pure virtual function call (C/C++)

armv7 toolchain Error

error message:
pure virtual function call

solve:
1. Occurs when calling a virtual function from a constructor or destructor.
2. Compiler option did not write -march==armv7-a.

example :
arm-linux-gnueabi-g++ -fno-omit-frame-pointer -march=armv7-a -funwind-tables

#toolchain #embedded #C #C++

Terminate called out an active extension / Aborted (C/C++)

You can build it, but when you run it,

Execute and die when an error occurs.

Error Message:

Terminate called out an active extension

Aborted

Problem

Occurs when coding using "std::thread"

Cause / Solution

When coding using "std::thread", it is caused by not inserting "join"

Example Code:

class TEST {

TEST();

~TEST();

void init();

void end();

std::shared_ptr<std::thread> th = nullptr;

void exec(){}

}

void TEST::init() {

    th = std::make_shared<std::thread>(&TEST::exec , this);

}

void TEST::end() {

if(th != nullptr) {

th->join();

th = nullptr;

}

}

int main() {

Test *t = new TEST();

t->init();

if( t != nullptr ) {

delete t;

t = nullptr;

}

// If this program ends here, an error will occur.

//add code

t->end();

if( t != nullptr ) {

delete t;

t = nullptr;

}

//solved code !

}

#linux #embedded #C #C++ #debug #error #thread #join

wstring to string / string to wstring / utf16 to utf8 / utf8 to utf16(C/C++)

wstring to string / string to wstring

for utf16 parsing error

#include <locale>
#include <codecvt>
#include <string>

std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;

std::string Str_UTF8 = converter.to_bytes(utf16String);

std::wstring wideString_UTF16 = converter.from_bytes(utf8String);

For use, you should modify the bold writing.

#utf16 #utf8 #wstring #string #C #C++ #Embedded #Linux

Function execution time Example. (C++)

std::chrono::system_clock::time_point start = std::chrono::system_clock::now();

myFunc();

std::chrono::duration<double> sec = std::chrono::system_clock::now() - start;

std::cout << "The time taken to perform the function myFunc()  : " << sec.count() << " seconds" << std::endl;

Create Thread Class Example (C++)

The class "std :: thread" exists but has been created for fun.

ThreadClass.h

#pragma once

#include <iostream>

#include <windows.h>

class ThreadClass

{

public:

ThreadClass();

~ThreadClass();

void start();

void stop();

bool isRun();

static DWORD __stdcall run_(void* p);

virtual void run() = 0;

protected:

bool threadRunFlag;

HANDLE m_Thread;

};

ThreadClass.cpp

#include "ThreadClass.h"

//

//\brief constructor,

//\param

//\return

//

ThreadClass::ThreadClass()

{

this->threadRunFlag = false;

}

//

//\brief destructor

//\param

//\return

//

ThreadClass::~ThreadClass()

{

if (this->isRun()) {

this->stop();

}

}

//

//\brief  thread start

//\param

//\return

//

void ThreadClass::start()

{

m_Thread = CreateThread(0, 0, run_, (void*)this, 0, 0);

}

///

///\brief thread end

///\param

///\return

///

void ThreadClass::stop()

{

this->threadRunFlag = false;

// to be...

}

//

//\brief thread status

//\param

//\return

//

bool ThreadClass::isRun()

{

return this->threadRunFlag;

}

//

//\brief thread run

//\param

//\return

//

DWORD __stdcall ThreadClass::run_(void * p)

{

ThreadClass* const THISCLASS = static_cast<ThreadClass*>(p);

THISCLASS->threadRunFlag = true;

THISCLASS->run();

return 0;

}

Shared folder permission setting (If you can not access the shared folder)

Problem :

I set up a shared folder in Virtualbox, but I can not access the shared folder.  

Solve :

Installing the VirtualBox Guest Additions  -> Automatically mount shared folders with VirtualBox ("/media /sh_foldername" will be shown) -> Add Ubuntu users to your vboxsf group

$ sudo -s

Input root password

$ usermod -aG vboxsf <youruser>

$ reboot

Qmake error (QT)

Error:

linux Could not determine which "make" command to run. Check the "make" step in the build configuration.

Solve :

$ sudo apt install cmake g++

$ sudo apt remove libgl1-mesa-dev
$ sudo apt install libgl1-mesa-dev