1 files changed, 99 insertions, 0 deletions

diff --git a/src/programlink.h b/src/programlink.h
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--- /dev/null
+++ b/src/programlink.h
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+#ifndef PROGRAMLINK_H
+#define PROGRAMLINK_H
+
+class ProgramLink;
+#include "queue.h"
+#include "linkmessage.h"
+#include "programchain.h"
+
+/**
+ * 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 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 hope 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