void* initThread(void* arg)
{
 window_init();//создание окна
 timer_init();//инициализация таймера
window_loop();//
}
int main()
{
pthread_t tid;
int thread;
thread = pthread_create(&tid,null,initThread,(void)arg);
тут многа кода
}

void window_loop()
{
	XEvent event;
	for (;;)
	{
		XNextEvent(display, &event);
		switch (event.type)
		{
		case Expose:
		{
			window_repaint();

			break;
		}
		case ResizeRequest:
		{
			XResizeRequestEvent *resize = (XResizeRequestEvent *) &event;

			window_width = resize->width;
			window_height = resize->height;

			break;
		}
		default:
		{
			break;
		}
		}
	}
}

void* initTimer(void* arg)
{
	window_init();
	timer_init();
	window_loop();
}
int main()
{       pthread id;
        sigset_t sigmask;
	int terror,arg;
	if( terror = pthread_create(&id,NULL,initTimer,(void*)arg)) {
                        printf("Thread creation failed: %d\n", terror);
					}
	pthread_sigmask(SIG_BLOCK,&sigmask,0); 				
	pthread_join (id, NULL); 

}

 #include "stdio.h"
#include "stdlib.h"
#include "signal.h"
#include "sys/time.h"
#include "time.h"
#include "timer.h"
#include "window.h"

int timer_value;

void timer_init()
{
	signal(SIGALRM, &timer_callback);

	struct timeval interval = { 1, 0 };
	struct timeval value = { 1, 0 };

	struct itimerval timerval;
	timerval.it_interval = interval;
	timerval.it_value = value;

	setitimer(ITIMER_REAL, &timerval, 0);
}

void timer_callback(int sign)
{
	if (timer_value > 0)
	{
		timer_value--;
	}

	window_repaint_send();
}

void timer_str(char *str)
{
	int hour, min, sec;

	if (timer_value)
	{
		hour = timer_value / 3600;
		min = timer_value % 3600 / 60;
		sec = timer_value % 3600 - min * 60;
	}
	else
	{
		time_t t = time(NULL);

		struct tm *lt = localtime(&t);

		hour = lt->tm_hour;
		min = lt->tm_min;
		sec = lt->tm_sec;
	}

	sprintf(str, "%.2i:%.2i:%.2i", hour, min, sec);
}

int timer_get_message(char *str)
{
	int min = 0;

	if (timer_value <= 60)
	{
		min = 1;
	}
	else if (timer_value <= 180)
	{
		min = 3;
	}
	else if (timer_value <= 300)
	{
		min = 5;
	}
	else
	{
		return 0;
	}

	sprintf(str, "Attention! Less than %i minutes!", min);

	return 1;
}

void timer_add_time(char *min_str)
{
	int sec = (int)(atof(min_str) * 60);

	timer_value += sec;
}

  |
  |+-----------+   <--------------- +
  |               |   mainloop      |
  |               +---------------- +
  |                         ^
  finish              ----- | thread killed

  |
  |+-----------+   <--------------- +
  |               |   mainloop      |
  |               +---------------- +
  |                           |
  p_thread_wait  <---  ждём завершения
  |
 finish

void* checkSignal()
{
sigset_t set;
int sig;

sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGQUIT);
sigaddset(&set, SIGTERM);
sigaddset(&set, SIGALRM);
pthread_sigmask(SIG_BLOCK, &set, NULL);

while (1) {
        sigwait(&set, &sig);
        switch (sig) {
                case SIGINT:
                        break;
                case SIGQUIT:
                        break;
                case SIGTERM:
                        break;
                case SIGALRM:
                        timer_callback(sig);
                        break;        
                default:
                        pthread_exit((void *)-1);
        }
 }
}

void window_repaint()
{
    printf("repaint\n");
    XClearArea(display, window, 0, 0, window_width, window_height, 0);


    XFontStruct *font = XLoadQueryFont(display, "10x20");
	if (!font)
	{
		exit(EXIT_FAILURE);
	}


	GC gc = XCreateGC(display, window, 0, NULL);



	XSetFont(display, gc, font->fid);

	char timer_message[100];

	timer_str(timer_message);

	int timer_message_pos_x = window_width / 2 - XTextWidth(font, timer_message, strlen(timer_message)) / 2;
    int timer_message_pos_y = window_height / 2 ;
	XDrawString(display, window, gc, timer_message_pos_x, timer_message_pos_y, timer_message, strlen(timer_message));

	char attention_message[100];
	if (timer_get_message(attention_message))
	{
		int attention_message_pos_x = window_width / 2 - XTextWidth(font, attention_message, strlen(attention_message)) / 2;
		int attention_message_pos_y = window_height / 2 + 30;

		XDrawString(display, window, gc, attention_message_pos_x, attention_message_pos_y, attention_message, strlen(attention_message));
	}

	XFreeGC(display, gc);
}

void window_repaint_send()
{
	XExposeEvent expose = { Expose, 0, 1, display, window, 0, 0, window_width, window_height, 0 };
	XSendEvent(display, window, 0, ExposureMask, (XEvent *) &expose);
	XFlush(display);
}