The speculation package

[Tags: bsd3, library]

A framework for safe, programmable, speculative parallelism, loosely based on http://research.microsoft.com/pubs/118795/pldi026-vaswani.pdf

spec g f a evaluates f g while forcing a, if g == a then f g is returned. Otherwise f a is evaluated.

Furthermore, if the argument has already been evaluated, we avoid sparking the parallel computation at all.

If a good guess at the value of a is available, this is one way to induce parallelism in an otherwise sequential task.

However, if the guess isn't available more cheaply than the actual answer, then this saves no work and if the guess is wrong, you risk evaluating the function twice.

 spec a f a = a `seq` f a

The best-case timeline looks like:

 [---- f g ----]
    [----- a -----]
 [-- spec g f a --]

The worst-case timeline looks like:

 [---- f g ----]
    [----- a -----]
                  [---- f a ----]
 [------- spec g f a -----------]

Compared to the unspeculated timeline of

 [---- a -----]
              [---- f a ----]

Changes since 0.0.1

Changes since 0.0.0


Properties

Versions0.0.0, 0.0.1, 0.0.2, 0.1.0, 0.2.0, 0.3.0, 0.4.0, 0.5.0, 0.5.1, 0.6.0, 0.7.0, 0.8.0, 0.8.0.1, 0.8.0.2, 0.8.1.0, 0.8.2.0, 0.9.0.0, 1.0.0.0, 1.1.0.0, 1.2.0.0, 1.2.0.1, 1.2.0.2, 1.3, 1.4, 1.4.1, 1.4.1.1, 1.4.1.2, 1.5, 1.5.0.1
Dependenciesarray (>=0.2 && <0.4), base (>=4 && <6), containers (>=0.2.0.1), parallel (==2.2.*)
LicenseBSD3
Copyright(c) 2010 Edward A. Kmett
AuthorEdward A. Kmett
MaintainerEdward A. Kmett <ekmett@gmail.com>
Stabilityexperimental
CategoryConcurrency
Home pagehttp://github.com/ekmett/speculation
Upload dateSun Jun 27 08:20:09 UTC 2010
Uploaded byEdwardKmett
DistributionsNixOS:1.5.0.1
Downloads2074 total (173 in last 30 days)

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