diff --git a/distributed-process-platform.cabal b/distributed-process-platform.cabal index 5fa90fe..ee1261c 100644 --- a/distributed-process-platform.cabal +++ b/distributed-process-platform.cabal @@ -70,6 +70,7 @@ library Control.Distributed.Process.Platform.Service.Registry, Control.Distributed.Process.Platform.Service.SystemLog, Control.Distributed.Process.Platform.Supervisor, + Control.Distributed.Process.Platform.Supervisor.Types, Control.Distributed.Process.Platform.Task.Queue.BlockingQueue, Control.Distributed.Process.Platform.Test, Control.Distributed.Process.Platform.Time, diff --git a/src/Control/Distributed/Process/Platform/Supervisor.hs b/src/Control/Distributed/Process/Platform/Supervisor.hs index b501c0b..1abac2c 100644 --- a/src/Control/Distributed/Process/Platform/Supervisor.hs +++ b/src/Control/Distributed/Process/Platform/Supervisor.hs @@ -270,6 +270,8 @@ module Control.Distributed.Process.Platform.Supervisor ) where import Control.DeepSeq (NFData) + +import Control.Distributed.Process.Platform.Supervisor.Types import Control.Distributed.Process hiding (call) import Control.Distributed.Process.Serializable() import Control.Distributed.Process.Platform.Internal.Primitives hiding (monitor) @@ -333,7 +335,7 @@ import Control.Distributed.Process.Platform.Service.SystemLog ) import qualified Control.Distributed.Process.Platform.Service.SystemLog as Log import Control.Distributed.Process.Platform.Time -import Control.Exception (SomeException, Exception, throwIO) +import Control.Exception (SomeException, throwIO) import Control.Monad.Error @@ -380,278 +382,8 @@ import GHC.Generics -- Types -- -------------------------------------------------------------------------------- --- external client/configuration API - -newtype MaxRestarts = MaxR { maxNumberOfRestarts :: Int } - deriving (Typeable, Generic, Show) -instance Binary MaxRestarts where -instance NFData MaxRestarts where - --- | Smart constructor for @MaxRestarts@. The maximum --- restart count must be a positive integer. -maxRestarts :: Int -> MaxRestarts -maxRestarts r | r >= 0 = MaxR r - | otherwise = error "MaxR must be >= 0" - --- | A compulsary limit on the number of restarts that a supervisor will --- tolerate before it terminates all child processes and then itself. --- If > @MaxRestarts@ occur within the specified @TimeInterval@, termination --- will occur. This prevents the supervisor from entering an infinite loop of --- child process terminations and restarts. --- -data RestartLimit = - RestartLimit - { maxR :: !MaxRestarts - , maxT :: !TimeInterval - } - deriving (Typeable, Generic, Show) -instance Binary RestartLimit where -instance NFData RestartLimit where - -limit :: MaxRestarts -> TimeInterval -> RestartLimit -limit mr ti = RestartLimit mr ti - -defaultLimits :: RestartLimit -defaultLimits = limit (MaxR 1) (seconds 1) - -data RestartOrder = LeftToRight | RightToLeft - deriving (Typeable, Generic, Eq, Show) -instance Binary RestartOrder where -instance NFData RestartOrder where - --- TODO: rename these, somehow... -data RestartMode = - RestartEach { order :: !RestartOrder } - {- ^ stop then start each child sequentially, i.e., @foldlM stopThenStart children@ -} - | RestartInOrder { order :: !RestartOrder } - {- ^ stop all children first, then restart them sequentially -} - | RestartRevOrder { order :: !RestartOrder } - {- ^ stop all children in the given order, but start them in reverse -} - deriving (Typeable, Generic, Show, Eq) -instance Binary RestartMode where -instance NFData RestartMode where - -data ShutdownMode = SequentialShutdown !RestartOrder - | ParallelShutdown - deriving (Typeable, Generic, Show, Eq) -instance Binary ShutdownMode where -instance NFData ShutdownMode where - --- | Strategy used by a supervisor to handle child restarts, whether due to --- unexpected child failure or explicit restart requests from a client. --- --- Some terminology: