This module provides communication entre processus signaux forex to use signal handlers in Python. Python will return from the signal handler to the C code, which is likely to raise the same signal again, causing Python to apparently hang. The Python signal handlers will be called when the calculation finishes. Python signal handlers are always executed in the main Python thread, even if the signal was received in another thread.
This means that signals can’t be used as a means of inter-thread communication. Besides, only the main thread is allowed to set a new signal handler. This is another standard signal handler, which will simply ignore the given signal. All the signal numbers are defined symbolically. For example, the hangup signal is defined as signal. One more than the number of the highest signal number.
Decrements interval timer only when the process is executing, and delivers SIGVTALRM upon expiration. Decrements interval timer both when the process executes and when the system is executing on behalf of the process. Coupled with ITIMER_VIRTUAL, this timer is usually used to profile the time spent by the application in user and kernel space. The returned value is then the number of seconds before any previously set alarm was to have been delivered.
If time is zero, no alarm is scheduled, and any scheduled alarm is canceled. If the return value is zero, no alarm is currently scheduled. Return the current signal handler for the signal signalnum. The returned value may be a callable Python object, or one of the special values signal. Send the signal signalnum to the thread thread_id, another thread in the same process as the caller.