java.net.SocketException: socket failed: EACCES (Permission denied)

App.manifests.Androidmanifest.xml

error:
java.net.SocketException: socket failed: EACCES (Permission denied)

solve:
add : Manifest.xml file

<uses-permissionandroid:name="android.permission.INTERNET"


example:

<?xmlversion="1.0"encoding="utf-8"?>
<manifestxmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.androidclient">

<uses-permissionandroid:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activityandroid:name=".MainActivity">
<intent-filter>
<actionandroid:name="android.intent.action.MAIN"/>

<categoryandroid:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>

</manifest>



#Android #Java #Permission denied

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