#ifndef __SITECING_SCOREBOARD_H
#define __SITECING_SCOREBOARD_H

#include <sys/types.h>

/**
 * @file
 * @brief the scoreboard manager.
 */

/**
 * @def MAX_SITECING_SCOREBOARD_SLOTS
 * The maximum number of slots scoreboard can hold.
 */
#define	MAX_SITECING_SCOREBOARD_SLOTS	512

namespace sitecing {
  
    /**
     * The scoreboard slot.
     */
    struct scoreboard_slot {
	/**
	 * The state enumeration.
	 */
	enum _state {
	    /**
	     * The slot is free.
	     */
	    state_free = 0,
	    /**
	     * The slot is allocated.
	     */
	    state_allocated,
	    /**
	     * The process is idle.
	     */
	    state_idle,
	    /**
	     * The process is accepting connection.
	     */
	    state_accept,
	    /**
	     * The process is processing request.
	     */
	    state_processing
	}   state;
	/**
	 * Process ID
	 */
	pid_t pid;
    };

    /**
     * The scoreboard manager.
     */
    class scoreboard {
	/**
	 * shared memory id.
	 */
	int shmid;
	public:
	    /**
	     * Pointer to the scoreboard slots.
	     */
	    scoreboard_slot *slots;

	    scoreboard();
	    ~scoreboard();

	    /**
	     * Allocate a scoreboard slot.
	     * @return the slot number.
	     */
	    int allocate_slot();
	    /**
	     * Free the slot allocated.
	     * @param slot the slot number.
	     */
	    void free_slot(int slot);

	    /**
	     * Get the pointer to the slot.
	     * @param slot the slot number.
	     * @return the pointer.
	     */
	    scoreboard_slot *get_slot(int slot);
	    /**
	     * Find the slot corresponding to the process ID.
	     * @param pid the process id.
	     * @return the slot number.
	     */
	    int get_slot_by_pid(pid_t pid);

	    /**
	     * Count the slots in the particular state.
	     * @param state the state.
	     * @return the number of slots found.
	     */
	    int count_slots(enum scoreboard_slot::_state state=scoreboard_slot::state_free);
    };

}

#endif /* __SITECING_SCOREBOARD_H */