[RESOLVED] application crashes with "real-time signal 1"

[johanneshau]

I am working on a console application under Linux. It transmits and receives data streams via special communication hardware (developed here in house). I am recording all data in RAM buffers (the communication links are at GBit/sec speed) printing to log files any anomalies after the transmission.
I have a timer which wakes my program every 100usec do fill / read data to/from DMA buffers.
Here is the problem:
The application works, but from time to time it would crash, just saying "real-time signal 1" on the terminal. This is very annoying and often ruins my test cycles. I am new to signal programming. How do I do this correctly? Do I have to employ some kind of locking within the timer function?

This is my application structure:

void bar(int sig)
{
}

main()   /* well, not really main() but called by main() */
{
  siginfo_t info;
  timer_t m_id = 0;
  int m_signal_control = SIGRTMIN;
  int m_signal_timer = SIGRTMIN + 1;
  struct sigevent timer_info;
  struct itimerspec m_spec;
  struct sigaction foo;
  sigset_t set;

  install_sig_handlers();

  sigemptyset(&set);
  sigaddset(&set, m_signal_control);
  sigaddset(&set, m_signal_timer);

  memset(&timer_info, 0, sizeof(timer_info));
  timer_info.sigev_notify = SIGEV_SIGNAL;
  timer_info.sigev_signo = m_signal_timer;

  timer_create(CLOCK_REALTIME, &timer_info, &m_id);
  m_spec.it_value.tv_sec = 0;
  m_spec.it_value.tv_nsec = app_loop * 1000;

  m_spec.it_interval.tv_sec = m_spec.it_value.tv_sec;
  m_spec.it_interval.tv_nsec = m_spec.it_value.tv_nsec;

  /* intialize other stuff */

  timer_settime(m_id, 0, &m_spec, NULL );

  foo.sa_handler = bar;
  sigemptyset(&foo.sa_mask);

  sigaction(m_signal_timer, &foo, NULL );

  while (!terminate)
  {
    sigwaitinfo(&set, &info);
    /* do stuff */
  }
  sigwaitinfo (&set, &info);
  timer_delete(m_id);

  /* output results */
}

This is the "sig_handler.c" module

/* set from a signal handler registered to the INT/QUIT/HUP signals */
volatile int terminate = 0;

/* set from a signal handler registered to the CHDL signal */
volatile int terminate_child = 0;

/* Signal handler for the QUIT/HUP/INT signals */
static void terminate_sig_handler(const int sig)
{
    terminate       = 1;
    terminate_child = 1;
}

/* Signal handler for the CHLD signal */
static void child_sig_handler(const int sig)
{
    terminate_child = 1;
}

/* Install the INT/HUP/QUIT and CHDL signal handlers. */
void install_sig_handlers(void)
{
    /* register signal handlers from INT/HUP/QUIT */
    signal(SIGINT,  terminate_sig_handler);
    signal(SIGHUP,  terminate_sig_handler);
    signal(SIGQUIT, terminate_sig_handler);
    signal(SIGTERM, terminate_sig_handler);
    signal(SIGPIPE, child_sig_handler);
    signal(SIGCHLD, child_sig_handler);
}

Interface to "sig_handler.c":

#ifndef __SIG_HANDLER_H_
#define __SIG_HANDLER_H_

/* set from a signal handler registered to the INT/QUIT/HUP signals */
extern volatile int terminate;

/* set from a signal handler registered to the CHDL signal */
extern volatile int terminate_child;

void install_sig_handlers ();

#endif

I am not the originator of this code, so there are some uncertainties about details ...

Any help is appreciated - tank you!!

Johannes