C 语言多线程怎么读文件高效

C语言---多个线程读取文件，其代码如下：

#include

#include

#include

#include

#include

#include

#define THREAD_NUM 25

typedef struct

{undefined

FILE *_fp

int _nThreadId//第几个线程

sem_t *_semLock

}IDD_THREAD_PARAM

void *ThreadFunc(void *args)

{undefined

char sLine[100+1]

FILE *fpRead = ((IDD_THREAD_PARAM *)args)->_fp

sem_t *semLock = ((IDD_THREAD_PARAM *)args)->_semLock

int nId = ((IDD_THREAD_PARAM *)args)->_nThreadId

sem_wait(semLock)

while(!feof(fpRead))

{undefined

memset(sLine,0,sizeof(sLine))

fgets(sLine,100,fpRead)

fprintf(stderr,"Thread ID-%d:%s",nId,sLine)

}

sem_post(semLock)

}

int main()

{undefined

pthread_t *pThreads

sem_t semLock

pThreads = (pthread_t *)malloc(THREAD_NUM*sizeof(pthread_t))

sem_init(&semLock,0,1)

FILE *fp = fopen("test.txt","r")

//开始线程循环

IDD_THREAD_PARAM param

for(int i=0i

{undefined

memset(param,0,sizeof(IDD_THREAD_PARAM))

param._fp = fp

param._nThreadId = i

param._semLock = &semLock

pthread_create((pThreads+i),NULL,ThreadFunc,param)

}

for(int i=0i

pthread_join(*(pThreads+i),NULL)

free(pThreads)

pThreads = NULL

fclose(fp)

fp = NULL

return 0

}

实现一个队列CQueue CQueue提供两个公有成员函数 addTail()：往队列尾部增加一个元素 removeHead()：读出并移除队列的第一个元素 生产者：两个线程通过调用CQueue::addTail()往队列中增加元素 消费者：一个线程通过调用CQueue::removeHead()从队列中读取元素 #include <iostream> #include <list> #include <windows.h> #include <process.h> using namespace std #define P(sem) WaitForSingleObject(sem,INFINITE) #define V(sem) ReleaseSemaphore(sem,1,NULL) class CQueue { public: void addTail()//往队列尾部增加一个元素 void removeHead()//读出并移除队列的第一个元素 private: list<int>L } CQueue buffer//全局的缓冲区 const int buf_size = 10//缓冲区大小 static int GOODS_ID = 0//商品序号 const int producers = 3//生产者数量 const int consumers = 8//消费者数量 void ProducerThread(void* param) void ConsumerThread(void* param) HANDLE empty,occupy,op_mutex int main() { int i int p_id[producers],c_id[consumers]

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