This is very much by design. There’s no reasonable way a user can select text when your program keeps scrolling the content of the console window. So the console host program simply stops reading your stdout/stderr output and your program hangs until the user completes the operation. This can be changed, you’ll have to call … Read more
You can’t have data of your own passed to the signal handler as parameters. Instead you’ll have to store your parameters in global variables. (And be really, really careful if you ever need to change those data after installing the the signal handler). Response to edit 0: Historical reasons. Signals are a really old and … Read more
17.4. signal — Set handlers for asynchronous events Although Python signal handlers are called asynchronously as far as the Python user is concerned, they can only occur between the “atomic” instructions of the Python interpreter. This means that signals arriving during long calculations implemented purely in C (such as regular expression matches on large bodies … Read more
The signals available on an OS are defined by the OS (usually following POSIX) – they’re not “strings” but rather integer constants with standard names. USR1 and USR2 are the two signals that have no attached specific meaning – intended for whatever arbitrary use the developer wants. On your linux machine, read man 7 signal … Read more
It seems they are suppressed by default. Running $ ulimit -c unlimited Will enable core dumps for the current terminal, and it will be placed in /cores as core.PID. When you open a new session, it will be set to the default value again.
What’s the best way to control which thread a signal is delivered to? As @zoli2k indicated, explicitly nominating a single thread to handle all signals you want handled (or a set of threads each with specific signal responsibilities), is a good technique. What is the best way to tell another thread (that might actually be … Read more
You can use a signal like this (I put mine in models.py) from django.contrib.auth.signals import user_logged_in def do_stuff(sender, user, request, **kwargs): whatever… user_logged_in.connect(do_stuff) See django docs: https://docs.djangoproject.com/en/dev/ref/contrib/auth/#module-django.contrib.auth.signals and here http://docs.djangoproject.com/en/dev/topics/signals/
You can’t do it from the command line, you have to write some code (I assume you’re not just looking for an utility otherwise Super User may be a better place to ask). I also assume your application has all the required permissions to do it (examples are without any error checking). Hard Way First … Read more
The previously accepted solution has race conditions and it does not work with map and async functions. The correct way to handle Ctrl+C/SIGINT with multiprocessing.Pool is to: Make the process ignore SIGINT before a process Pool is created. This way created child processes inherit SIGINT handler. Restore the original SIGINT handler in the parent process … Read more
If you do not lock the mutex in the codepath that changes the condition and signals, you can lose wakeups. Consider this pair of processes: Process A: pthread_mutex_lock(&mutex); while (condition == FALSE) pthread_cond_wait(&cond, &mutex); pthread_mutex_unlock(&mutex); Process B (incorrect): condition = TRUE; pthread_cond_signal(&cond); Then consider this possible interleaving of instructions, where condition starts out as FALSE: … Read more