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Closes #146
Closes #147
Closes #156
This commit is contained in:
Michael Walker 2017-11-22 22:58:26 +00:00
parent 988032c9a2
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18
README.markdown
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@ -112,12 +112,12 @@ we'll get onto that shortly. First, the result of testing:
```
> autocheck myFunction
[pass] Never Deadlocks (checked: 12)
[pass] No Exceptions (checked: 12)
[fail] Consistent Result (checked: 11)
"hello" S0----S1-P2-S0--
[pass] Never Deadlocks
[pass] No Exceptions
[fail] Consistent Result
"hello" S0----S1--S0--
"world" S0----S2--S0-P1-S0-
"world" S0----S2--S0--
False
```
@ -145,10 +145,10 @@ These approaches are inadequate for a few reasons:
- **How do you know if you've fixed a bug you saw previously?**
Because the scheduler is a black box, you don't know if the
previously buggy schedule has been re-run.
- **You won't actually get that much scheduling variety!** Operating
systems and language runtimes like to run threads for long periods
of time, which reduces the variety you get (and so drives up the
number of runs you need).
- **You won't get that much scheduling variety!** Operating systems
and language runtimes like to run threads for long periods of time,
which reduces the variety you get (and so drives up the number of
runs you need).
Déjà Fu addresses these points by offering *complete* testing. You
can run a test case and be guaranteed to find all results with some

40
concurrency/Control/Concurrent/Classy/CRef.hs
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@ -48,28 +48,28 @@ module Control.Concurrent.Classy.CRef
--
-- We can see this by testing with different memory models:
--
-- > > autocheck' SequentialConsistency crefs
-- > [pass] Never Deadlocks (checked: 6)
-- > [pass] No Exceptions (checked: 6)
-- > [fail] Consistent Result (checked: 5)
-- > (False,True) S0-------S1-----S0--S2-----S0---
-- > (True,False) S0-------S1-P2-----S1----S0----
-- > (True,True) S0-------S1--P2-----S1---S0----
-- > (False,True) S0-------S1---P2-----S1--S0----
-- > (True,False) S0-------S2-----S1-----S0----
-- > ...
-- > > autocheckWay defaultWay SequentialConsistency relaxed
-- > [pass] Never Deadlocks
-- > [pass] No Exceptions
-- > [fail] Consistent Result
-- > (False,True) S0---------S1----S0--S2----S0--
-- >
-- > (True,True) S0---------S1-P2----S1---S0---
-- >
-- > (True,False) S0---------S2----S1----S0---
-- > False
--
-- > > autocheck' TotalStoreOrder crefs
-- > [pass] Never Deadlocks (checked: 303)
-- > [pass] No Exceptions (checked: 303)
-- > [fail] Consistent Result (checked: 302)
-- > (False,True) S0-------S1-----C-S0--S2-----C-S0---
-- > (True,False) S0-------S1-P2-----C-S1----S0----
-- > (True,True) S0-------S1-P2--C-S1----C-S0--S2---S0---
-- > (False,True) S0-------S1-P2--P1--C-C-S1--S0--S2---S0---
-- > (False,False) S0-------S1-P2--P1----S2---C-C-S0----
-- > ...
-- > > autocheckWay defaultWay TotalStoreOrder relaxed
-- > [pass] Never Deadlocks
-- > [pass] No Exceptions
-- > [fail] Consistent Result
-- > (False,True) S0---------S1----S0--S2----S0--
-- >
-- > (False,False) S0---------S1--P2----S1--S0---
-- >
-- > (True,False) S0---------S2----S1----S0---
-- >
-- > (True,True) S0---------S1-C-S2----S1---S0---
-- > False
--
-- Traces for non-sequentially-consistent memory models show where

3
concurrency/Control/Monad/Conc/Class.hs
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@ -289,8 +289,7 @@ class ( Applicative m, Monad m
-- @since 1.0.0.0
myThreadId :: m (ThreadId m)
-- | Allows a context-switch to any other currently runnable thread
-- (if any).
-- | Allows a context-switch to any other unblocked thread (if any).
--
-- @since 1.0.0.0
yield :: m ()

13
concurrency/README.markdown
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@ -3,16 +3,15 @@ concurrency
A typeclass abstraction over much of Control.Concurrent (and some
extras!). If you're looking for a general introduction to Haskell
concurrency, you should check out the excellent
[Parallel and Concurrent Programming in Haskell][parconc], by Simon
Marlow. If you are already familiar with concurrent Haskell, just
change all the imports from Control.Concurrent.* to
Control.Concurrent.Classy.* and fix the type errors.
concurrency, you should check out the excellent [Parallel and
Concurrent Programming in Haskell][parconc], by Simon Marlow. If you
are already familiar with concurrent Haskell, just change all the
imports from Control.Concurrent.* to Control.Concurrent.Classy.* and
fix the type errors.
A brief list of supported functionality:
- Threads: the `forkIO*` and `forkOn*` functions, although bound
threads are not supported.
- Threads: both unbound and bound.
- Getting and setting capablities.
- Yielding and delaying.
- Mutable state: STM, `MVar`, and `IORef`.

