|
|
Sponsored Content
Top Forums
Programming
Signal Handler Hangs
Post 302405334 by Loic Domaigne on Thursday 18th of March 2010 02:18:35 PM
03-18-2010
Quote:
@jim mcnamara
Thank you for the explanation.
It means the same instruction which would have caused trouble keeps on getting to the execution point and OS alerts me infinite times.
So , this would be the case for all SIGSEGV/SIGBUS cases. Then can anyone tell me what could be the best possible algorithm to handle these types of signals.
Would it be anything like
1. Check the reason for signal.
2. Alert user/ get information for debugging
2. Terminate execution from the signal handler itself.(if i return from sig handler, it means that i am eligible for another signal, isn't it?)
Regards,
Sree
Thank you for the explanation.
It means the same instruction which would have caused trouble keeps on getting to the execution point and OS alerts me infinite times.
So , this would be the case for all SIGSEGV/SIGBUS cases. Then can anyone tell me what could be the best possible algorithm to handle these types of signals.
Would it be anything like
1. Check the reason for signal.
2. Alert user/ get information for debugging
2. Terminate execution from the signal handler itself.(if i return from sig handler, it means that i am eligible for another signal, isn't it?)
Regards,
Sree
- log whatever I can to locate the problem post-mortem. This could be for instance the address of the IP (Instruction Pointer) that generates the exception, or better of stack frame, or even fire a debugger (if you can afford it). Make sure however to only call functions that can be safely used in signal handlers (POSIX calls them async-signal-safe).
- restore the default signal handler for the signal caught.
- return from the handler.
The return from the handler triggers again the exception, but that time the default signal handler is called, causing normally process termination (and usually, a core dump too).
HTH,
Loïc.
|
|
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
AIX 4.3.3
I am trying to write a signal handler into a ksh shell script. I would like to capture the SIGTERM, SIGINT, and the SIGTSTP signals, print out a message to the terminal, and continue executing the script. I have found a way to block the signals:
#! /bin/ksh
SIGTERM=15
SIGINT=2... (2 Replies)
Discussion started by: jalburger
2 Replies
2. Programming
Hi,
I have an c++ application which uses the function fork and execvp().
The parent does not wait until the child ends. The parents just creates children and let them do their stuff.
You can see the parent program as a batch-manager.
I have added a SIGCHLD handler to the program:
void... (3 Replies)
Discussion started by: jens
3 Replies
3. Programming
Hey guys,
I am trying to write a little shell, and was writing a signal handler to handle SIGINT (I am using 'stty intr ^C' and using ctrl-C to give SIGINT).
I wrote this signal handler: void handle_sigint()
{
write(2,"handling sigint\n",16);
write(1,"\nshell% ",8);
}
... (4 Replies)
Discussion started by: blowtorch
4 Replies
4. Programming
I have written a program to demonstrate a problem I have encountered when using BSD style asynchronous input using the O_ASYNC flag in conjunction with a real time interval timer sending regular SIGALRM signals to the program. The SIGIO handler obeys all safe practices, using only an atomic update... (8 Replies)
Discussion started by: stewartw
8 Replies
5. Programming
Is it ok to use exit() inside a signal handler?
I catch SIGUSR1 in a signal handler and I try to close a file and then exit. The result is inconsistent. Sometimes the process exit and sometimes it returns to the original state before the signal handler was invoked.
Perhaps exit is not legal in... (8 Replies)
Discussion started by: Tuvia
8 Replies
6. Programming
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)
Discussion started by: soeckel
2 Replies
7. Shell Programming and Scripting
I have a problem with signal handlers not working.
I have a long 1000 line code and somehow this code for signal handling is not working:
$SIG{INT} = \&interrupt;
sub interrupt {
print STDERR "Caught a control c!\n";
exit; # or just about anything else you'd want to do
}
Any... (2 Replies)
Discussion started by: som.nitk
2 Replies
8. Shell Programming and Scripting
I was working on some Perl code that does signal handling and I came across this one liner and wasn't sure what it was doing.
local $SIG{__DIE__} = sub {$! = 2; die $_;};
I think the first part of the anonymous subroutine is setting $! to 2, but I am not sure what the second part is doing. ... (1 Reply)
Discussion started by: SFNYC
1 Replies
9. Programming
i m unble to execute code of
signal handler using
a) Wait b) Waitpid (1 Reply)
Discussion started by: madhura
1 Replies
10. Programming
Hello,
I'm writing some serial(UART) handler but have stuck on few issues, maybe anyone can help to show me what I'm doing wrong.
Basically I'm intending to write serial RX signal handler.
Application receives defined packages of data over serial which contains header and payload. Handler... (3 Replies)
Discussion started by: Lauris_k
3 Replies