Haskell Cookbook

How it works...

monad-par defines the Par monad which defines the following primitives:

• new: Define a new empty IVar
• get: Wait for having some value in IVar
• put: Put some value into IVar
• fork: Signal that the input Par action can be run in parallel
• spawn: A function to run an action in parallel to produce an IVar

Internally, monad-par implements a way to balance these activities across threads by scheduling and balancing them. monad-par allows us to specify parallel tasks without getting into the nitty-gritty of actually scheduling tasks.

Also note that, in this recipe, we have used a threshold to run the task sequentially. This is to increase the granularity of the tasks. This speeds up more speedup when there is no threshold. As because ...