153
dejafu/README.markdown Executable file → Normal file
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@ -7,57 +7,124 @@ dejafu
>
> -- Terry Pratchett, Thief of Time
Concurrency is nice, deadlocks and race conditions not so much. The
`Par` monad family, as defined in [abstract-par][] provides
deterministic parallelism, but sometimes we can tolerate a bit of
nondeterminism.
- [Installation](#installation)
- [Quick start guide](#quick-start-guide)
- [Why Déjà Fu?](#why-déjà-fu)
- [Contributing](#contributing)
- [Release notes](#release-notes)
- [Questions, feedback, discussion](#questions-feedback-discussion)
- [Bibliography](#bibliography)
- **[The website!](http://dejafu.readthedocs.io/)**
This package builds on the concurrency package (also in this
repository) by enabling you to systematically and deterministically
test your concurrent programs.
Déjà Fu is a unit-testing library for concurrent Haskell programs.
Tests are deterministic and expressive, making it easy and convenient
to test your threaded code. Available on [GitHub][], [Hackage][], and
[Stackage][].
The documentation of the latest developmental version is
[available online][docs]. Examples can be found in the test suite.
[GitHub]: https://github.com/barrucadu/dejafu
[Hackage]: https://hackage.haskell.org/package/dejafu
[Stackage]: https://www.stackage.org/package/dejafu
**Note on the test suite:** This is in a separate project
(dejafu-tests) because Cabal-the-library is a bit naff. See this
[issue][].
Déjà Fu and `IO`
----------------
The core assumption underlying Déjà Fu is that any apparent
nondeterminism arises purely from the scheduling behaviour. To put it
another way, a given computation, parametrised with a fixed set of
scheduling decisions, is deterministic.
Whilst this assumption may not hold in general when `IO` is involved,
you should strive to produce test cases where it does.
Memory Model
Installation
------------
The testing functionality supports a few different memory models, for
computations which use non-synchronised `CRef` operations. The
supported models are:
Install from Hackage globally:
- **Sequential Consistency:** A program behaves as a simple
interleaving of the actions in different threads. When a CRef is
written to, that write is immediately visible to all threads.
```
$ cabal-install dejafu
```
- **Total Store Order (TSO):** Each thread has a write buffer. A
thread sees its writes immediately, but other threads will only
see writes when they are committed, which may happen later. Writes
are committed in the same order that they are created.
Or add it to your cabal file:
- **Partial Store Order (PSO):** Each CRef has a write buffer. A
thread sees its writes immediately, but other threads will only
see writes when they are committed, which may happen later. Writes
to different CRefs are not necessarily committed in the same order
that they are created.
```
build-depends: ...
, dejafu
```
Or to your package.yaml:
```
dependencies:
...
- dejafu
```
Quick start guide
-----------------
Déjà Fu supports unit testing, and comes with a helper function called
`autocheck` to look for some common issues. Let's see it in action:
```haskell
import Control.Concurrent.Classy
myFunction :: MonadConc m => m String
myFunction = do
var <- newEmptyMVar
fork (putMVar var "hello")
fork (putMVar var "world")
readMVar var
```
That `MonadConc` is a typeclass abstraction over concurrency, but
we'll get onto that shortly. First, the result of testing:
```
> autocheck myFunction
[pass] Never Deadlocks
[pass] No Exceptions
[fail] Consistent Result
"hello" S0----S1--S0--
"world" S0----S2--S0--
False
```
There are no deadlocks or uncaught exceptions, which is good; but the
program is (as you probably spotted) nondeterministic!
Along with each result, Déjà Fu gives us a representative execution
trace in an abbreviated form. `Sn` means that thread `n` started
executing, and `Pn` means that thread `n` pre-empted the previously
running thread.
Why Déjà Fu?
------------
Testing concurrent programs is difficult, because in general they are
nondeterministic. This leads to people using work-arounds like
running their testsuite many thousands of times; or running their
testsuite while putting their machine under heavy load.
These approaches are inadequate for a few reasons:
- **How many runs is enough?** When you are just hopping to spot a bug
by coincidence, how do you know to stop?
- **How do you know if you've fixed a bug you saw previously?**
Because the scheduler is a black box, you don't know if the
previously buggy schedule has been re-run.
- **You won't get that much scheduling variety!** Operating systems
and language runtimes like to run threads for long periods of time,
which reduces the variety you get (and so drives up the number of
runs you need).
Déjà Fu addresses these points by offering *complete* testing. You
can run a test case and be guaranteed to find all results with some
bounds. These bounds can be configured, or even disabled! The
underlying approach used is smarter than merely trying all possible
executions, and will in general explore the state-space quickly.
If your test case is just too big for complete testing, there is also
a random scheduling mode, which is necessarily *incomplete*. However,
Déjà Fu will tend to produce much more schedule variety than just
running your test case in `IO` the same number of times, and so bugs
will tend to crop up sooner. Furthermore, as you get execution traces
out, you can be certain that a bug has been fixed by simply following
the trace by eye.
If a testing function does not take the memory model as a parameter,
it uses TSO.
Contributing
------------
@ -66,7 +133,3 @@ Bug reports, pull requests, and comments are very welcome!
Feel free to contact me on GitHub, through IRC (#haskell on freenode),
or email (mike@barrucadu.co.uk).
[docs]: https://docs.barrucadu.co.uk/dejafu
[abstract-par]: https://hackage.haskell.org/package/abstract-par/docs/Control-Monad-Par-Class.html
[issue]: https://github.com/commercialhaskell/stack/issues/1122

