Golang syscall.GetQueuedCompletionStatus函数代码示例

func (s *resultSrv) Run() {
	var o *syscall.Overlapped
	var key uint32
	var r ioResult
	for {
		r.err = syscall.GetQueuedCompletionStatus(s.iocp, &(r.qty), &key, &o, 0)
		if r.err == syscall.Errno(syscall.WAIT_TIMEOUT) && o == nil {
			runtime_blockingSyscallHint()
			r.err = syscall.GetQueuedCompletionStatus(s.iocp, &(r.qty), &key, &o, syscall.INFINITE)
		}
		switch {
		case r.err == nil:
			// Dequeued successfully completed IO packet.
		case r.err == syscall.Errno(syscall.WAIT_TIMEOUT) && o == nil:
			// Wait has timed out (should not happen now, but might be used in the future).
			panic("GetQueuedCompletionStatus timed out")
		case o == nil:
			// Failed to dequeue anything -> report the error.
			panic("GetQueuedCompletionStatus failed " + r.err.Error())
		default:
			// Dequeued failed IO packet.
		}
		(*anOp)(unsafe.Pointer(o)).resultc <- r
	}
}

// TODO(pknap) : doc
func (r *readdcw) loop() {
	var n, key uint32
	var overlapped *syscall.Overlapped
	for {
		err := syscall.GetQueuedCompletionStatus(r.cph, &n, &key, &overlapped, syscall.INFINITE)
		if key == stateCPClose {
			r.Lock()
			handle := r.cph
			r.cph = syscall.InvalidHandle
			r.Unlock()
			syscall.CloseHandle(handle)
			r.wg.Done()
			return
		}
		if overlapped == nil {
			// TODO: check key == rewatch delete or 0(panic)
			continue
		}
		overEx := (*overlappedEx)(unsafe.Pointer(overlapped))
		if n == 0 {
			r.loopstate(overEx)
		} else {
			r.loopevent(n, overEx)
			if err = overEx.parent.readDirChanges(); err != nil {
				// TODO: error handling
			}
		}
	}
}

func initJob() {
	// Create Job object and assign current process to it.
	jobObject, err := createJobObject(nil, nil)
	if err != nil {
		log.Printf("CreateJobObject failed: %v", err)
		return
	}
	if err = assignProcessToJobObject(jobObject, currentProcess); err != nil {
		log.Printf("AssignProcessToJobObject failed: %v", err)
		syscall.Close(jobObject)
		return
	}
	iocp, err := syscall.CreateIoCompletionPort(syscall.InvalidHandle, 0, 0, 1)
	if err != nil {
		log.Printf("CreateIoCompletionPort failed: %v", err)
		syscall.Close(jobObject)
		return
	}
	port := JOBOBJECT_ASSOCIATE_COMPLETION_PORT{
		CompletionKey:  uintptr(jobObject),
		CompletionPort: iocp,
	}
	err = setInformationJobObject(jobObject, JobObjectAssociateCompletionPortInformation, uintptr(unsafe.Pointer(&port)), uint32(unsafe.Sizeof(port)))
	if err != nil {
		log.Printf("SetInformationJobObject failed: %v", err)
		syscall.Close(jobObject)
		syscall.Close(iocp)
		return
	}
	// Read Job notifications about new "child" processes and collect them in childProcesses.
	go func() {
		var code, key uint32
		var o *syscall.Overlapped
		for {
			err := syscall.GetQueuedCompletionStatus(iocp, &code, &key, &o, syscall.INFINITE)
			if err != nil {
				log.Printf("GetQueuedCompletionStatus failed: %v", err)
				return
			}
			if key != uint32(jobObject) {
				panic("Invalid GetQueuedCompletionStatus key parameter")
			}
			if code == JOB_OBJECT_MSG_NEW_PROCESS {
				pid := int(uintptr(unsafe.Pointer(o)))
				if pid == syscall.Getpid() {
					continue
				}
				c, err := syscall.OpenProcess(syscall.PROCESS_QUERY_INFORMATION, false, uint32(pid))
				if err != nil {
					log.Printf("OpenProcess failed: %v", err)
					continue
				}
				childMu.Lock()
				childProcesses = append(childProcesses, c)
				childMu.Unlock()
			}
		}
	}()
}

