boost and c ++ 11 regular expression regex and contrast thread thread

Test platform (virtual machine)

System: ubuntu 15.1

Compiler Version:

g++ --version
g++ 5.2.1

boost Version: boost 1.59

 

1. Regular Expressions regex

A regular expression used to match the search string.

Here is the test code.

c ++ 11 version test_regex.cpp

#include <stdio.h>
#include <regex>
#include <string>
#include <time.h>

bool matchIp(const std::string &message)
{
    try {
		std::regex m_p("^(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])$");

		return std::regex_match(message, m_p);
    }
    catch (std::exception &ex)
	{
		printf("std::regex err: %s", ex.what());
		return false;
	}
}

int main ()
{
    setbuf(stdout, NULL);
    std::string ip = "192.168.0.128";
    std::string ip2 = "192.aaa168.0.128";
    
    clock_t start,end;
    start=clock();
    
    for(int i = 0; i < 1000; i++)
    {
        bool match = matchIp(ip);
        bool match2 = matchIp(ip2);
        //printf("match:%d, match2:%d\n", (int)match, (int)match2);
    }
    
    end=clock();
    printf("Thetimewas:%f\n",(double)(end-start)/CLOCKS_PER_SEC);
    
    return 0;
}

　　Compile command g ++ test_regex.cpp -o test_regex -std = c ++ 11 -O2

boost version

#include <stdio.h>
#include <boost/regex.hpp>
#include <string>
#include <time.h>

bool matchIp(const std::string &message)
{
    try {
		boost::regex m_p("^(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])$");

		return boost::regex_match(message, m_p);
    }
    catch (std::exception &ex)
	{
		printf("boost::regex err: %s", ex.what());
		return false;
	}
}

int main ()
{
    setbuf(stdout, NULL);
    std::string ip = "192.168.0.128";
    std::string ip2 = "192.aaa168.0.128";
    
    clock_t start,end;
    start=clock();
    
    for(int i = 0; i < 1000; i++)
    {
        bool match = matchIp(ip);
        bool match2 = matchIp(ip2);
        //printf("match:%d, match2:%d\n", (int)match, (int)match2);
    }
    
    end=clock();
    printf("Thetimewas:%f\n",(double)(end-start)/CLOCKS_PER_SEC);
    return 0;
}

　　Compile command g ++ test_boost_regex.cpp -g -o test_boost_regex -I / boost_1_59_0 / /boost_1_59_0/stage/lib/libboost_regex.a /boost_1_59_0/stage/lib/libboost_system.a -O2

It matches the same IP, 1000 cycles, the time comparison

boost regular c ++ 11 standard library than the regular 40 times faster!

 

2. Thread thread test

c ++ 11 version

#include <stdio.h>
#include <thread>
#include <stdexcept>

void func5();
void func2();
void func3(int &a);
void func4();
void func5();


void func1()
{
    func2();
}
void func2()
{
    int a = 2;
    func3(a);
    
}
void func3(int &a)
{
    func4 ();
}
void func4()
{
    Func5 ();
}
void func5()
{
    throw std::runtime_error("test exception");
}


int main ()
{
    std::thread t(&func1);
    t.join();
    return 0;
}

Compile command: g ++ test_thread.cpp -o test_thread -O2 -std = c ++ 11 -lpthread -g -lrt

Directly after running a leave, which we expected.

Check run with gdb

gdb ./test_thread

Our code exception thrown location information, call stack is completely gone.

 

boost version

#include <stdio.h>
#include <boost/thread.hpp>
#include <stdexcept>

void func5();
void func2();
void func3(int &a);
void func4();
void func5();


void func1()
{
    func2();
}
void func2()
{
    int a = 2;
    func3(a);
    
}
void func3(int &a)
{
    func4 ();
}
void func4()
{
    Func5 ();
}
void func5()
{
    throw std::runtime_error("test exception");
}


int main ()
{
    boost::thread t(&func1);
    t.join();
    return 0;
}

　　

Compile command: g ++ test_boost_thread.cpp -g -o test_boost_thread -I / boost_1_59_0 /boost_1_59_0/stage/lib/libboost_thread.a /boost_1_59_0/stage/lib/libboost_system.a -lpthread -lrt -O2

Similarly execution test_boost_thread quit unexpectedly.

Debugging with gdb

gdb ./test_boost_thread

You can clearly see

#7 0x0804a9dd in func5 () at test_boost_thread.cpp:32
#8 0x0804aa38 in func1() () at test_boost_thread.cpp:28

It places in the code where the exception is thrown, a very convenient location problem.

 

Thread section concludes that (this version) c ++ 11 standard library thread thread will swallow the exception stack, if a problem want to troubleshoot the cause, will be very difficult.