641
dejafu/Test/DejaFu.hs
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@ -2,191 +2,159 @@
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TupleSections #-}
-- |
-- Module : Test.DejaFu
-- Copyright : (c) 2016 Michael Walker
-- License : MIT
-- Maintainer : Michael Walker <mike@barrucadu.co.uk>
-- Stability : experimental
-- Portability : LambdaCase, MultiParamTypeClasses, TupleSections
--
-- Deterministic testing for concurrent computations.
--
-- As an example, consider this program, which has two locks and a
-- shared variable. Two threads are spawned, which claim the locks,
-- update the shared variable, and release the locks. The main thread
-- waits for them both to terminate, and returns the final result.
--
-- > example1 :: MonadConc m => m Int
-- > example1 = do
-- > a <- newEmptyMVar
-- > b <- newEmptyMVar
-- >
-- > c <- newMVar 0
-- >
-- > let lock m = putMVar m ()
-- > let unlock = takeMVar
-- >
-- > j1 <- spawn $ lock a >> lock b >> modifyMVar_ c (return . succ) >> unlock b >> unlock a
-- > j2 <- spawn $ lock b >> lock a >> modifyMVar_ c (return . pred) >> unlock a >> unlock b
-- >
-- > takeMVar j1
-- > takeMVar j2
-- >
-- > takeMVar c
--
-- The correct result is 0, as it starts out as 0 and is incremented
-- and decremented by threads 1 and 2, respectively. However, note the
-- order of acquisition of the locks in the two threads. If thread 2
-- pre-empts thread 1 between the acquisition of the locks (or if
-- thread 1 pre-empts thread 2), a deadlock situation will arise, as
-- thread 1 will have lock @a@ and be waiting on @b@, and thread 2
-- will have @b@ and be waiting on @a@.
--
-- Here is what Deja Fu has to say about it:
--
-- > > autocheck example1
-- > [fail] Never Deadlocks (checked: 5)
-- > [deadlock] S0------------S1-P2--S1-
-- > [pass] No Exceptions (checked: 12)
-- > [fail] Consistent Result (checked: 11)
-- > 0 S0------------S2-----------------S1-----------------S0----
-- >
-- > [deadlock] S0------------S1-P2--S1-
-- > False
--
-- It identifies the deadlock, and also the possible results the
-- computation can produce, and displays a simplified trace leading to
-- each failing outcome. The trace contains thread numbers, and the
-- names (which can be set by the programmer) are displayed beneath.
-- It also returns @False@ as there are test failures. The automatic
-- testing functionality is good enough if you only want to check your
-- computation is deterministic, but if you have more specific
-- requirements (or have some expected and tolerated level of
-- nondeterminism), you can write tests yourself using the @dejafu*@
-- functions.
--
-- __Warning:__ If your computation under test does @IO@, the @IO@
-- will be executed lots of times! Be sure that it is deterministic
-- enough not to invalidate your test results. Mocking may be useful
-- where possible.
module Test.DejaFu
( -- * Testing
{- |
Module : Test.DejaFu
Copyright : (c) 2016 Michael Walker
License : MIT
Maintainer : Michael Walker <mike@barrucadu.co.uk>
Stability : experimental
Portability : LambdaCase, MultiParamTypeClasses, TupleSections
-- | Testing in Deja Fu is similar to unit testing, the programmer
-- produces a self-contained monadic action to execute under
-- different schedules, and supplies a list of predicates to apply
-- to the list of results produced.
--
-- If you simply wish to check that something is deterministic, see
-- the 'autocheck' function.
--
-- These functions use a Total Store Order (TSO) memory model for
-- unsynchronised actions, see \"Testing under Alternative Memory
-- Models\" for some explanation of this.
dejafu is a library for unit-testing concurrent Haskell programs,
written using the [concurrency](https://hackage.haskell.org/package/concurrency)
package's 'MonadConc' typeclass.
__A first test:__ This is a simple concurrent program which forks two
threads and each races to write to the same @MVar@:
> example = do
> var <- newEmptyMVar
> fork (putMVar var "hello")
> fork (putMVar var "world")
> readMVar var
We can test it with dejafu like so:
> > autocheck example
> [pass] Never Deadlocks
> [pass] No Exceptions
> [fail] Consistent Result
> "hello" S0----S1--S0--
>
> "world" S0----S2--S0--
The 'autocheck' function takes a concurrent program to test and looks
for some common unwanted behaviours: deadlocks, uncaught exceptions in
the main thread, and nondeterminism. Here we see the program is
nondeterministic, dejafu gives us all the distinct results it found
and, for each, a summarised execution trace leading to that result:
* \"Sn\" means that thread \"n\" started executing after the previous
thread terminated or blocked.
* \"Pn\" means that thread \"n\" started executing, even though the
previous thread could have continued running.
* Each \"-\" represents one \"step\" of the computation.
__Failures:__ If a program doesn't terminate successfully, we say it
has /failed/. dejafu can detect a few different types of failure:
* 'Deadlock', if every thread is blocked.
* 'STMDeadlock', if every thread is blocked /and/ the main thread is
blocked in an STM transaction.
* 'UncaughtException', if the main thread is killed by an exception.
There are two types of failure which dejafu itself may raise:
* 'Abort', used in systematic testing (the default) if there are no
allowed decisions remaining. For example, by default any test case
which takes more than 250 scheduling points to finish will be
aborted. You can use the 'systematically' function to supply (or
disable) your own bounds.
* 'InternalError', used if something goes wrong. If you get this and
aren't using a scheduler you wrote yourself, please [file a
bug](https://github.com/barrucadu/dejafu/issues).
Finally, there is one failure which can arise through improper use of
dejafu:
* 'IllegalSubconcurrency', the "Test.DejaFu.Conc.subconcurrency"
function is used when multiple threads exist, or is used inside
another @subconcurrency@ call.
__Beware of 'liftIO':__ dejafu works by running your test case lots of
times with different schedules. If you use 'liftIO' at all, make sure
that any @IO@ you perform is deterministic when executed in the same
order.
If you need to test things with /nondeterministc/ @IO@, see the
'autocheckWay', 'dejafuWay', and 'dejafusWay' functions: the
'randomly', 'uniformly', and 'swarmy' testing modes can cope with
nondeterminism.
-}
