死锁示例代码

死锁产生实例，两个线程两个互斥锁，每个线程占有一个互斥锁，同时想获得另一个互斥锁则会产生死锁。
解决方案：
　　1.一次占有全部资源
　　2.每个线程占有锁的顺序是一致的。比如都是同时占有A，然后占有B锁。

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <pthread.h>
#include <signal.h>pthread_mutex_t mutex_one,mutex_two;
pthread_mutex_t mutex;
pthread_cond_t cond;void *thread_routine_one(void *arg)
{
pthread_cond_wait(&cond,&mutex);//确保two线程先运行

printf("thread_routine_one: lock mutex_one!\n");
pthread_mutex_lock(&mutex_one);printf("thread_routine_one: lock mutex_two!\n");
pthread_mutex_lock(&mutex_two);//获取two锁，这个要等待two线程对two锁的释放

sleep(1);
printf("thread_routine_one: unlock mutex_two!\n");
pthread_mutex_unlock(&mutex_two);printf("thread_routine_one: unlock mutex_one!\n");
pthread_mutex_unlock(&mutex_one);return NULL;}void *thread_routine_two(void *arg)
{
printf("thread_routine_two: lock mutex_two!\n");
pthread_mutex_lock(&mutex_two);//获取two锁
pthread_cond_signal(&cond);//让one线程运行
sleep(1);//休眠，让one可以先运行获取one锁

printf("thread_routine_two: lock mutex_one!\n");pthread_mutex_lock(&mutex_one);//获取one锁，这个同样必须等待one线程多one锁的释放/**这时出现死锁现象了，在two线程要等待one线程对one锁的释放，同时two锁没有释放
* * 然而在one线程需要等待two线程对two锁的释放，然后才会对one锁的释放！出现相互等待的过程**/printf("thread_routine_two: unlock mutex_one!\n");
pthread_mutex_unlock(&mutex_one);printf("thread_routine_two: unlock mutex_two!\n");
pthread_mutex_unlock(&mutex_two);return NULL;}void main()
{
pthread_t pthread_one,pthread_two;pthread_mutex_init(&mutex_one,NULL);
pthread_mutex_init(&mutex_two,NULL);
pthread_mutex_init(&mutex,NULL);
pthread_cond_init(&cond,NULL);pthread_create(&pthread_one,NULL,thread_routine_one,NULL);
pthread_create(&pthread_two,NULL,thread_routine_two,NULL);while(1)
sleep(1);}