We refer to child processes managed by the same supervisor --- as /siblings/. When restarting a child process, the 'RestartNone' policy --- indicates that sibling processes should be left alone, whilst the 'RestartAll' --- policy will cause /all/ children to be restarted (in the same order they were --- started). --- --- The other two restart strategies refer to /prior/ and /subsequent/ --- siblings, which describe's those children's configured position --- (i.e., insertion order). These latter modes allow one to control the order --- in which siblings are restarted, and to exclude some siblings from the restart --- without having to resort to grouping them using a child supervisor. --- -data RestartStrategy = - RestartOne - { intensity :: !RestartLimit - } -- ^ restart only the failed child process - | RestartAll - { intensity :: !RestartLimit - , mode :: !RestartMode - } -- ^ also restart all siblings - | RestartLeft - { intensity :: !RestartLimit - , mode :: !RestartMode - } -- ^ restart prior siblings (i.e., prior /start order/) - | RestartRight - { intensity :: !RestartLimit - , mode :: !RestartMode - } -- ^ restart subsequent siblings (i.e., subsequent /start order/) - deriving (Typeable, Generic, Show) -instance Binary RestartStrategy where -instance NFData RestartStrategy where - --- | Provides a default 'RestartStrategy' for @RestartOne@. --- > restartOne = RestartOne defaultLimits --- -restartOne :: RestartStrategy -restartOne = RestartOne defaultLimits - --- | Provides a default 'RestartStrategy' for @RestartAll@. --- > restartOne = RestartAll defaultLimits (RestartEach LeftToRight) --- -restartAll :: RestartStrategy -restartAll = RestartAll defaultLimits (RestartEach LeftToRight) - --- | Provides a default 'RestartStrategy' for @RestartLeft@. --- > restartOne = RestartLeft defaultLimits (RestartEach LeftToRight) --- -restartLeft :: RestartStrategy -restartLeft = RestartLeft defaultLimits (RestartEach LeftToRight) - --- | Provides a default 'RestartStrategy' for @RestartRight@. --- > restartOne = RestartRight defaultLimits (RestartEach LeftToRight) --- -restartRight :: RestartStrategy -restartRight = RestartRight defaultLimits (RestartEach LeftToRight) - --- | Identifies a child process by name. -type ChildKey = String - --- | A reference to a (possibly running) child. -data ChildRef = - ChildRunning !ProcessId -- ^ a reference to the (currently running) child - | ChildRunningExtra !ProcessId !Message -- ^ also a currently running child, with /extra/ child info - | ChildRestarting !ProcessId -- ^ a reference to the /old/ (previous) child (now restarting) - | ChildStopped -- ^ indicates the child is not currently running - | ChildStartIgnored -- ^ a non-temporary child exited with 'ChildInitIgnore' - deriving (Typeable, Generic, Show) -instance Binary ChildRef where -instance NFData ChildRef where - -instance Eq ChildRef where - ChildRunning p1 == ChildRunning p2 = p1 == p2 - ChildRunningExtra p1 _ == ChildRunningExtra p2 _ = p1 == p2 - ChildRestarting p1 == ChildRestarting p2 = p1 == p2 - ChildStopped == ChildStopped = True - ChildStartIgnored == ChildStartIgnored = True - _ == _ = False - -isRunning :: ChildRef -> Bool -isRunning (ChildRunning _) = True -isRunning (ChildRunningExtra _ _) = True -isRunning _ = False - -isRestarting :: ChildRef -> Bool -isRestarting (ChildRestarting _) = True -isRestarting _ = False - -instance Resolvable ChildRef where - resolve (ChildRunning pid) = return $ Just pid - resolve (ChildRunningExtra pid _) = return $ Just pid - resolve _ = return Nothing - --- these look a bit odd, but we basically want to avoid resolving --- or sending to (ChildRestarting oldPid) -instance Routable ChildRef where - sendTo (ChildRunning addr) = sendTo addr - sendTo _ = error "invalid address for child process" - - unsafeSendTo (ChildRunning ch) = unsafeSendTo ch - unsafeSendTo _ = error "invalid address