powerpods/goTool/shutdown.go
simon e4ce18edd8 Close UART gracefully on SIGINT/SIGTERM in goTool.
Go exits on Ctrl+C without running defers, leaving the serial port locked; register shutdown hooks for serve and CLI commands.

Co-authored-by: Cursor <cursoragent@cursor.com>
2026-05-31 16:40:22 +02:00

76 lines
1.6 KiB
Go

package main
import (
"context"
"log"
"net/http"
"os"
"os/signal"
"sync"
"syscall"
"time"
)
var (
shutdownMu sync.Mutex
shutdownFns []func()
hooksOnce sync.Once
bgHandlerOnce sync.Once
)
// registerShutdown runs fn on SIGINT/SIGTERM (LIFO order).
func registerShutdown(fn func()) {
shutdownMu.Lock()
shutdownFns = append(shutdownFns, fn)
shutdownMu.Unlock()
}
func runShutdownHooks() {
hooksOnce.Do(func() {
shutdownMu.Lock()
fns := shutdownFns
shutdownMu.Unlock()
for i := len(fns) - 1; i >= 0; i-- {
fns[i]()
}
})
}
// enableShutdownOnInterrupt listens for SIGINT/SIGTERM in the background and exits
// after running shutdown hooks. Use for one-shot CLI commands (OTA, etc.).
func enableShutdownOnInterrupt() {
bgHandlerOnce.Do(func() {
ch := make(chan os.Signal, 1)
signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
go func() {
sig := <-ch
signal.Stop(ch)
log.Printf("received %v, shutting down…", sig)
runShutdownHooks()
os.Exit(0)
}()
})
}
// waitForShutdown blocks until SIGINT/SIGTERM, runs hooks, and returns.
// Use for long-running servers (serve/dashboard).
func waitForShutdown() {
ch := make(chan os.Signal, 1)
signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
sig := <-ch
signal.Stop(ch)
log.Printf("received %v, shutting down…", sig)
runShutdownHooks()
}
func shutdownHTTPServer(srv *http.Server) {
if srv == nil {
return
}
ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
defer cancel()
if err := srv.Shutdown(ctx); err != nil {
log.Printf("HTTP shutdown: %v", err)
}
}