github.com/hustcat/docker@v1.3.3-0.20160314103604-901c67a8eeab/pkg/system/events_windows.go (about)

     1  package system
     2  
     3  // This file implements syscalls for Win32 events which are not implemented
     4  // in golang.
     5  
     6  import (
     7  	"syscall"
     8  	"unsafe"
     9  )
    10  
    11  var (
    12  	procCreateEvent = modkernel32.NewProc("CreateEventW")
    13  	procOpenEvent   = modkernel32.NewProc("OpenEventW")
    14  	procSetEvent    = modkernel32.NewProc("SetEvent")
    15  	procResetEvent  = modkernel32.NewProc("ResetEvent")
    16  	procPulseEvent  = modkernel32.NewProc("PulseEvent")
    17  )
    18  
    19  // CreateEvent implements win32 CreateEventW func in golang. It will create an event object.
    20  func CreateEvent(eventAttributes *syscall.SecurityAttributes, manualReset bool, initialState bool, name string) (handle syscall.Handle, err error) {
    21  	namep, _ := syscall.UTF16PtrFromString(name)
    22  	var _p1 uint32
    23  	if manualReset {
    24  		_p1 = 1
    25  	}
    26  	var _p2 uint32
    27  	if initialState {
    28  		_p2 = 1
    29  	}
    30  	r0, _, e1 := procCreateEvent.Call(uintptr(unsafe.Pointer(eventAttributes)), uintptr(_p1), uintptr(_p2), uintptr(unsafe.Pointer(namep)))
    31  	use(unsafe.Pointer(namep))
    32  	handle = syscall.Handle(r0)
    33  	if handle == syscall.InvalidHandle {
    34  		err = e1
    35  	}
    36  	return
    37  }
    38  
    39  // OpenEvent implements win32 OpenEventW func in golang. It opens an event object.
    40  func OpenEvent(desiredAccess uint32, inheritHandle bool, name string) (handle syscall.Handle, err error) {
    41  	namep, _ := syscall.UTF16PtrFromString(name)
    42  	var _p1 uint32
    43  	if inheritHandle {
    44  		_p1 = 1
    45  	}
    46  	r0, _, e1 := procOpenEvent.Call(uintptr(desiredAccess), uintptr(_p1), uintptr(unsafe.Pointer(namep)))
    47  	use(unsafe.Pointer(namep))
    48  	handle = syscall.Handle(r0)
    49  	if handle == syscall.InvalidHandle {
    50  		err = e1
    51  	}
    52  	return
    53  }
    54  
    55  // SetEvent implements win32 SetEvent func in golang.
    56  func SetEvent(handle syscall.Handle) (err error) {
    57  	return setResetPulse(handle, procSetEvent)
    58  }
    59  
    60  // ResetEvent implements win32 ResetEvent func in golang.
    61  func ResetEvent(handle syscall.Handle) (err error) {
    62  	return setResetPulse(handle, procResetEvent)
    63  }
    64  
    65  // PulseEvent implements win32 PulseEvent func in golang.
    66  func PulseEvent(handle syscall.Handle) (err error) {
    67  	return setResetPulse(handle, procPulseEvent)
    68  }
    69  
    70  func setResetPulse(handle syscall.Handle, proc *syscall.LazyProc) (err error) {
    71  	r0, _, _ := proc.Call(uintptr(handle))
    72  	if r0 != 0 {
    73  		err = syscall.Errno(r0)
    74  	}
    75  	return
    76  }
    77  
    78  var temp unsafe.Pointer
    79  
    80  // use ensures a variable is kept alive without the GC freeing while still needed
    81  func use(p unsafe.Pointer) {
    82  	temp = p
    83  }