/ 
Imager-0.92_01
River stage three • 112 direct dependents • 130 total dependents
/ Imager::Threads

NAME

Imager::Threads - Imager and threads

SYNOPSIS

use Imager;
use threads;
Imager->preload;

threads->create(...);

DESCRIPTION

Starting from version 0.93 Imager attempts to work safely with perl's ithreads.

Previous versions stored some state in global variables, in particular the internal error stack.

However there are some limitations:

  • Imager's debug malloc isn't thread safe and will never be. Imager's debug malloc is disabled by default.

  • libtiff, which Imager uses for TIFF file support is not thread safe, Imager::File::TIFF works around this by single-threading its access to libtiff.

  • giflib, which Imager uses for GIF support is not thread safe before version 5. Imager::File::GIF works around this by single threading its access to giflib.

  • killing a thread reading or writing TIFF or GIF files may deadlock other threads when they attempt to read or write TIFF or GIF files.

Note that if you have another module using libtiff or giflib it may interact with Imager's use of those libraries in a threaded environment, since there's no way to co-ordinate access to the global information libtiff and giflib maintain.

Imager currently doesn't use threads itself.

SEE ALSO

Imager, threads

AUTHOR

Tony Cook <tony@cpan.org>