module Test.DejaFu
( -- * Unit testing
autocheck
, dejafu
, dejafus
-- * Testing with different settings
-- ** Configuration
{- |
There are a few knobs to tweak to control the behaviour of dejafu.
The defaults should generally be good enough, but if not you have a
few tricks available.
* The 'Way', which controls how schedules are explored.
* The 'MemType', which controls how reads and writes to @CRef@s (or
@IORef@s) behave.
* The 'Discard' function, which saves memory by throwing away
uninteresting results during exploration.
-}
, autocheckWay
, dejafuWay
, dejafusWay
, dejafuDiscard
-- *** Defaults
, defaultWay
, defaultMemType
, defaultDiscarder
-- *** Exploration
, Way
, defaultWay
, systematically
, randomly
, uniformly
, swarmy
, autocheckWay
, dejafuWay
, dejafusWay
-- **** Schedule bounding
, Discard(..)
, defaultDiscarder
{- |
, dejafuDiscard
Schedule bounding is used by the 'systematically' approach to limit
the search-space, which in general will be huge.
-- ** Memory Models
There are three types of bounds used:
-- | Threads running under modern multicore processors do not behave
-- as a simple interleaving of the individual thread
-- actions. Processors do all sorts of complex things to increase
-- speed, such as buffering writes. For concurrent programs which
-- make use of non-synchronised functions (such as 'readCRef'
-- coupled with 'writeCRef') different memory models may yield
-- different results.
--
-- As an example, consider this program (modified from the
-- Data.IORef documentation). Two @CRef@s are created, and two
-- threads spawned to write to and read from both. Each thread
-- returns the value it observes.
--
-- > example2 :: MonadConc m => m (Bool, Bool)
-- > example2 = do
-- > r1 <- newCRef False
-- > r2 <- newCRef False
-- >
-- > x <- spawn $ writeCRef r1 True >> readCRef r2
-- > y <- spawn $ writeCRef r2 True >> readCRef r1
-- >
-- > (,) <$> readMVar x <*> readMVar y
--
-- Under a sequentially consistent memory model the possible results
-- are @(True, True)@, @(True, False)@, and @(False, True)@. Under
-- total or partial store order, @(False, False)@ is also a possible
-- result, even though there is no interleaving of the threads which
-- can lead to this.
--
-- We can see this by testing with different memory models:
--
-- > > autocheckWay defaultWay SequentialConsistency example2
-- > [pass] Never Deadlocks (checked: 6)
-- > [pass] No Exceptions (checked: 6)
-- > [fail] Consistent Result (checked: 5)
-- > (False,True) S0-------S1-----S0--S2-----S0---
-- > (True,False) S0-------S1-P2-----S1----S0----
-- > (True,True) S0-------S1--P2-----S1---S0----
-- > (False,True) S0-------S1---P2-----S1--S0----
-- > (True,False) S0-------S2-----S1-----S0----
-- > ...
-- > False
--
-- > > autocheckWay defaultWay TotalStoreOrder example2
-- > [pass] Never Deadlocks (checked: 303)
-- > [pass] No Exceptions (checked: 303)
-- > [fail] Consistent Result (checked: 302)
-- > (False,True) S0-------S1-----C-S0--S2-----C-S0---
-- > (True,False) S0-------S1-P2-----C-S1----S0----
-- > (True,True) S0-------S1-P2--C-S1----C-S0--S2---S0---
-- > (False,True) S0-------S1-P2--P1--C-C-S1--S0--S2---S0---
-- > (False,False) S0-------S1-P2--P1----S2---C-C-S0----
-- > ...
-- > False
--
-- Traces for non-sequentially-consistent memory models show where
-- writes to @CRef@s are /committed/, which makes a write visible to
-- all threads rather than just the one which performed the
-- write. Only 'writeCRef' is broken up into separate write and
-- commit steps, 'atomicModifyCRef' is still atomic and imposes a
-- memory barrier.
* The 'PreemptionBound', which bounds the number of pre-emptive
context switches. Empirical evidence suggests @2@ is a good value
for this, if you have a small test case.
, MemType(..)
, defaultMemType
* The 'FairBound', which bounds the difference between how many times
threads can yield. This is necessary to test certain kinds of
potentially non-terminating behaviour, such as spinlocks.
-- ** Schedule Bounding
* The 'LengthBound', which bounds how long a test case can run, in
terms of scheduling decisions. This is necessary to test certain
kinds of potentially non-terminating behaviour, such as livelocks.
-- | Schedule bounding is an optimisation which only considers
-- schedules within some /bound/. This sacrifices completeness
-- outside of the bound, but can drastically reduce the number of
-- schedules to test, and is in fact necessary for non-terminating
-- programs.
--
-- The standard testing mechanism uses a combination of pre-emption
-- bounding, fair bounding, and length bounding. Pre-emption + fair
-- bounding is useful for programs which use loop/yield control
-- flows but are otherwise terminating. Length bounding makes it
-- possible to test potentially non-terminating programs.
Schedule bounding is not used by the non-systematic exploration
behaviours.
-}
, Bounds(..)
, defaultBounds
@ -198,30 +166,109 @@ module Test.DejaFu
, LengthBound(..)
, defaultLengthBound
-- * Results
-- *** Memory model
-- | The results of a test can be pretty-printed to the console, as
-- with the above functions, or used in their original, much richer,
-- form for debugging purposes. These functions provide full access
-- to this data type which, most usefully, contains a detailed trace
-- of execution, showing what each thread did at each point.
{- |
When executed on a multi-core processor some @CRef@ / @IORef@ programs
can exhibit \"relaxed memory\" behaviours, where the apparent
behaviour of the program is not a simple interleaving of the actions
of each thread.
__Example:__ This is a simple program which creates two @CRef@s
containing @False@, and forks two threads. Each thread writes @True@
to one of the @CRef@s and reads the other. The value that each thread
reads is communicated back through an @MVar@:
> relaxed = do
> r1 <- newCRef False
> r2 <- newCRef False
> x <- spawn $ writeCRef r1 True >> readCRef r2
> y <- spawn $ writeCRef r2 True >> readCRef r1
> (,) <$> readMVar x <*> readMVar y
We see something surprising if we ask for the results:
> > autocheck relaxed
> [pass] Never Deadlocks
> [pass] No Exceptions
> [fail] Consistent Result
> (False,True) S0---------S1----S0--S2----S0--
>
> (False,False) S0---------S1--P2----S1--S0---
>
> (True,False) S0---------S2----S1----S0---
>
> (True,True) S0---------S1-C-S2----S1---S0---