for child process" - --- | Specifies whether the child is another supervisor, or a worker. -data ChildType = Worker | Supervisor - deriving (Typeable, Generic, Show, Eq) -instance Binary ChildType where -instance NFData ChildType where - --- | Describes when a terminated child process should be restarted. -data RestartPolicy = - Permanent -- ^ a permanent child will always be restarted - | Temporary -- ^ a temporary child will /never/ be restarted - | Transient -- ^ A transient child will be restarted only if it terminates abnormally - | Intrinsic -- ^ as 'Transient', but if the child exits normally, the supervisor also exits normally - deriving (Typeable, Generic, Eq, Show) -instance Binary RestartPolicy where -instance NFData RestartPolicy where - -{- -data ChildRestart = - Restart RestartPolicy -- ^ restart according to the given policy - | DelayedRestart RestartPolicy TimeInterval -- ^ perform a /delayed restart/ - deriving (Typeable, Generic, Eq, Show) -instance Binary ChildRestart where --} - -data ChildTerminationPolicy = - TerminateTimeout !Delay - | TerminateImmediately - deriving (Typeable, Generic, Eq, Show) -instance Binary ChildTerminationPolicy where -instance NFData ChildTerminationPolicy where - -data RegisteredName = - LocalName !String - | GlobalName !String - | CustomRegister !(Closure (ProcessId -> Process ())) - deriving (Typeable, Generic) -instance Binary RegisteredName where -instance NFData RegisteredName where - -instance Show RegisteredName where - show (CustomRegister _) = "Custom Register" - show (LocalName n) = n - show (GlobalName n) = "global::" ++ n - -data ChildStart = - RunClosure !(Closure (Process ())) - | CreateHandle !(Closure (SupervisorPid -> Process (ProcessId, Message))) - | StarterProcess !ProcessId - deriving (Typeable, Generic, Show) -instance Binary ChildStart where -instance NFData ChildStart where - --- | Specification for a child process. The child must be uniquely identified --- by it's @childKey@ within the supervisor. The supervisor will start the child --- itself, therefore @childRun@ should contain the child process' implementation --- e.g., if the child is a long running server, this would be the server /loop/, --- as with e.g., @ManagedProces.start@. -data ChildSpec = ChildSpec { - childKey :: !ChildKey - , childType :: !ChildType - , childRestart :: !RestartPolicy - , childStop :: !ChildTerminationPolicy - , childStart :: !ChildStart - , childRegName :: !(Maybe RegisteredName) - } deriving (Typeable, Generic, Show) -instance Binary ChildSpec where -instance NFData ChildSpec where - -data ChildInitFailure = - ChildInitFailure !String - | ChildInitIgnore - deriving (Typeable, Generic, Show) -instance Exception ChildInitFailure where - -data SupervisorStats = SupervisorStats { - _children :: Int - , _supervisors :: Int - , _workers :: Int - , _running :: Int - , _activeSupervisors :: Int - , _activeWorkers :: Int - -- TODO: usage/restart/freq stats - , totalRestarts :: Int - } deriving (Typeable, Generic, Show) -instance Binary SupervisorStats where -instance NFData SupervisorStats where - --- | Static labels (in the remote table) are strings. -type StaticLabel = String - --- | Provides failure information when (re-)start failure is indicated. -data StartFailure = - StartFailureDuplicateChild !ChildRef -- ^ a child with this 'ChildKey' already exists - | StartFailureAlreadyRunning !ChildRef -- ^ the child is already up and running - | StartFailureBadClosure !StaticLabel -- ^ a closure cannot be resolved - | StartFailureDied !DiedReason -- ^ a child died (almost) immediately on starting - deriving (Typeable, Generic, Show, Eq) -instance Binary StartFailure where -instance NFData StartFailure where - --- | The result of a call to 'removeChild'. -data DeleteChildResult = - ChildDeleted -- ^ the child specification was successfully removed - | ChildNotFound -- ^ the child specification