vendor/github.com/Microsoft/hcsshim/callback.go

   1 package hcsshim
   2
   3 import (
   4         "sync"
   5         "syscall"
   6 )
   7
   8 var (
   9         nextCallback    uintptr
  10         callbackMap     = map[uintptr]*notifcationWatcherContext{}
  11         callbackMapLock = sync.RWMutex{}
  12
  13         notificationWatcherCallback = syscall.NewCallback(notificationWatcher)
  14
  15         // Notifications for HCS_SYSTEM handles
  16         hcsNotificationSystemExited          hcsNotification = 0x00000001
  17         hcsNotificationSystemCreateCompleted hcsNotification = 0x00000002
  18         hcsNotificationSystemStartCompleted  hcsNotification = 0x00000003
  19         hcsNotificationSystemPauseCompleted  hcsNotification = 0x00000004
  20         hcsNotificationSystemResumeCompleted hcsNotification = 0x00000005
  21
  22         // Notifications for HCS_PROCESS handles
  23         hcsNotificationProcessExited hcsNotification = 0x00010000
  24
  25         // Common notifications
  26         hcsNotificationInvalid           hcsNotification = 0x00000000
  27         hcsNotificationServiceDisconnect hcsNotification = 0x01000000
  28 )
  29
  30 type hcsNotification uint32
  31 type notificationChannel chan error
  32
  33 type notifcationWatcherContext struct {
  34         channels notificationChannels
  35         handle   hcsCallback
  36 }
  37
  38 type notificationChannels map[hcsNotification]notificationChannel
  39
  40 func newChannels() notificationChannels {
  41         channels := make(notificationChannels)
  42
  43         channels[hcsNotificationSystemExited] = make(notificationChannel, 1)
  44         channels[hcsNotificationSystemCreateCompleted] = make(notificationChannel, 1)
  45         channels[hcsNotificationSystemStartCompleted] = make(notificationChannel, 1)
  46         channels[hcsNotificationSystemPauseCompleted] = make(notificationChannel, 1)
  47         channels[hcsNotificationSystemResumeCompleted] = make(notificationChannel, 1)
  48         channels[hcsNotificationProcessExited] = make(notificationChannel, 1)
  49         channels[hcsNotificationServiceDisconnect] = make(notificationChannel, 1)
  50         return channels
  51 }
  52 func closeChannels(channels notificationChannels) {
  53         close(channels[hcsNotificationSystemExited])
  54         close(channels[hcsNotificationSystemCreateCompleted])
  55         close(channels[hcsNotificationSystemStartCompleted])
  56         close(channels[hcsNotificationSystemPauseCompleted])
  57         close(channels[hcsNotificationSystemResumeCompleted])
  58         close(channels[hcsNotificationProcessExited])
  59         close(channels[hcsNotificationServiceDisconnect])
  60 }
  61
  62 func notificationWatcher(notificationType hcsNotification, callbackNumber uintptr, notificationStatus uintptr, notificationData *uint16) uintptr {
  63         var result error
  64         if int32(notificationStatus) < 0 {
  65                 result = syscall.Errno(win32FromHresult(notificationStatus))
  66         }
  67
  68         callbackMapLock.RLock()
  69         context := callbackMap[callbackNumber]
  70         callbackMapLock.RUnlock()
  71
  72         if context == nil {
  73                 return 0
  74         }
  75
  76         context.channels[notificationType] <- result
  77
  78         return 0
  79 }