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version 1.4, 2000/01/13 10:57:10 |
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%%$OpenXM: OpenXM/doc/issac2000/ox-messages.tex,v 1.1 2000/01/02 07:32:12 takayama Exp $ |
%%$OpenXM: OpenXM/doc/issac2000/ox-messages.tex,v 1.3 2000/01/11 05:35:48 noro Exp $ |
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\section{OX messages} (Ohara) |
\section{OX messages} |
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An OX message for TCP/IP is a byte stream consisting of |
An OX message for TCP/IP is a byte stream consisting of |
a header and a body. |
a header and a body. |
Line 17 and the second one is a serial number of the OX messag |
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Line 17 and the second one is a serial number of the OX messag |
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Negative numbers are expressed by the two's complement. |
Negative numbers are expressed by the two's complement. |
Several byte orders including the network byte order |
Several byte orders including the network byte order |
are allowed and the byte order is determined as a part of |
are allowed and the byte order is determined as a part of |
the establishment of a connection. |
the establishment of a connection. See Section \ref{secsession}. |
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The OX messages are classifed into three types: |
The OX messages are classified into three types: |
DATA, COMMAND, and others. |
DATA, COMMAND, and others. |
We have the following main tags for the OX messages. |
We have the following main tags for the OX messages. |
\begin{verbatim} |
\begin{verbatim} |
Line 36 New OX tags may be added. |
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Line 36 New OX tags may be added. |
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The new tag should be classified into DATA or COMMAND. |
The new tag should be classified into DATA or COMMAND. |
For example, \verb+ OX_DATA_ASIR_LOCAL_BINARY + was added a few month ago |
For example, \verb+ OX_DATA_ASIR_LOCAL_BINARY + was added a few month ago |
to send internal serialized objects of asir via the OpenXM protocol. |
to send internal serialized objects of asir via the OpenXM protocol. |
This is a tag classifed to DATA. |
This is a tag classified to DATA. |
See the home page of OpenXM to add a new tag. |
See the web page of OpenXM to add a new tag. |
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In OpenXM, a distributed computation is done as follows: |
In OpenXM, a distributed computation is done as follows: |
\begin{enumerate} |
\begin{enumerate} |
\item A client requests something to a server. |
\item A client requests something to a server. |
\item The server does works according to the request. |
\item The server does some work according to the request. |
\item The client requests to send data to the server. |
\item The client requests to send data to the server. |
\item The server sends the data to the client and the client gets the data. |
\item The server sends the data to the client and the client gets the data. |
\end{enumerate} |
\end{enumerate} |
The server is a stackmachine. |
The server is a stack machine. (see Section~\ref{sec:ox-stackmachines} |
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for detail) |
That is {\it OX data} message sent by the client |
That is {\it OX data} message sent by the client |
are pushed to the stack of the server. |
are pushed to the stack of the server. |
If the server gets an {\it OX command} message, then the data are |
If the server gets an {\it OX command} message, then the server extract |
popped form the stack and they are used as arguments of a function call. |
a stack machine code in the OX command message and interpret the code. |
For example, the asir command |
For example, in case of SM\_executeFunction, some data are popped from |
\verb+ ox_push_cmo(P,1) + (push integer $1$ to the server P) |
the stack and they are used as arguments of a function call. |
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We explain an implementation of handling OX messages. |
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For example, the asir command {\tt ox\_push\_cmo(P,1)} |
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(push integer $1$ to the server $P$) |
sends an OX data message |
sends an OX data message |
(OX\_DATA,(CMO\_ZZ,1)) to the server $P$. |
{\tt (OX\_DATA,(CMO\_ZZ,1))} to the server $P$. |
Here, |
Here, |
OX\_DATA stands for OX\_DATA header and |
OX\_DATA stands for OX\_DATA header and |
(CMO\_ZZ,1) is a body standing for $1$ expressed |
{\tt (CMO\_ZZ,1)} is a body standing for $1$ expressed |
in the CMO data encoding format. |
in the CMO data encoding format. |
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The server tranlates $(CMO\_ZZ, 1)$ to its own internal object fotrmat |
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for integers and pushs the object to the stack. |
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An OpenXM client admit that its own command sends some OX messages |
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sequentially at once. |
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For example, the asir command |
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{\tt ox\_execute\_string(P, "Print[x+y]")} sends an OX data message |
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{\tt (OX\_DATA, (CMO\_STRING, "Print[x+y]"))} and an OX command message |
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{\tt (OX\_COMMAND, (SM\_executeStringByLocalParser))} to an OpenXM |
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server. |
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