github.com/kaisenlinux/docker.io@v0.0.0-20230510090727-ea55db55fac7/engine/pkg/signal/signal.go (about)

     1  // Package signal provides helper functions for dealing with signals across
     2  // various operating systems.
     3  package signal // import "github.com/docker/docker/pkg/signal"
     4  
     5  import (
     6  	"fmt"
     7  	"os"
     8  	"os/signal"
     9  	"strconv"
    10  	"strings"
    11  	"syscall"
    12  )
    13  
    14  // CatchAll catches all signals and relays them to the specified channel.
    15  // SIGURG is not handled, as it's used by the Go runtime to support
    16  // preemptable system calls.
    17  func CatchAll(sigc chan os.Signal) {
    18  	var handledSigs []os.Signal
    19  	for n, s := range SignalMap {
    20  		if n == "URG" {
    21  			// Do not handle SIGURG, as in go1.14+, the go runtime issues
    22  			// SIGURG as an interrupt to support preemptable system calls on Linux.
    23  			continue
    24  		}
    25  		handledSigs = append(handledSigs, s)
    26  	}
    27  	signal.Notify(sigc, handledSigs...)
    28  }
    29  
    30  // StopCatch stops catching the signals and closes the specified channel.
    31  func StopCatch(sigc chan os.Signal) {
    32  	signal.Stop(sigc)
    33  	close(sigc)
    34  }
    35  
    36  // ParseSignal translates a string to a valid syscall signal.
    37  // It returns an error if the signal map doesn't include the given signal.
    38  func ParseSignal(rawSignal string) (syscall.Signal, error) {
    39  	s, err := strconv.Atoi(rawSignal)
    40  	if err == nil {
    41  		if s == 0 {
    42  			return -1, fmt.Errorf("Invalid signal: %s", rawSignal)
    43  		}
    44  		return syscall.Signal(s), nil
    45  	}
    46  	signal, ok := SignalMap[strings.TrimPrefix(strings.ToUpper(rawSignal), "SIG")]
    47  	if !ok {
    48  		return -1, fmt.Errorf("Invalid signal: %s", rawSignal)
    49  	}
    50  	return signal, nil
    51  }
    52  
    53  // ValidSignalForPlatform returns true if a signal is valid on the platform
    54  func ValidSignalForPlatform(sig syscall.Signal) bool {
    55  	for _, v := range SignalMap {
    56  		if v == sig {
    57  			return true
    58  		}
    59  	}
    60  	return false
    61  }