Signal Handler

Definitions

1. A user-defined function registered with the operating system to execute when a process receives a specific signal (e.g., SIGTERM, SIGINT, SIGHUP). Because handlers run asynchronously and interrupt normal execution, they must be async-signal-safe — only calling a restricted set of reentrant functions.

   In plain English: A piece of code that runs automatically when the operating system sends your program a specific notification, like 'please shut down now.'

   Example: "We installed a SIGTERM handler that flushes the write-ahead log and closes connections before the container is killed."

Related Terms

• SIGKILL
• Level Triggered
• Memory Alignment
• Microkernel
• Named Pipe
• Process Group
• Qemu
• Raw Pointer