wait(0.5) is there a way? --fflush() block stop stdin?

Question

The objective is to make workin() a low priority thread while other really heavy calculations are being made.

Is there a way to make a wait() of, lets say, 0.5 seconds?

Is it possible to block incoming characters to terminal while on wait() ? because it messes up with the characters printed to "processing ... " this part is solved, see solution below

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>

void *workin(){
    int i=0,count=10;
    char v[]={' ',' ','-','-','-',' ',' ',' ',' ',' '};

    for(;;){
        for(i=count-1;i>=0;i--){
            v[(i+1)%(count)]=v[i];
        }
        fflush(stdout);
        printf("\r");
        printf("processing ");
        printf("%s ",v);
        sleep(1);
    }
}

int main(int argc, char *argv[]){

    pthread_t tid;  
    pthread_create(&tid,NULL,workin,NULL);

    sleep(15);/*HEAVY stuff here*/

    pthread_cancel(tid);
    printf("\r\n");

    return 0;
}

Half solved, missing wait(0.5)

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>

char getch(){
    /*#include <unistd.h>   //_getch*/
    /*#include <termios.h>  //_getch*/
    char buf=0;
    struct termios old = {0};
    fflush(stdout);
    if(tcgetattr(0, &old) < 0)
        perror("tcsetattr()");
    old.c_lflag&=~ICANON;
    old.c_lflag&=~ECHO;
    old.c_cc[VMIN]=1;
    old.c_cc[VTIME]=0;
    if(tcsetattr(0, TCSANOW, &old) < 0)
        perror("tcsetattr ICANON");
    if(read(0,&buf,1)<0)
        perror("read()");
    old.c_lflag|=ICANON;
    old.c_lflag|=ECHO;
    if(tcsetattr(0, TCSADRAIN, &old) < 0)
        perror ("tcsetattr ~ICANON");

    return buf;
}

void *workin(){
    int i=0,count=10;

    char v[]={' ',' ','>','>','>',' ',' ',' ',' ',' '};

    for(;;){
        for(i=count-1;i>=0;i--){
            v[(i+1)%(count)]=v[i];
        }
        fflush(stdout);
        printf("processing ");
        printf("%s ",v);
        printf("\r");
        sleep(1);

    }
}

int main(int argc, char *argv[]){
    char ch=0;

    pthread_t tid;  
    pthread_create(&tid,NULL,workin,NULL);

    do{
        ch=getch();/*HEAVY CALCULATIONS HERE*/
    }while(1);

    pthread_cancel(tid);
    printf("\r\n");

    return 0;
}

Answer 1

一种方法是将特定的线程输出传递到终端（手动打开），就像写入文件内容一样

Answer 2

The way I have learned to "flush" stdin is to read from it and discard the information.

The way I have found to do a wait() of half a second (0.5s) is using:

#define _XOPEN_SOURCE 600

usleep(500000);