It's possible for both threads to read the value @False@, even though
each writes @True@ to the other @CRef@ before reading. This is
because processors are free to re-order reads and writes to
independent memory addresses in the name of performance.
Execution traces for relaxed memory computations can include \"C\"
actions, as above, which show where @CRef@ writes were explicitly
/committed/, and made visible to other threads.
However, modelling this behaviour can require more executions. If you
do not care about the relaxed-memory behaviour of your program, use
the 'SequentialConsistency' model.
-}
, MemType(..)
-- *** Reducing memory usage
{- |
Sometimes we know that a result is uninteresting and cannot affect the
result of a test, in which case there is no point in keeping it
around. Execution traces can be large, so any opportunity to get rid
of them early is possibly a great saving of memory.
A discard function, which has type @Either Failure a -> Maybe
Discard@, can selectively discard results or execution traces before
the schedule exploration finishes, allowing them to be garbage
collected sooner.
__Note:__ This is only relevant if you are producing your own
predicates. The predicates and helper functions provided by this
module do discard results and traces wherever possible.
-}
, Discard(..)
-- ** Manual testing
{- |
The standard testing functions print their result to stdout, and throw
away some information. The traces are pretty-printed, and if there
are many failures, only the first few are shown.
If you need more information, use these functions.
-}
, Result(..)
, Failure(..)
, runTest
, runTestWay
-- * Predicates
-- ** Predicates
-- | Predicates evaluate a list of results of execution and decide
-- whether some test case has passed or failed. They can be lazy and
-- make use of short-circuit evaluation to avoid needing to examine
-- the entire list of results, and can check any property which can
-- be defined for the return type of your monadic action.
--
-- A collection of common predicates are provided, along with helper
-- functions to lift predicates over a single result to over a
-- collection of results.
{- |
A dejafu test has two parts: the concurrent program to test, and a
predicate to determine if the test passes, based on the results of the
schedule exploration.
All of these predicates discard results and traces as eagerly as
possible, to reduce memory usage.
-}
, Predicate
, ProPredicate(..)
@ -234,10 +281,17 @@ module Test.DejaFu
, exceptionsNever
, exceptionsAlways
, exceptionsSometimes
, gives
, gives'
-- ** Predicate Helpers
-- *** Helpers
{- |
Helper functions to produce your own predicates. Such predicates
discard results and traces as eagerly as possible, to reduce memory
usage.
-}
, representative
, alwaysSame
, alwaysSameOn
@ -247,8 +301,16 @@ module Test.DejaFu
, somewhereTrue
, alwaysNothing
, somewhereNothing
, gives
, gives'
-- ** Failures
-- *** Failures
{- |
Helper functions to identify failures.
-}
, isInternalError
, isAbort
@ -256,30 +318,64 @@ module Test.DejaFu
, isUncaughtException
, isIllegalSubconcurrency
-- * Refinement property testing
-- * Property testing
{- |
dejafu can also use a property-testing style to test stateful
operations for a variety of inputs. Inputs are generated using the
[leancheck](https://hackage.haskell.org/package/leancheck) library for
enumerative testing.
__Testing @MVar@ operations with multiple producers__:
These are a little different to the property tests you may be familiar
with from libraries like QuickCheck (and leancheck). As we're testing
properties of /stateful/ and /concurrent/ things, we need to provide
some extra information.
A property consists of two /signatures/ and a relation between them.
A signature contains:
* An initialisation function, to construct the initial state.
* An observation function, to take a snapshot of the state at the
end.
* An interference function, to mess with the state in some way.
* The expression to evaluate, as a function over the state.
> sig e = Sig
> { initialise = maybe newEmptyMVar newMVar
> , observe = \v _ -> tryReadMVar v
> , interfere = \v _ -> putMVar v 42
> , expression = void . e
> }
This is a signature for operations over @Num n => MVar n@ values where
there are multiple producers. The initialisation function takes a
@Maybe n@ and constructs an @MVar n@, empty if it gets @Nothing@; the
observation function reads the @MVar@; and the interference function
puts a new value in.
Given this signature, we can check if @readMVar@ is the same as a
@takeMVar@ followed by a @putMVar@:
> > check $ sig readMVar === sig (\v -> takeMVar v >>= putMVar v)
> *** Failure: (seed Just 0)
> left: [(Nothing,Just 0)]
> right: [(Nothing,Just 0),(Just Deadlock,Just 42)]
The two expressions are not equivalent, and we get a counterexample:
if the @MVar@ is nonempty, then the left expression (@readMVar@) will
preserve the value, but the right expression (@\v -> takeMVar v >>=
putMVar v@) may cause it to change. This is because of the concurrent
interference we have provided: the left term never empties a full
@MVar@, but the Right term does.
-}
-- | Consider this statement about @MVar@s: \"using @readMVar@ is
-- better than @takeMVar@ followed by @putMVar@ because the former
-- is atomic but the latter is not.\"
--
-- Deja Fu can test properties like that:
--
-- @
-- sig e = Sig
-- { initialise = maybe newEmptyMVar newMVar
-- , observe = \\v _ -> tryReadMVar v
-- , interfere = \\v s -> tryTakeMVar v >> maybe (pure ()) (void . tryPutMVar v) s
-- , expression = e
-- }
--
-- > check $ sig (void . readMVar) \`equivalentTo\` sig (\\v -> takeMVar v >>= putMVar v)
-- *** Failure: (seed Just ())
-- left: [(Nothing,Just ())]
-- right: [(Nothing,Just ()),(Just Deadlock,Just ())]
-- @
--
-- The two expressions are not equivalent, and we get given the
-- counterexample!
, module Test.DejaFu.Refinement
) where
@ -305,29 +401,50 @@ import Test.DejaFu.SCT
-------------------------------------------------------------------------------
-- DejaFu
-- | Automatically test a computation. In particular, look for
-- deadlocks, uncaught exceptions, and multiple return values.
-- | Automatically test a computation.
--
-- In particular, look for deadlocks, uncaught exceptions, and
-- multiple return values. Returns @True@ if all tests pass
--
-- > > autocheck example
