How to read error codes which appear in the console?
<Warning>: ....... -exited abnormally with signal 9: Killed: 9
<Warning>: ....... -1 err = Bad file descriptor (0x00000009)
Here what does signal 9 mean, are there any more signals apart from it. Any documentation available for it.
I get this kind of error, when a App. launched from Xcode is terminated by "Stop" button in Xcode toolbar.
(Another way to get this error is , to press home button, then double tap home button and close the app.)
Things even get worse when I launch the App. again, by tapping on App. icon on iPad Screen, App crashes and throws "libMobileGestalt copySystemVersionDictionaryValue: Could not lookup ReleaseType from system version dictionary"
From finding on stack overflow , I see that this error is found in iOS 6 devices.
This url states that it's a SIGKILL error and it happens when "application is being terminated immediately, without any chance to clean up or catch and handle the signal"
So, I think releasing objets in -(void) didReceiveMemoryWarning would not help to solve it, then what could be a definite solution?
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release objects.
obj1 = nil;
[view1 removeFromSuperView];
view1 = nil;
...
}
It means that the application received a signal. Some signal could be handled by the applications, others, not. Signal 9 means that the application needs to be killed, it is not handled by the process, but by the Linux scheduler. The signal to terminate the process that is handled by the process is SIGTERM(15), but, if the process doesn't handle it property, then the process continues to live.
here are the major signals:
Signal Value Action Comment
──────────────────────────────────────────────────────────────────────
SIGHUP 1 Term Hangup detected on controlling terminal
or death of controlling process
SIGINT 2 Term Interrupt from keyboard
SIGQUIT 3 Core Quit from keyboard
SIGILL 4 Core Illegal Instruction
SIGABRT 6 Core Abort signal from abort(3)
SIGFPE 8 Core Floating point exception
SIGKILL 9 Term Kill signal
SIGSEGV 11 Core Invalid memory reference
SIGPIPE 13 Term Broken pipe: write to pipe with no
readers
SIGALRM 14 Term Timer signal from alarm(2)
SIGTERM 15 Term Termination signal
SIGUSR1 30,10,16 Term User-defined signal 1
SIGUSR2 31,12,17 Term User-defined signal 2
SIGCHLD 20,17,18 Ign Child stopped or terminated
SIGCONT 19,18,25 Cont Continue if stopped
SIGSTOP 17,19,23 Stop Stop process
SIGTSTP 18,20,24 Stop Stop typed at terminal
SIGTTIN 21,21,26 Stop Terminal input for background process
SIGTTOU 22,22,27 Stop Terminal output for background process
On UNIX systems the normal way to force terminate an app process is with
kill -9 PROCESS_ID
This sends the app the signal number nine which means: "you quit, NOW"
Generally unhandled exceptions will also cause the OS to terminate apps with this signal. Also killing an app via the "task switcher" does the same thing.
I know the original question was asking what does signal 9 mean, but I found this while looking for how to prevent it.
For me this was caused by sending a Local Notification and not implementing
application:didReceiveLocalNotification
in my AppDelegate. Once I did this, even with the method empty the crash did not reappear. Chances are there is something being called by the system that is not being handled by your code.
in linux there are around 64 signals (more than 64 in some system) ..if you want to see all signals numbering just type "kill -l" without quote on the terminal you will see all the list of signal these. signals are generated by the kernel or by kill system call by user on the particular application(e.g. kill -n app_name ). signal 9 is SIGKILL this is use to kill the application. though we can also mask some of the signals but not all signals can be masked in an application. for future ref. u can go here
http://en.wikipedia.org/wiki/Unix_signal
and also see the man page of signal you will get to know more
I was getting this from docker container, the reason came out to be low memory for docker while building the project. Make sure you have enough memory or memory is not leaking anywhere.
Related
If process A link to B and A monitor B, when B dies, what happens to A? will A receive two messages? one is monitor 'Down' message and the other is exit message from B, if it is, what's the order abd what will A do?
When links and monitors are triggered they send out signals - you can read about this in more detail here: https://www.erlang.org/doc/reference_manual/processes.html#signals
Looking at the BEAM emulator code, it turns out that the links are triggered before the monitors when a process dies - see erl_process.c: https://github.com/erlang/otp/blob/master/erts/emulator/beam/erl_process.c#L14149
I can't seem to find this fact documented anywhere, but I would guess it's to ensure that if process A doesn't trap exits, it gets killed immediately when the exit signal from process B arrives. If it got the monitor signal first, it might start acting on it but then get killed halfway through the action when the exit signal is received.
I have an iOS app connected to a peripheral and as such running in the background. Sometimes when there is a low memory situation, jetsam decides to close my app even though according to the jetsam log it is not the largest running process. So far my app didn't get any memory warnings so it is not even possible to respond to such event by releasing resources.
First I would like to know if there are any criteria for closing an app due to a low memory event.
Second, what are the keys in the log? for example the state key - does it represent the current state of the process, i.e. when it is suspended, it means that the app was closed by jetsam? or maybe that was the app's state regardless of the low memory event
Can several processes be closed? Because when I look at all JSONs, only one process has the killDelta key, and it doesn't always happen to be the largest one, and even so I can see that several processes are suspended, meaning again that not only one was closed?
I'd appreciate any help
Thank you
I am developing in iOS.
The App call the function in library , and send the packet via wifi.
When the App is running , I push the power button(not home button) on iPhone 5C and push again to open it. But it crash...
And it did not show which line is error , it only show the error like the following picture:
How to analyse this crash log via above picture?
Thanks in advance.
As mentioned by Apple, in Avoiding Common Networking Mistakes, you need to handle or disable SIGPIPE:
Use POSIX sockets efficiently (if at all).
If you are using POSIX sockets directly:
Handle or disable SIGPIPE.
When a connection closes, by default, your
process receives a SIGPIPE signal. If your program does not handle or
ignore this signal, your program will quit immediately. You can handle
this in one of two ways:
Ignore the signal globally with the following line of code:
signal(SIGPIPE, SIG_IGN);
Tell the socket not to send the signal in
the first place with the following lines of code (substituting the
variable containing your socket in place of sock):
int value = 1;
setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, &value, sizeof(value));
For maximum compatibility, you should set this flag on each incoming
socket immediately after calling accept in addition to setting the
flag on the listening socket itself.
Got this debug info when debug a today extension app
"host connection < NSXPCConnection: 0x170113560 > connection from pid 53 invalidated"
does anyone know what this means? it shows almost every time when "widgetPerformUpdateWithCompletionHandler" called.
NSXPCConnection API is used to perform interprocess connection between Xcode client and your app on iPhone. So you do not need to worry about this one.
Link:
https://developer.apple.com/library/mac/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/CreatingXPCServices.html
So there may be 2 reasons that your widget is terminated.
You need to call completionHandler(NCUpdateResultNoData); right after your widgetPerformUpdateWithCompletionHandler has been called even when the response hasn't been returned.
Your app is terminated because of the automatic app termination. It terminates the widgets/apps for 2 reasons:
a. It terminates apps that are not being used and allowing the
reclamation of resources such as memory.
b. It terminates widgets that use too much memory.
I'm debugging a background task issue where my app is being killed by the watchdog when socket data is received too often in the background.
Does the watchdog perform it's operations under the context of a debugger?
My answer is: I do not believe so.
Based on some logs I have seen about apps failing to respond for 10 seconds while paused in the debugger, I would say yes it is watching, but it does not enforce its rules. It simply informs you.