buffer.h

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#ifndef BUFFER_H
#define BUFFER_H

namespace SMP{


const int BUF_MAX = 1024;

typedef unsigned char byte;
    
struct packet
{
    int      header;        
    unsigned size;          
    unsigned start_time;    
    unsigned duration;      
    char     priority;      
    void    *data;          
};

enum { NORMAL = 0, RESET, INPUT_EOF, OUTPUT_EOF};
enum { DATA_BUFFER = 0, SIGNAL_BUFFER};


class SMPBufferBase
{
    friend class SMPKernel;
    //friend class SMPSignalManager;
protected:
    int id;

    /*-------------------------------------------------------------------
     * Buffer connectivity info, set via SMPKernel
     */
    int buf_src;
    int buf_src_port;
    
    int *buf_dest;
    int *buf_dest_port;
    int num_dest;
public:
    SMPBufferBase()
        : buf_dest(NULL), buf_dest_port(NULL)
    { }
};



class SMPBuffer : public SMPBufferBase
{
    friend class SMPKernel;
    enum op{ READ=0, WRITE };
private:
    
#ifdef USE_PTHREAD
    //pthread mutex object for buffer's internal data sync
    pthread_mutex_t mutex;
    //pthread mutex object for condition variable's data sync
    pthread_mutex_t cond_mutex_w, cond_mutex_r;
    //pthread condition variable
    pthread_cond_t cond_w, cond_r;
    //boolean predicate
    bool cond_met_w, cond_met_r;
#endif

    /*-------------------------------------------------------------------
     * Buffer Properties
     */
    long size;
    long used_size;
    long *used;
    byte *data;       

    int status;

    op last_op;
    
    /*-------------------------------------------------------------------
     * Buffer status
     */ 
    long w_flag;
    long *r_flag;

    void reset_flag(void);
    long get_r_flag(void);
    
public:
    SMPBuffer(void);
    
    SMPBuffer(size_t buf_size);

    ~SMPBuffer(void);


    void initialize();   

    inline void set_status(int b_status);
    inline int get_status(void);
    
    inline size_t available(void);

    ssize_t read_space(int fid);

    inline size_t occuppied(void);
    inline size_t occuppied(int fid);
    
    int write(const void *buff, size_t nbytes);
    
    int read(void *buff, size_t nbytes, int fid=0);

    void print_status(int nbytes=0);


#ifdef  USE_PTHREAD

    void cond_wait_w();
    void cond_broadcast_w(bool trylock=false);
    void cond_wait_r();
    void cond_broadcast_r(bool trylock=false);

#endif

};

void SMPBuffer::set_status(int b_status)
{
    status = b_status;
    //printf("set_status called: id=%d, status=%d", id, status);///
}

int SMPBuffer::get_status(void)
{
    return status;
}

size_t SMPBuffer::available(void)
{
    return size - used_size;
}

size_t SMPBuffer::occuppied(void)
{
    return used_size;
}

size_t SMPBuffer::occuppied(int fid)
{
    // find which read flag to modify
    int index;
    for(index = 0; index < num_dest ; index++)
        if(buf_dest[index] == fid)
            break;
    return used[index];
}



class SMPSignalBuffer : public SMPBufferBase
{

};



} //end namespace

#endif

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