-- > [pass] Never Deadlocks
-- > [pass] No Exceptions
-- > [fail] Consistent Result
-- > "hello" S0----S1--S0--
-- >
-- > "world" S0----S2--S0--
--
-- @since 1.0.0.0
autocheck :: (MonadConc n, MonadIO n, MonadRef r n, Eq a, Show a)
=> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
autocheck = autocheckWay defaultWay defaultMemType
-- | Variant of 'autocheck' which takes a way to run the program and a
-- memory model.
--
-- Schedule bounding is used to filter the large number of possible
-- schedules, and can be iteratively increased for further coverage
-- guarantees. Empirical studies (/Concurrency Testing Using Schedule
-- Bounding: an Empirical Study/, P. Thompson, A. Donaldson, and
-- A. Betts) have found that many concurrency bugs can be exhibited
-- with as few as two threads and two pre-emptions, which is part of
-- what 'dejafus' uses.
--
-- __Warning:__ Using larger bounds will almost certainly
-- significantly increase the time taken to test!
-- > > autocheckWay defaultWay defaultMemType relaxed
-- > [pass] Never Deadlocks
-- > [pass] No Exceptions
-- > [fail] Consistent Result
-- > (False,True) S0---------S1----S0--S2----S0--
-- >
-- > (False,False) S0---------S1--P2----S1--S0---
-- >
-- > (True,False) S0---------S2----S1----S0---
-- >
-- > (True,True) S0---------S1-C-S2----S1---S0---
-- >
-- > > autocheckWay defaultWay SequentialConsistency relaxed
-- > [pass] Never Deadlocks
-- > [pass] No Exceptions
-- > [fail] Consistent Result
-- > (False,True) S0---------S1----S0--S2----S0--
-- >
-- > (True,True) S0---------S1-P2----S1---S0---
-- >
-- > (True,False) S0---------S2----S1----S0---
--
-- @since 1.0.0.0
autocheckWay :: (MonadConc n, MonadIO n, MonadRef r n, Eq a, Show a)
@ -336,7 +453,7 @@ autocheckWay :: (MonadConc n, MonadIO n, MonadRef r n, Eq a, Show a)
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
autocheckWay way memtype = dejafusWay way memtype autocheckCases
@ -351,20 +468,44 @@ autocheckCases =
-- | Check a predicate and print the result to stdout, return 'True'
-- if it passes.
--
-- A dejafu test has two parts: the program you are testing, and a
-- predicate to determine if the test passes. Predicates can look for
-- anything, including checking for some expected nondeterminism.
--
-- > > dejafu "Test Name" alwaysSame example
-- > [fail] Test Name
-- > "hello" S0----S1--S0--
-- >
-- > "world" S0----S2--S0--
--
-- @since 1.0.0.0
dejafu :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
=> String
-- ^ The name of the test
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
dejafu = dejafuWay defaultWay defaultMemType
-- | Variant of 'dejafu' which takes a way to run the program and a
-- memory model.
--
-- > > import System.Random
-- >
-- > > dejafuWay (randomly (mkStdGen 0) 100) defaultMemType "Randomly!" alwaysSame example
-- > [fail] Randomly!
-- > "hello" S0----S1--S0--
-- >
-- > "world" S0----S2--S0--
-- >
-- > > dejafuWay (randomly (mkStdGen 1) 100) defaultMemType "Randomly!" alwaysSame example
-- > [fail] Randomly!
-- > "hello" S0----S1--S0--
-- >
-- > "world" S0----S2--S1-S0--
--
-- @since 1.0.0.0
dejafuWay :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
=> Way
@ -372,16 +513,22 @@ dejafuWay :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> String
-- ^ The name of the test
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
dejafuWay = dejafuDiscard (const Nothing)
-- | Variant of 'dejafuWay' which can selectively discard results.
--
-- > > dejafuDiscard (\_ -> Just DiscardTrace) defaultWay defaultMemType "Discarding" alwaysSame example
-- > [fail] Discarding
-- > "hello" <trace discarded>
-- >
-- > "world" <trace discarded>
--
-- @since 1.0.0.0
dejafuDiscard :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
=> (Either Failure a -> Maybe Discard)
@ -391,11 +538,11 @@ dejafuDiscard :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> String
-- ^ The name of the test
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
dejafuDiscard discard way memtype name test conc = do
let discarder = strengthenDiscard discard (pdiscard test)
@ -405,18 +552,34 @@ dejafuDiscard discard way memtype name test conc = do
-- | Variant of 'dejafu' which takes a collection of predicates to
-- test, returning 'True' if all pass.
--
-- > > dejafus [("A", alwaysSame), ("B", deadlocksNever)] example
-- > [fail] A
-- > "hello" S0----S1--S0--
-- >
-- > "world" S0----S2--S0--
-- > [pass] B
--
-- @since 1.0.0.0
dejafus :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
=> [(String, ProPredicate a b)]
-- ^ The list of predicates (with names) to check
-- ^ The list of predicates (with names) to check.
-> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
dejafus = dejafusWay defaultWay defaultMemType
-- | Variant of 'dejafus' which takes a way to run the program and a
-- memory model.
--
-- > > dejafusWay defaultWay SequentialConsistency [("A", alwaysSame), ("B", exceptionsNever)] relaxed
-- > [fail] A
-- > (False,True) S0---------S1----S0--S2----S0--
-- >
-- > (True,True) S0---------S1-P2----S1---S0---
-- >
-- > (True,False) S0---------S2----S1----S0---
-- > [pass] B
--
-- @since 1.0.0.0
dejafusWay :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
=> Way
@ -424,9 +587,9 @@ dejafusWay :: (MonadConc n, MonadIO n, MonadRef r n, Show b)
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> [(String, ProPredicate a b)]
-- ^ The list of predicates (with names) to check
-- ^ The list of predicates (with names) to check.
-> ConcT r n a
-- ^ The computation to test
-- ^ The computation to test.
-> n Bool
dejafusWay way memtype tests conc = do
traces <- runSCTDiscard discarder way memtype conc
@ -488,6 +651,10 @@ instance Foldable Result where
-- | Run a predicate over all executions within the default schedule
-- bounds.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases. This may
-- affect which failing traces are reported, when there is a failure.
--
-- @since 1.0.0.0
runTest :: (MonadConc n, MonadRef r n)
=> ProPredicate a b
@ -500,6 +667,10 @@ runTest = runTestWay defaultWay defaultMemType
-- | Variant of 'runTest' which takes a way to run the program and a
-- memory model.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases. This may
-- affect which failing traces are reported, when there is a failure.
--
-- @since 1.0.0.0
runTestWay :: (MonadConc n, MonadRef r n)
=> Way

