Unix Signal
A signal is a limited form of inter-process communication used in Unix, Unix-like, and other POSIX-compliant operating systems. It is an asynchronous notification sent to a process or to a specific thread within the same process in order to notify it of an event that occurred. When a signal is sent, the operating system interrupts the target process's normal flow of execution. Execution can be interrupted during any non-atomic instruction. If the process has previously registered a signal handler, that routine is executed. Otherwise the default signal handler is executed. Signals have been around since the 1970s Bell Labs Unix and are more recently specified in the POSIX standard.
Read more about Unix Signal: Sending Signals, Handling Signals, Relationship With Hardware Exceptions, POSIX Signals, Miscellaneous Signals
Famous quotes containing the word signal:
“Certainly the effort to remain unchanged, young, when the body gives so impressive a signal of change as the menopause, is gallant; but it is a stupid, self-sacrificial gallantry, better befitting a boy of twenty than a woman of forty-five or fifty. Let the athletes die young and laurel-crowned. Let the soldiers earn the Purple Hearts. Let women die old, white-crowned, with human hearts.”
—Ursula K. Le Guin (b. 1929)