Add winpowrprof package

common/winpowrprof/event.go

@@ -0,0 +1,13 @@
+package winpowrprof
+
+import "io"
+
+const (
+	EVENT_SUSPEND = iota
+	EVENT_RESUME
+	EVENT_RESUME_AUTOMATIC // Because the user is not present, most applications should do nothing.
+)
+
+type EventListener interface {
+	io.Closer
+}

common/winpowrprof/event_stub.go

@@ -0,0 +1,11 @@
+//go:build !windows
+
+package winpowrprof
+
+import (
+	"os"
+)
+
+func NewEventListener(callback func(event int)) (EventListener, error) {
+	return nil, os.ErrInvalid
+}

common/winpowrprof/event_windows.go

@@ -0,0 +1,74 @@
+package winpowrprof
+
+// modify from https://github.com/golang/go/blob/b634f6fdcbebee23b7da709a243f3db217b64776/src/runtime/os_windows.go#L257
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	modpowerprof                                 = windows.NewLazySystemDLL("powrprof.dll")
+	procPowerRegisterSuspendResumeNotification   = modpowerprof.NewProc("PowerRegisterSuspendResumeNotification")
+	procPowerUnregisterSuspendResumeNotification = modpowerprof.NewProc("PowerUnregisterSuspendResumeNotification")
+)
+
+type eventListener struct {
+	callback uintptr
+	handle   uintptr
+}
+
+func NewEventListener(callback func(event int)) (EventListener, error) {
+	if err := procPowerRegisterSuspendResumeNotification.Find(); err != nil {
+		return nil, err // Running on Windows 7, where we don't need it anyway.
+	}
+	if err := procPowerUnregisterSuspendResumeNotification.Find(); err != nil {
+		return nil, err // Running on Windows 7, where we don't need it anyway.
+	}
+
+	const (
+		PBT_APMSUSPEND         uint32 = 4
+		PBT_APMRESUMESUSPEND   uint32 = 7
+		PBT_APMRESUMEAUTOMATIC uint32 = 18
+	)
+
+	const (
+		_DEVICE_NOTIFY_CALLBACK = 2
+	)
+	type _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS struct {
+		callback uintptr
+		context  uintptr
+	}
+
+	var fn interface{} = func(context uintptr, changeType uint32, setting uintptr) uintptr {
+		switch changeType {
+		case PBT_APMSUSPEND:
+			callback(EVENT_SUSPEND)
+		case PBT_APMRESUMESUSPEND:
+			callback(EVENT_RESUME)
+		case PBT_APMRESUMEAUTOMATIC:
+			callback(EVENT_RESUME_AUTOMATIC)
+		}
+		return 0
+	}
+	var listener eventListener
+	listener.callback = windows.NewCallback(fn)
+	params := _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS{
+		callback: listener.callback,
+	}
+	_, _, err := procPowerRegisterSuspendResumeNotification.Call(
+		_DEVICE_NOTIFY_CALLBACK,
+		uintptr(unsafe.Pointer(&params)),
+		uintptr(unsafe.Pointer(&listener.handle)),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &listener, nil
+}
+
+func (l *eventListener) Close() error {
+	_, _, err := procPowerUnregisterSuspendResumeNotification.Call(uintptr(unsafe.Pointer(&l.handle)))
+	return err
+}