So I've tested it on a OpenSuse machine. And there it behaves a little bit different. Instead of finishing there will be raised a segmentation fault. Here is the sample output for UPPER_BOUND = 500000000 and 500 ms intveral:
Ubuntu and VMWare:
What could be the reason of this segmentation fault. Could it be raised because of some mistakes in initializing the alternative signal stack? Does anyone has a good source, which explains, what happens inside the OS, when a context is swapped or a signal is raised? I didn't find anything on the web... :/
HI,
I need to handle SIGUSR2 signal in my application to change the state of the application dynamically. I have implemented the signal handler. However the application is able to catch only one SIGUSR2 signal. The second SIGUSR2 signal causes the application to crash. This is happning only with... (3 Replies)
Hi folks
I'm trying to write a signal handler (in c on HPUX) that will catch the child process launched by execl when it's finished so that I can check a compliance file.
The signal handler appears to catch the child process terminating however when the signal handler completes the parent... (3 Replies)
Guys,
I'm doing signal handling in Perl. I'm trying to catch ^C signal inside the script.
There two scripts : one shell script and one perl script.
The shell script calls the perl script.
For e.g. shell script a.sh and perl scipt sig.pl.
Shell script a.sh looks something like this :... (6 Replies)
#1: does anyone know how to detect how many times (and/or the time length) a given thread has been context switched out of the CPU?
#2: are there any tchniques that minimize/eliminate your thread getting context switched?
I would be happy to know the answers to these questions for ANY... (2 Replies)
Hello all,
I am starting to learn signal handling in Linux and have been trying out some simple codes to deal with SIGALRM. The code shown below sets a timer to count down. When the timer is finished a SIGALRM is produced. The handler for the signal just increments a variable called count. This... (7 Replies)
I am trying to write a small program where I can send signals and then ask for an action to be triggered if that signal is received. For example, here is an example where I am trying to write a programme that will say you pressed ctrl*c when someone presses ctrl+c. My questions are what you would... (1 Reply)
i wrote handler for sigsegv such that i can allocate memory for a variable to which
sigsegv generated for illlegal acces of memory.
my code is
#include <signal.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
char *j;
void segv_handler(int dummy)
{
j=(char *)malloc(10);
... (4 Replies)
hi friends i have a problem in signal handling ...
let me explain my problem clearly..
i have four process ..
main process forks two child process and each child process again forks another new process respectively...
the problem is whenever i kill the child process it is reforking and the... (2 Replies)
Discussion started by: senvenugopal
2 Replies
LEARN ABOUT REDHAT
getcontext
GETCONTEXT(2) Linux Programmer's Manual GETCONTEXT(2)NAME
getcontext, setcontext - get or set the user context
SYNOPSIS
#include <ucontext.h>
int getcontext(ucontext_t *ucp);
int setcontext(const ucontext_t *ucp);
where:
ucp points to a structure defined in <ucontext.h> containing the signal mask, execution stack, and machine registers.
DESCRIPTION getcontext(2) gets the current context of the calling process, storing it in the ucontext struct pointed to by ucp.
setcontext(2) sets the context of the calling process to the state stored in the ucontext struct pointed to by ucp. The struct must either
have been created by getcontext(2) or have been passed as the third parameter of the sigaction(2) signal handler.
The ucontext struct created by getcontext(2) is defined in <ucontext.h> as follows:
typedef struct ucontext
{
unsigned long int uc_flags;
struct ucontext *uc_link;
stack_t uc_stack;
mcontext_t uc_mcontext;
__sigset_t uc_sigmask;
struct _fpstate __fpregs_mem;
} ucontext_t;
RETURN VALUES getcontext(2) returns 0 on success and -1 on failure. setcontext(2) does not return a value on success and returns -1 on failure.
STANDARDS
These functions comform to: XPG4-UNIX.
NOTES
When a signal handler executes, the current user context is saved and a new context is created by the kernel. If the calling process
leaves the signal handler using longjmp(2), the original context cannot be restored, and the result of future calls to getcontext(2) are
unpredictable. To avoid this problem, use siglongjmp(2) or setcontext(2) in signal handlers instead of longjmp(2).
SEE ALSO sigaction(2), sigaltstack(2), sigprocmask(2), sigsetjmp(3), setjmp(3).
Red Hat Linux 6.1 20 September 1999 GETCONTEXT(2)