[KimDaBa] Multithreaded image loader?
Jesper K. Pedersen
blackie at blackie.dk
Mon Jan 10 13:50:35 GMT 2005
On Monday 10 January 2005 14:39, Robert L Krawitz wrote:
| From: "Jesper K. Pedersen" <blackie at blackie.dk>
| Date: Mon, 10 Jan 2005 14:30:05 +0100
| Cc: Robert L Krawitz <rlk at alum.mit.edu>
| On Monday 10 January 2005 14:24, Robert L Krawitz wrote:
| | I notice a comment in the image manager that the image loader can't be
| | made multithreaded because the JPEG loader isn't MT-safe. Is this an
| | issue in the JPEG library or somewhere else? Particularly (but not
| | exclusively) on an SMP/CMP or HT system, multithreading the loader
| | might offer a significant performance improvement.
| Well. only if you have more than one cpu in your system, or?
| Not necessarily. While that's becoming increasingly common
| (particularly in form of hyperthreading), the ability to overlap I/O
| with computation may offer benefits even on single CPU systems. If
| the I/O system can reorder requests to improve latency (which is
| normally the issue when loading thumbnails), there may be considerable
| benefit, particularly on a fast CPU.
| This is the kind of thing where it's often hard to predict what's
| going to happen, and experimentation yields benefits.
My answer stay the same nevertheless - I've no clue whose fault it is
1) I remember trying to have multiple loaders in the very first days of
KimDaBa, and remember seeing failiures - those might come from somewhere else
I think it is the loadJPEG function which has some issues.
Maybe Marcus can shed some light on this, he added a mutex to loadJpeg a long
Having trouble finding a given image in your collection containing
thousands of images?
http://ktown.kde.org/kimdaba might be the answer.
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