Hello Jacob,
It seems like you have answered your own question ;). The thing is that
the locking doesn't have to be all that hard. You can simply check if the
file is already in the open files cache (from previous thread). If it
isn't, the thread will open the file. Or you don't even have to do the
check yourself because tables.openFile() will do this for you. If the file
is already there, openFile() will just return you a reference to that File
instance, which is what you wanted anyways. This takes care of opening.
On the other side of things, don't allow any thread to close a file.
Simply close all files in the cache when your code is about to exit.
Keeping the file handles open and available for future reading isn't
*that*expensive.
So use openFile() for opening and don't close until the end and this should
be thread safe for reading. Obviously, writing is more difficult.
Be Well
Anthony
On Mon, Jul 2, 2012 at 5:38 AM, Jacob Bennett <jacob.bennet...@gmail.com>wrote:
> Hello PyTables Users,
>
> I am developing an API to access the current data stored in my pytables
> instance. Note at this point that this is only reading, no writing to the
> files. The big question on my mind at this point is how am I supposed to
> handle the opening and closing of files on read requests that are
> multithreaded? PyTables supports multithreading for read only; however, I
> don't know how to handle two threads opening the same file or one thread
> closing a file while the other is still reading it, besides putting a lock
> on it thus disabling the multithreaded operations.
>
> Thanks,
> Jacob
>
> --
> Jacob Bennett
> Massachusetts Institute of Technology
> Department of Electrical Engineering and Computer Science
> Class of 2014| benne...@mit.edu
>
>
>
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