package daemon import ( "fmt" "os" "syscall" "unsafe" winio "github.com/Microsoft/go-winio" "github.com/Sirupsen/logrus" "github.com/docker/docker/pkg/signal" "github.com/docker/docker/pkg/system" ) func (d *Daemon) setupDumpStackTrap(root string) { // Windows does not support signals like *nix systems. So instead of // trapping on SIGUSR1 to dump stacks, we wait on a Win32 event to be // signaled. ACL'd to builtin administrators and local system ev := "Global\\docker-daemon-" + fmt.Sprint(os.Getpid()) sd, err := winio.SddlToSecurityDescriptor("D:P(A;;GA;;;BA)(A;;GA;;;SY)") if err != nil { logrus.Errorf("failed to get security descriptor for debug stackdump event %s: %s", ev, err.Error()) return } var sa syscall.SecurityAttributes sa.Length = uint32(unsafe.Sizeof(sa)) sa.InheritHandle = 1 sa.SecurityDescriptor = uintptr(unsafe.Pointer(&sd[0])) h, err := system.CreateEvent(&sa, false, false, ev) if h == 0 || err != nil { logrus.Errorf("failed to create debug stackdump event %s: %s", ev, err.Error()) return } go func() { logrus.Debugf("Stackdump - waiting signal at %s", ev) for { syscall.WaitForSingleObject(h, syscall.INFINITE) path, err := signal.DumpStacks(root) if err != nil { logrus.WithError(err).Error("failed to write goroutines dump") } else { logrus.Infof("goroutine stacks written to %s", path) } } }() }