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最新推荐文章于 2025-12-30 20:41:53 发布

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#java #开发语言

#include <iohead.h>
int rdp,wdp;
long size;
pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER;
void* pre(void*arg)
{
	pthread_mutex_lock(&mutex);
	lseek(rdp,0,SEEK_SET);
	lseek(wdp,0,SEEK_SET);
	char ch;
	for(int i=0;i<size/2;i++)
	{
		read(rdp,&ch,1);
		write(wdp,&ch,1);
	}
	pthread_mutex_unlock(&mutex);
	pthread_exit(NULL);
}
void* next(void*arg)
{
	pthread_mutex_lock(&mutex);
	lseek(rdp,size/2,SEEK_SET);
	lseek(wdp,size/2,SEEK_SET);
	char ch;
	for(int i=0;i<size/2;i++)
	{
		read(rdp,&ch,1);
		write(wdp,&ch,1);
	}
	pthread_mutex_unlock(&mutex);
	pthread_exit(NULL);
}
int main(int argc, const char *argv[])
{
	umask(0);
	rdp=open("./111.jpg",O_RDONLY);
	wdp=open("./cp_11.jpg",O_WRONLY|O_CREAT|O_TRUNC,0644);
	size=lseek(rdp,0,SEEK_END);
	pthread_t tid1,tid2;
	if(0!=(errno=pthread_create(&tid1,NULL,pre,NULL)))
	{
		ERRLOG("pthread_create error\n");
	}
	if(0!=(errno=pthread_create(&tid1,NULL,next,NULL)))
	{
		ERRLOG("pthread_create error\n");
	}
	pthread_join(tid1,NULL);
	pthread_join(tid2,NULL);
	pthread_mutex_destroy(&mutex);
	return 0;
}