8
dejafu/Test/DejaFu/Common.hs
View File

@ -792,7 +792,7 @@ instance NFData TAction where
-- Traces
-- | One of the outputs of the runner is a @Trace@, which is a log of
-- decisions made, all the runnable threads and what they would do,
-- decisions made, all the unblocked threads and what they would do,
-- and the action a thread took in its step.
--
-- @since 0.8.0.0
@ -909,9 +909,11 @@ data Failure
-- bounds (there have been too many pre-emptions, the computation
-- has executed for too long, or there have been too many yields).
| Deadlock
-- ^ The computation became blocked indefinitely on @MVar@s.
-- ^ Every thread is blocked, and the main thread is /not/ blocked
-- in an STM transaction.
| STMDeadlock
-- ^ The computation became blocked indefinitely on @TVar@s.
-- ^ Every thread is blocked, and the main thread is blocked in an
-- STM transaction.
| UncaughtException SomeException
-- ^ An uncaught exception bubbled to the top of the computation.
| IllegalSubconcurrency

30
dejafu/Test/DejaFu/SCT.hs
View File

@ -210,6 +210,9 @@ swarmy = Weighted
-- | Explore possible executions of a concurrent program according to
-- the given 'Way'.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases.
--
-- @since 1.0.0.0
runSCT :: (MonadConc n, MonadRef r n)
=> Way
@ -288,6 +291,9 @@ strengthenDiscard d1 d2 efa = case (d1 efa, d2 efa) of
-- | A variant of 'runSCT' which can selectively discard results.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases.
--
-- @since 1.0.0.0
runSCTDiscard :: (MonadConc n, MonadRef r n)
=> (Either Failure a -> Maybe Discard)
@ -325,6 +331,9 @@ resultsSetDiscard discard way memtype conc =
-- Demanding the result of this will force it to normal form, which
-- may be more efficient in some situations.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases.
--
-- @since 1.0.0.0
runSCT' :: (MonadConc n, MonadRef r n, NFData a)
=> Way -> MemType -> ConcT r n a -> n [(Either Failure a, Trace)]
@ -345,6 +354,9 @@ resultsSet' = resultsSetDiscard' (const Nothing)
-- Demanding the result of this will force it to normal form, which
-- may be more efficient in some situations.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases.
--
-- @since 1.0.0.0
runSCTDiscard' :: (MonadConc n, MonadRef r n, NFData a)
=> (Either Failure a -> Maybe Discard) -> Way -> MemType -> ConcT r n a -> n [(Either Failure a, Trace)]
@ -471,8 +483,8 @@ fBound (FairBound fb) k prior lhead =
then Just k'
else Nothing
-- | Add a backtrack point. If the thread isn't runnable, or performs
-- a release operation, add all runnable threads.
-- | Add a backtrack point. If the thread doesn't exist or is blocked,
-- or performs a release operation, add all unblocked threads.
fBacktrack :: BacktrackFunc
fBacktrack = backtrackAt check where
-- True if a release operation is performed.
@ -496,8 +508,8 @@ lBound (LengthBound lb) len _ _ =
let len' = maybe 1 (+1) len
in if len' < lb then Just len' else Nothing
-- | Add a backtrack point. If the thread isn't runnable, add all
-- runnable threads.
-- | Add a backtrack point. If the thread doesn't exist or is blocked,
-- add all unblocked threads.
lBacktrack :: BacktrackFunc
lBacktrack = backtrackAt (\_ _ -> False)
@ -516,6 +528,9 @@ lBacktrack = backtrackAt (\_ _ -> False)
-- do some redundant work as the introduction of a bound can make
-- previously non-interfering events interfere with each other.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases.
--
-- @since 1.0.0.0
sctBound :: (MonadConc n, MonadRef r n)
=> MemType
@ -529,6 +544,9 @@ sctBound = sctBoundDiscard (const Nothing)
-- | A variant of 'sctBound' which can selectively discard results.
--
-- The exact executions tried, and the order in which results are
-- found, is unspecified and may change between releases.
--
-- @since 1.0.0.0
sctBoundDiscard :: (MonadConc n, MonadRef r n)
=> (Either Failure a -> Maybe Discard)
@ -588,6 +606,8 @@ sctUniformRandom = sctUniformRandomDiscard (const Nothing)
-- | A variant of 'sctUniformRandom' which can selectively discard
-- results.
--
-- This is not guaranteed to find all distinct results.
--
-- @since 1.0.0.0
sctUniformRandomDiscard :: (MonadConc n, MonadRef r n, RandomGen g)
=> (Either Failure a -> Maybe Discard)
@ -635,6 +655,8 @@ sctWeightedRandom = sctWeightedRandomDiscard (const Nothing)
-- | A variant of 'sctWeightedRandom' which can selectively discard
-- results.
--
-- This is not guaranteed to find all distinct results.
--
-- @since 1.0.0.0
sctWeightedRandomDiscard :: (MonadConc n, MonadRef r n, RandomGen g)
=> (Either Failure a -> Maybe Discard)

19
dejafu/Test/DejaFu/Schedule.hs
View File

@ -40,7 +40,7 @@ import Test.DejaFu.Common
-- 1. The last thread executed (if this is the first invocation, this
-- is @Nothing@).
--
-- 2. The runnable threads at this point.
-- 2. The unblocked threads.
--
-- 3. The state.
--
@ -68,15 +68,16 @@ tidOf _ (Start t) = t
tidOf _ (SwitchTo t) = t
tidOf tid _ = tid
-- | Get the 'Decision' that would have resulted in this thread identifier,
-- given a prior thread (if any) and list of runnable threads.
-- | Get the 'Decision' that would have resulted in this thread
-- identifier, given a prior thread (if any) and collection of threads
-- which are unblocked at this point.
--
-- @since 0.5.0.0
decisionOf :: Foldable f
=> Maybe ThreadId
-- ^ The prior thread.
-> f ThreadId
-- ^ The runnable threads.
-- ^ The threads.
-> ThreadId
-- ^ The current thread.
-> Decision
@ -118,16 +119,18 @@ roundRobinSched = Scheduler go where
-------------------------------------------------------------------------------
-- Non-preemptive
-- | A random scheduler which doesn't preempt the running
-- thread. That is, if the last thread scheduled is still runnable,
-- run that, otherwise schedule randomly.
-- | A random scheduler which doesn't preempt the running thread. That
-- is, if the previously scheduled thread is not blocked, it is picked
-- again, otherwise schedule randomly.
--
-- @since 0.8.0.0
randomSchedNP :: RandomGen g => Scheduler g
randomSchedNP = makeNonPreemptive randomSched
-- | A round-robin scheduler which doesn't preempt the running
-- thread.
-- thread. That is, if the previously scheduled thread is not blocked,
-- it is picked again, otherwise schedule the thread with the next
-- 'ThreadId'.
--
-- @since 0.8.0.0
roundRobinSchedNP :: Scheduler ()

16
dejafu/dejafu.cabal
View File

@ -3,21 +3,17 @@
name: dejafu
version: 1.0.0.0
synopsis: Systematic testing for Haskell concurrency.
synopsis: A library for unit-testing concurrent programs.
description:
/[Déjà Fu is] A martial art in which the user's limbs move in time as well as space, […] It is best described as "the feeling that you have been kicked in the head this way before"/ -- Terry Pratchett, Thief of Time
.
Concurrency is nice, deadlocks and race conditions not so much. The
@Par@ monad family, as defined in
<https://hackage.haskell.org/package/abstract-par/docs/Control-Monad-Par-Class.html abstract-par>
provides deterministic parallelism, but sometimes we can tolerate a
bit of nondeterminism.
.
This package builds on the
<https://hackage.haskell.org/package/concurrency concurrency>
package by enabling you to systematically and deterministically test
your concurrent programs.
[concurrency](https://hackage.haskell.org/package/concurrency)
package by enabling you to deterministically test your concurrent
programs.
.
See the [website](https://dejafu.readthedocs.io) or README for more.
homepage: https://github.com/barrucadu/dejafu
license: MIT

