[Interest] QFileSystemWatcher malfunctioning

[Andreas Pakulat]

On 02.02.12 14:36:35, Bo Thorsen wrote:
> Den 02-02-2012 14:29, Andreas Pakulat skrev:
> > On 02.02.12 14:19:25, Sujan Dasmahapatra wrote:
> >> But after updating I am still getting the message that the file is
> >> updated. The signal is not blocked. Please tell me whats going wrong in
> >> this. Thanks in advance for your help.
> >
> > Most probably the watcher notices the change asynchronously, i.e. after
> > your function has ended and the signal blocker has been deleted. You
> > should be able to verify that either using a debugger or by printing
> > some timestamps to see when the function is exited and when the slot
> > connected to the signal is received
> 
> That is a bit surprising to me, since I actually used it exactly for 
> blocking a file watcher, and that worked fine. Perhaps a flush is 
> necessary on the stream.

Well, it depends on how the Filewatcher does the watching, which depends
on what the OS provides for watching files and wether its
enabled/disabled. QFSWatcher uses a Polling-Backend in case it cannot
use some native notification system and that one surely is asynchronous.

Andreas