diff options
Diffstat (limited to 'docs/tutorials/010/page02.html')
-rw-r--r-- | docs/tutorials/010/page02.html | 129 |
1 files changed, 0 insertions, 129 deletions
diff --git a/docs/tutorials/010/page02.html b/docs/tutorials/010/page02.html deleted file mode 100644 index 342f71e5e4c..00000000000 --- a/docs/tutorials/010/page02.html +++ /dev/null @@ -1,129 +0,0 @@ -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="Author" CONTENT="James CE Johnson"> - <TITLE>ACE Tutorial 010</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> - -<CENTER><B><FONT SIZE=+2>ACE Tutorial 010</FONT></B></CENTER> - -<CENTER><B><FONT SIZE=+2>Passing chunks of data through an ACE_Message_Queue</FONT></B></CENTER> - - -<P> -<HR WIDTH="100%"> - -We'll look first at <A HREF="message_queue.cpp">main()</A>. -<P> - -<HR WIDTH="100%"> -<PRE> - -<font color=red>// $Id$</font> - -<font color=red>/* - To illustrate the ACE_Message_Queue, we use a derivative of ACE_Task<>. We - also derive from ACE_Message_Block to show that we don't have memory leaks. - */</font> -<font color=blue>#include</font> "<font color=green>task.h</font>" -<font color=blue>#include</font> "<font color=green>block.h</font>" - -int run_test( int iterations, int threads ) -{ - <font color=red>/* - Create and star an instance of our Task object. - */</font> - Task task; - - if (task.start (threads) == -1) - { - ACE_ERROR_RETURN ((LM_ERROR, "<font color=green>%p\n</font>", "<font color=green>start</font>"), -1); - } - - <font color=red>/* - Give the threads a moment to open. This isn't really necessary but if we - don't we find that all of our blocks are constructed and enqueued before - any of the threads get created. Basically, the sleep() makes the output - look more interesting. - */</font> - <font color=#008888>ACE_OS::sleep</font> (ACE_Time_Value (1)); - - int i; - for (i = 0; i < iterations; ++i) - { - <font color=red>/* - Create a new message block to hold our data. Here, we ask for a block - that has 128 bytes of data space. - */</font> - Block *message = new Block (128); - - <font color=red>/* - Grab the "<font color=green>write pointer</font>". This is a pointer into the data area where we - can write our data. After writting the data you have to increment the - wr_ptr() so that subsequent writes won't clobber what you've put there. - */</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 ())); - - <font color=red>/* - Put the message block into the queue. One of the threads in the Task - object will pick up the block and "<font color=green>do work</font>" on it. - */</font> - if (task.putq (message) == -1) - { - break; - } - } - - <font color=red>/* - Once we're done, we have to signal the Task objects to shut down. There - are several choices including: - Send a message of zero length - Send a - message with a special content I don't like these choices because they're - likely to interfere with application logic. Instead, I use the message - type feature to send a message of type "<font color=green>hangup</font>". The default type is - MB_DATA, so when the tasks get a MB_HANGUP type, they know to go away. - */</font> - Block *message = new Block (); - message->msg_type (<font color=#008888>ACE_Message_Block::MB_HANGUP</font>); - task.putq (message); - - <font color=red>/* - Wait for the threads in our task object to go away. - */</font> - task.wait (); - - return(0); -} - -int main (int argc, char *argv[]) -{ - <font color=red>/* - Set the number of iterations through our putq() loop and the number of - threads to use in our Task<> derivative. - */</font> - int iterations = argc > 1 ? atoi (argv[1]) : 9; - int threads = argc > 2 ? atoi (argv[2]) : 2; - - (void)run_test(iterations,threads); - - ACE_DEBUG ((LM_DEBUG, "<font color=green>(%P|%t) Application exiting\n</font>")); - - return(0); -} -</PRE> -<HR WIDTH="100%"> -<P> -This looks a lot like our thread-pool server and it even does some things -better. In particular, I've scoped the Task object so that it's destructor -will have a chance to get called before the application exits. -Notice how we write actual data into the message block though. In the thread-pool -server we just provided a pointer. Writting the data is actually a more correct -way of doing things since you don't get into strange pointer casting situations. -What if you want to put complex objects into the message block though? We'll do -that in the next tutorial, let's stick with the basics first. -<P> -On the next page we'll take a look at our Block object... -<P> -<P><HR WIDTH="100%"> -<CENTER>[<A HREF="../online-tutorials.html">Tutorial Index</A>] [<A HREF="page03.html">Continue This Tutorial</A>]</CENTER> |