X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=results.mtask.tex;h=1b46df106c84f958e62eb7ab145d1c86f0510e5f;hb=2a4d91380ae0d2a7dfac58b8d5194d57d61af3ae;hp=2ad243a5a03089d378e917f884fb496b883988d3;hpb=e0645e1487f71512352f4fe8ace2e7a8e1e73d71;p=msc-thesis1617.git

diff --git a/results.mtask.tex b/results.mtask.tex
index 2ad243a..1b46df1 100644
--- a/results.mtask.tex
+++ b/results.mtask.tex
@@ -94,8 +94,8 @@ accordingly.
 	, sdsval :: BCValue
 	}
 :: BCState = 
-	{ freshl :: [Int]
-	, freshs :: [Int]
+	{ freshl :: Int
+	, freshs :: Int
 	, sdss :: [BCShare]
 	}
 
@@ -209,7 +209,7 @@ since the labels are resolved to real addresses later on anyways.
 
 \begin{lstlisting}[label={lst:controlflow},%
 	caption={Bytecode view for \texttt{arith}}]
-freshlabel = get >>= \st=:{freshl=[fr:frs]}->put {st & freshl=frs} >>| pure fr
+freshlabel = get >>= \st=:{freshl}->put {st & freshl=freshl+1} >>| pure freshl
 
 instance If ByteCode Stmt Stmt Stmt where If b t e = BCIfStmt b t e
 instance If ByteCode e Stmt Stmt    where If b t e = BCIfStmt b t e
@@ -238,7 +238,7 @@ implementation is shown in Listing~\ref{lst:shareview}.
 
 \begin{lstlisting}[label={lst:shareview},%
 	caption={Bytecode view for \texttt{arith}}]
-freshshare = get >>= \st=:{freshl=[fr:frs]}->put {st & freshl=frs} >>| pure fr
+freshshare = get >>= \st=:{freshs}->put {st & freshs=freshs+1} >>| pure freshs
 
 instance sds ByteCode where
 	sds f = {main = BC (freshshare
@@ -324,7 +324,50 @@ position in the program memory.
 20   : BCDigitalWrite (Digital D0)
 \end{lstlisting}
 
-\todo{add more elaborate example?}
-
-\section{Interpretation}
-\todo{details about the interpreter on the client}
+\section{Interpreter}
+The client contains an interpreter to execute a \gls{Task}'s bytecode.
+
+First some preparatory work is done. The stack will be initialized and the
+program counter and stack pointer are set to zero and the bottom respectively.
+Then the interpreter executes one step at the time while the program counter is
+smaller than the program length. The code for this is listed in
+Listing~\ref{lst:interpr}. One execution step is basically a big switch
+statement going over all possible bytecode instructions. Some instructions are
+detailed upon in the listing. The \CI{BCPush} instruction is a little more
+complicated in real life because some decoding will take place as not all
+\CI{BCValue}'s are of the same length.
+
+\begin{lstlisting}[language=C,label={lst:interpr},%
+	caption={Rough code outline for interpretation}]
+#define f16(p) program[pc]*265+program[pc+1]
+
+void run_task(struct task *t){
+	uint8_t *program = t->bc;
+	int plen = t->tasklength;
+	int pc = 0;
+	int sp = 0;
+	while(pc < plen){
+		switch(program[pc++]){
+		case BCNOP:
+			break;
+		case BCPUSH:
+			stack[sp++] = pc++ //Simplified
+			break;
+		case BCPOP:
+			sp--;
+			break;
+		case BCSDSSTORE:
+			sds_store(f16(pc), stack[--sp]);
+			pc+=2;
+			break;
+		// ...
+		case BCADD: trace("add");
+			stack[sp-2] = stack[sp-2] + stack[sp-1];
+			sp -= 1;
+			break;
+		// ...
+		case BCJMPT: trace("jmpt to %d", program[pc]);
+			pc = stack[--sp] ? program[pc]-1 : pc+1;
+			break;
+}
+\end{lstlisting}