was not found - | ChildNotStopped !ChildRef -- ^ the child was not removed, as it was not stopped. - deriving (Typeable, Generic, Show, Eq) -instance Binary DeleteChildResult where -instance NFData DeleteChildResult where - -type Child = (ChildRef, ChildSpec) -type SupervisorPid = ProcessId +-- TODO: ToChildStart belongs with rest of types in +-- Control.Distributed.Process.Platform.Supervisor.Types -- | A type that can be converted to a 'ChildStart'. class ToChildStart a where @@ -725,7 +457,8 @@ injectIt proc' supervisor sendPidPort = do expectTriple :: Process (ProcessId, ChildKey, SendPort ProcessId) expectTriple = expect --- internal APIs +-- internal APIs. The corresponding XxxResult types are in +-- Control.Distributed.Process.Platform.Supervisor.Types data DeleteChild = DeleteChild !ChildKey deriving (Typeable, Generic) @@ -756,27 +489,11 @@ instance NFData AddChildReq where data AddChildRes = Exists ChildRef | Added State -data AddChildResult = - ChildAdded !ChildRef - | ChildFailedToStart !StartFailure - deriving (Typeable, Generic, Show, Eq) -instance Binary AddChildResult where -instance NFData AddChildResult where - data StartChildReq = StartChild !ChildKey deriving (Typeable, Generic) instance Binary StartChildReq where instance NFData StartChildReq where -data StartChildResult = - ChildStartOk !ChildRef - | ChildStartFailed !StartFailure - | ChildStartUnknownId - | ChildStartInitIgnored - deriving (Typeable, Generic, Show, Eq) -instance Binary StartChildResult where -instance NFData StartChildResult where - data RestartChildReq = RestartChildReq !ChildKey deriving (Typeable, Generic, Show, Eq) instance Binary RestartChildReq where @@ -788,28 +505,11 @@ data DelayedRestartReq = DelayedRestartReq !ChildKey !DiedReason instance Binary DelayedRestartReq where -} -data RestartChildResult = - ChildRestartOk !ChildRef - | ChildRestartFailed !StartFailure - | ChildRestartUnknownId - | ChildRestartIgnored - deriving (Typeable, Generic, Show, Eq) - -instance Binary RestartChildResult where -instance NFData RestartChildResult where - data TerminateChildReq = TerminateChildReq !ChildKey deriving (Typeable, Generic, Show, Eq) instance Binary TerminateChildReq where instance NFData TerminateChildReq where -data TerminateChildResult = - TerminateChildOk - | TerminateChildUnknownId - deriving (Typeable, Generic, Show, Eq) -instance Binary TerminateChildResult where -instance NFData TerminateChildResult where - data IgnoreChildReq = IgnoreChildReq !ProcessId deriving (Typeable, Generic) instance Binary IgnoreChildReq where diff --git a/src/Control/Distributed/Process/Platform/Supervisor/Types.hs b/src/Control/Distributed/Process/Platform/Supervisor/Types.hs new file mode 100644 index 0000000..f0c10f1 --- /dev/null +++ b/src/Control/Distributed/Process/Platform/Supervisor/Types.hs @@ -0,0 +1,365 @@ +{-# LANGUAGE DeriveGeneric #-} +{-# LANGUAGE DeriveDataTypeable #-} +----------------------------------------------------------------------------- +-- | +-- Module : Control.Distributed.Process.Platform.Supervisor.Types +-- Copyright : (c) Tim Watson 2012 +-- License : BSD3 (see the file LICENSE) +-- +-- Maintainer : Tim Watson +-- Stability : experimental +-- Portability : non-portable (requires concurrency) +-- +----------------------------------------------------------------------------- + +module Control.Distributed.Process.Platform.Supervisor.Types + ( -- * Defining and Running a Supervisor + ChildSpec(..) + , ChildKey + , ChildType(..) + , ChildTerminationPolicy(..) + , ChildStart(..) + , RegisteredName(LocalName, GlobalName, CustomRegister) + , RestartPolicy(..) + , ChildRef(..) + , isRunning + , isRestarting + , Child + , StaticLabel + , SupervisorPid + -- * Limits and Defaults + , MaxRestarts(..) + , maxRestarts + , RestartLimit(..) + , limit + , defaultLimits + , RestartMode(..) + , RestartOrder(..) + , RestartStrategy(..) + , ShutdownMode(..) + , restartOne + , restartAll + , restartLeft + , restartRight + -- * Adding and Removing Children + , AddChildResult(..) + , StartChildResult(..) + , TerminateChildResult(..) + , DeleteChildResult(..) + , RestartChildResult(..) + -- * Additional (Misc) Types + , SupervisorStats(..) + , StartFailure(..) + , ChildInitFailure(..) + ) where + +import GHC.Generics +import Data.Typeable (Typeable) +import Data.Binary + +import Control.DeepSeq (NFData) +import Control.Distributed.Process hiding (call) +import Control.Distributed.Process.Serializable() +import Control.Distributed.Process.Platform.Time +import Control.Distributed.Process.Platform.Internal.Primitives hiding (monitor) +import Control.Exception (Exception) + + +newtype MaxRestarts = MaxR { maxNumberOfRestarts :: Int } + deriving (Typeable, Generic, Show) +instance Binary MaxRestarts where +instance NFData MaxRestarts where + +-- | Smart constructor for @MaxRestarts@. The maximum +-- restart count must be a positive integer. +maxRestarts :: Int -> MaxRestarts +maxRestarts r | r >= 0 = MaxR r + | otherwise = error "MaxR must be >= 0" + +-- | A compulsary limit on the number of restarts that a supervisor will +-- tolerate before it terminates all child processes and then itself. +-- If > @MaxRestarts@ occur within the specified @TimeInterval@, termination +-- will occur. This prevents the supervisor from entering an infinite loop of +-- child process terminations and restarts. +-- +data RestartLimit = + RestartLimit + { maxR :: !MaxRestarts + , maxT :: !TimeInterval + } + deriving (Typeable, Generic, Show) +instance Binary RestartLimit where +instance NFData RestartLimit where + +limit :: MaxRestarts -> TimeInterval -> RestartLimit +limit mr = RestartLimit mr + +defaultLimits :: RestartLimit +defaultLimits = limit (MaxR 1) (seconds 1) + +data RestartOrder = LeftToRight | RightToLeft + deriving (Typeable, Generic, Eq, Show) +instance Binary RestartOrder where +instance NFData RestartOrder where + +-- TODO: rename these, somehow... +data RestartMode = + RestartEach { order :: !RestartOrder } + {- ^ stop then start each child sequentially, i.e., @foldlM stopThenStart children@ -} + | RestartInOrder { order :: !RestartOrder } + {- ^ stop all children first, then restart them sequentially -} + | RestartRevOrder { order :: !RestartOrder } + {- ^ stop all children in the given order, but start them in reverse -} + deriving (Typeable, Generic, Show, Eq) +instance Binary RestartMode where +instance NFData RestartMode where + +data ShutdownMode = SequentialShutdown !RestartOrder + | ParallelShutdown + deriving (Typeable, Generic, Show, Eq) +instance Binary ShutdownMode where +instance NFData ShutdownMode where + +-- | Strategy used by a supervisor to handle child restarts, whether due to +-- unexpected child failure or explicit restart requests from a client. +-- +-- Some terminology: We refer to child processes managed by the same supervisor +-- as /siblings/. When restarting a child process, the 'RestartNone' policy +-- indicates that sibling processes should be left alone, whilst the 'RestartAll' +-- policy will cause /all/ children to be restarted (in the same order they were +-- started). +-- +-- The other two restart strategies refer to /prior/ and /subsequent/ +-- siblings, which describe's those children's configured position +-- (i.e., insertion order). These latter modes allow one to control the order +-- in which siblings are restarted, and to exclude some siblings from the restart +-- without having to resort to grouping them using a child supervisor. +-- +data RestartStrategy = + RestartOne + { intensity :: !RestartLimit + } -- ^ restart only the failed child process + | RestartAll + { intensity :: !RestartLimit + , mode :: !RestartMode + } -- ^ also restart all siblings + | RestartLeft + { intensity :: !RestartLimit + , mode :: !RestartMode + } -- ^ restart prior