NULL;
}int main() {//初始化互斥量pthread_mutex_init(&mutex, NULL);//创建子线程pthread_t tid1, tid2, tid3;pthread_create(&tid1, NULL, sellticket, NULL);pthread_create(&tid2, NULL, sellticket, NULL);pthread_create(&tid3, NULL, sellticket, NULL);pthread_join(tid1, NULL);pthread_join(tid2, NULL);pthread_join(tid3, NULL);pthread_exit(NULL);pthread_mutex_destroy(&mutex);return 0;
}