基于linux下的高并发服务器开发（第三章）- 3.10 死锁

deadlock.c

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>// 全局变量，所有的线程都共享这一份资源。
int tickets = 1000;// 创建一个互斥量
pthread_mutex_t mutex;void * sellticket(void * arg) {// 卖票while(1) {// 加锁pthread_mutex_lock(&mutex);pthread_mutex_lock(&mutex);if(tickets > 0) {usleep(6000);printf("%ld 正在卖第 %d 张门票\n", pthread_self(), tickets);tickets--;}else {// 解锁pthread_mutex_unlock(&mutex);break;}// 解锁pthread_mutex_unlock(&mutex);pthread_mutex_unlock(&mutex);}return NULL;
}int main() {// 初始化互斥量pthread_mutex_init(&mutex, NULL);// 创建3个子线程pthread_t tid1, tid2, tid3;pthread_create(&tid1, NULL, sellticket, NULL);pthread_create(&tid2, NULL, sellticket, NULL);pthread_create(&tid3, NULL, sellticket, NULL);// 回收子线程的资源,阻塞pthread_join(tid1, NULL);pthread_join(tid2, NULL);pthread_join(tid3, NULL);pthread_exit(NULL); // 退出主线程// 释放互斥量资源pthread_mutex_destroy(&mutex);return 0;
}

deadlock1.c

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>// 创建2个互斥量
pthread_mutex_t mutex1, mutex2;void * workA(void * arg) {pthread_mutex_lock(&mutex1);sleep(1);pthread_mutex_lock(&mutex2);printf("workA....\n");pthread_mutex_unlock(&mutex2);pthread_mutex_unlock(&mutex1);return NULL;
}void * workB(void * arg) {pthread_mutex_lock(&mutex2);sleep(1);pthread_mutex_lock(&mutex1);printf("workB....\n");pthread_mutex_unlock(&mutex1);pthread_mutex_unlock(&mutex2);return NULL;
}int main() {// 初始化互斥量pthread_mutex_init(&mutex1, NULL);pthread_mutex_init(&mutex2, NULL);// 创建2个子线程pthread_t tid1, tid2;pthread_create(&tid1, NULL, workA, NULL);pthread_create(&tid2, NULL, workB, NULL);// 回收子线程资源pthread_join(tid1, NULL);pthread_join(tid2, NULL);// 释放互斥量资源pthread_mutex_destroy(&mutex1);pthread_mutex_destroy(&mutex2);return 0;
}