OpenCV multithreading XInitThreads error - c

Question

I am an embedded programmer and using a multithreaded application which is going to receive pixel data over serial line and display it in a window. I am using openCV's cvSetData() method to copy the data received over serial line and populate it to an openCV array. Also using the cvShowImage() function I am displaying the continuously updating pixel data( concept of displaying a video).
Here is a snippet from my code:
//-------------------------------------Start of code------------------------------------//
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#include <sys/select.h>
#include "serial_comm_defines.h"
#include <opencv2/highgui/highgui.hpp>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <pthread.h>
extern unsigned char array[COUNT_LIM];
IplImage *newimage;
img_disp_method(void)
{
cvSetData((CvArr*)newimage, (void*)array, 1556);
cvNamedWindow("Mywindow",CV_WINDOW_FREERATIO);
cvResizeWindow("Mywindow", 1556, 360);
cvShowImage("Mywindow",(CvArr*)newimage);
cvWaitKey(1);
}
void *serial_thread_method(void* my_fd)
{
clock_t start = 0, end = 0;
double time_taken = 0;
if ((int)my_fd<0)
printf("\nError opening device file\n");
else
{
printf("\nDevice file opened successfully\n");
if ( serial_config((int)my_fd) < 0)
printf("\nUnable to configure serial port\n");
else
{
printf("\nSerial port configured successfully\n");
for(;;)
{
start = clock();
serial_read((int)my_fd);
end = clock();
printf("\nTime taken:%f seconds\n", (double)((end-start)/CLOCKS_PER_SEC));
}
}
}
close ((int)my_fd);
return NULL;
}
int main(int argc, char **argv)
{
pthread_t serial_read_thread;
int my_fd=0, i=0, temp=0, serial_thread_ret=0;
newimage = cvCreateImageHeader(cvSize(HEIGHT, WIDTH), IPL_DEPTH_8U, 0x01);
struct timeval my_value={0,10000};
struct timeval my_interval={0,10000};
struct itimerval my_timer={my_interval,my_value};
setitimer(ITIMER_REAL, &my_timer, 0);
signal(SIGALRM, img_disp_method);
my_fd = open_device_file((char**)argv);
if ( (serial_thread_ret = pthread_create(&serial_read_thread, NULL, serial_thread_method, (void*)my_fd) == 0))
fprintf(stdout, "\nSerial read thread created successfully\n");
else
perror("\nError creating serial read thread\n");
pthread_join(&serial_read_thread, NULL);
cvReleaseImageHeader(&newimage);
return NULL;
}
//----------------------------------------End of code--------------------------------------//
The code is compiling fine. But when I execute the binary it throws the following error. I also observed that if change the value of timer (value of my_value and my_interval) to anywhere greater than 30ms (30000) the code works just fine. Please explain what is happening.

Answer 1

Try using a virtual timer instead of a real timer.
Something like this
setitimer(SIGVTALRM, &my_timer, 0);
signal(SIGVTALRM, img_disp_method);