c++ - 带有 boost:asio 的线程组

问题描述

我编写了具有以下目的的小程序

它读取目录，并且需要为每个线程分配每个路径，这决定了目录的大小
/home/dir1
/home/dir2 我确实参考了这个问题。

我看到它比单线程应用程序更慢。任何错误。

#include<boost/tokenizer.hpp>
#include<boost/asio.hpp>
#include <boost/bind/bind.hpp>
#include "scan_dir.h"  //local file
using namespace std::chrono;

/*
 * Process directory fucntion
 * Input : Project path, maxdepth
 */
void process_dir(const std::string &proj, uint64_t &count, std::vector<std::string> &dirs) {
    std::cout<<"Creating Directory"<<std::endl;
    //dirs  = Util::get_top_dir_depth(proj, 0);
    dirs  = Util::traverse_dir(proj, 1);
    count = dirs.size();
}

int main(int argc, char *argv[]) {
    po::options_description desc("DiskAnalyzer Tool");
    po::variables_map vm;
    std::string user, proj;
    uint64_t f_size, maxdepth=0, dir_size=0;
    bool show_dir;

    Dirs d;
    
    desc.add_options()
        ("help,h", "DiskAnalyzer option")
        ("proj,p", po::value<string>(),"provide directory path which you would like to search data")
        ("user,u", po::value<string>(), "display file which is associated/Owner with user")
        ("dirsize,ds", po::value<uint64_t>()->default_value(1000000), "display dir which dir_size>=size by default 1000000 Byte:1MB")
        ("showdir,sh", po::value<bool>()->default_value(false), "show only dir which is associated with user")
        ("maxdepth", po::value<uint64_t>()->default_value(5), "show only dir which is associated with user")
        ("filesize,fs", po::value<uint64_t>()->default_value(10000), "display file which file_size>=size by default 10000 Byte:10KB");
    
    try {
        po::store(po::parse_command_line(argc, argv, desc), vm);
        po::notify(vm);
    }catch(const std::exception &err) {
        std::cerr<<err.what()<<std::endl;
        std::cout<<desc<<std::endl;
    }
    catch(...) {
        std::cout<<"Unkown exception"<<std::endl;
    }
    if(vm.count("help")) {
        std::cout<<"scan -p <proj_name> -u <user_name> -maxdepth <maxdepth> -fs <file_size> -d <debug>\n\n";
        std::cout<<desc<<std::endl;
        return 1;
    }
    if(vm.count("user")){
        user = vm["user"].as<string>();
    }
    if(vm.count("proj")){
        proj = vm["proj"].as<string>();
    }
    if(vm.count("filesize")){
        f_size = vm["filesize"].as<uint64_t>();
    }
    if(vm.count("showdir")) {
        show_dir = vm["showdir"].as<bool>();
    }
    if(vm.count("dirsize")) {
        dir_size = vm["dirsize"].as<uint64_t>();
    }
    if(vm.count("maxdepth")){
        maxdepth = vm["maxdepth"].as<uint64_t>();
    }
    
    if(show_dir) {
        d.scan_dir_name(proj, user, dir_size, maxdepth);
        return 0;
    } else {
        uint64_t count = 0;
        std::vector<std::string> dir;
        process_dir(proj, count, dir);
        std::cout<<"createing database["<<proj<<"   "<<count<<"  ]"<<std::endl;
        std::string db_name = Command::basename(proj);
        DataBase db[count];
        for (uint64_t i = 0; i<count; i++){
            db[i].set_db_name("DiskAnalyzer_"+ std::to_string(i)+"_" +db_name);
            if(!db[i].prepare_db()){
                std::cerr<<"[Error] DataBase operation failed"<<std::endl;
                return 1;
            }
        }
        std::size_t max_thread = dir.size() > 1000 ? 1000 : dir.size();
        //max_thread = 10;
        std::cout<<dir.size()<<std::endl;
        //contain directory information
        while(dir.size()){
            std::size_t dir_traverse = 0, db_count = 0;
            boost::asio::io_service io_service;
            boost::asio::io_service::work work(io_service);
            boost::thread_group threads;
            for (std::size_t i = 0; i < max_thread; ++i)
                threads.create_thread(boost::bind(&boost::asio::io_service::run, &io_service));
            
            for(auto it = dir.begin(); it != dir.end() && dir_traverse <max_thread; ++it){
                if(db_count>=count)
                    db_count = 0;
                try {
                    //this function determine determine size of directory. I had expectation
                    // each directory will go each thread
                    io_service.post(boost::bind(&Dirs::scan_dir, boost::ref(d), *it, db[db_count], user));
                } catch(...) {
                    std::cerr<<"got error"<<std::endl;
                    continue;
                }
                dir_traverse++;
                //dir_traverse = dir_traverse + max_thread;
                db_count++;
                //boost::this_thread::sleep(boost::posix_time::seconds(1));
            }
            io_service.stop();
            threads.join_all();
            dir.erase(dir.begin(), dir.begin()+dir_traverse);
            std::cout<<" [Remaining Processing dir cout  "<<dir.size()<<std::endl;
        }
        return 0;
    }
    std::cout<<desc<<std::endl;
    return 0;
}

标签： c++boostboost-asio

每次围绕顶层循环时，您都会停止整个池。

这不仅会在重新创建和销毁线程时产生大量开销。

它还通过执行stop. 即使任务没有完成，也会stop强制执行上下文停止。事实上，在线程加入之前，可能根本没有任何任务开始。

自然的解决方法是将池从循环中取出并在最后加入它（不stop-ping 服务，因此所有任务都完成）。但是，在您的情况下，它需要进行更多更改，因为 tasks post-ed 在循环中引用了本地变量。

c++ - 带有 boost:asio 的线程组

问题描述

解决方案

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