siblings (i.e., prior /start order/) + | RestartRight + { intensity :: !RestartLimit + , mode :: !RestartMode + } -- ^ restart subsequent siblings (i.e., subsequent /start order/) + deriving (Typeable, Generic, Show) +instance Binary RestartStrategy where +instance NFData RestartStrategy where + +-- | Provides a default 'RestartStrategy' for @RestartOne@. +-- > restartOne = RestartOne defaultLimits +-- +restartOne :: RestartStrategy +restartOne = RestartOne defaultLimits + +-- | Provides a default 'RestartStrategy' for @RestartAll@. +-- > restartOne = RestartAll defaultLimits (RestartEach LeftToRight) +-- +restartAll :: RestartStrategy +restartAll = RestartAll defaultLimits (RestartEach LeftToRight) + +-- | Provides a default 'RestartStrategy' for @RestartLeft@. +-- > restartOne = RestartLeft defaultLimits (RestartEach LeftToRight) +-- +restartLeft :: RestartStrategy +restartLeft = RestartLeft defaultLimits (RestartEach LeftToRight) + +-- | Provides a default 'RestartStrategy' for @RestartRight@. +-- > restartOne = RestartRight defaultLimits (RestartEach LeftToRight) +-- +restartRight :: RestartStrategy +restartRight = RestartRight defaultLimits (RestartEach LeftToRight) + +-- | Identifies a child process by name. +type ChildKey = String + +-- | A reference to a (possibly running) child. +data ChildRef = + ChildRunning !ProcessId -- ^ a reference to the (currently running) child + | ChildRunningExtra !ProcessId !Message -- ^ also a currently running child, with /extra/ child info + | ChildRestarting !ProcessId -- ^ a reference to the /old/ (previous) child (now restarting) + | ChildStopped -- ^ indicates the child is not currently running + | ChildStartIgnored -- ^ a non-temporary child exited with 'ChildInitIgnore' + deriving (Typeable, Generic, Show) +instance Binary ChildRef where +instance NFData ChildRef where + +instance Eq ChildRef where + ChildRunning p1 == ChildRunning p2 = p1 == p2 + ChildRunningExtra p1 _ == ChildRunningExtra p2 _ = p1 == p2 + ChildRestarting p1 == ChildRestarting p2 = p1 == p2 + ChildStopped == ChildStopped = True + ChildStartIgnored == ChildStartIgnored = True + _ == _ = False + +isRunning :: ChildRef -> Bool +isRunning (ChildRunning _) = True +isRunning (ChildRunningExtra _ _) = True +isRunning _ = False + +isRestarting :: ChildRef -> Bool +isRestarting (ChildRestarting _) = True +isRestarting _ = False + +instance Resolvable ChildRef where + resolve (ChildRunning pid) = return $ Just pid + resolve (ChildRunningExtra pid _) = return $ Just pid + resolve _ = return Nothing + +-- these look a bit odd, but we basically want to avoid resolving +-- or sending to (ChildRestarting oldPid) +instance Routable ChildRef where + sendTo (ChildRunning addr) = sendTo addr + sendTo _ = error "invalid address for child process" + + unsafeSendTo (ChildRunning ch) = unsafeSendTo ch + unsafeSendTo _ = error "invalid address for child process" + +-- | Specifies whether the child is another supervisor, or a worker. +data ChildType = Worker | Supervisor + deriving (Typeable, Generic, Show, Eq) +instance Binary ChildType where +instance NFData ChildType where + +-- | Describes when a terminated child process should be restarted. +data RestartPolicy = + Permanent -- ^ a permanent child will always be restarted + | Temporary -- ^ a temporary child will /never/ be restarted + | Transient -- ^ A transient child will be restarted only if it terminates abnormally + | Intrinsic -- ^ as 'Transient', but if the child exits normally, the supervisor also exits normally + deriving (Typeable, Generic, Eq, Show) +instance Binary RestartPolicy where +instance NFData RestartPolicy where + +data ChildTerminationPolicy = + TerminateTimeout !Delay + | TerminateImmediately + deriving (Typeable, Generic, Eq, Show) +instance Binary ChildTerminationPolicy where +instance NFData ChildTerminationPolicy where + +data RegisteredName = + LocalName !String + | GlobalName !String + | CustomRegister !