// Handle lifecycle events
func handleSignals(srv *falcore.Server) {
var sig os.Signal
var sigChan = make(chan os.Signal)
signal.Notify(sigChan, syscall.SIGHUP, syscall.SIGUSR1, syscall.SIGINT, syscall.SIGTERM, syscall.SIGTSTP)
pid := syscall.Getpid()
for {
sig = <-sigChan
switch sig {
case syscall.SIGHUP:
// send this to the paraent process to initiate the restart
fmt.Println(pid, "Received SIGHUP. forking.")
cpid, err := forker(srv)
fmt.Println(pid, "Forked pid:", cpid, "errno:", err)
case syscall.SIGUSR1:
// child sends this back to the parent when it's ready to Accept
fmt.Println(pid, "Received SIGUSR1. Stopping accept.")
srv.StopAccepting()
case syscall.SIGINT:
fmt.Println(pid, "Received SIGINT. Shutting down.")
os.Exit(0)
case syscall.SIGTERM:
fmt.Println(pid, "Received SIGTERM. Terminating.")
os.Exit(0)
case syscall.SIGTSTP:
fmt.Println(pid, "Received SIGTSTP. Stopping.")
syscall.Kill(pid, syscall.SIGSTOP)
default:
fmt.Println(pid, "Received", sig, ": ignoring")
}
}
}
// setup and fork/exec myself. Make sure to keep open important FD's that won't get re-created by the child
// specifically, std* and your listen socket
func forker(srv *falcore.Server) (pid int, err error) {
var socket string
// At version 1.0.3 the socket FD behavior changed and the fork socket is always 3
// 0 = stdin, 1 = stdout, 2 = stderr, 3 = acceptor socket
// This is because the ForkExec dups all the saved FDs down to
// start at 0. This is also why you MUST include 0,1,2 in the
// attr.Files
if goVersion103OrAbove() {
socket = "3"
} else {
socket = fmt.Sprintf("%v", srv.SocketFd())
}
fmt.Printf("Forking now with socket: %v\n", socket)
mypath := os.Args[0]
args := []string{mypath, "-socket", socket}
attr := new(syscall.ProcAttr)
attr.Files = append([]uintptr(nil), 0, 1, 2, uintptr(srv.SocketFd()))
pid, err = syscall.ForkExec(mypath, args, attr)
return
}
// setup and fork/exec myself. Make sure to keep open important FD's that won't get re-created by the child
// specifically, std* and your listen socket
func forker(srv *falcore.Server) (pid int, err error) {
fmt.Printf("Forking now with socket: %v\n", srv.SocketFd())
mypath := os.Args[0]
args := []string{mypath, "-socket", fmt.Sprintf("%v", srv.SocketFd())}
attr := new(syscall.ProcAttr)
attr.Files = append([]uintptr(nil), 0, 1, 2, uintptr(srv.SocketFd()))
pid, err = syscall.ForkExec(mypath, args, attr)
return
}