In the Windows Based IDE 4.6.0 I have project with  8 threads and one thread (thread number 4 with code as above) use 
timer event by signal.

When I start project in Run mode - all threads working without problem.

When I start project in IDE Debug mode every time this thread suspended with red color message in Console:

Switching to process nnn thread 4 ( state=0x03)
Warning: Signal ? does not exist on this system

I can't found the source of this unexisted Signal ? and every time suspended state of thread don't get me possible to 
debug my project.

Please help.

---

#include <signal.h>
#include <pthread.h>
#include <unistd.h>
#include <sched.h>
#include <sys/trace.h>
#include <sys/dispatch.h>

 sigset_t set;             
 struct sigevent evp;
 int sig;

#define VK_SIG	41

evp.sigev_signo = VK_SIG;
evp.sigev_notify = SIGEV_SIGNAL_THREAD;

sigemptyset(&set);           
sigaddset(&set, VK_SIG);

pthread_sigmask(SIG_BLOCK, &set, NULL);

timer_create(CLOCK_REALTIME, &evp, &timerid);

  struct timespec n_time={0,10000000};
  value.it_interval=n_time;
  value.it_value=n_time;
  timer_settime(timerid, flags, &value, NULL);

  while(1)
  {
       some_work();	
	
        sigwait(&set, &sig);

  }

...