(Closure (ProcessId -> Process ())) + deriving (Typeable, Generic) +instance Binary RegisteredName where +instance NFData RegisteredName where + +instance Show RegisteredName where + show (CustomRegister _) = "Custom Register" + show (LocalName n) = n + show (GlobalName n) = "global::" ++ n + +data ChildStart = + RunClosure !(Closure (Process ())) + | CreateHandle !(Closure (SupervisorPid -> Process (ProcessId, Message))) + | StarterProcess !ProcessId + deriving (Typeable, Generic, Show) +instance Binary ChildStart where +instance NFData ChildStart where + +-- | Specification for a child process. The child must be uniquely identified +-- by it's @childKey@ within the supervisor. The supervisor will start the child +-- itself, therefore @childRun@ should contain the child process' implementation +-- e.g., if the child is a long running server, this would be the server /loop/, +-- as with e.g., @ManagedProces.start@. +data ChildSpec = ChildSpec { + childKey :: !ChildKey + , childType :: !ChildType + , childRestart :: !RestartPolicy + , childStop :: !ChildTerminationPolicy + , childStart :: !ChildStart + , childRegName :: !(Maybe RegisteredName) + } deriving (Typeable, Generic, Show) +instance Binary ChildSpec where +instance NFData ChildSpec where + + +data ChildInitFailure = + ChildInitFailure !String + | ChildInitIgnore + deriving (Typeable, Generic, Show) +instance Exception ChildInitFailure where + +data SupervisorStats = SupervisorStats { + _children :: Int + , _supervisors :: Int + , _workers :: Int + , _running :: Int + , _activeSupervisors :: Int + , _activeWorkers :: Int + -- TODO: usage/restart/freq stats + , totalRestarts :: Int + } deriving (Typeable, Generic, Show) +instance Binary SupervisorStats where +instance NFData SupervisorStats where + +-- | Static labels (in the remote table) are strings. +type StaticLabel = String + +-- | Provides failure information when (re-)start failure is indicated. +data StartFailure = + StartFailureDuplicateChild !ChildRef -- ^ a child with this 'ChildKey' already exists + | StartFailureAlreadyRunning !ChildRef -- ^ the child is already up and running + | StartFailureBadClosure !StaticLabel -- ^ a closure cannot be resolved + | StartFailureDied !DiedReason -- ^ a child died (almost) immediately on starting + deriving (Typeable, Generic, Show, Eq) +instance Binary StartFailure where +instance NFData StartFailure where + +-- | The result of a call to 'removeChild'. +data DeleteChildResult = + ChildDeleted -- ^ the child specification was successfully removed + | ChildNotFound -- ^ the child specification was not found + | ChildNotStopped !ChildRef -- ^ the child was not removed, as it was not stopped. + deriving (Typeable, Generic, Show, Eq) +instance Binary DeleteChildResult where +instance NFData DeleteChildResult where + +type Child = (ChildRef, ChildSpec) +type SupervisorPid = ProcessId + +-- exported result types of internal APIs + +data AddChildResult = + ChildAdded !ChildRef + | ChildFailedToStart !StartFailure + deriving (Typeable, Generic, Show, Eq) +instance Binary AddChildResult where +instance NFData AddChildResult where + +data StartChildResult = + ChildStartOk !ChildRef + | ChildStartFailed !StartFailure + | ChildStartUnknownId + | ChildStartInitIgnored + deriving (Typeable, Generic, Show, Eq) +instance Binary StartChildResult where +instance NFData StartChildResult where + +data RestartChildResult = + ChildRestartOk !ChildRef + | ChildRestartFailed !StartFailure + | ChildRestartUnknownId + | ChildRestartIgnored + deriving (Typeable, Generic, Show, Eq) + +instance Binary RestartChildResult where +instance NFData RestartChildResult where + +data TerminateChildResult = + TerminateChildOk + | TerminateChildUnknownId + deriving (Typeable, Generic, Show, Eq) +instance Binary TerminateChildResult where +instance NFData TerminateChildResult where