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Postings from August 2013
On Sun, Aug 25, 2013 at 05:37:39PM -0700, James E Keenan via RT wrote: > On Fri Aug 23 17:28:00 2013, johnh@isi.edu wrote: > > Why is Thread::Queue *so* slow? > > > > I understand it has to do locking and be careful about data > > structures, but it seems like it is about 20x slower than opening up a > > Unix pipe, printing to that, reading it back and parsing the result. Because it is nothing like a UNIX pipe. A UNIX pipe takes a stream of bytes, and read and writes chunks of them into a shared buffer. A T::Q buffer takes a stream of perl "things", which might be objects or other such complex structures, and ensures they they are accessible by both the originating thread and any potential consumer thread. Migrating a perl "thing" across a thread boundary is considerably more complex than copying a byte across. > > To speculate, I'm thinking the cost is in making all IPC data shared. > > It would be great if one could have data that is sent over > > Thread::Queue that is copied, not shared. But T::Q is build upon a shared array, and is designed to handled shared data. I think the performance you are seeing is the performance I would expect, and that this is not a bug. -- In England there is a special word which means the last sunshine of the summer. That word is "spring".Thread Previous | Thread Next