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<cref>
<header>
<copyright>
<year>2004</year>
<year>2007</year>
<holder>Ericsson AB, All Rights Reserved</holder>
</copyright>
<legalnotice>
The contents of this file are subject to the Erlang Public License,
Version 1.1, (the "License"); you may not use this file except in
compliance with the License. You should have received a copy of the
Erlang Public License along with this software. If not, it can be
retrieved online at http://www.erlang.org/.
Software distributed under the License is distributed on an "AS IS"
basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
the License for the specific language governing rights and limitations
under the License.
The Initial Developer of the Original Code is Ericsson AB.
</legalnotice>
<title>IC C Protocol Functions</title>
<prepared></prepared>
<docno></docno>
<date>2004-04-06</date>
<rev>A</rev>
</header>
<lib>ic_c_protocol</lib>
<libsummary>IC C Protocol Functions</libsummary>
<description>
<p>This manual page lists some of the functions of the IC C runtime
library that are used internally for the IC protocol.
</p>
<p>The listed functions are used internally by generated C client
and server code. They are documented here for <em>the advanced user</em> that want to replace the default protocol (Erlang
distribution + gen_server) by his own protocol, For each set of
client or sever functions below with prefix <c>oe</c>, the user
has to implement his own set of functions, the names of which
are obtained by replacing the <c>oe</c> prefix by <c>Prefix</c>.
The <c>Prefix</c> has to be set with the option
<c>{user_protocol, Prefix}</c> at compile time.</p>
<p>The following terminology is used (reflected in names of
functions): a <em>notification</em> is a message send from
client to server, without any reply back (i.e. a
<em>oneway</em> operation); a <em>request</em> is a message sent
from client to server, and where a <em>reply</em> message is
sent back from the server to the client.</p>
<p>In order to understand how the functions work and what they do
the user <em>must</em> study their implementation in the IC C
library (source file is <c>ic.c</c>), and also consider how they
are used in the C code of ordinary generated client stubs or
server skeletons.</p>
<p></p>
</description>
<section>
<title>Client Protocol Functions</title>
<p>The following functions are used internally by generated C
client code.</p>
</section>
<funcs>
<func>
<name><ret>int</ret><nametext>oe_prepare_notification_encoding(CORBA_Environment *env)</nametext></name>
<fsummary>Prepare client notification encoding.</fsummary>
<desc>
<p>The result of this function is the beginning of a binary of
in external format of the tuple <c>{'$gen_cast', X}</c> where
<c>X</c> is not yet filled in. </p>
<p>In generated client code this function is the first to be called
in the encoding function for each oneway operation.</p>
</desc>
</func>
<func>
<name><ret>int</ret><nametext>oe_send_notification(CORBA_Environment *env)</nametext></name>
<name><ret>int</ret><nametext>oe_send_notification_tmo(CORBA_Environment *env, unsigned int send_ms)</nametext></name>
<fsummary>Send client notification.</fsummary>
<desc>
<p>Sends a client notification to a server according to the
Erlang distribution + gen_server protocol.</p>
<p>The <c>send_ms</c> parameter specified a timeout in milliseconds.</p>
</desc>
</func>
<func>
<name><ret>int</ret><nametext>oe_prepare_request_encoding(CORBA_Environment *env)</nametext></name>
<fsummary>Prepare client request encoding.</fsummary>
<desc>
<p>The result of this function is the beginning of a binary in
the external format of the tuple <c>{'$gen_call', {Pid, Ref}, X}</c> where <c>X</c> is not yet filled in.</p>
<p>In generated client code this function is the first to be called
in the encoding function for each twoway operation.</p>
</desc>
</func>
<func>
<name><ret>int</ret><nametext>oe_send_request_and_receive_reply(CORBA_Environment *env)</nametext></name>
<name><ret>int</ret><nametext>oe_send_request_and_receive_reply_tmo(CORBA_Environment *env, unsigned int send_ms, unsigned int recv_ms)</nametext></name>
<fsummary>Send client request and receive reply.</fsummary>
<desc>
<p>Sends a client request and receives the reply according to
the Erlang distribution + gen_server protocol. This function
calls the <c>oe_prepare_reply_decoding</c> function in order
to obtain the gen_server reply.
</p>
<p><c>send_ms</c> and <c>recv_ms</c> specify timeouts for send
and receive, respectively, in milliseconds.</p>
</desc>
</func>
<func>
<name><ret>int</ret><nametext>oe_prepare_reply_decoding(CORBA_Environment *env)</nametext></name>
<fsummary>Prepare client decoding of reply.</fsummary>
<desc>
<p>Decodes the binary version of the tuple <c>{Ref, X}</c>,
where <c>X</c> is to be decoded later by the specific client
decoding function.</p>
</desc>
</func>
</funcs>
<section>
<title>Server Protocol Functions</title>
<p>The following functions are used internally by generated C
server code.</p>
</section>
<funcs>
<func>
<name><ret>int</ret><nametext>oe_prepare_request_decoding(CORBA_Environment *env)</nametext></name>
<fsummary>Prepare server decoding of request.</fsummary>
<desc>
<p>Decodes the binary version of the tuple <c>{'$gen_cast', Op}</c> (<c>Op</c> an atom), or the tuple <c>{'$gen_cast', {Op, X}}</c>, where <c>Op</c> is the operation name, and
where <c>X</c> is to be decoded later by the specific
operation decoding function; or</p>
<p>decodes the binary version of the tuple <c>{'$gen_call', {Pid, Ref}, Op}</c> (<c>Op</c> an atom), or the tuple
<c>{'$gen_call', {Pid, Ref}, {Op, X}}</c>, where <c>Op></c>
is the operation name, and <c>X</c> is to be decode later by
the specific operation decoding function.</p>
</desc>
</func>
<func>
<name><ret>int</ret><nametext>oe_prepare_reply_encoding(CORBA_Environment *env)</nametext></name>
<fsummary>Prepare server encoding of reply.</fsummary>
<desc>
<p>Encodes the beginning of the binary version of the tuple
<c>{{Ref,X}</c>, where <c>X</c> is to be filled in by the
specific server encoding function.</p>
</desc>
</func>
</funcs>
<section>
<title>SEE ALSO</title>
<p>ic(3), ic_clib(3), <seealso marker="ch_ic_protocol">IC Protocol</seealso></p>
</section>
</cref>
