Make the link between a monitored async operation and its monitor be explicit. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7346 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Async alarm changes: (dm)
  Rename asyncAbsoluteAlarm() to asyncSetAlarmTo().
  Rename asyncRelativeAlarm() to asyncSetAlarmIn().
  Add asyncResetAlarmTo().


git-svn-id: svn://mielke.cc/main/brltty@7347 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Add asyncResetAlarmIn(). (dm)


git-svn-id: svn://mielke.cc/main/brltty@7348 91a5dbb7-01b9-0310-9b5f-b28072856b6e
When cancelling the last operation of an async function, cancel the whole function. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7349 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Add support for cancelling an active async operation. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7350 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Add support for cancelling an async operation which is using allocated resources. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7351 91a5dbb7-01b9-0310-9b5f-b28072856b6e
asyncCancel() should actually cancel the underlying Windows operation. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7352 91a5dbb7-01b9-0310-9b5f-b28072856b6e