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| 1 | +package winpowrprof |
| 2 | + |
| 3 | +// modify from https://github.com/golang/go/blob/b634f6fdcbebee23b7da709a243f3db217b64776/src/runtime/os_windows.go#L257 |
| 4 | + |
| 5 | +import ( |
| 6 | + "syscall" |
| 7 | + "unsafe" |
| 8 | + |
| 9 | + "golang.org/x/sys/windows" |
| 10 | +) |
| 11 | + |
| 12 | +var ( |
| 13 | + modpowerprof = windows.NewLazySystemDLL("powrprof.dll") |
| 14 | + procPowerRegisterSuspendResumeNotification = modpowerprof.NewProc("PowerRegisterSuspendResumeNotification") |
| 15 | + procPowerUnregisterSuspendResumeNotification = modpowerprof.NewProc("PowerUnregisterSuspendResumeNotification") |
| 16 | +) |
| 17 | + |
| 18 | +const ( |
| 19 | + PBT_APMSUSPEND uint32 = 4 |
| 20 | + PBT_APMRESUMESUSPEND uint32 = 7 |
| 21 | + PBT_APMRESUMEAUTOMATIC uint32 = 18 |
| 22 | +) |
| 23 | + |
| 24 | +const ( |
| 25 | + _DEVICE_NOTIFY_CALLBACK = 2 |
| 26 | +) |
| 27 | + |
| 28 | +type _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS struct { |
| 29 | + callback uintptr |
| 30 | + context uintptr |
| 31 | +} |
| 32 | + |
| 33 | +type eventListener struct { |
| 34 | + params _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS |
| 35 | + handle uintptr |
| 36 | +} |
| 37 | + |
| 38 | +func NewEventListener(callback func(event int)) (EventListener, error) { |
| 39 | + if err := procPowerRegisterSuspendResumeNotification.Find(); err != nil { |
| 40 | + return nil, err // Running on Windows 7, where we don't need it anyway. |
| 41 | + } |
| 42 | + if err := procPowerUnregisterSuspendResumeNotification.Find(); err != nil { |
| 43 | + return nil, err // Running on Windows 7, where we don't need it anyway. |
| 44 | + } |
| 45 | + |
| 46 | + var fn interface{} = func(context uintptr, changeType uint32, setting uintptr) uintptr { |
| 47 | + switch changeType { |
| 48 | + case PBT_APMSUSPEND: |
| 49 | + callback(EVENT_SUSPEND) |
| 50 | + case PBT_APMRESUMESUSPEND: |
| 51 | + callback(EVENT_RESUME) |
| 52 | + case PBT_APMRESUMEAUTOMATIC: |
| 53 | + callback(EVENT_RESUME_AUTOMATIC) |
| 54 | + } |
| 55 | + return 0 |
| 56 | + } |
| 57 | + return &eventListener{ |
| 58 | + params: _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS{ |
| 59 | + callback: windows.NewCallback(fn), |
| 60 | + }, |
| 61 | + }, nil |
| 62 | +} |
| 63 | + |
| 64 | +func (l *eventListener) Start() error { |
| 65 | + _, _, errno := syscall.SyscallN( |
| 66 | + procPowerRegisterSuspendResumeNotification.Addr(), |
| 67 | + _DEVICE_NOTIFY_CALLBACK, |
| 68 | + uintptr(unsafe.Pointer(&l.params)), |
| 69 | + uintptr(unsafe.Pointer(&l.handle)), |
| 70 | + ) |
| 71 | + if errno != 0 { |
| 72 | + return errno |
| 73 | + } |
| 74 | + return nil |
| 75 | +} |
| 76 | + |
| 77 | +func (l *eventListener) Close() error { |
| 78 | + _, _, errno := syscall.SyscallN(procPowerUnregisterSuspendResumeNotification.Addr(), uintptr(unsafe.Pointer(&l.handle))) |
| 79 | + if errno != 0 { |
| 80 | + return errno |
| 81 | + } |
| 82 | + return nil |
| 83 | +} |
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