restic/cmd/restic/cleanup.go
Michael Eischer 306a29980a Print stacktrace in SIGINT handler if RESTIC_DEBUG_STACKTRACE_SIGINT set
The builtin mechanism to capture a stacktrace in Go is to send a SIGQUIT
to the running process. However, this mechanism is not avaiable on
Windows. Thus, tweak the SIGINT handler to dump a stacktrace if the
environment variable `RESTIC_DEBUG_STACKTRACE_SIGINT` is set.
2023-04-23 15:50:40 +02:00

89 lines
2 KiB
Go

package main
import (
"os"
"os/signal"
"sync"
"syscall"
"github.com/restic/restic/internal/debug"
)
var cleanupHandlers struct {
sync.Mutex
list []func(code int) (int, error)
done bool
ch chan os.Signal
}
func init() {
cleanupHandlers.ch = make(chan os.Signal, 1)
go CleanupHandler(cleanupHandlers.ch)
signal.Notify(cleanupHandlers.ch, syscall.SIGINT)
}
// AddCleanupHandler adds the function f to the list of cleanup handlers so
// that it is executed when all the cleanup handlers are run, e.g. when SIGINT
// is received.
func AddCleanupHandler(f func(code int) (int, error)) {
cleanupHandlers.Lock()
defer cleanupHandlers.Unlock()
// reset the done flag for integration tests
cleanupHandlers.done = false
cleanupHandlers.list = append(cleanupHandlers.list, f)
}
// RunCleanupHandlers runs all registered cleanup handlers
func RunCleanupHandlers(code int) int {
cleanupHandlers.Lock()
defer cleanupHandlers.Unlock()
if cleanupHandlers.done {
return code
}
cleanupHandlers.done = true
for _, f := range cleanupHandlers.list {
var err error
code, err = f(code)
if err != nil {
Warnf("error in cleanup handler: %v\n", err)
}
}
cleanupHandlers.list = nil
return code
}
// CleanupHandler handles the SIGINT signals.
func CleanupHandler(c <-chan os.Signal) {
for s := range c {
debug.Log("signal %v received, cleaning up", s)
Warnf("%ssignal %v received, cleaning up\n", clearLine(0), s)
if val, _ := os.LookupEnv("RESTIC_DEBUG_STACKTRACE_SIGINT"); val != "" {
_, _ = os.Stderr.WriteString("\n--- STACKTRACE START ---\n\n")
_, _ = os.Stderr.WriteString(debug.DumpStacktrace())
_, _ = os.Stderr.WriteString("\n--- STACKTRACE END ---\n")
}
code := 0
if s == syscall.SIGINT {
code = 130
} else {
code = 1
}
Exit(code)
}
}
// Exit runs the cleanup handlers and then terminates the process with the
// given exit code.
func Exit(code int) {
code = RunCleanupHandlers(code)
debug.Log("exiting with status code %d", code)
os.Exit(code)
}