try{
        {
            std::lock_guard<std::mutex> lock(g_pages_mutex);
            g_pages[url] = result;
        }
        if( url.find("thrd2", 0) != std::string::npos )
            throw "I'm naipnulosya";
    }
    catch(const char * msg){
         std::lock_guard<std::mutex> lock(g_pages_mutex);
         g_pages[url] = msg;
    }

#include <iostream>
#include <thread>
#include <mutex>
#include <string>


std::mutex g_pages_mutex;

class cButtonEmul{
protected:
    bool bState;
public:
    cButtonEmul(bool bState = true){
        cButtonEmul::bState = bState;
    }
    bool getState(){return bState;}
    bool setState(bool bState){
        cButtonEmul::bState = bState;
    }
};

struct sThreadParam{
    std::string *url;
    cButtonEmul *btn;
};
 

void save_page(const sThreadParam &param)
{
    if( param.btn )
        param.btn->setState(false);
    g_pages_mutex.lock();
    try
    {
        try
        {
            if( param.url ){
            if( param.url->find("thrd2", 0) != std::string::npos )
                throw "I'm naipnulosya";
            else
            if( param.url->find("thrd1", 0) != std::string::npos )
                throw 0;
            else
               *param.url = "fake content";
            }
        }
        catch(const char * msg){
            if( param.url )
               *param.url = msg;
        }
    }
    catch(...){
        g_pages_mutex.unlock();
        if( param.url )
           *param.url = "unhandled exception occured!";
        if( param.btn )
            param.btn->setState(true);
        return;//àâàð³éíèé âèõ³ä
    }
    g_pages_mutex.unlock();
    if( param.btn )
        param.btn->setState(true);
}
 
int main()
{
    cButtonEmul btn1(false);std::string sDownload1 = "http://thrd1URL";
    cButtonEmul btn2(false);std::string sDownload2 = "http://thrd2URL";
    cButtonEmul btn3(false);std::string sDownload3 = "http://thrd3URL";
    sThreadParam prm1 = {&sDownload1, &btn1};
    sThreadParam prm2 = {&sDownload2, &btn2};
    sThreadParam prm3 = {&sDownload3, &btn3};
    std::thread t1(save_page, prm1);
    std::thread t2(save_page, prm2);
    std::thread t3(save_page, prm3);
    t1.join();
    t2.join();
    t3.join();
 
    g_pages_mutex.lock();  
    std::cout<< sDownload1 <<" btn1 state : "<<std::string(btn1.getState() ? "enabled" : "disabled")<<std::endl;
    std::cout<< sDownload2 <<" btn2 state : "<<std::string(btn2.getState() ? "enabled" : "disabled")<<std::endl;
    std::cout<< sDownload3 <<" btn3 state : "<<std::string(btn3.getState() ? "enabled" : "disabled")<<std::endl;
    g_pages_mutex.unlock();  
    return 0;
}