The speculation package

[Tags: bsd3, library]

A framework for safe, programmable, speculative parallelism, loosely based on:

This package provides speculative function application and speculative folds. Speculative STM transactions take the place of the transactional rollback machinery from the paper.

For example:

spec g f a evaluates f g while forcing a, if g == a then f g is returned, otherwise f a is evaluated and returned. Furthermore, if the argument has already been evaluated, we skip the f g computation entirely. 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.

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 -----------]

Compare these to the timeline of f $! a:

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

specSTM provides a similar time table for STM actions, but also rolls back side-effects.


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
Dependenciesbase (>=4 && <6), parallel (==2.2.*), stm (==2.1.*)
LicenseBSD3
Copyright(c) 2010 Edward A. Kmett
AuthorEdward A. Kmett
MaintainerEdward A. Kmett <ekmett@gmail.com>
Stabilityexperimental
CategoryConcurrency
Home pagehttp://github.com/ekmett/speculation
Source repositoryhead: git clone http://github.com/ekmett/speculation.git -b master
Executablesbenchmark-speculation, test-speculation
Upload dateMon Jun 28 07:18:36 UTC 2010
Uploaded byEdwardKmett
DistributionsNixOS:1.5.0.1
Downloads2223 total (152 in last 30 days)

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Flags

NameDescriptionDefault
optimizeEnable optimizationsEnabled
testsBuild the testsEnabled
benchmarksBuild the benchmarksEnabled
hpcUse HPC for testsEnabled
nolibDon't build the library. Useful for speeding up the modify-build-test cycle.Disabled

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info

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