func (s *pollServer) getCompletedIO() (ov *syscall.Overlapped, result *ioResult, err os.Error) {
	var r ioResult
	var o *syscall.Overlapped
	_, e := syscall.GetQueuedCompletionStatus(s.iocp, &r.qty, &r.key, &o, syscall.INFINITE)
	switch {
	case e == 0:
		// Dequeued successfully completed io packet.
		return o, &r, nil
	case e == syscall.WAIT_TIMEOUT && o == nil:
		// Wait has timed out (should not happen now, but might be used in the future).
		return nil, &r, os.NewSyscallError("GetQueuedCompletionStatus", e)
	case o == nil:
		// Failed to dequeue anything -> report the error.
		return nil, &r, os.NewSyscallError("GetQueuedCompletionStatus", e)
	default:
		// Dequeued failed io packet.
		r.errno = e
		return o, &r, nil
	}
	return
}

// readEvents reads from the I/O completion port, converts the
// received events into Event objects and sends them via the Event channel.
// Entry point to the I/O thread.
func (w *Watcher) readEvents() {
	var (
		n, key uint32
		ov     *syscall.Overlapped
	)
	runtime.LockOSThread()

	for {
		e := syscall.GetQueuedCompletionStatus(w.port, &n, &key, &ov, syscall.INFINITE)
		watch := (*watch)(unsafe.Pointer(ov))

		if watch == nil {
			select {
			case ch := <-w.quit:
				w.mu.Lock()
				indexes := make([]indexMap, 0)
				for _, index := range w.watches {
					indexes = append(indexes, index)
				}
				w.mu.Unlock()
				for _, index := range indexes {
					for _, watch := range index {
						w.deleteWatch(watch)
						w.startRead(watch)
					}
				}
				var err error
				if e := syscall.CloseHandle(w.port); e != nil {
					err = os.NewSyscallError("CloseHandle", e)
				}
				close(w.internalEvent)
				close(w.Error)
				ch <- err
				return
			case in := <-w.input:
				switch in.op {
				case opAddWatch:
					in.reply <- w.addWatch(in.path, uint64(in.flags))
				case opRemoveWatch:
					in.reply <- w.remWatch(in.path)
				}
			default:
			}
			continue
		}

		switch e {
		case sys_ERROR_MORE_DATA:
			if watch == nil {
				w.Error <- errors.New("ERROR_MORE_DATA has unexpectedly null lpOverlapped buffer")
			} else {
				//The i/o succeeded but buffer is full
				//in theory we should be building up a full packet
				//in practice we can get away with just carrying on
				n = uint32(unsafe.Sizeof(watch.buf))
			}
		case syscall.ERROR_ACCESS_DENIED:
			// Watched directory was probably removed
			w.sendEvent(watch.path, watch.mask&sys_FS_DELETE_SELF)
			w.deleteWatch(watch)
			w.startRead(watch)
			continue
		case syscall.ERROR_OPERATION_ABORTED:
			// CancelIo was called on this handle
			continue
		default:
			w.Error <- os.NewSyscallError("GetQueuedCompletionPort", e)
			continue
		case nil:
		}

		var offset uint32
		for {
			if n == 0 {
				w.internalEvent <- &FileEvent{mask: sys_FS_Q_OVERFLOW}
				w.Error <- errors.New("short read in readEvents()")
				break
			}

