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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. + diff --git a/Parry.cabal b/Parry.cabal new file mode 100644 --- /dev/null +++ b/Parry.cabal @@ -0,0 +1,33 @@ +name: Parry +version: 0.1.0.0 +synopsis: A proven synchronization server for high performance computing. + +category: Parry +description: Parry is a scheduler for the exhaustive exploration of tree-like spaces. It is designed to be robust to client crashes and cluster walltimes, and is guaranteed to never \"forget about\" a job until it is done. + + +homepage: http://parry.lif.univ-mrs.fr +license: GPL-3 +license-file: LICENSE +author: Pierre-Etienne Meunier +maintainer: pierre-etienne.meunier@lif.univ-mrs.fr + +build-type: Simple + +cabal-version: >=1.10 + +library + exposed-modules: Parry.Server, Parry.Client, Parry.Protocol,Parry.WebUI + other-modules: Parry.Util + -- other-extensions: + if !os(windows) + build-depends: base>=4.6 && <5,random,binary,time,bytestring>=0.10,RSA,network,directory,process,containers,SafeSemaphore,old-locale,ghc-prim,unix + else + build-depends: base>=4.6 && <5,random,binary,time,bytestring>=0.10,RSA,network,directory,process,containers,SafeSemaphore,old-locale,ghc-prim + -- hs-source-dirs: + default-language: Haskell2010 + + if !os(windows) + cpp-options: "-DUNIX" + else + cpp-options: "" diff --git a/Parry/Client.lhs b/Parry/Client.lhs new file mode 100644 --- /dev/null +++ b/Parry/Client.lhs @@ -0,0 +1,372 @@ +\ignore{ +\begin{code} +{-#OPTIONS -cpp #-} +{-| +Module : Parry.Client +Copyright : (c) Pierre-Étienne Meunier 2014 +License : GPL-3 +Maintainer : pierre-etienne.meunier@lif.univ-mrs.fr +Stability : experimental +Portability : All + +Tool to build clients for Parry. +-} +\end{code} +} + +We now prove the client functions. More precisely, we prove that the clients +that can be built using the functions in this module are valid and fluent, +provided that their ``worker'' function explores the space correctly. We include +the whole source code of this module for the sake of completeness. + +\hfill + +\begin{code} +module Parry.Client( + -- * Jobs on the client side + Client(..), + -- * Writing clients + client,Config(..),defaultConfig + ) where +import Network +import System.IO +import System.Exit +#ifdef UNIX +import System.Posix.Signals +#endif +import Control.Concurrent +import Control.Exception as E +import Data.List +import Codec.Crypto.RSA.Pure +import qualified Data.ByteString.Lazy.Char8 as B8 +import qualified Data.ByteString.Char8 as S +import Data.Binary +import Parry.Util +import Parry.Protocol + + +-- | For a job to be usable by Parry's clients, it must be a member of this class. +class Client j where + -- | This function is used by the client to distinguish results from regular jobs. + isResult::j->Bool +\end{code} +\ignore{ +\begin{code} +-- | Client configuration +data Config=Config { + -- | The server's host name (either a DNS name or an IP address). + server::String, + -- | The port number (for instance @'Network.PortNumber' 5129@). + port::PortID, + -- | The private key to sign messages. + privateKey::PrivateKey, + -- | The public key, that the server must know of before the clients connect. + publicKey::PublicKey + } + +-- | A default configuration, matching the server's +-- 'Parry.Server.defaultConfig'. Note that, like in the server, you +-- must provide your own private key for signing the protocol +-- messages. See 'Parry.Server.defaultConfig' for an example method to +-- generate these keys. +defaultConfig::PrivateKey->PublicKey->Config +defaultConfig pr pu=Config { + server="127.0.0.1", + port=PortNumber 5129, + privateKey=pr, + publicKey=pu + } +\end{code} +} +\begin{lemma} +\label{lem:signAndSend} +The {\tt signAndSend\_} and {\tt signAndSend} functions send only one kind of +messages on the network, with two lines: the first line is an encoding +via {\tt encode16l} of $m$, the encoding via {\tt encode} of a constructor +of the {\tt ClientMessage} type. +The second line is the RSA signature of $m$ using the private key in the +{\tt conf} argument. +\begin{proof} + +The results follows from the fact that this function uses only two lines to send +messages on the network, and these two lines have the claimed form. + +\hfill + +\begin{code} +-- | A wrapper around signAndSend, to force the type of @j@, which is +-- needed for the protocol's @Alive@ messages. +signAndSend_::(Binary j)=>Config->j->ClientMessage j->IO (ServerMessage j) +signAndSend_ conf _ a=signAndSend conf a + +-- | Sign a message and send it. +signAndSend::(Binary j)=>Config->ClientMessage j->IO (ServerMessage j) +signAndSend conf m=do { + let { msg=encode m }; + case sign (privateKey conf) msg of { + Right b->E.catch (do { + l<-bracket (connectTo (server conf) (port conf)) (hClose) + (\h->do { + B8.hPutStrLn h $ encode16l msg; + B8.hPutStrLn h $ encode16l b; + hFlush h; + S.hGetLine h; + }); + case decodeOrFail $ decode16l $ B8.fromStrict l of { + Right (_,_,a)->return a; + Left _->do { + threadDelay 1000000; + signAndSend conf m + } + }}) + (\e->do { + let { _=e::IOError }; + print e; + threadDelay 1000000;signAndSend conf m + }); + er->do { + print er;hFlush stdout;threadDelay 100000;signAndSend conf m + } + }} +\end{code} + +\end{proof} +\end{lemma} + +To prove the remaining functions, we need to introduce the following invariant +on their arguments: +\begin{invariant} +\label{h} +When the {\tt cur} variable is not {\tt Nothing}, +the {\tt jobs} and {\tt results} variables contain, +respectively, the list of all jobs of the contents of {\tt cur} that have not +been completely explored, and the list of results found during the exploration +of all other subjobs of the job in {\tt cur}. +\end{invariant} + + +\begin{lemma} +\label{lem:dowork} +If there is a function {\tt doWork} such that, at the same time: +\begin{enumerate} +\item For all values of {\tt b}, {\tt save} and {\tt j}, {\tt doWork b save j} +only calls {\tt save} with arguments {\tt l} and {\tt r}, where {\tt r} is the +list of all results that have been found when the subjobs of {\tt j} that have +not been completely explored are all in list {\tt l}. + +\item For all values of {\tt b}, {\tt save} and {\tt j}, {\tt doWork b save +j} returns the list of all subjobs of {\tt j} that have not been explored, and +all results that have been found in {\tt j}, in the remaining subjobs of {\tt j}. + +\end{enumerate} +Then {\tt client conf doWork} is a valid and fluent client. +\begin{proof} + +We first prove fluency: in the two functions below ({\tt work} and {\tt +client}), the only messages sent to the network are either sent using {\tt +signAndSend}, or else consist of a single line containing exactly {\tt Hello}, +which is the definition of fluency (by Lemma \ref{lem:signAndSend}). + +We now prove that {\tt client conf doWork} is valid. Indeed, condition +\ref{valid:newjobs} of validity ({\tt NewJobs} messages contain all subjobs of +the current job) is clearly respected by the {\tt work} function: indeed, by the +definition of a result, the {\tt todo} variable in {\tt work} is the list of all +subjobs that have not been explored. Condition \ref{valid:jobdone} is also +respected, because it is not applicable to the {\tt work} function. + +Moreover, the {\tt work} function returns either {\tt Nothing}, or {\tt Just +(j,r)} where {\tt j} is a job, and {\tt r} is the list of all results found +during the exploration of {\tt j}. We prove this recursively on its code: + +\hfill +\begin{code} +work::(Client j,Binary j)=>Config->MVar [j]->MVar[j]->MVar (Maybe j)-> + (Bool->([j]->[j]->IO ())->j->IO [j])->Bool->Integer->j->IO (Maybe (j,[j])) +work conf jobs results cur doWork shared num j=do + let save jobs_ results_ jobs results=do + modifyMVar_ jobs_ $ \_->return jobs + modifyMVar_ results_ $ \_->return results + someWork<-doWork shared (save jobs results) j + let (result,todo)=partition isResult someWork + case todo of +\end{code} +\hfill + +Either {\tt doWork} has returned no new jobs, in which case the induction +hypothesis clearly holds, because the exploration of the current job is over. + +\hfill +\begin{code} + []->return (Just (j,result)) +\end{code} +\hfill + +Or {\tt doWork} returns some new jobs. In this case, {\tt work} is called on +{\tt u} only after reply {\tt Ack} has been received from the server, +acknowledging that the current job registered for this client has been updated. +Therefore, {\tt work} is called recursively on the current job of this client, +and hence, the claim also holds, by recursion. + +\hfill +\begin{code} + u:v->do + x<-signAndSend conf (NewJobs {clientId=num,jobResults=result, + currentJob=j,nextJob=u,newJobs=v }) + modifyMVar_ cur (\_->do { + modifyMVar_ results (\_->return []); + modifyMVar_ jobs (\_->return [u]); + return (Just u) + }) + case x of + Ack->work conf jobs results cur doWork (shared && (null v)) num u; + _->return Nothing +\end{code} +\hfill + +We will now prove validity for the code of the {\tt client} function. +We have assumed that the {\tt save} function above is only called on +a list {\tt l} of subjobs, and a list {\tt r} of results, such that +{\tt l} contains all subjobs of the initial job {\tt j} that have +not been completely explored when results {\tt r} are found. + +Therefore, in the {\tt work} function above, Invariant \ref{h} on +the {\tt jobs\_} and {\tt results\_} variables is clearly maintained: + +\hfill +\ignore{ +\begin{code} +-- | @'client' config work@ calls its argument function @work@ on a +-- boolean @s@ (if the server asked to share jobs) and the actual job +-- @j@ that must be done. @work@ must return a list of resulting jobs, +-- that may include results (see 'Parry.Protocol.Client'). +-- +-- Workers asked to share their input job should share it as early as +-- possible: this usually means that the job already got killed in a +-- previous attempt, probably because of its length. +\end{code} +} +\begin{code} +client::(Binary j,Client j)=> + Config->(Bool->([j]->[j]->IO())->j->IO [j])->IO () +client conf doWork= + let startConnection=do + hPutStrLn stderr "Connecting..." + hFlush stderr + l<-E.catch (bracket (connectTo (server conf) (port conf)) hClose + (\h->do { + B8.hPutStrLn h (B8.pack "Hello"); + hFlush h; + l<-S.hGetLine h; + case decodeOrFail (decode16l (B8.fromStrict l)) of { + Right x->return (Right x); + Left _->return (Left ()) + }})) + (\e->let _=e::IOError in do { hPutStrLn stderr $ show e; return (Left ()) }) + case l of + Right (_,_,num)->do + jobs<-newMVar [] + results<-newMVar [] + cur<-newMVar Nothing +\end{code} +\hfill + +At this point, {\tt cur} contains {\tt Nothing}: Invariant \ref{h} is clearly +maintained. + +Now remark that, when the {\tt saveAll} function below is called, and the {\tt +cur} variable contains {\tt Nothing}, no message is sent. Therefore, if +Invariant \ref{h} holds when {\tt saveAll} is called, the corresponding {\tt NewJobs} +message respects the validity condition. + +\hfill +\begin{code} + let saveAll=withMVar jobs $ \j-> + withMVar cur $ \curj-> + case (j,curj) of { + (h:s,Just cu)-> + withMVar results $ \res->do { + _<-signAndSend conf ( + NewJobs { clientId=num, + jobResults=res, + currentJob=cu, + nextJob=h, + newJobs=s + }); + return ()}; + _->return () + } + myth<-myThreadId + threads<-newMVar myth +#ifdef UNIX + installHandler sigTERM + (Catch (modifyMVar_ threads (\a->do {if a==myth then return () else + killThread a;return myth}))) Nothing +#endif + let getAJob=do + job_<-signAndSend conf (GetJob num (publicKey conf)); + case job_ of + Job share j->do + modifyMVar_ cur (\_->do { + modifyMVar_ jobs (\_->return [j]); + modifyMVar_ results (\_->return []); + return (Just j) + }); + workerMVar<-newEmptyMVar; +\end{code} +\hfill + +At this point, Invariant \ref{h} still holds: the only subjob of the current job +is itself, and no results have been found. + +\hfill +\begin{code} + workerThread<- + forkFinally + (do { + x<-work conf jobs results cur doWork share num j; + case x of { + Just (j',r)->do { + _<-signAndSend conf + (JobDone {clientId=num, + currentJob=j', + jobResults=r }); + return () }; + Nothing->return () + }}) + (\_->putMVar workerMVar ()) +\end{code} +\hfill + +Here, the validity condition holds for the {\tt JobDone} message: indeed, the +current job has been completely explored, and found exactly the results in {\tt +r}. + +\hfill +\begin{code} + let heartbeat=do + answer<-signAndSend_ conf j (Alive num) + case answer of + Ack->do { threadDelay 300000000; heartbeat } + _->do { saveAll; killThread workerThread } + heartbeatMVar<-newEmptyMVar + hbThread<-forkIO + (heartbeat`finally`(putMVar heartbeatMVar ())) + modifyMVar_ threads (\_->return workerThread) + takeMVar workerMVar + killThread hbThread + takeMVar heartbeatMVar + stop<-withMVar threads (\t->return (t==myth)) + if stop then do { saveAll; exitSuccess } else getAJob + Finished->return (); + _->do + threadDelay 10000000 + getAJob + getAJob + Left _->do + threadDelay 5000000 + startConnection + in + startConnection +\end{code} +\end{proof} +\end{lemma} diff --git a/Parry/Protocol.lhs b/Parry/Protocol.lhs new file mode 100644 --- /dev/null +++ b/Parry/Protocol.lhs @@ -0,0 +1,54 @@ +\ignore{ +\begin{code} +{-| +Module : Parry.Protocol +Copyright : (c) Pierre-Étienne Meunier 2014 +License : GPL-3 +Maintainer : pierre-etienne.meunier@lif.univ-mrs.fr +Stability : experimental +Portability : All + +This module contains all data types exchanged between the client +and the server, except for the initial \"@Hello@\" message, and is +mostly exposed for full disclosure of the protocol's proof. +-} +{-# LANGUAGE DeriveGeneric #-} +\end{code} +} + +The first module we need is {\tt Parry.Protocol}, that defines the type of +messages exchanged between the client and server. We assume, in the rest of the +proof, that the {\tt encode} and {\tt decode} functions generated by the {\tt +Binary} instances of these datatypes verify {\tt decode.encode} is the identity. + +\hfill + +\begin{code} +module Parry.Protocol where +import Data.Binary +import GHC.Generics (Generic) +import Codec.Crypto.RSA.Pure + +-- | The type of messages sent by the client, exposed here for full +-- disclosure of the protocol's proof. +data ClientMessage j= + GetJob Integer PublicKey + | JobDone { clientId::Integer, jobResults::[j], currentJob::j } + | NewJobs { clientId::Integer, jobResults::[j], currentJob::j, + nextJob::j, newJobs::[j] } + | Alive Integer + deriving (Generic, Show) + +-- | The type of messages sent by the server, exposed here for full +-- disclosure of the protocol's proof. +data ServerMessage j= + Job Bool j + | Finished + | Ack + | Die + deriving (Generic,Show) + +instance (Binary j)=>Binary (ClientMessage j) +instance (Binary j)=>Binary (ServerMessage j) +\end{code} +\vspace{1em} diff --git a/Parry/Server.lhs b/Parry/Server.lhs new file mode 100644 --- /dev/null +++ b/Parry/Server.lhs @@ -0,0 +1,595 @@ +\ignore{ +\begin{code} +{-#OPTIONS -cpp #-} +{-#LANGUAGE OverloadedStrings,MultiParamTypeClasses,DeriveGeneric,BangPatterns #-} +{-| +Module : Parry.Server +Copyright : (c) Pierre-Étienne Meunier 2014 +License : GPL-3 +Maintainer : pierre-etienne.meunier@lif.univ-mrs.fr +Stability : experimental +Portability : All + +Tools to build synchronization servers. For instance, to write a simple +server with just a web interface on port 8000, you would use: + +> import Control.Concurrent +> import Parry.Server +> import Parry.WebUI +> +> main::IO () +> main=do +> state<-initState initial +> _<-forkIO $ webUI 8000 state +> server (defaultConfig public) state +-} +\end{code} +} + +We now proceed to the proof of the server. The file is included for the sake of +completeness. In particular, remark that the whole state of the server is defined as +a single data type called {\tt State}. We will use this fact to prove +invariants on the whole server state. +\vspace{1em} + +\begin{code} +module Parry.Server ( + -- * Jobs on the server side + Exhaustive(..), + Result(..), + -- * Server's internal state + initState, + stateFromFile, + saveThread, + State(..), + -- * Server configuration and functions + Config(..),defaultConfig,server + ) where +import Control.Concurrent +import Control.Exception as E +import Control.Monad +import Control.Concurrent.MSem as Sem +import Network +import System.IO +import System.Directory +import Data.List +import Data.Time.Format() +import Data.Time.Clock.POSIX +#ifdef UNIX +import System.Posix.Signals +#endif + +import qualified Data.ByteString.Char8 as B +import qualified Data.ByteString.Lazy.Char8 as LB +import qualified Data.Map as M +import qualified Data.Set as S +import GHC.Generics +import Data.Binary + +import Codec.Crypto.RSA.Pure + +import Parry.Protocol +import Parry.Util + +-- | The class of jobs and job results that Parry can deal with. For +-- efficiency and to keep types simple, jobs and results are stored in +-- a single type. +class Exhaustive j where + -- | Indication of the depth of a job in the explored tree. The server sends + -- the least deep jobs first, as an optimization of network use. + depth :: j->Int + -- | Number of times a job has been killed. When a job is killed, + -- either because it must be reshared, or because the client itself + -- was killed, it is scheduled to be re-executed by the server. + killed::j->Int + -- | Called each time a job needs to be killed. For better resharing, + -- this function must verify @killed (kill j) >= killed j@. + kill::j->j + +-- | The class of results, and how to combine them in the server state. +class Result j r where + -- | A function to tell how to combine job results. That function will be + -- called on the hostname of the reporting client, with the finished job it + -- sent, and the current result from the server state. + addResult::HostName->r->j->r + +-- | This type is exposed mostly for writing alternative user interfaces. +-- Other operations must be done using the functions in this module, or +-- the correction of the protocol can be lost. +data State j r=State { + -- | Available jobs + jobs::S.Set (Int,j), + -- | Map from the machine id to its hostname, its current job, its + -- starting time, the last time we heard from it. + ongoing::M.Map Integer (HostName,PublicKey,j,Double,Double), + -- | Set of unemployed machines + unemployed::S.Set Integer, + -- | The results. + results::r, + -- | The smallest available machine id. In a run of the server, it + -- is guaranteed that are never assigned the same. + newId::Integer, + -- | Total number of jobs killed from the beginning (for benchmarking purposes). + killings::Int, + -- | Number of jobs finished (for benchmarking purposes). + solved::Integer, + -- | The list of authorized RSA public keys. + authorizedKeys::[PublicKey] + } deriving (Show,Read,Generic) + +instance (Binary j,Binary r)=>Binary (State j r) +\end{code} + + +\hfill + +\begin{definition} +In a server state {\tt st}, the \emph{current job} of a client is the job +registered in the {\tt ongoing} field of {\tt st}. +\end{definition} + +\begin{definition} +\label{def:valid} +We call a client \emph{valid} if, at the same time: +\begin{enumerate} + +\item \label{valid:newjobs} +Its {\tt NewJobs} messages contain all the results in subjobs of its +current job that have been completely explored, and the subjobs of its current +job that have not been completely explored, divided into three fields: the +results it has found, its next current job, and other subjobs. + +\item \label{valid:jobdone} +It does not send a {\tt JobDone} message before the task representing its +current job is completely explored. + +\end{enumerate} +\end{definition} + + + +The main function, {\tt answer}, keeps track of the clients. We now prove the +following Lemma: + +\begin{lemma} +\label{lem:answer} +If {\tt st} is a state of the server containing (in the union of {\tt job st} +and {\tt ongoing st}) jobs representing all the tasks that have not yet been explored, +and for any job {\tt j}, {\tt j} and {\tt kill j} represent the same task, +then for any message {\tt m} sent by a valid client, all values of {\tt host} +and {\tt time}, {\tt answer host time st m} (the Haskell syntax for ``the value +of function {\tt answer}, called with arguments {\tt t}, {\tt host}, {\tt st} and +{\tt m}'') +is a couple + $(\mathtt{st'},\mathtt{m'})$, where {\tt st'} is a state of the server +containing the roots of all subtrees that have not yet been explored ({\tt m'} +is the message to be sent to the client). + +Moreover, all results sent by the clients are added to the server state using +the {\tt addResult} function. + +\begin{proof} + +We prove it for all the cases. + +\begin{code} +answer::(Exhaustive j,Result j r,Eq j,Ord j,Binary j)=> + Double->String->State j r->ClientMessage j + ->(State j r,ServerMessage j) +answer t host st (GetJob num key)= + case M.lookup num (ongoing st) of + Just (ho,key0,j0,t0,_)-> +\end{code} + +If the client is registered as an ``ongoing'' job, we can simply send it the job +it is supposed to be working on. In this case, the invariant is still +maintained, as we do not change its recorded current job (here, we only update the +time at which we last saw this client). + +\begin{code} + if ho==host && key0==key then + (st { ongoing=M.insert num (ho,key,j0,t0,t) (ongoing st) }, + Job (not $ S.null $ unemployed st) j0) + else + (st,Die) + Nothing-> +\end{code} +Else, client {\tt num} is not in the map of ongoing jobs. +If there are no more jobs to be done: + +\begin{itemize} + +\item if there are no more jobs being worked on, we do not modify the state, and +we tell the client to stop (with a {\tt Finished} message). + +\item else, we simply record that job as ``unemployed''. The next time a client +reports its state, it will be asked to share its current job. This does not +change the jobs registered in the server's state anyway. +\end{itemize} + +\begin{code} + if S.null (jobs st) then + if M.null (ongoing st) then + (st,Finished) + else + (st { unemployed=S.insert num (unemployed st) },Die) +\end{code} + +Else, if there are still jobs to be done, we pick any such job (using {\tt +S.deleteFindMin}). According to the documentation of Haskell's {\tt Data.Map} +module, $\mathtt{jobs\ st}$ is equal to +$\{\mathtt{h}\}\cup\mathtt{nextJobs}$. Therefore, since {\tt num} is not a +member of {\tt ongoing st}, the returned state contains, in the union of its +{\tt ongoing} and {\tt jobs} fields, exactly the same jobs as in {\tt st}. + +\begin{code} + else + let ((_,h),nextJobs)=S.deleteFindMin (jobs st) + shareIt=killed h>0 + in + (st { jobs=nextJobs, + unemployed=S.delete num (unemployed st), + ongoing=M.insert num (host,key,h,t,t) (ongoing st) }, + Job shareIt h) +\end{code} +\hfill + +Another message the server can receive is the {\tt NewJobs} message, when +clients reshare their work: +In this case, the client sends its number {\tt num}, the initial +job {\tt initialJob} it was given, the new job {\tt job} that it will now work +on, a list {\tt js} of jobs that need to be shared, and a list of results. +We can think of this message as equivalent to \emph{``I, valid client {\tt num}, +hereby RSA-certify that job {\tt currentJob j} you gave me has subjobs +{\tt newJobs j}, and results {\tt results j}''}. + +\hfill +\begin{code} +answer t host st j@(NewJobs {})= + case M.lookup (clientId j) (ongoing st) of + Nothing->(st,Die) + Just (ho,key,j0,t0,_)-> + if host==ho && j0==currentJob j then + (st { jobs=foldl' (\s x->S.insert (depth x,x) s) (jobs st) (newJobs j), + ongoing=M.insert (clientId j) + (host,key,nextJob j,t0,t) + (ongoing st), + results=foldl' (addResult host) (results st) (jobResults j) }, Ack) + else + (st, Die) +\end{code} +\hfill + + +If the client is not registered as an ``ongoing job'', this message is ignored, +the state is not modified, and the client is sent the {\tt Die} message. + +Else, we assumed that this {\tt NewJobs} message can only be sent by a valid +client. Therefore, it contains all subjobs of its current job that have not +been explored, along with the job it will start working on, and the list of all +results that have been found during the exploration of the other subjobs of its +current job. Since all these subjobs are stored in the {\tt jobs} field of the +state, and the {\tt ongoing} field is updated with the client's new current job, +our claim still holds. + +\hfill + +\begin{code} +answer _ _ st j@(JobDone {})= + case M.lookup (clientId j) (ongoing st) of + Nothing->(st,Die); + Just (host,_,j0,_,_)-> + if j0==currentJob j then + (st { ongoing=M.delete (clientId j) (ongoing st), + results=foldl' (addResult host) (results st) (jobResults j), + solved=solved st+1 }, Ack) + else + (st,Die) +\end{code} + +\hfill + +In this case, if the client is not registered as an ongoing job, we do not +modify the state. Else, we can safely delete the corresponding job from the +state, and add its results to the state's results field: indeed, since we +assumed that this message is sent by a valid client, that job has been explored +completely. The intuitive version of this message is \emph{``I, valid client +{\tt num}, hereby RSA-certify that I have explored job {\tt currentJob j} +completely, and that it contains exactly results {\tt results j}''}. + +\hfill + +The last case of {\tt answer} is when the client sends an ``Alive'' message: +\begin{code} +answer t host st (Alive num)= + case M.lookup num (ongoing st) of + Nothing->(st,Die); + Just (ho,key,j,t0,_)-> + if ho==host && (S.null (unemployed st) || (not $ S.null $ jobs st)) then + (st { ongoing=M.insert num (ho,key,j,t0,t) (ongoing st) },Ack) + else + (st,Die) +\end{code} + +\hfill + +In this case, the set of jobs is not modified, and hence our claim holds. +\end{proof} +\end{lemma} + +Our next task is to prove {\tt reply}, the network interface to the {\tt answer} +function. We first need hypotheses on how this interface works, and especially +how the messages are written and read at the ends of the connection. + +\begin{definition} + +A client is \emph{fluent} if the messages it sends on the network are of exactly +two kinds: + +\begin{itemize} + +\item Messages with a single line containing exactly {\tt Hello}. + +\item Messages with two lines: +\begin{itemize} + +\item the first line is the encoding via {\tt encode16l} of $m$, where $m$ is +the encoding via {\tt encode} of a constructor of the {\tt ClientMessage} type. + +\item the second line is the RSA signature, using the client's private key, +of $m$. +\end{itemize} + +\end{itemize} + +\end{definition} + +\begin{lemma} \label{lem:reply} If all the clients that have their public key in +{\tt authorizedKeys st}, where {\tt st} is the state of the server, are valid +and fluent, and {\tt st} contains all the jobs that have not been completely +explored (in the {\tt ongoing} and {\tt jobs} fields), then so does it after one +run of {\tt reply}, assuming that $\mathtt{decode}\circ\mathtt{encode}$ (from +Haskell's {\tt Data.Binary} module) is the identity, and +$\mathtt{decode16}\circ\mathtt{encode16l}$ (from module {\tt Parry.Util}) is the +identity. + +\begin{proof} +We prove this invariant on the code of the {\tt reply} function, which handles +every connection to our server.\vspace{1em} + +\begin{code} +reply::(Binary j,Exhaustive j,Result j r,Ord j)=> + MVar (State j r) -> Handle -> HostName -> IO () +reply state rhandle host=(do + l<-B.hGetLine rhandle + if l==B.pack "Hello" then + modifyMVar_ state $ \st->do + LB.hPutStrLn rhandle $ encode16l $ encode $ newId st + return $ st { newId=newId st+1 } +\end{code} + +\hfill + +When the first line is the initial {\tt Hello} message, the claim holds: indeed, +the only field of the server state that is modified is the {\tt newId} one, +which represents the first unused client number. + +In all other cases, we do the following: + +\hfill +\begin{code} + else do + st<-withMVar state return + sig<-B.hGetLine rhandle + let dec=LB.fromStrict $ decode16 l + msg=decode dec + num=case msg of + GetJob x _->x + JobDone x _ _->x + NewJobs x _ _ _ _->x + Alive x->x + key=case msg of + GetJob _ pub-> + if any (==pub) (authorizedKeys st) then + Just pub + else + Nothing + _->(case M.lookup num $ ongoing st of + Just (_,pub,_,_,_)->Just pub + Nothing->Nothing) +\end{code} + +\hfill + +We will now verify the message signature, using either the public key registered +for this client in the {\tt ongoing} field of the server's state, or the public +key sent by the client itself, in the case of the {\tt GetJob} message (if that +key is registered in the {\tt authorizedKeys} field of the server state): + +\hfill + +\begin{code} + message<-case key of + Nothing->return Die + Just pub-> + case verify pub dec (LB.fromStrict $ decode16 sig) of + Right True->do + t<-getPOSIXTime + modifyMVar state $ \st0-> + let (!a,!b)=answer (realToFrac t) host st0 msg in + return (a,b) + _->return Die + LB.hPutStrLn rhandle (encode16l $ encode message) + ) +\end{code} + +\hfill + +Since we assumed that $\mathtt{decode}\circ\mathtt{encode}$ and + $\mathtt{decode16}\circ\mathtt{encode16l}$ are both the identity function, +variable {\tt msg} contains the message sent by the client. Because the client +is valid (because its public key is in the {\tt authorizedKeys} field of the +server state), we can conclude using Lemma \ref{lem:answer} that the invariant +is maintained by the {\tt reply} function, because the only call modifying the +state is a call to {\tt answer}. + +\end{proof} +\end{lemma} + +The last piece of server code that we need to prove is the {\tt cleanupThread} +function, whose aim is to collect all dead machines. We do need this function, +especially on standard clusters with small walltimes compared to the task. + +\begin{lemma} +\label{lem:cleanupThread} +If the {\tt kill} function, defined on jobs, does not change the task +represented by the job, and {\tt state} is a server state containing (in the +{\tt ongoing} and {\tt jobs} fields) all the jobs that have not been explored, +then so is it after one run of {\tt cleanupThread state}. + +\begin{proof} + +In the following function: the state is only modified by partitionning the {\tt +ongoing st} map into two maps {\tt a} and {\tt b}, and adding all the jobs of +{\tt a} to the {\tt jobs st} set, possibly calling {\tt kill} on some of +them. Therefore, the tasks represented by jobs in the union of {\tt jobs st} and +{\tt ongoing st} is not modified. + +\hfill +\begin{code} +cleanupThread::(Ord j,Exhaustive j)=>MVar (State j r)->IO () +cleanupThread state=do { + t_<-getPOSIXTime; + let { t=realToFrac t_ }; + modifyMVar_ state $ \st0->do { + -- Find machines that have not given news for more than 10 minutes. + let { (a,b)=M.partition (\(_,_,_,_,t1)->(t-t1) > 600) (ongoing st0); + st=st0 { jobs= + M.foldl' (\set (_,_,job,t0,_)-> + S.insert (depth job, + if t-t0 > 3600 then + kill job + else job) set) + (jobs st0) + a, + ongoing=b } + }; + return st + }; + -- Sleep 30 seconds, and clean again. + threadDelay 30000000; + cleanupThread state + } +\end{code} +\end{proof} +\end{lemma} + +Finally, the entry point to our server library is the {\tt server} function: + +\begin{lemma} +\label{lem:server} +If: +\begin{itemize} + +\item all tasks that have not been completely explored have job representants +in the {\tt ongoing} and {\tt jobs} fields of the {\tt state} argument to {\tt server}, + +\item all clients that sign their messages with a private RSA key whose corresponding +public key is in the {\tt state} variable are valid and fluent, + +\item $\mathtt{decode}\circ\mathtt{encode}$ and + $\mathtt{decode16}\circ\mathtt{encode16l}$ are both the identity function, +\end{itemize} + +then after any number of messages received by the server, variable {\tt state} +also contains jobs representing tasks that have not been completely explored, +in the union of its {\tt ongoing} and {\tt jobs} fields. + +\begin{proof} + +Clearly, everything {\tt server} does is calling functions that maintain this +invariant, by Lemmas \ref{lem:reply} for {\tt reply} and \ref{lem:cleanupThread} +for {\tt cleanupThread}. + +\begin{code} +-- | Starts the synchronization server. +server::(Ord j, Binary j, Exhaustive j, Result j r)=> + Config->MVar (State j r)->IO () +server config state=withSocketsDo $ do { +#ifdef UNIX + installHandler sigPIPE Ignore Nothing; +#endif + threads<-Sem.new $ maxThreads config; + _<-forkIO $ cleanupThread state; + forever $ do { + E.catch (bracket (listenOn (port config)) sClose $ + \sock->forever $ do { + bracket (do { (s,a,_)<-accept sock; wait threads; return (s,a) }) + (\(s,_)->do { signal threads; hClose s}) + (\(s,a)->reply state s a) + }) + (\e->let _=e::SomeException in appendFile (logFile config) (show e++"\n")); + threadDelay 100000; + }; + } +\end{code} +\end{proof} +\end{lemma} +\ignore{ +\begin{code} +-- | Server configuration +data Config=Config { + -- | The network port the synchronization server will listen on. + port::PortID, + -- | The maximal number of simultaneous threads that can be launched. + maxThreads::Int, + -- | Log file + logFile::FilePath + } + +-- | Default server configuration, matching the client. Note that you +-- must provide your own public key for signing the messages. + +defaultConfig::Config +defaultConfig=Config { port=PortNumber 5129, maxThreads=20, logFile="parry.err" } + +-- | Creates a valid server state from an initial job. +initState::(Exhaustive j,Ord j,Result j r)=>[j]->r->IO (MVar (State j r)) +initState initial r0= + newMVar $ State { jobs=foldl (\s j->S.insert (depth j,j) s) S.empty initial, + ongoing=M.empty, + results=r0, + unemployed=S.empty, + newId=0, + killings=0,solved=0, + authorizedKeys=[] }; +\end{code} + +\begin{code} +-- | Reads initial state from a file, or calls 'initState' if the file does +-- not exist. +stateFromFile::(Binary r,Binary j,Exhaustive j, Result j r,Ord j)=>FilePath->[j]->r->IO (MVar (State j r)) +stateFromFile f initial r0=do { + e<-doesFileExist f; + state<-if e then do { + st<-decodeFile f; + newMVar st + } else initState initial r0; + return state + } + +-- | Saves state to the given file with the given periodicity, in +-- microseconds. This function does not return, so calling it inside a +-- 'Control.Concurrent.forkIO' is probably the best thing to do. +saveThread::(Binary r,Binary j)=>FilePath->Int->MVar (State j r)->IO () +saveThread f del state= + let { save=do { + e<-doesFileExist f; + if e then renameFile f (f++".last") else return (); + withMVar state $ \st->LB.writeFile f $ encode st; + threadDelay del; + save + }} + in save +\end{code} +} diff --git a/Parry/Util.hs b/Parry/Util.hs new file mode 100644 --- /dev/null +++ b/Parry/Util.hs @@ -0,0 +1,65 @@ +-- | Common utility functions, used both in the client and the server. +module Parry.Util( + -- * Hexadecimal encoders and decoders. + encode16,decode16,encode16l,decode16l + ) where + +import qualified Data.ByteString.Lazy.Internal as ILB +import qualified Data.ByteString.Internal as IB +import qualified Data.ByteString as B +import qualified Data.ByteString.Unsafe as UB +import qualified Data.ByteString.Char8 as B8 +import Foreign.Ptr +import Foreign.Storable +import Data.Bits +import Data.Word + +-- | Encodes a strict bytestring to its hexadecimal representation. See 'decode16'. +encode16 :: B.ByteString -> B.ByteString +encode16 bytes= + let { len=B.length bytes } in + IB.unsafeCreate (len*2) $ \pp-> + let { fill p0 i + | i>=len=return () + | otherwise=do { + let { c=UB.unsafeIndex bytes i; + c0=c`shiftR`4; + c1=c.&.0xf }; + poke p0 $ if c0<=9 then 48+c0 else 97+c0-10; + poke (p0`plusPtr`1) $ if c1<=9 then 48+c1 else 97+c1-10; + fill (p0`plusPtr`2) $ i+1 + }} + in + fill pp 0 + +atomHex::Word8->Word8 +atomHex c= + if c<=(fromIntegral $ fromEnum '9') then + c-(fromIntegral $ fromEnum '0') + else + c-(fromIntegral $ fromEnum 'a')+10 + +-- | Decodes a strict bytestring from its hexadecimal representation. See 'encode16'. +decode16::B8.ByteString->B8.ByteString +decode16 bytes= + let { len=B.length bytes } in + IB.unsafeCreate (len`quot`2) $ \pp-> + let { fill p0 i + | i>=len=return () + | otherwise=do { + let { c0=atomHex $ UB.unsafeIndex bytes i; c1=atomHex $ UB.unsafeIndex bytes (i+1) }; + poke p0 $ (c0`shiftL`4) .|. c1; + fill (p0`plusPtr`1) $ i+2 + }} + in + fill pp 0 + +-- | Encodes a lazy bytestring to its hexadecimal representation. +encode16l::ILB.ByteString->ILB.ByteString +encode16l ILB.Empty=ILB.Empty +encode16l (ILB.Chunk x xs)=ILB.Chunk (encode16 x) (encode16l xs) + +-- | Decodes a lazy bytestring from its hexadecimal representation. +decode16l::ILB.ByteString->ILB.ByteString +decode16l ILB.Empty=ILB.Empty +decode16l (ILB.Chunk x xs)=ILB.Chunk (decode16 x) (decode16l xs) diff --git a/Parry/WebUI.hs b/Parry/WebUI.hs new file mode 100644 --- /dev/null +++ b/Parry/WebUI.hs @@ -0,0 +1,241 @@ +{-#LANGUAGE OverloadedStrings,MultiParamTypeClasses #-} +{-| +Module : Parry.DefaultUI +Copyright : (c) Pierre-Étienne Meunier 2014 +License : GPL-3 +Maintainer : pierre-etienne.meunier@lif.univ-mrs.fr +Stability : experimental +Portability : All +-} +module Parry.WebUI ( + webUI,Html(..) + ) where +import Control.Concurrent +import Network +import qualified Data.Map as M +import qualified Data.Set as S +import System.IO +import Data.Time.Clock +import Data.Time.Clock.POSIX +import Data.Time.Format +import System.Locale +import System.Directory +import System.Process +import qualified Data.ByteString.Char8 as B +import qualified Data.ByteString.Lazy.Char8 as L +import Data.ByteString.Lazy.Builder +import Data.ByteString.Lazy.Builder.ASCII +import Control.Exception +import Numeric +import Parry.Server +import Data.Monoid + +type Graphs=MVar (L.ByteString,L.ByteString,L.ByteString,L.ByteString) + +makeSvg::(Exhaustive j)=>Graphs->MVar (State j r)->IO () +makeSvg graphs state=onException ( + do { + st<-withMVar state $ return; + if M.size (ongoing st)==0 && (S.size (jobs st)==0) then return () else do { + t<-getPOSIXTime; + let { show_t=intDec $ round $ realToFrac t }; + + L.appendFile "parry.log" $ + toLazyByteString $ + show_t `mappend` (byteString " ") `mappend` (intDec $ M.size $ ongoing st) + `mappend` (byteString " ") `mappend` (intDec $ S.size $ jobs st) + `mappend` (byteString "\n"); + + let { jobs_=jobs st; + ongoing_=ongoing st; + (adepth0,njobs0)=M.foldl' (\(d,n) (_,_,j,_,_)->(d+depth j,n+1)) (0,0) $ ongoing_ :: (Int,Int); + (adepth1,njobs1)=S.foldl' (\(d,n) (_,j)->(d+depth j,n+1)) (0,0) $ jobs_ :: (Int,Int); + depth0=if njobs0>0 then (fromIntegral adepth0)/(fromIntegral njobs0) else 0 :: Double; + depth1=if njobs1>0 then (fromIntegral adepth1)/(fromIntegral njobs1) else 0 :: Double; + depth2=M.foldl' (\d (_,_,j,_,_)->min d $ depth j) maxBound $ ongoing_ :: Int; + depth3=S.foldl' (\d (_,j)->min d $ depth j) maxBound $ jobs_ :: Int + }; + + L.appendFile "solved.log" $ + toLazyByteString $ + show_t `mappend` (byteString " ") `mappend` (integerDec $ solved st) `mappend` (byteString "\n"); + + if njobs0>0 then + L.appendFile "depth.log" $ + toLazyByteString $ + show_t `mappend` (byteString " ") `mappend` (doubleDec depth0)`mappend` (byteString "\n") + else L.appendFile "depth.log" "\n"; + + if njobs1>0 then + L.appendFile "depth_av.log" $ + toLazyByteString $ + show_t `mappend` (byteString " ") `mappend` (doubleDec depth1)`mappend` (byteString "\n") + else L.appendFile "depth_av.log" "\n"; + + + if depth2return (a,b,c,e); + return () + }}) + (return ()) + +class Html a where + toHtml::a->Builder + + +webserver::(Html j,Html r)=> + Graphs + ->MVar (State j r) + ->Handle->IO() +webserver graphs state dsth=do { + req<-B.hGetLine dsth; + let { getHeaders hdr=do { + h<-B.hGetLine dsth; + if B.length h<=1 then return $ reverse hdr else + let { (a,b)=B.span (/=':') h } in + getHeaders $ (B.takeWhile (/=' ') a,B.dropWhile (/=' ') $ B.drop 1 b):hdr + }; + }; + hdr<-getHeaders []; + _<-case lookup "Content-Length" hdr of { + Just x->case reads (B.unpack x) of { + [(a,_)]->B.hGet dsth a; + _->return B.empty + }; + _->return B.empty + }; + let { repl code typ dat=do { + B.hPutStr dsth "HTTP/1.1 "; + B.hPutStr dsth code; + B.hPutStr dsth " \r\n"; + B.hPutStr dsth typ; + if L.length dat>0 then do { + B.hPutStr dsth "Content-Length: "; + L.hPutStr dsth (toLazyByteString $ int64Dec $ L.length dat); + B.hPutStr dsth "\r\n\r\n"; + L.hPutStr dsth dat + } else B.hPutStr dsth "\r\n" + }; + ok dat=repl "200 OK" "Content-Type: text/html; charset=utf-8\r\n" dat; + img dat=repl "200 OK" "Content-Type: image/svg+xml; charset=utf-8\r\n" dat; + notFound dat=repl "404 Not found" "Content-Type: text/html; charset=utf-8\r\n" dat; + }; + case B.split ' ' req of { + "GET":addr:_-> + case addr of { + "/machines.svg"-> do { + (a,_,_,_)<-withMVar graphs return; + img a + }; + "/depth_min.svg" -> do { + (_,a,_,_)<-withMVar graphs return; + img a + }; + "/depth_av.svg" -> do { + (_,_,a,_)<-withMVar graphs return; + img a + }; + "/solved.svg" -> do { + (_,_,_,a)<-withMVar graphs return; + img a + }; + "/"->do { + st<-withMVar state $ return; + let {page= + toLazyByteString $ + (mconcat [ + byteString $ "Parry Web UI

Results

", + toHtml $ results st, + byteString "



", + byteString "

Available jobs

" + ]) + `mappend` + {- + (mconcat $ map (\(_,x)-> + mconcat [byteString "

",toHtml x,byteString "

"] + ) $ S.toList $ jobs st) +-} + (intDec $ S.size $ jobs st) + `mappend` + (byteString "

Ongoing jobs

") + `mappend` + (mconcat $ map (\(x,(h,_,j,t,t'))-> + (byteString "

") + `mappend` + integerDec x + `mappend` + (byteString " ") + `mappend` + (byteString $ B.pack h) + `mappend` + (byteString "
Started: ") + `mappend` + (string8 $ + formatTime defaultTimeLocale "%c" $ + posixSecondsToUTCTime $ realToFrac t) + `mappend` + (byteString "
") + `mappend` + toHtml j + `mappend` + (byteString "

") + ) $ M.toList $ ongoing st) + `mappend` + (byteString "
") + }; + ok $ page + }; + _->notFound "" + }; + _->ok "" + }; + hClose dsth; + } + + +blankSvg::L.ByteString +blankSvg= + "" + + +-- | Starts the default web server. +webUI::(Exhaustive j,Html j,Html r)=>PortNumber->MVar (State j r)->IO () +webUI wport state=do { + sock <- listenOn (PortNumber wport); + graphs<-newMVar $ (blankSvg,blankSvg,blankSvg,blankSvg); + makeSvg graphs state; + let {list=do { + (s,_,_)<-accept sock; + _<-forkIO $ webserver graphs state s; + list + }; + svg=do { + threadDelay $ 30000000; + makeSvg graphs state; + svg + }}; + _<-forkIO svg; + list + } diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain