Its always best to keep it simple.
Most texts you read on signals recommend getting out of the handler ASAP.
A simple way it just use the handler to set a flag.
Code:
static int signal;
void call_cleanup(int sig)
{
signal = sig;
}
int sigs[] = { 1, 2, 3, 15, 0 };
set_signal_handler(sigs, call_cleanup);
for (;;) {
if (signal) break;
blah(this)
blah(that);
}
// cleanup code here
Hi Everybody,
I have gone through man of sigwait and new to UNIX signals. Could anyone explain me about the following lines mentioned in sigwait man help ?
"The selection of a signal in set is independent of the signal
mask of the calling thread or LWP. This means a thread or
LWP can ... (1 Reply)
Hello,
Can anyone, please, guide me on the use of nanosleep. I'm learning threads. I want to introduce a delay (not nested for loops, something more customizable). Nanosleep looked useful (or any other form of customizable and easy-to-use delay). Sleep is too long. :) (2 Replies)
Hi,
Ho do I differentiate system call from library call?
for example if I am using chmod , how do I find out if it is a system call or library call?
Thanks
Muru (2 Replies)
Hi,
I have encountered the following problem on Solaris 10:
I have a thread that is asleep on nanosleep (set to 24 hours).
Something that happens on another thread, causes the nanosleep to exit, even though the time has not elapsed.
The returned value is 0 (so it doesn't look like it... (1 Reply)
Hi,
I have a daq program that runs in an infinite loop until it receives SIGINT. A handler catches the signal and sets a flag to stop the while loop. After the loop some things have to be cleaned up.
The problem is that I want my main while loop to wait until the next full second begins, to... (2 Replies)
Hello,
I have a problem with package and name space.
require "/Mehran/DSGateEngineLib/general.pl";
use strict;
sub System_Status_Main_Service_Status_Intrusion_Prevention
{
my %idpstatus;
my @result;
&General_ReadHash("/var/dsg/idp/settings",\%idpstatus);
#print... (4 Replies)
Application runs on both solaris 6 and 10.
solaris 6 having only posix4.so library, solaris 10 having libposix4.so and librt.so
Can we link application to lposix4 instead of lrt for nanosleep, sothat application will run in both machines? (2 Replies)
Discussion started by: satish@123
2 Replies
LEARN ABOUT REDHAT
nanosleep
NANOSLEEP(2) Linux Programmer's Manual NANOSLEEP(2)NAME
nanosleep - pause execution for a specified time
SYNOPSIS
#include <time.h>
int nanosleep(const struct timespec *req, struct timespec *rem);
DESCRIPTION
nanosleep delays the execution of the program for at least the time specified in *req. The function can return earlier if a signal has
been delivered to the process. In this case, it returns -1, sets errno to EINTR, and writes the remaining time into the structure pointed
to by rem unless rem is NULL. The value of *rem can then be used to call nanosleep again and complete the specified pause.
The structure timespec is used to specify intervals of time with nanosecond precision. It is specified in <time.h> and has the form
struct timespec
{
time_t tv_sec; /* seconds */
long tv_nsec; /* nanoseconds */
};
The value of the nanoseconds field must be in the range 0 to 999 999 999.
Compared to sleep(3) and usleep(3), nanosleep has the advantage of not affecting any signals, it is standardized by POSIX, it provides
higher timing resolution, and it allows to continue a sleep that has been interrupted by a signal more easily.
ERRORS
In case of an error or exception, the nanosleep system call returns -1 instead of 0 and sets errno to one of the following values:
EINTR The pause has been interrupted by a non-blocked signal that was delivered to the process. The remaining sleep time has been written
into *rem so that the process can easily call nanosleep again and continue with the pause.
EINVAL The value in the tv_nsec field was not in the range 0 to 999 999 999 or tv_sec was negative.
BUGS
The current implementation of nanosleep is based on the normal kernel timer mechanism, which has a resolution of 1/HZ s (i.e, 10 ms on
Linux/i386 and 1 ms on Linux/Alpha). Therefore, nanosleep pauses always for at least the specified time, however it can take up to 10 ms
longer than specified until the process becomes runnable again. For the same reason, the value returned in case of a delivered signal in
*rem is usually rounded to the next larger multiple of 1/HZ s.
As some applications require much more precise pauses (e.g., in order to control some time-critical hardware), nanosleep is also capable of
short high-precision pauses. If the process is scheduled under a real-time policy like SCHED_FIFO or SCHED_RR, then pauses of up to 2 ms
will be performed as busy waits with microsecond precision.
CONFORMING TO
POSIX.1b (formerly POSIX.4).
SEE ALSO sleep(3), usleep(3), sched_setscheduler(2), timer_create(2)Linux 1.3.85 1996-04-10 NANOSLEEP(2)