I'm using the following code to try to read an input from user and timeout and exit if more than 5 seconds pass. This is accomplished through a combination of setjmp/longjmp and the SIGALRM signal. Here's the code: #include <stdio.h> #include <setjmp.h> #include <unistd.h> #include <string.h> #include <sys/signal.h> jmp_buf buffer; /...
We have a library that deals with many aspects of error reporting. I have been tasked to port this library to Linux. When running though my little test suite, one of the tests failed. A simplified version of the test appears below. /* Compiler: 4.1.1 20070105 RedHat 4.1.1-52 Output terminate called after th...
Does the POSIX standard or another C standard provide a way to recover a meaningful message from a signal number, in the same way that strerror() makes it possible to recover a message from errno? The Gnu C library has strsignal(), but if possible, I would like something portable to BSD and other Unix variants. ...
I am facing a problem in my C++ server program. The request XML comes from the front end (Java) and the back end server (C++) process the request and returns the reply XML. As part of testing after submitting the request to back-end we killed the Tomcat server. The back-end application (threaded server application) after processing the ...
I am trying to catch write faults on write protected memory pages from my program. I have done following to achieve this : protect memory page using mprotect() : allowing only read access register signal handler for SIGSEGV called write-fault-handler using sigaction() inside signal handler : siginfo->si_addr gives me memory addres...
I have a destructor that performs some necessary cleanup (it kills processes). It needs to run even when SIGINT is sent to the program. My code currently looks like: typedef boost::shared_ptr<PidManager> PidManagerPtr void PidManager::handler(int sig) { std::cout << "Caught SIGINT\n"; instance_.~PidManagerPtr(); //PidManager is a...
I am trying to create a child process and then send SIGINT to the child without terminating the parent. I tried this: pid=fork(); if (!pid) { setpgrp(); cout<<"waiting...\n"; while(1); } else { cout<<"parent"; wait(NULL); } but when I hit C-c both process were terminated ...
I wrote this simple program: void sig_ha(int signum) { cout<<"received SIGINT\n"; } int main() { string name; struct sigaction newact, old; newact.sa_handler = sig_ha; sigemptyset(&newact.sa_mask); newact.sa_flags = 0; sigaction(SIGINT,&newact,&old); for (int i=0;i<5;i++) { cout<<"Enter text: "; getline(cin,name)...
#include <stdio.h> #include <signal.h> void ALARMhandler(int sig) { signal(SIGALRM, SIG_IGN); /* ignore this signal */ printf("Hello"); signal(SIGALRM, ALARMhandler); /* reinstall the handler */ } int main(int argc, char *argv[]) { alarm(2); /* set alarm clock */ while (1...
I'm currently slamming my head against the table trying to get a QObject.connect to work with KWindowSystem, with PyKDE, my code is as follows: from PyKDE4.kdecore import * from PyKDE4.kdeui import * from PyQt4.QtCore import * #Omitted Stupid KApplication parts. def winCheck(WId): print WId kWinSys = KWindowSystem.self() QObject....
Im making a wrapper for the pthread library that allows each thread to have its own set of non-shared memory. Right now the way c is set up if any thread tries to rwe another threads data, the program segfaults. This is fine, I can catch it with a sighandler and call pthread_exit() and continue on with the program. But not every segfaul...
Python provides a signals module and os.kill; does it have a facility for sigqueue() (real-time signals with attached data)? What are the alternatives? ...
In a device driver for some PCI hardware, I have an ioctl call that waits for an incoming interrupt on the PCI bus. Using wait_queue_head_t, I put the task to sleep by calling schedule(). Then, the irq_handler function wakes up this task when the interrupt is raised on the PCI bus. Everything seems to work correctly. My question is how...
Which signal should I send to a background process to move it foreground? SIGTTIN, SIGTOU or...? ...
Hi, Please correct me if i am wrong. Here is my understanding about signals: As far as i know, signal generation and signal delivery are 2 different things. In order to generate a signal, the OS simply sets a bit in a bitarray maintained in the Process Control Block(PCB) of the process. Each bit corresponds to a particul...
In my sample application, I have basically two threads. The main thread contains a Lua engine (which is not thread-safe) and registers some C++ functions into this engine. However, one of these functions takes too long to perform (since it downloads some file over the internet) and I want the Lua engine to continue doing other stuff wit...
I need to find the number of signals pending in the signal queue of a thread in linux. Is there any API that is provided by Linux ? This API needs to be called from thread, other than the thread we are querying. sigpending gives the API for the calling thread. Is there any API, which takes thread id as arg, and provides some informatio...
hi everyone, I need to intercept and trace signals from any binaries, like strace does it under linux. I don't need a so verbose output like the real one strace. I just want to know how it works, how can I intercept signal and how can I trace them. Thanks in advance :) ...
Hello, I need some help with sending email when an order is placed. To illustrate the problem, following is the abstract code: class Order(models.Model): user = models.ForeignKey(User) class OrderItem(modes.Model): order = models.ForeignKey(Order, related_name='items') item = models.CharField(max_length=255) unit_price ...
I've done lots of stuff with pygtk however i'm deciding to learn pyqt, im stuck at the qgraphicsview i have absolutley no idea how to get signals from the items i place on the graphics view, primarily mouse events.How do i get the mouse events from idividual items in a scene? ...