source: trunk/src/testing/app/bitplay/bpio.h @ 4

/******************************************************************************
 * SAGE - Scalable Adaptive Graphics Environment
 *
 * Copyright (C) 2004 Electronic Visualization Laboratory,
 * University of Illinois at Chicago
 *
 * All rights reserved.
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 *    in the documentation and/or other materials provided with the distribution.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef BPIO_H
#define BPIO_H 1

#define _FILE_OFFSET_BITS  64

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <pthread.h>

typedef struct bpbuf_s bpbuf_t;

typedef struct bpio_s {
    int nfillers;       /* readers read from disk -> bufs */
    bpbuf_t *bpb;       /* bpb[reader(0..nfillers-1)] */
    int bufsize;        /* matching that of bpb->bufsize */
    int readsize;       /* ditto */
    int drain;          /* next bpbuf_t to drain (dynamic, but owned by drain thread) */
    int fwd;            /* bpb->incrpos = fwd * nfillers * bufsize */

} bpio_t;

/* Is someone waiting on our condition-variable?  Why? */
enum business { NO, EMPTY, FULL, PAUSED };

struct bpbuf_s {
                /* Static stuff */
    bpio_t        *bpio;
    int           nbufs;        /* number of buffers per reader */
    int           bufsize;
    int           readsize;
    unsigned char *bufspace;
    unsigned char **bufs;       /* page-aligned buffers  bufs[0..nbufs-1] */
    int           bpbno;        /* our index in parent */
    int           fd;           /* file descriptor */

    volatile off_t *curpos;     /* curpos[0..nbufs-1] -- filepos whence read */
    volatile off_t wrappos;     /* wrap back to poswrap after passing EOF */
    volatile off_t eofpos;      /* here's the nominal EOF point */
    volatile off_t incrpos;     /* increment from one read to the next */
    volatile int  doloop;       /* automatically loop at EOF? */

                /* Dynamic stuff, held under locks */
    volatile int     fillwaiting; /* is filler waiting? */
    volatile int     drainwaiting; /* is drainer waiting? */
    volatile int     filling;   /* is filler thread supposed to be running? */
    volatile int     busy;      /* is filler busy reading? (if "filling" was cleared, has it noticed?) */

    volatile off_t      filepos;/* file offset for next buffer to be filled*/
    volatile int        wp;     /* next-buffer-to-be-drained (to display) index */
    volatile int        rp;     /* next-buffer-to-be-filled (from file) index */

    pthread_t        bthread;
    pthread_mutex_t  bmut;
    pthread_cond_t   bfillwait; /* filler waiting (due to not-yet-setup or full queue)? */
    pthread_cond_t   bdrainwait; /* drainer wait (due to empty queue)? */

};

extern void bpclose( bpio_t *bpio );
extern int bpopen( bpio_t *bpio, char *fname );
extern int bpbfull( bpbuf_t *bpb );
extern int bpbempty( bpbuf_t *bpb );
extern bpio_t *bpinit( bpio_t *bpio, int nfillers, int bufsize, int readsize, int nbufseach );
extern void bpseek( bpio_t *bpio, off_t pos );
extern unsigned char *bpcurbuf( bpio_t *bpio );
extern off_t bptell( bpio_t *bpio );
extern void bpstart( bpio_t *bpio, int wrap );
extern void bpstop( bpio_t *bpio );
extern void bpforward( bpio_t *bpio, int fwd );
extern void bprange( bpio_t *bpio, off_t from, off_t to );

extern void *bpfiller( void *vbpb );
extern int  bpdrain( bpio_t *bpio, int (*sink)( unsigned char *buf, int nbytes, void *arg ), void *arg );
extern void bpsync( bpio_t *bpio );

#endif