package signal

import "github.com/docker/cli/components/engine/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(dir string) (string, error)
• func ParseSignal(rawSignal string) (syscall.Signal, error)
• func StopCatch(sigc chan os.Signal)
• func Trap(cleanup func(), logger interface { Info(args ...interface{}) })
• 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{
	"ABRT":   syscall.SIGABRT,
	"ALRM":   syscall.SIGALRM,
	"BUG":    syscall.SIGBUS,
	"CHLD":   syscall.SIGCHLD,
	"CONT":   syscall.SIGCONT,
	"EMT":    syscall.SIGEMT,
	"FPE":    syscall.SIGFPE,
	"HUP":    syscall.SIGHUP,
	"ILL":    syscall.SIGILL,
	"INFO":   syscall.SIGINFO,
	"INT":    syscall.SIGINT,
	"IO":     syscall.SIGIO,
	"IOT":    syscall.SIGIOT,
	"KILL":   syscall.SIGKILL,
	"PIPE":   syscall.SIGPIPE,
	"PROF":   syscall.SIGPROF,
	"QUIT":   syscall.SIGQUIT,
	"SEGV":   syscall.SIGSEGV,
	"STOP":   syscall.SIGSTOP,
	"SYS":    syscall.SIGSYS,
	"TERM":   syscall.SIGTERM,
	"TRAP":   syscall.SIGTRAP,
	"TSTP":   syscall.SIGTSTP,
	"TTIN":   syscall.SIGTTIN,
	"TTOU":   syscall.SIGTTOU,
	"URG":    syscall.SIGURG,
	"USR1":   syscall.SIGUSR1,
	"USR2":   syscall.SIGUSR2,
	"VTALRM": syscall.SIGVTALRM,
	"WINCH":  syscall.SIGWINCH,
	"XCPU":   syscall.SIGXCPU,
	"XFSZ":   syscall.SIGXFSZ,
}

SignalMap is a map of Darwin signals.

Functions ¶

func CatchAll ¶

func CatchAll(sigc chan os.Signal)

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

func DumpStacks ¶

func DumpStacks(dir string) (string, error)

DumpStacks appends the runtime stack into file in dir and returns full path to that file.

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(), logger interface {
	Info(args ...interface{})
})

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_darwin.go signal_unix.go trap.go

Directories ¶