Scheduling, interpreting and rasterising tasks in a multi-threaded raster image processor

A computer readable storage medium having a program recorded thereon, the program being executable by a processor to rasterise a document using a plurality of threads associated with the processor, the program comprising:

• code for interpreting objects of the document by performing interpreting tasks associated with said objects, wherein objects associated with different pages are interpreted in parallel;
• code for establishing a plurality of rasterising tasks associated with the performed interpreting tasks, each performed interpreting task establishing a plurality of rasterising tasks;
• code for estimating an amount of parallelisable work available to be performed using the plurality of threads, the amount of parallelisable work being estimated using the established plurality of rasterising tasks and an expected number of interpreting tasks to be performed;
• code for selecting, based on the estimated amount of parallelisable work, one of:
• (i) an interpreting task to interpret objects of the document, and
• (ii) a rasterising task from the established plurality of rasterising tasks;
• and
• code for executing the selected task using at least one thread to rasterize the document.

Computerised apparatus comprising a processor, a memory coupled to the processor in which a program is stored and executable by the processor to rasterise a document using a plurality of processing threads associated with the processor, the program comprising:

• code for interpreting objects of the document by performing interpreting tasks associated with said objects, wherein objects associated with different pages are interpreted in parallel;
• code for establishing a plurality of rasterising tasks associated with the performed interpreting tasks, each performed interpreting task establishing a plurality of rasterising tasks;
• code for estimating an amount of parallelisable work available to be performed using the plurality of threads, the amount of parallelisable work being estimated using the established plurality of rasterising tasks and an expected number of interpreting tasks to be performed;
• code for selecting, based on the estimated amount of parallelisable work, one of:
• (i) an interpreting task to interpret objects of the document, and
• (ii) a rasterising task from the established plurality of rasterising tasks;
• and
• code for executing the selected task using at least one thread to rasterize the document.