Golang信号处理和如何实现进程的优雅退出

      Signal     Value     Action   Comment
       ----------------------------------------------------------------------
       SIGHUP        1       Term    Hangup detected on controlling terminal
                                     or death of controlling process
       SIGINT        2       Term    Interrupt from keyboard
       SIGQUIT       3       Core    Quit from keyboard
       SIGILL        4       Core    Illegal Instruction
       SIGABRT       6       Core    Abort signal from abort(3)
       SIGFPE        8       Core    Floating point exception
       SIGKILL       9       Term    Kill signal
       SIGSEGV      11       Core    Invalid memory reference
       SIGPIPE      13       Term    Broken pipe: write to pipe with no
                                     readers
       SIGALRM      14       Term    Timer signal from alarm(2)
       SIGTERM      15       Term    Termination signal
       SIGUSR1   30,10,16    Term    User-defined signal 1
       SIGUSR2   31,12,17    Term    User-defined signal 2
       SIGCHLD   20,17,18    Ign     Child stopped or terminated
       SIGCONT   19,18,25    Cont    Continue if stopped
       SIGSTOP   17,19,23    Stop    Stop process
       SIGTSTP   18,20,24    Stop    Stop typed at tty
       SIGTTIN   21,21,26    Stop    tty input for background process
       SIGTTOU   22,22,27    Stop    tty output for background process

      Signal       Value     Action   Comment
       --------------------------------------------------------------------
       SIGBUS      10,7,10     Core    Bus error (bad memory access)
       SIGPOLL                 Term    Pollable event (Sys V).
                                       Synonym for SIGIO
       SIGPROF     27,27,29    Term    Profiling timer expired
       SIGSYS      12,-,12     Core    Bad argument to routine (SVr4)
       SIGTRAP        5        Core    Trace/breakpoint trap
       SIGURG      16,23,21    Ign     Urgent condition on socket (4.2BSD)
       SIGVTALRM   26,26,28    Term    Virtual alarm clock (4.2BSD)
       SIGXCPU     24,24,30    Core    CPU time limit exceeded (4.2BSD)
       SIGXFSZ     25,25,31    Core    File size limit exceeded (4.2BSD)

       Signal       Value     Action   Comment
       --------------------------------------------------------------------
       SIGIOT         6        Core    IOT trap. A synonym for SIGABRT
       SIGEMT       7,-,7      Term
       SIGSTKFLT    -,16,-     Term    Stack fault on coprocessor (unused)
       SIGIO       23,29,22    Term    I/O now possible (4.2BSD)
       SIGCLD       -,-,18     Ign     A synonym for SIGCHLD
       SIGPWR      29,30,19    Term    Power failure (System V)
       SIGINFO      29,-,-             A synonym for SIGPWR
       SIGLOST      -,-,-      Term    File lock lost
       SIGWINCH    28,28,20    Ign     Window resize signal (4.3BSD, Sun)
       SIGUNUSED    -,31,-     Term    Unused signal (will be SIGSYS)

package main

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"
)

func main() {
	sigs := make(chan os.Signal, 1)
	done := make(chan bool, 1)
	// signal.Notify(c)
	signal.Notify(sigs, os.Interrupt, os.Kill, syscall.SIGUSR1, syscall.SIGUSR2, syscall.SIGINT, syscall.SIGTERM)

	go func() {
		sig := <-sigs
		fmt.Println(sig)
		done <- true
	}()


	fmt.Println("wait for signal")
	<- done
	fmt.Println("got signal and exit")
	fmt.Println("run done")
}

package main

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"
)

func main() {
	sigs := make(chan os.Signal, 1)
	// done := make(chan bool, 1)

	// signal.Notify(sigs)
	// signal.Notify(sigs, os.Interrupt, os.Kill, syscall.SIGUSR1, syscall.SIGUSR2, syscall.SIGINT, syscall.SIGTERM)
	signal.Notify(sigs, syscall.SIGUSR1, syscall.SIGUSR2, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGQUIT)

	// go func() {
	// 	sig := <-sigs
	// 	fmt.Println(sig)
	// 	done <- true
	// }()
	go func() {
		for s := range sigs {
			switch s {
			case syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGQUIT:
				fmt.Println("got signal and try to exit: ", s)
				do_exit()
			case syscall.SIGUSR1:
				fmt.Println("usr1: ", s)
			case syscall.SIGUSR2:
				fmt.Println("usr2: ", s)
			default:
				fmt.Println("other: ", s)
			}
		}
	}()


	fmt.Println("wait for signal")
	i := 0
	for {
		i++
		fmt.Println("times: ", i)
		time.Sleep(1 * time.Second)
	}
	// <- done
	fmt.Println("got signal and exit")
	fmt.Println("run done")
}
 
func do_exit() {
	fmt.Println("try do some clear jobs")
	fmt.Println("run done")
	os.Exit(0)
}

kill -USR1 pid 
usr1 user defined signal 1

kill -USR2 pid 
usr2 user defined signal 2

kill  -QUIT pid 
got signal and try to exit: quit
try do some clear jobs
run done