			// Point "raw" to the event in the buffer
			raw := (*syscall.FileNotifyInformation)(unsafe.Pointer(&watch.buf[offset]))
			buf := (*[syscall.MAX_PATH]uint16)(unsafe.Pointer(&raw.FileName))
			name := syscall.UTF16ToString(buf[:raw.FileNameLength/2])
			fullname := watch.path + "\\" + name

			var mask uint64
			switch raw.Action {
			case syscall.FILE_ACTION_REMOVED:
				mask = sys_FS_DELETE_SELF
			case syscall.FILE_ACTION_MODIFIED:
				mask = sys_FS_MODIFY
			case syscall.FILE_ACTION_RENAMED_OLD_NAME:
				watch.rename = name
			case syscall.FILE_ACTION_RENAMED_NEW_NAME:
				if watch.names[watch.rename] != 0 {
					watch.names[name] |= watch.names[watch.rename]
					delete(watch.names, watch.rename)
//.........这里部分代码省略.........

// readEvents reads from the I/O completion port, converts the
// received events into Event objects and sends them via the Event channel.
// Entry point to the I/O thread.
func (w *Watcher) readEvents() {
	var (
		n, key uint32
		ov     *syscall.Overlapped
	)
	runtime.LockOSThread()

	for {
		e := syscall.GetQueuedCompletionStatus(w.port, &n, &key, &ov, syscall.INFINITE)
		watch := (*watch)(unsafe.Pointer(ov))

		if watch == nil {
			select {
			case ch := <-w.quit:
				for _, index := range w.watches {
					for _, watch := range index {
						w.deleteWatch(watch)
						w.startRead(watch)
					}
				}
				var err error
				if e := syscall.CloseHandle(w.port); e != nil {
					err = os.NewSyscallError("CloseHandle", e)
				}
				close(w.Event)
				close(w.Error)
				ch <- err
				return
			case in := <-w.input:
				switch in.op {
				case opAddWatch:
					in.reply <- w.addWatch(in.path, uint64(in.flags))
				case opRemoveWatch:
					in.reply <- w.removeWatch(in.path)
				}
			default:
			}
			continue
		}

		switch e {
		case syscall.ERROR_ACCESS_DENIED:
			// Watched directory was probably removed
			w.sendEvent(watch.path, watch.mask&FS_DELETE_SELF)
			w.deleteWatch(watch)
			w.startRead(watch)
			continue
		case syscall.ERROR_OPERATION_ABORTED:
			// CancelIo was called on this handle
			continue
		default:
			w.Error <- os.NewSyscallError("GetQueuedCompletionPort", e)
			continue
		case nil:
		}

		var offset uint32
		for {
			if n == 0 {
				w.Event <- &FileEvent{mask: FS_Q_OVERFLOW}
				w.Error <- errors.New("short read in readEvents()")
				break
			}

			// Point "raw" to the event in the buffer
			raw := (*syscall.FileNotifyInformation)(unsafe.Pointer(&watch.buf[offset]))
			buf := (*[syscall.MAX_PATH]uint16)(unsafe.Pointer(&raw.FileName))
			name := syscall.UTF16ToString(buf[:raw.FileNameLength/2])
			fullname := watch.path + "/" + name

			var mask uint64
			switch raw.Action {
			case syscall.FILE_ACTION_REMOVED:
				mask = FS_DELETE_SELF
			case syscall.FILE_ACTION_MODIFIED:
				mask = FS_MODIFY
			case syscall.FILE_ACTION_RENAMED_OLD_NAME:
				watch.rename = name
			case syscall.FILE_ACTION_RENAMED_NEW_NAME:
				if watch.names[watch.rename] != 0 {
					watch.names[name] |= watch.names[watch.rename]
					delete(watch.names, watch.rename)
					mask = FS_MOVE_SELF
				}
			}

			sendNameEvent := func() {
				if w.sendEvent(fullname, watch.names[name]&mask) {
					if watch.names[name]&FS_ONESHOT != 0 {
						delete(watch.names, name)
					}
				}
			}
			if raw.Action != syscall.FILE_ACTION_RENAMED_NEW_NAME {
				sendNameEvent()
			}
			if raw.Action == syscall.FILE_ACTION_REMOVED {
//.........这里部分代码省略.........