pipe.h

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/*
 * Author: Wei Shen <cquark@gmail.com>
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */
 
#ifndef _RTEMS_PIPE_H
#define _RTEMS_PIPE_H
 
#include <rtems/libio.h>
#include <rtems/thread.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
/* Control block to manage each pipe */
typedef struct pipe_control {
  char *Buffer;
  unsigned int Size;
  unsigned int Start;
  unsigned int Length;
  unsigned int Readers;
  unsigned int Writers;
  unsigned int waitingReaders;
  unsigned int waitingWriters;
  unsigned int readerCounter;     /* incremental counters */
  unsigned int writerCounter;     /* for differentiation of successive opens */
  rtems_mutex Mutex;
  rtems_condition_variable readBarrier;   /* wait queues */
  rtems_condition_variable writeBarrier;
#if 0
  boolean Anonymous;      /* anonymous pipe or FIFO */
#endif
} pipe_control_t;
 
extern void pipe_release(
  pipe_control_t **pipep,
  rtems_libio_t *iop
);
 
extern int fifo_open(
  pipe_control_t **pipep,
  rtems_libio_t *iop
);
 
extern ssize_t pipe_read(
  pipe_control_t *pipe,
  void           *buffer,
  size_t          count,
  rtems_libio_t  *iop
);
 
extern ssize_t pipe_write(
  pipe_control_t *pipe,
  const void     *buffer,
  size_t          count,
  rtems_libio_t  *iop
);
 
extern int pipe_ioctl(
  pipe_control_t  *pipe,
  ioctl_command_t  cmd,
  void            *buffer,
  rtems_libio_t   *iop
);
 
#ifdef __cplusplus
}
#endif
 
#endif