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diff --git a/docs/tutorials/012/page03.html b/docs/tutorials/012/page03.html deleted file mode 100644 index c0a94ee30a1..00000000000 --- a/docs/tutorials/012/page03.html +++ /dev/null @@ -1,100 +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 012</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> - -<CENTER><B><FONT SIZE=+2>ACE Tutorial 012</FONT></B></CENTER> - -<CENTER><B><FONT SIZE=+2>Passing classes through ACE_Message_Queue</FONT></B></CENTER> - - -<P> -<HR WIDTH="100%"> -<P> -In the previous tutorial we moved our complex data into the queue by -copy()ing it directly into the message block's data area. I hope that -most readers got a queasy feeling when I did that. It just isn't a -good idea... -<P> -A better idea would be to teach the message queue about our data types -(or at least a baseclass) so that it can more efficiently handle things: -<P> -<HR WIDTH="100%"> -<PRE> -/* - We derive a Message_Block from ACE_Message_Block and teach it about - our Unit_Of_Work object. When our task's svc() method pulls a block - out of the queue, it can then invoke the virtual methods of the work - object safely. In this implementation we've also retained the - original ACE_Message_Block functionallity so that we can use the - underlying ACE_Data_Block objects to store data other than our - Unit_Of_Work. -*/ -class Message_Block : public ACE_Message_Block -{ -public: - typedef ACE_Message_Block inherited; - - /* - Construct our underlying ACE_Message_Block with the requested - data size and initialize our Unit_Of_Work pointer with the - given object instance. Note that this Message_Block instance - now assumes ownership of the Unit_Of_Work and will delete it - when the Message_Block is deleted. - */ - Message_Block( size_t size, Unit_Of_Work * _data ) - : inherited(size), data_(_data) - { - ACE_DEBUG ((LM_DEBUG, "(%P|%t) Message_Block ctor 0x%x for 0x%x\n", (void *) this, data_)); - } - - ~Message_Block(void) - { - ACE_DEBUG ((LM_DEBUG, "(%P|%t) Message_Block dtor 0x%x for 0x%x\n", (void *) this, data_)); - delete data_; - } - - /* - Return the Unit_Of_Work so that the task can invoke methods on - it. - */ - Unit_Of_Work * data(void) - { - return this->data_; - } - -protected: - Unit_Of_Work * data_; - - /* - Disallow these very dangerous operations. - If we were to copy a Message_Block object then the data_ - pointer would get copied and we would eventually end up - deleting the same object multiple times! That's not good. By - preventing the copy, we can avoid this. - */ - Message_Block &operator= (const Message_Block &); - Message_Block (const Message_Block &); -}; -</PRE> -<HR WIDTH="100%"> -<P> -Ok, this looks pretty good. We just construct our specialized -Message_Block instead of the generic ACE_Message_Block and let it -carry our data along. When our application is done with the message -block and release()es it, we know that our work object will also be -taken care of. -<P> -Let's now go to main() and see what we had to change there to use this -specialization. -<P> -<HR WIDTH="100%"> -<P> -<CENTER>[<A HREF="..">Tutorial Index</A>] [<A HREF="page04.html">Continue -This Tutorial</A>]</CENTER> - -</BODY> -</HTML> |