出典:Wikipedia
出典:『Wikipedia』 (2011/06/07 16:10 UTC 版)
A signal is a limited form of inter-process communication used in Unix, Unix-like, and other POSIX-compliant operating systems. Essentially it is an asynchronous notification sent to a process in order to notify it of an event that occurred. When a signal is sent to a process, the operating system interrupts the 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.