1、简单描述生产者和消费者的问题。
有一个缓冲区和两个线程：生产者和消费者。生产者把产品放入缓冲区，而消费者从缓冲区中拿走。当缓冲区满时，生产者必须等待；另外，当缓冲区空时，消费者必须等待，并且缓冲区不能同时进行生产者和消费者的操作。
[cpp:nogutter]view plaincopy
- #include<stdio.h>#include<stdlib.h>#include<pthread.h>#include<semaphore.h>#include<errno.h>#include<fcntl.h>#include<string.h>#defineFIFO"my_fifo"#defineN10#definereturn_if_fail(p)if((p)==0){printf("[%s]:funcerror!/n",__func__);return;}typedefstruct_PrivInfo{sem_tavail;sem_tfull;sem_tmutex;charbuf_r[255];time_tend_time;intfd;}PrivInfo;staticvoidinfo_init(PrivInfo*thiz);staticvoidinfo_destroy(PrivInfo*thiz);staticvoid*productor(PrivInfo*thiz);staticvoid*consumer(PrivInfo*thiz);intmain(intargc,char*argv[]){pthread_tpt_1=0;pthread_tpt_2=0;intret=0;PrivInfo*thiz=NULL;thiz=(PrivInfo*)malloc(sizeof(PrivInfo));if(thiz==NULL){printf("[%s]:FailedtomallocPrivInfo./n",__func__);return-1;}info_init(thiz);ret=pthread_create(&pt_1,NULL,(void*)productor,thiz);if(ret!=0){perror("pthread_1_create:");}ret=pthread_create(&pt_2,NULL,(void*)consumer,thiz);if(ret!=0){perror("pthread_2_func:");}pthread_join(pt_1,NULL);pthread_join(pt_2,NULL);info_destroy(thiz);thiz=NULL;return0;}staticvoidinfo_init(PrivInfo*thiz){return_if_fail(thiz!=NULL);thiz->end_time=time(NULL)+10;sem_init(&thiz->avail,0,N);sem_init(&thiz->full,0,0);sem_init(&thiz->mutex,0,1);if(mkfifo(FIFO,O_CREAT|O_EXCL)&&(errno!=EEXIST)){printf("cannotcreatefifoserver./n");}printf("Prepareingforreadingbytes…/n");memset(thiz->buf_r,0,sizeof(thiz->buf_r));thiz->fd=open(FIFO,O_RDWR|O_NONBLOCK,0777);if(thiz->fd==-1){perror("openFIFO:");info_destroy(thiz);exit(1);}return;}staticvoidinfo_destroy(PrivInfo*thiz){return_if_fail(thiz!=NULL);sem_destroy(&thiz->avail);sem_destroy(&thiz->full);sem_destroy(&thiz->mutex);free(thiz);thiz=NULL;return;}staticvoid*productor(PrivInfo*thiz){return_if_fail(thiz!=NULL);intret=0;while(time(NULL)<thiz->end_time){sem_wait(&thiz->avail);sem_wait(&thiz->mutex);if((ret=write(thiz->fd,"hello",5))==-1){if(errno==EAGAIN){printf("TheFIFOhasnotbeenread,Pleasetrylateragain./n");}else{printf("writehellototheFIFO./n");}}sem_post(&thiz->full);sem_post(&thiz->mutex);sleep(1);}return;}staticvoid*consumer(PrivInfo*thiz){return_if_fail(thiz!=NULL);intret=0;while(time(NULL)<thiz->end_time){sem_wait(&thiz->full);sem_wait(&thiz->mutex);if((ret=read(thiz->fd,thiz->buf_r,255))>0){printf("read%sfrmFIFO./n",thiz->buf_r);}else{if(errno==EAGAIN){printf("nodatayet./n");}}sem_post(&thiz->avail);sem_post(&thiz->mutex);sleep(1);}return;}
从上面的经典例子中，结合了多线程的同时性编程问题。学习线程算是告了一段落，在以后的编程应用中，希望能落实到实践中去，大家一起加油~~
每个人在他的人生发轫之初，总有一段时光，
