Gdzie jest błąd klasa z thread zle wyświetlającza wartości

#include "sendemailthreads.h"

SendEmailThreads::SendEmailThreads( int id )
{
    thread_info tinfo;
    tinfo.client = id;
    tinfo.ctx = id;
    tinfo.th_id = id;
   
    // error -1, ok > 0
    int ret = pthread_create( & thread, NULL, & worker_thread, & tinfo );
   
    if( ret != 0 ) {
        cout << "Error: pthread_create() failed " << "\n ";
        exit( EXIT_FAILURE );
    } else {
        cout << "In main: creating thread " << " \n";
    }
   
    if( ret > 0 ) {
        fprintf( stderr, "Mam mowego klienta, pid=%d\n", ret );
    }
   
    if( ret < 0 ) {
        perror( "Unable to accept" );
        exit( EXIT_FAILURE );
    }
}

bool SendEmailThreads::SaveToFile( string filename, string text ) {
    try {
        // save to file
        std::ofstream outfile;
        mkdir( "files", S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH );
        outfile.open( "files/" + filename + ".log", std::ios_base::app );
        outfile << text << endl;
        outfile.close();
        return 1;
    } catch( const std::exception & exc ) {
        return 0;
    }
}

// Doo this jobs in the loop
void * SendEmailThreads::worker_thread( void * arg )
{
    thread_info * tinfo =( thread_info * ) arg;
    while( 1 ) {
        // Send emails from DATABASE
       
        // Save to file logs
        time_t seconds = time( NULL );
        SaveToFile( "thread", "Thread " + std::to_string(( int ) tinfo->client ) + " time " + std::to_string(( int ) seconds ) );
        // micro seconds 1s = 1000000
        usleep( 1000000 );
    }
    pthread_exit( NULL );
}
// send to thread data struct
struct SendEmailThreads::thread_info;
// new thread
pthread_t SendEmailThreads::thread;