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:
“The experience of a sense of guilt for wrong-doing is necessary for the development of self-control. The guilt feelings will later serve as a warning signal which the child can produce himself when an impulse to repeat the naughty act comes over him. When the child can produce his on warning signals, independent of the actual presence of the adult, he is on the way to developing a conscience.”
—Selma H. Fraiberg (20th century)