signals

问题 It is my objective to make a program with a parent and child process, and when either one them is killed, they are replaced. The part I am struggling with is the case of the parent's death. In this case, the child must step up to become the new parent, and then fork() a child of its own. When I send a SIGKILL to the parent process, my entire program seems to end abruptly, and since I cannot handle a SIGKILL, I am unsure of how to do this properly. Is there a way to keep the child running in

问题 I have created a class for handling data received from slots and have created several overloaded methods of the same name with a different parameter type. Is it possible to use overloaded methods as slots? I have two declarations so far: void notify(uint uintData); void notify(float fltData); However the 2nd produces a warning at runtime: QObject::connect: No such slot clsSlot::notify(float) Found this which implies it should work: http://doc.qt.io/qt-5/signalsandslots.html But it doesn't...

问题 Here are some related discussions. But I don't think the answers are relevant to my question. Piping Rscript gives error after output Normal linux commands work just fine upon receiving SIGPIPE $ seq 10 |head -n 1 1 But Rscript behaves differently as shown in the above discussion URL. But littler's r does not have this problem. Is there a way to make Rscript use the default SIGPIPE handler so that it will have a similar behavior to other linux programs? Here mentions how to set it a the C

问题 int main(int argc, char * argv[]){ @autoreleasepool { return UIApplicationMain(argc, argv, nil, NSStringFromClass([StudentCouncilAppDelegate class])); } } I am pretty new to XCode and just trying to create an app. However, when I run my code, it stops and says Thread 1: Signal SIGBART. I don't know how to fix it. I have tried to continue over it by debugging it, but then it crashes. Then when I try to read the debug error, none is there. Does anyone know how to fix this? Please help. I wish I

问题 I've got a QTableWidget with some columns inside. Due to my needs I set QComboBox inside some columns and fill them with necessary data. void settingsDialog::onAddFieldButtonClicked() { fieldsTable->setRowCount(++rowCount); combo = new QComboBox(); combo->addItem(QString("Choose from list...")); foreach( int height, heightsAvailable) combo->addItem(QString("%1").arg(height)); fieldsTable->setCellWidget(rowCount-1, 3, combo); // etc for other columns ... } The quetsion is how to catch signals

问题 I'm trying to following the code from this post to have signal handlers print a backtrace on errors such as floating point and segmentation faults. I'm using seg fault signals as a starting point. Here is the code: #include <cstdlib> //for exit() #include <signal.h> //signal handling #include <execinfo.h> //backtrace, backtrace_symbols and backtrace_fd #include <iostream> #include <string.h> #include <stdio.h> #define TRACE_MSG fprintf(stderr, "TRACE at: %s() [%s:%d]\n", \ __FUNCTION__, _

问题 I have a UNIX daemon, which wait of SIGHUP for refresh a data. I try to send a signal from the Perl script (under Apache www-data:www-data on the same server) by Proc::Killall ("killall('HUP', 'mydaemon');"), but I have no properly permissions. suid bit doesn't work too. 'kill -n HUP ' from shell are working. Does you have any idea to do this? 回答1: The usual work-around is to employ a »touch file« to indicate a reload, see Apache2::Reload for a real life example. Listen to notifications set

问题 I am writing a Multithreaded Python application, in which each thread should wake up under the following circumstances: A signal from a main thread A Timer call started by itself In other words, threads should wake up according to a timer they set for themselves, and be able to respond to a signal from a managing thread whenever a relevant event appears. What's the idiomatic way to implement a dual (Timer/Event) wake-up mechanism? 回答1: Well, threading.Event, has a wait method, which takes a

问题 My program recently crashed with following stack; Program terminated with signal 7, Bus error. #0 0x00007f0f323beb55 in raise () from /lib64/libc.so.6 (gdb) bt #0 0x00007f0f323beb55 in raise () from /lib64/libc.so.6 #1 0x00007f0f35f8042e in skgesigOSCrash () from /usr/lib/oracle/11.2/client64/lib/libclntsh.so.11.1 #2 0x00007f0f36222ca9 in kpeDbgSignalHandler () from /usr/lib/oracle/11.2/client64/lib/libclntsh.so.11.1 #3 0x00007f0f35f8063e in skgesig_sigactionHandler () from /usr/lib/oracle/11

问题 Problem: Detecting cyclical patterns in daily data using periodogram and FFT in R. The issue is how to code in R the periodogram to detect monthly, quarterly, semi-annual, annual..etc cyclical patterns in the data. In other words I need to detect the existence of cyclical patterns for low frequencies ( ie: 1 year=> 2*pi/365, 6 months = > 4*pi/365, etc) Reproducible Example: library(weatherData) w2009=getWeatherForYear("sfo",2009) w2010=getWeatherForYear("sfo",2010) w2011=getWeatherForYear(