2
doc/adding_a_new_primitive.rst
View File

@ -159,7 +159,7 @@ The ``rewind`` function converts between ``ThreadAction`` and
Finally, we need to make sure the systematic testing will treat our
new primitive correctly. As setting the value of an ``MVar`` may
cause previously blocked threads to become runnable, it is a *release*
cause previously blocked threads to be unblocked, it is a *release*
action. Furthermore, as it writes to an ``MVar`` it is a
*synchronised write*:

18
doc/advanced.rst
View File

@ -53,9 +53,9 @@ We can see this by testing with different memory models:
.. code-block:: none
> autocheckWay defaultWay SequentialConsistency example
[pass] Never Deadlocks (checked: 6)
[pass] No Exceptions (checked: 6)
[fail] Consistent Result (checked: 5)
[pass] Never Deadlocks
[pass] No Exceptions
[fail] Consistent Result
(False,True) S0---------S1----S0--S2----S0--
(True,True) S0---------S1-P2----S1---S0---
@ -64,9 +64,9 @@ We can see this by testing with different memory models:
False
> autocheckWay defaultWay TotalStoreOrder example
[pass] Never Deadlocks (checked: 28)
[pass] No Exceptions (checked: 28)
[fail] Consistent Result (checked: 27)
[pass] Never Deadlocks
[pass] No Exceptions
[fail] Consistent Result
(False,True) S0---------S1----S0--S2----S0--
(False,False) S0---------S1--P2----S1--S0---
@ -95,8 +95,8 @@ There are three supported types of bounds:
Pre-emption bounding
Restricts the number of pre-emptive context switches. A context
switch is pre-emptive if the previously executing thread is still
runnable and did not explicitly yield.
switch is pre-emptive if the previously executing thread is not
blocked and did not explicitly yield.
Fair bounding
Restricts how many times each thread can yield, by bounding the
@ -136,7 +136,7 @@ There are three variants:
Perform the given number of executions using weighted random
scheduling. On creation, a thread is given a random weight, which
is used to perform a nonuniform random selection amongst the
runnable threads at every scheduling point.
enabled (not blocked) threads at every scheduling point.
``uniformly randomGen numExecutions``
Like ``randomly``, but rather than a weighted selection, it's a

10
doc/getting_started.rst
View File

@ -98,12 +98,12 @@ we'll get onto that shortly. First, the result of testing:
.. code-block:: none
> autocheck myFunction
[pass] Never Deadlocks (checked: 12)
[pass] No Exceptions (checked: 12)
[fail] Consistent Result (checked: 11)
"hello" S0----S1-P2-S0--
[pass] Never Deadlocks
[pass] No Exceptions
[fail] Consistent Result
"hello" S0----S1--S0--
"world" S0----S2--S0-P1-S0-
"world" S0----S2--S0--
False
There are no deadlocks or uncaught exceptions, which is good; but the

26
hunit-dejafu/Test/HUnit/DejaFu.hs
View File

@ -106,7 +106,7 @@ assertableP = alwaysTrue $ \case
-- @since 1.0.0.0
testAuto :: (Eq a, Show a)
=> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testAuto = testAutoWay defaultWay defaultMemType
@ -120,7 +120,7 @@ testAutoWay :: (Eq a, Show a)
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testAutoWay way memtype = testDejafusWay way memtype autocheckCases
@ -137,11 +137,11 @@ autocheckCases =
-- @since 1.0.0.0
testDejafu :: Show b
=> String
-- ^ The name of the test
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testDejafu = testDejafuWay defaultWay defaultMemType
@ -157,9 +157,9 @@ testDejafuWay :: Show b
-> String
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testDejafuWay = testDejafuDiscard (const Nothing)
@ -176,9 +176,9 @@ testDejafuDiscard :: Show b
-> String
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testDejafuDiscard discard way memtype name test =
testconc discard way memtype [(name, test)]
@ -190,9 +190,9 @@ testDejafuDiscard discard way memtype name test =
-- @since 1.0.0.0
testDejafus :: Show b
=> [(String, ProPredicate a b)]
-- ^ The list of predicates (with names) to check
-- ^ The list of predicates (with names) to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testDejafus = testDejafusWay defaultWay defaultMemType
@ -206,9 +206,9 @@ testDejafusWay :: Show b
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> [(String, ProPredicate a b)]
-- ^ The list of predicates (with names) to check
-- ^ The list of predicates (with names) to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> Test
testDejafusWay = testconc (const Nothing)

24
tasty-dejafu/Test/Tasty/DejaFu.hs
View File

@ -139,7 +139,7 @@ instance IsOption Way where
-- @since 1.0.0.0
testAuto :: (Eq a, Show a)
=> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testAuto = testAutoWay defaultWay defaultMemType
@ -153,7 +153,7 @@ testAutoWay :: (Eq a, Show a)
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testAutoWay way memtype = testDejafusWay way memtype autocheckCases
@ -172,9 +172,9 @@ testDejafu :: Show b
=> TestName
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testDejafu = testDejafuWay defaultWay defaultMemType
@ -190,9 +190,9 @@ testDejafuWay :: Show b
-> TestName
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testDejafuWay = testDejafuDiscard (const Nothing)
@ -209,9 +209,9 @@ testDejafuDiscard :: Show b
-> String
-- ^ The name of the test.
-> ProPredicate a b
-- ^ The predicate to check
-- ^ The predicate to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testDejafuDiscard discard way memtype name test =
testconc discard way memtype [(name, test)]
@ -223,9 +223,9 @@ testDejafuDiscard discard way memtype name test =
-- @since 1.0.0.0
testDejafus :: Show b
=> [(TestName, ProPredicate a b)]
-- ^ The list of predicates (with names) to check
-- ^ The list of predicates (with names) to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testDejafus = testDejafusWay defaultWay defaultMemType
@ -239,9 +239,9 @@ testDejafusWay :: Show b
-> MemType
-- ^ The memory model to use for non-synchronised @CRef@ operations.
-> [(TestName, ProPredicate a b)]
-- ^ The list of predicates (with names) to check
-- ^ The list of predicates (with names) to check.
-> Conc.ConcIO a
-- ^ The computation to test
-- ^ The computation to test.
-> TestTree
testDejafusWay = testconc (const Nothing)