[Pan-users] Re: If SQLite has NFS locking problems... (was Re: Big XML files... (was ...))

[Duncan]

Ron Johnson <address@hidden> posted
address@hidden, excerpted below, on  Sat, 04 Jul 2009 15:13:10
-0500:

> Is Pan multi-threaded, so that the data store (currently, flat files) is
> concurrently accessed?

pan is "selectively multithreaded", that is, generally single threaded 
for simplicity of code without races (old-pan was multithreaded and 
Charles didn't like the debugging or difficulty of no-race coding, I 
guess), but it spawns worker threads at the worst bottlenecks.  One of 
those was when first setting up the network connections.  I'm not sure 
about the others.  (I'm not really a coder myself, but pay attention to 
what I read, and know enough about it to follow a decent bit of it.)

> a) breaking tasks.nzb into multiple files under tasks/, and having
>     a b-tree index to make it quick to rearrange queued tasks, and to
>     delete tasks once they are completed or deleted.

tasks.nzb was new with new-pan, and is a cross-application standard, as 
are the newsrc files.  I'm not sure what the tradeoffs were or whether 
that's enough of the bottleneck to be worth breaking the standard to 
attempt to fix.


-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman