+\section{Overview}
+The goal of the architecture is to facilitate an ecosystem in which an
+\gls{iTasks}-system can add, change and remove devices at runtime. Moreover,
+the \gls{iTasks}-system can send \glspl{mTask}, compiled at runtime to
+bytecode, to the device. The device runs an interpreter which can execute the
+\gls{Task}'s bytecode. Devices are persistent during reboots of the
+\gls{iTasks}-system. The methods of interacting with \glspl{mTask} is analogous
+to interacting with \gls{iTasks}-\glspl{Task}.
+
+An overview of the architecture is visible in Figure~\ref{fig:system}.
+
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=\linewidth]{system}
+ \caption{Overview of the architecture}\label{fig:system}
+\end{figure}
+
+
\section{Devices}
The client code for the devices is compiled from one codebase. For a device to
be eligible for \glspl{mTask}, it must be able to compile the shared codebase
\section{Specification}
Devices are stored in a record type and all devices in the system are stored in
a \gls{SDS} containing all devices. From the macro settings in the interface
-file a profile is created for the device that describes the specification. When
+file, a profile is created for the device that describes the specification. When
a connection between the server and a client is established the server will
send a request for specification. The client will serialize his specification
and send it to the server so that the server knows what the client is capable
\begin{lstlisting}[label={lst:devicespec},
caption={Device specification for \glspl{mTask}}]
:: MTaskDeviceSpec =
- {haveLed :: Bool
- ,haveAio :: Bool
- ,haveDio :: Bool
- ,bytesMemory :: Int
+ { haveLed :: Bool
+ , haveAio :: Bool
+ , haveDio :: Bool
+ , bytesMemory :: Int
}
\end{lstlisting}
uses the newly developed serial port library of \gls{Clean}\footnote{\url{%
https://gitlab.science.ru.nl/mlubbers/CleanSerial}}.
-Besides all the communication information the record also keeps track of the
-\glspl{Task} currently on the device and the according \glspl{SDS}. Finally it
-stores the specification of the device that is received when connecting.
-All of this is listed in Listing~\ref{lst:mtaskdevice}. The definitions of the
-message format are explained in the following section.
+Besides all the communication information, the record also keeps track of the
+\glspl{Task} currently on the device, the compiler state (see
+Section~\ref{sec:compiler}) and the according \glspl{SDS}. Finally it stores
+the specification of the device that is received when connecting. All of this
+is listed in Listing~\ref{lst:mtaskdevice}. The definitions of the message
+format are explained in the following section.
\begin{lstlisting}[caption={Device type},label={lst:mtaskdevice}]
deviceStore :: Shared [MTaskDevice]
:: Channels :== ([MTaskMSGRecv], [MTaskMSGSend], Bool)
+:: BCState = ... // Compiler state, explained in later sections
:: MTaskResource
= TCPDevice TCPSettings
| SerialDevice TTYSettings
, deviceError :: Maybe String
, deviceChannels :: String
, deviceName :: String
+ , deviceState :: BCState
, deviceTasks :: [MTaskTask]
, deviceData :: MTaskResource
, deviceSpec :: Maybe MTaskDeviceSpec
function and the record is updated accordingly.
\begin{figure}[H]
+ \centering
\begin{sequencediagram}
\newthread{s}{Server}
\newinst[4]{c}{Client}
\caption{Connect a device}\label{fig:handshake}
\end{figure}
-\subsection{\glspl{Task}}
-\subsection{\glspl{SDS}}
-\todo{Connectie, hoe gaat dat in zijn werk}
+\subsection{\glspl{Task} \& \glspl{SDS}}
+When a \gls{Task} is sent to the device it is added to the device record
+without an identifier. The actual identifier is added to the record when the
+acknowledgement of the task by the device is received. The connection diagram
+is shown in Figure~\ref{fig:tasksend}.
+
+\begin{figure}[H]
+ \centering
+ \begin{sequencediagram}
+ \newthread{s}{Server}
+ \newinst[4]{c}{Client}
+ \begin{call}{s}{MTSDS}{c}{MTSDSAck}
+ \end{call}
+ \begin{call}{s}{MTTask}{c}{MTTaskAck}
+ \end{call}
+ \end{sequencediagram}
+ \caption{Sending a \gls{Task} to a device}\label{fig:tasksend}
+\end{figure}
+
+The function for sending a task to the device is shown in
+Listing~\ref{lst:sendtask}. First the task is compiled into messages. The
+details of the compilation process are given in Section~\ref{sec:compiler}.
+The new shares that were made during compilation are added to the deviceshares
+that were made during the compilation are merged with the existing shares on
+the device. Furthermore the messages are placed in the channel share of the
+device. This will result in sending the actual \gls{SDS} and \gls{Task}
+specifications to the device. A \gls{Task} record is created with the
+identifier $-1$ to denote a \gls{Task} not yet acknowledged. Finally the device
+itself is updated with the new state and with the new \gls{Task}. When the
+device returns an acknowledgement the \gls{Task} is updated accordingly.
+
+\begin{lstlisting}[label={lst:sendtask},%
+ caption={Sending a \gls{Task} to a device}]
+makeTask :: String Int -> Task MTaskTask
+makeTask name ident = get currentDateTime @ \dt->{MTaskTask | name=name,ident=ident,dateAdded=dt}
+
+makeShare :: String Int BCValue -> MTaskShare
+makeShare withTask identifier value = {MTaskShare |withTask=[withTask], identifier=identifier,value=value}
+
+sendTaskToDevice :: String (Main (ByteCode a Stmt)) (MTaskDevice, MTaskInterval) -> Task [MTaskDevice]
+sendTaskToDevice wta mTask (device, timeout)
+# (msgs, newState) = toMessages timeout mTask device.deviceState
+# shares = [makeShare wta sdsi sdsval\\{sdsi,sdsval}<-newState.sdss, (MTSds sdsi` _)<-msgs | sdsi == sdsi`]
+= updateShares device ((++) shares)
+ >>| sendMessages msgs device
+ >>| makeTask wta -1
+ >>= withDevices device o addTaskUpState newState
+ where
+ addTaskUpState :: BCState MTaskTask MTaskDevice -> MTaskDevice
+ addTaskUpState st task device = {MTaskDevice | device &
+ deviceState=st, deviceTasks=[task:device.deviceTasks]}
+\end{lstlisting}
+
+\subsection{Miscellaneous Messages}
+There exists one special type of message that is sent to the device only when
+it needs to reboot. When the server wants to stop the bond with the device it
+sends the \CI{MTShutdown} message. The device will then clear his memory, thus
+losing all the \glspl{SDS} and \glspl{Task} that were stored and reset itself.
+Shortly after the shutdown message a new server can connect to the device
+because the device is back in listening mode.
repositories / msc-thesis1617.git / blobdiff