62.多线程多文件检索,每个线程检索一个文件,用于内存不够的情况下

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include <string.h>
#include <memory.h>
#include <process.h>
#include <Windows.h>
//多线程多文件，实现线程的调度
//释放内存
//内存不够的情况，排队完成任务

//创建多线程结构体
struct infos
{
    //路径
    char path[256];
    //线程id
    int id;
    //把文件的内容载入
    char **g_pp;
    //文件的长度
    int length;
    //要查询的数据
    char findstr[100];
}myinfo[22] = {0};//22个结构体保存了22个文件的信息
HANDLE inithd[22] = {0};//22个初始化线程地址
HANDLE findhd[22] = { 0 };//22个查找线程地址

//根据路径初始化线程地址,把数据写入到infos结构体中
void runthreadinit(void *p)
{
    struct infos *pinfo = p;
    FILE *pf = fopen(pinfo->path, "r");
    if (pf!=NULL)
    {
        //测试多少行
        int i = 0;
        while (!feof(pf))
        {
            char str[256] = { 0 };
            fgets(str, 256, pf);//读取
            i++;
        }
        //i记录行数
        rewind(pf);//回到开头 fseek(pf,0,SEEK_SET);
        pinfo->g_pp = calloc(i, sizeof(char*));//分配内存初始化
        pinfo->length = i;//记录长度

        //读取并把数据拷贝到g_pp[i]中
        for (int j = 0; j < i;j++)
        {
            char str[256] = { 0 };
            //读取
            fgets(str, 256, pf);
            //获取长度
            int length = strlen(str);
            //分配内存
            pinfo->g_pp[j] = calloc(length + 1, sizeof(char));
            //拷贝到**g_pp中
            if (pinfo->g_pp[j]!=NULL)
            {
                strcpy(pinfo->g_pp[j], str);
            }
        }
    } 
    //关闭文件
    fclose(pf);
    printf("线程%d init  over
", pinfo->id);
}

//调用线程函数
void runthreadsearch(void *p)
{
    //指针类型转换
    struct infos *pinfo = p;
    //每个线程都进行相应的检索
    for (int i = 0; i < pinfo->length;i++)
    {
        if (pinfo->g_pp[i]!=NULL)
        {
            char *px = strstr(pinfo->g_pp[i], pinfo->findstr);
            if (px!=NULL)
            {
                printf("
%s", pinfo->g_pp[i]);
            }
        }
    }

    printf("线程%d find over
", pinfo->id);
}

//释放内存
void freeall(struct infos *pinfo)
{
    printf("freeall   start");
    //释放指针数组每一个指针对于的内存
    for (int i = 0; i < pinfo->length;i++)
    {
        free(pinfo->g_pp[i]);
    }
    free(pinfo->g_pp);//释放g_pp

    printf("freeall   end;");

}

void main()
{
    //给线程结构体初始化地址和要查询的字符串
    for (int i = 0; i < 15;i++)
    {
        myinfo[i].id = i+1;
        sprintf(myinfo[i].path, "dangdangwang%d.txt", i + 1);
        strcpy(myinfo[i].findstr, "小王");
    }

    //根据地址初始化结构体
    for (int i = 0; i < 15;i++)
    {
         inithd[i] = _beginthread(runthreadinit, 0, &myinfo[i]);
    }
    //等待
    WaitForMultipleObjects(15, inithd, TRUE, INFINITE);
    system("pause");

    //执行查找线程
    for (int i = 0; i < 15;i++)
    {
        findhd[i] = _beginthread(runthreadsearch, 0, &myinfo[i]);
    }    
    //等待
    WaitForMultipleObjects(15, findhd, TRUE, INFINITE);
    system("pause");

    //释放所有内存
    printf("开始释放");
    for (int i = 0; i < 15;i++)
    {
        freeall(&myinfo[i]);
    }
    printf("结束释放");

    system("pause");
}