Safe Haskell	None

Ganeti.WConfd.Monad

Contents

Monoid of the locations to flush the configuration to
Pure data types used in the monad
The monad and its instances
Basic functions in the monad

Description

All RPC calls are run within this monad.

It encapsulates:

IO operations, * failures, * working with the daemon state.

Code that is specific either to the configuration or the lock management, should go into their corresponding dedicated modules.

Synopsis

Monoid of the locations to flush the configuration to

data DistributionTarget Source

Data type describing where the configuration has to be distributed to.

Constructors

Everywhere
ToGroups (Set String)

Instances

Show DistributionTarget
Monoid DistributionTarget

Pure data types used in the monad

data DaemonState Source

Constructors

DaemonState
Fields dsConfigState :: ConfigState dsLockWaiting :: GanetiLockWaiting dsTempRes :: TempResState

dsTempResL :: Lens' DaemonState TempResState Source

dsLockWaitingL :: Lens' DaemonState GanetiLockWaiting Source

dsConfigStateL :: Lens' DaemonState ConfigState Source

data DaemonHandle Source

Constructors

DaemonHandle

Fields

dhDaemonState :: IORef DaemonState
dhConfigPath :: FilePath: The configuration file path all static information that doesn't change during the life-time of the daemon should go here; all IDs of threads that do asynchronous work should probably also go here
dhSaveConfigWorker :: AsyncWorker (Any, DistributionTarget) ()
dhSaveLocksWorker :: AsyncWorker () ()
dhSaveTempResWorker :: AsyncWorker () ()
dhLivelock :: Livelock

mkDaemonHandle Source

Arguments

:: FilePath
-> ConfigState
-> GanetiLockWaiting
-> TempResState
-> (IO ConfigState -> [AsyncWorker DistributionTarget ()] -> ResultG (AsyncWorker (Any, DistributionTarget) ()))	A function that creates a worker that asynchronously saves the configuration to the master file.
-> (IO ConfigState -> ResultG (AsyncWorker DistributionTarget ()))	A function that creates a worker that asynchronously distributes the configuration to master candidates
-> (IO ConfigState -> ResultG (AsyncWorker DistributionTarget ()))	A function that creates a worker that asynchronously distributes SSConf to nodes
-> (IO GanetiLockWaiting -> ResultG (AsyncWorker () ()))	A function that creates a worker that asynchronously saves the lock allocation state.
-> (IO TempResState -> ResultG (AsyncWorker () ()))	A function that creates a worker that asynchronously saves the temporary reservations state.
-> Livelock
-> ResultG DaemonHandle

The monad and its instances

type WConfdMonadIntType = ReaderT DaemonHandle IOSource

newtype WConfdMonadInt a Source

The internal part of the monad without error handling.

Constructors

WConfdMonadInt
Fields getWConfdMonadInt :: WConfdMonadIntType a

Instances

Monad WConfdMonadInt
Functor WConfdMonadInt
Applicative WConfdMonadInt
MonadIO WConfdMonadInt
MonadLog WConfdMonadInt
MonadBase IO WConfdMonadInt
MonadBaseControl IO WConfdMonadInt

runWConfdMonadInt :: WConfdMonadInt a -> DaemonHandle -> IO aSource

Runs the internal part of the WConfdMonad monad on a given daemon handle.

type WConfdMonad = ResultT GanetiException WConfdMonadInt Source

The complete monad with error handling.

type AtomicModifyMonad a = ResultT GanetiException WriterLog aSource

Basic functions in the monad

daemonHandle :: WConfdMonad DaemonHandle Source

Returns the daemon handle.

readConfigState :: WConfdMonad ConfigState Source

Returns the current configuration, given a handle

unpackConfigResult :: ClockTime -> ConfigState -> (a, ConfigState) -> ((a, Bool, Bool), ConfigState)Source

modifyConfigStateErrWithImmediate :: (TempResState -> ConfigState -> AtomicModifyMonad (a, ConfigState)) -> WConfdMonad () -> WConfdMonad aSource

modifyConfigStateErr :: (TempResState -> ConfigState -> AtomicModifyMonad (a, ConfigState)) -> WConfdMonad aSource

modifyConfigStateErr_ :: (TempResState -> ConfigState -> AtomicModifyMonad ConfigState) -> WConfdMonad ()Source

modifyConfigState :: (ConfigState -> (a, ConfigState)) -> WConfdMonad aSource

Atomically modifies the configuration state in the WConfdMonad.

modifyConfigStateWithImmediate :: (ConfigState -> (a, ConfigState)) -> WConfdMonad () -> WConfdMonad aSource

Atomically modifies the configuration state in WConfdMonad; immediately afterwards (while the config write-out is not necessarily finished) do another acation.

forceConfigStateDistribution :: DistributionTarget -> WConfdMonad ()Source

Force the distribution of configuration without actually modifying it.

We need a separate call for this operation, because modifyConfigState only triggers the distribution when the configuration changes.

modifyConfigDataErr_ :: (TempResState -> ConfigData -> AtomicModifyMonad ConfigData) -> WConfdMonad ()Source

Atomically modifies the configuration data in the WConfdMonad with a computation that can possibly fail.

modifyTempResStateErr :: (ConfigData -> StateT TempResState ErrorResult a) -> WConfdMonad aSource

Atomically modifies the state of temporary reservations in WConfdMonad in the presence of possible errors.

modifyTempResState :: (ConfigData -> State TempResState a) -> WConfdMonad aSource

Atomically modifies the state of temporary reservations in WConfdMonad.

readTempResState :: WConfdMonad (ConfigData, TempResState)Source

Reads the state of of the configuration and temporary reservations in WConfdMonad.

modifyLockWaiting :: (GanetiLockWaiting -> (GanetiLockWaiting, (a, Set ClientId))) -> WConfdMonad aSource

Atomically modifies the lock waiting state in WConfdMonad.

modifyLockWaiting_ :: (GanetiLockWaiting -> (GanetiLockWaiting, Set ClientId)) -> WConfdMonad ()Source

Atomically modifies the lock allocation state in WConfdMonad, not producing any result

readLockWaiting :: WConfdMonad GanetiLockWaiting Source

Read the lock waiting state in WConfdMonad.

readLockAllocation :: WConfdMonad (LockAllocation GanetiLocks ClientId)Source

Read the underlying lock allocation.

modifyConfigAndReturnWithLock :: (TempResState -> ConfigState -> AtomicModifyMonad (a, ConfigState)) -> State TempResState () -> WConfdMonad (Maybe a)Source

Modify the configuration while temporarily acquiring the configuration lock. If the configuration lock is held by someone else, nothing is changed and Nothing is returned.

modifyConfigWithLock :: (TempResState -> ConfigState -> AtomicModifyMonad ConfigState) -> State TempResState () -> WConfdMonad (Maybe ())Source