auto BufferedFile keeps file locked

[Ben Hinkle]

"Lionello Lunesu" <lio at lunesu.remove.com> wrote in message 
news:e2akhb$2au3$1 at digitaldaemon.com...
> Hi,
>
> Been playing around with the stream classes in Phobos some more and I've 
> noticed the following:
>
> #void bla( char[] fn ) {
> #  auto BufferedFile bf = new BufferedFile;
> #  bf.open(fn);
> #}
>
> After calling the function "bla", the opened file remains locked. Adding 
> "bf.close" at the end of the function correctly closes the file and does 
> not keep the file locked. Using "File" instead of "BufferedFile" also 
> solves the problem.
>
> After thinking about it for half an hour I finally got it: the 
> BufferedFile, which had a reference to a File instance, got destructed 
> like it should but the File's not being collected together with the 
> BufferedFile.
>
> It seems the File instance inside BufferedFile should be linked somehow to 
> the BufferedFile instance.
>
> Would adding a destructor to BufferedFile solve the problem?
>
> #class BufferedFile: BufferedStream {
> #
> #  // opens file for reading
> #  this() { super(new File()); }
> #  ~this() { close(); }
> ...

An object's destructor cannot refer to any other gc-managed resource. In 
particular the BufferedFile's destructor cannot close the associated File. 
See the help section about garbage collection for more info. With the 
current language design there is no way to have a 'auto' class clean up more 
than just itself. For example by the time the BufferedFile destructor runs 
the buffer used to hold the data of the BufferedFile might be gone and 
unreachable.

> L.
>
> PS. Who else thinks it should be "BufferFile" (and not "BufferedFile"; 
> (analogous to "FilterStream" and not "FilteredStream")?