Nanosleep in signal call Post: 302963488

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Top Forums Programming Nanosleep in signal call Post 302963488 by mattdj on Thursday 31st of December 2015 08:54:21 AM

12-31-2015

Registered User

THX for ansewer, mate !

Ok, so: I have to have some random numbers - Can I do that better? (1)
Second - I try to block SIGUSR1 -I will be grateful if you could tell if I do this in the right way.

Code:

void handler_signal(int signal)
{
   sigset_t pending; // syngaly oczekujace
   int losowy_czas ;  
   struct timespec ts; 
   int ret; 
   sigset_t mask; 
  
   sigemptyset (&mask);
   sigaddset (&mask, SIGUSR1); // block SIGUSR1
   
   srand((unsigned int) time(NULL));    //transfer RAND here
   losowy_czas = rand() % 15 + 5;  
   ts.tv_sec = 0; 
   ts.tv_nsec = losowy_czas * 100000000;
   
   ret = clock_nanosleep(CLOCK_MONOTONIC,0,&ts,NULL); 

   if(ret)
	perror("Blad funkcji clock_nanosleep");   	


   switch(signal)
   {
   	case SIGUSR1: 
		break;
	default:
		fprintf(stderr,"Zlapany zly sygnal: %d \n", signal); 
		return; 
  }

  //unsafe
  printf("To ja - sygnal !  Wylosowany czas %d \n", losowy_czas);  

}

In the singal will be some read function but first I want to have sure that everything is all right.

mattdj

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LEARN ABOUT FREEBSD

nanosleep

NANOSLEEP(2)						      BSD System Calls Manual						      NANOSLEEP(2)

NAME

     nanosleep -- suspend process execution for an interval measured in nanoseconds

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <time.h>

     int
     nanosleep(const struct timespec *rqtp, struct timespec *rmtp);

DESCRIPTION

     The nanosleep() system call causes the calling thread to sleep until the time interval specified by rqtp has elapsed.  An unmasked signal
     will cause it to terminate the sleep early, regardless of the SA_RESTART value on the interrupting signal.

RETURN VALUES

     If the nanosleep() system call returns because the requested time has elapsed, the value returned will be zero.

     If the nanosleep() system call returns due to the delivery of a signal, the value returned will be -1, and the global variable errno will be
     set to indicate the interruption.	If rmtp is non-NULL, the timespec structure it references is updated to contain the unslept amount (the
     request time minus the time actually slept).

ERRORS

     The nanosleep() system call fails if:

     [EFAULT]		Either rqtp or rmtp points to memory that is not a valid part of the process address space.

     [EINTR]		The nanosleep() system call was interrupted by the delivery of a signal.

     [EINVAL]		The rqtp argument specified a nanosecond value less than zero or greater than or equal to 1000 million.

     [ENOSYS]		The nanosleep() system call is not supported by this implementation.

SEE ALSO

     sigsuspend(2), sleep(3)

STANDARDS

     The nanosleep() system call conforms to IEEE Std 1003.1b-1993 (``POSIX.1'').

BSD
								  April 17, 1997							       BSD

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