---------- Forwarded message ----------
On Sun, Jan 4, 2015 at 11:49 PM, Bob Friesenhahn < email@example.com> wrote:
> On Sun, 4 Jan 2015, Aaron Boxer wrote:
> Another finding: reading files with four threads (I have a quad core i7)
>> is about twice as fast as single threaded
> With this approach do you have one thread calling libtiff APIs at a time?
With the threaded approach, I have a thread safe list of files in a directory, and each thread gets the next file name in the list and loads with libtiff. So, yes, I haven't changes the
library, just calling it from multiple threads.
What would be interesting is to use multiple threads to read a single TIFF image. This would be particularly advantageous for BigTIFF. My library is using C++11, so threading support is
baked in. Its quite easy, keeping in mind that threads are evil.
For libtiff, one would need to find a good cross platform C threading library.
For a single file, the approach could be similar: a thread safe list of strips, and each thread gets the next strip and reads it in.
> Actually, this would be a perfect job for OpenMP. And you wouldn't need a thread safe list, just divide up the strips evenly across threads.