1 files changed, 100 insertions, 0 deletions

diff --git a/src/programlink.h b/src/programlink.h
new file mode 100644
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--- /dev/null
+++ b/src/programlink.h
@@ -0,0 +1,100 @@
+#ifndef PROGRAMLINK_H
+#define PROGRAMLINK_H
+
+#include "bu/linkmessage.h"
+#include "bu/programchain.h"
+
+namespace Bu
+{
+        /**
+         * Program Link is the base class for any object that will be a piece of the
+         * main program chain loop.
+         *@author Mike Buland
+         */
+        class ProgramLink
+        {
+        friend class Bu::ProgramChain;
+        public:
+                /**
+                 * Construct a program link.
+                 */
+                ProgramLink();
+
+                /**
+                 * Deconstruct.
+                 */
+                virtual ~ProgramLink();
+
+                /**
+                 * Initialization code required for a link that wasn't performed in the
+                 * constructor.
+                 *@returns true if initialization was successful.  A false value will halt
+                 * the chain.
+                 */
+                virtual bool init()=0;
+
+                /**
+                 * DeInitialization code that should happen, but doesn't belong in the
+                 * destructor.
+                 *@returns true means everything worked, false means failure, but is
+                 * meaningless.
+                 */
+                virtual bool deInit()=0;
+
+                /**
+                 * Executed once per link per chain pass.  Contains the guts of the program.
+                 *@returns true if everything went well.  A false value will halt the chain.
+                 */
+                virtual bool timeSlice()=0;
+
+                /**
+                 * This must be handled in order to process Instant Response Messages.
+                 * This function should return null on all messages that it doesn't
+                 * understand how to handle, and construct new messages to return to sender
+                 * in the cases where it does understand.
+                 *@param pMsgIn The message that must be processed.
+                 *@returns Either a new message in cases where a response is required,
+                 * or null if nothing needs to be done by this link.
+                 */
+                virtual LinkMessage *processIRM( LinkMessage *pMsgIn ) = 0;
+
+                /**
+                 * Broadcast a LinkMessage to all other links in the system.  Each other
+                 * link will get a call of their processIRM function.  If the message gets
+                 * a response then you will regain control immediately, otherwise the system
+                 * will give all other Links a chance to respond before returning NULL.
+                 *@param pMsgOut The message to broadcast.
+                 *@returns The message response, or NULL if no Link understood your message.
+                 */
+                LinkMessage *sendIRM( LinkMessage *pMsgOut );
+
+        private:
+                /**
+                 * Set which chain we're assosiated with.  This is how IRM messages make
+                 * it out to the rest of the world.
+                 *@param pNewChain A pointer to the containing program chain.
+                 */
+                void setChain( class ProgramChain *pNewChain );
+
+                /**
+                 * The pointer to the containing chain.
+                 */
+                class ProgramChain *pChain;
+        /*
+                void postMessage( LinkMessage *pMsg, int nLvl );
+                LinkMessage *getMessage( int nLvl );
+
+                enum
+                {
+                        msgToChain,
+                        msgToLink
+                };
+
+        private:
+                Queue qMsgToChain;
+                Queue qMsgToLink;
+        */
+        };
+}
+
+#endif