<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META NAME="Author" CONTENT="James CE Johnson">
<TITLE>ACE Tutorial 015</TITLE>
</HEAD>
<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F">
<CENTER><B><FONT SIZE=+2>ACE Tutorial 015</FONT></B></CENTER>
<CENTER><B><FONT SIZE=+2>Building a protocol stream</FONT></B></CENTER>
<P>
<HR WIDTH="100%">
We'll take a look first at the client application. As usual, our goal
is to keep the main() application as simple as possible and
delegate the tricky stuff to another object.
<HR>
<PRE>
<font color=red>// $Id$</font>
<font color=red>/* The Client object will implement the nasty details of connecting to
communicating with the server
*/</font>
<font color=blue>#include</font> "<font color=green>Client_i.h</font>"
int main(int argc, char *argv[])
{
<font color=red>// How many messages will we send?</font>
int mcount = argc > 1 ? <font color=#008888>ACE_OS::atoi</font>(argv[1]) : 3;
<font color=red>// Construct a Client with our desired endpoint.</font>
Client client(ACE_DEFAULT_SERVER_PORT,ACE_DEFAULT_SERVER_HOST);
<font color=red>// Attempt to open the connection to the server.</font>
if( client.open() == -1 )
{
ACE_ERROR_RETURN ((LM_ERROR, "<font color=green>%p\n</font>", "<font color=green><font color=#008888>Client::open</font>()</font>"), -1);
}
<font color=red>// Send a few messages to the server and get some responses...</font>
for( int i = 0 ; i < mcount ; ++i )
{
<font color=red>// Since we'll be using a Protocol Stream (even though we</font>
<font color=red>// don't know that at this level) we require the use of</font>
<font color=red>// ACE_Message_Block objects to send/receive data.</font>
ACE_Message_Block * message = new ACE_Message_Block( 128 );
<font color=red>// Construct a silly message to send to the server.</font>
<font color=red>// Notice that we're careful to add one to the strlen() so </font>
<font color=red>// that we also send the end-of-string NULL character.</font>
<font color=#008888>ACE_OS::sprintf</font> (message->wr_ptr (), "<font color=green>This is message %d.</font>", i);
message->wr_ptr (strlen (message->rd_ptr ())+1);
<font color=red>// client will take ownership of the message block so that </font>
<font color=red>// we don't have to remember to release(). We *do* have</font>
<font color=red>// to remember not to use it after put() since it may be</font>
<font color=red>// released almost immediately.</font>
client.put( message );
ACE_Message_Block * response;
<font color=red>// get() takes an ACE_Message_Block pointer reference. We then</font>
<font color=red>// assume ownership of it and must release() when we're done.</font>
if( client.get( response ) == -1 )
{
ACE_DEBUG ((LM_INFO, "<font color=green>(%P|%t) Failed to get response from server\n</font>" ));
break;
}
ACE_DEBUG ((LM_INFO, "<font color=green>(%P|%t) The server's response: (%s)\n</font>",
response->rd_ptr()));
<font color=red>// Now that we're through with the response we have to</font>
<font color=red>// release() it to avoid memory leaks.</font>
response->release();
}
ACE_DEBUG ((LM_INFO, "<font color=green>(%P|%t) Shutting down the stream\n</font>" ));
<font color=red>// Before we exit, it's a good idea to properly close() the connection.</font>
if( client.close() == -1 )
{
ACE_ERROR_RETURN ((LM_ERROR, "<font color=green>%p\n</font>", "<font color=green><font color=#008888>Client::close</font>()</font>"), -1);
}
return(0);
}
</PRE>
<P><HR WIDTH="100%">
<CENTER>[<A HREF="../online-tutorials.html">Tutorial Index</A>] [<A HREF="page03.html">Continue This Tutorial</A>]</CENTER>