package signal

import "github.com/docker/docker/pkg/signal"

Package signal provides helper functions for dealing with signals across various operating systems.

Index ¶

• Constants
• Variables
• func CatchAll(sigc chan os.Signal)
• func DumpStacks()
• func ParseSignal(rawSignal string) (syscall.Signal, error)
• func StopCatch(sigc chan os.Signal)
• func Trap(cleanup func())
• func ValidSignalForPlatform(sig syscall.Signal) bool

Constants ¶

const (
	// SIGCHLD is a signal sent to a process when a child process terminates, is interrupted, or resumes after being interrupted.
	SIGCHLD = syscall.SIGCHLD
	// SIGWINCH is a signal sent to a process when its controlling terminal changes its size
	SIGWINCH = syscall.SIGWINCH
	// SIGPIPE is a signal sent to a process when a pipe is written to before the other end is open for reading
	SIGPIPE = syscall.SIGPIPE
	// DefaultStopSignal is the syscall signal used to stop a container in unix systems.
	DefaultStopSignal = "SIGTERM"
)

Variables ¶

var SignalMap = map[string]syscall.Signal{}

SignalMap is an empty map of signals for unsupported platform.

Functions ¶

func CatchAll ¶

func CatchAll(sigc chan os.Signal)

CatchAll catches all signals and relays them to the specified channel.

func DumpStacks ¶

func DumpStacks()

DumpStacks dumps the runtime stack.

func ParseSignal ¶

func ParseSignal(rawSignal string) (syscall.Signal, error)

ParseSignal translates a string to a valid syscall signal. It returns an error if the signal map doesn't include the given signal.

func StopCatch ¶

func StopCatch(sigc chan os.Signal)

StopCatch stops catching the signals and closes the specified channel.

func Trap ¶

func Trap(cleanup func())

Trap sets up a simplified signal "trap", appropriate for common behavior expected from a vanilla unix command-line tool in general (and the Docker engine in particular).

• If SIGINT or SIGTERM are received, `cleanup` is called, then the process is terminated.
• If SIGINT or SIGTERM are received 3 times before cleanup is complete, then cleanup is skipped and the process is terminated immediately (allows force quit of stuck daemon)
• A SIGQUIT always causes an exit without cleanup, with a goroutine dump preceding exit.
• Ignore SIGPIPE events. These are generated by systemd when journald is restarted while the docker daemon is not restarted and also running under systemd. Fixes https://github.com/docker/docker/issues/19728

func ValidSignalForPlatform ¶

func ValidSignalForPlatform(sig syscall.Signal) bool

ValidSignalForPlatform returns true if a signal is valid on the platform

Source Files ¶

signal.go signal_unix.go signal_unsupported.go trap.go