forked from Imagelibrary/rtems
122 lines
2.3 KiB
C
122 lines
2.3 KiB
C
/*
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* pipe.h: header of POSIX FIFO/pipe
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*
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* Author: Wei Shen <cquark@gmail.com>
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.com/license/LICENSE.
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*
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* $Id$
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*/
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#ifndef _RTEMS_PIPE_H
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#define _RTEMS_PIPE_H
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#include <rtems/libio.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* Control block to manage each pipe */
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typedef struct pipe_control {
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char *Buffer;
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uint Size;
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uint Start;
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uint Length;
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uint Readers;
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uint Writers;
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uint waitingReaders;
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uint waitingWriters;
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uint readerCounter; /* incremental counters */
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uint writerCounter; /* for differentiation of successive opens */
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rtems_id Semaphore;
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rtems_id readBarrier; /* wait queues */
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rtems_id writeBarrier;
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#if 0
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boolean Anonymous; /* anonymous pipe or FIFO */
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#endif
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} pipe_control_t;
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/*
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* Called by pipe() to create an anonymous pipe.
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*/
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extern int pipe_create(
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int filsdes[2]
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);
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/*
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* Interface to file system close.
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*
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* *pipep points to pipe control structure. When the last user releases pipe,
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* it will be set to NULL.
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*/
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extern int pipe_release(
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pipe_control_t **pipep,
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rtems_libio_t *iop
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);
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/*
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* Interface to file system open.
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*
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* *pipep points to pipe control structure. If called with *pipep = NULL,
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* fifo_open will try allocating and initializing a control structure. If the
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* call succeeds, *pipep will be set to address of new control structure.
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*/
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extern int fifo_open(
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pipe_control_t **pipep,
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rtems_libio_t *iop
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);
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/*
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* Interface to file system read.
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*/
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extern ssize_t pipe_read(
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pipe_control_t *pipe,
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void *buffer,
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size_t count,
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rtems_libio_t *iop
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);
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/*
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* Interface to file system write.
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*/
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extern ssize_t pipe_write(
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pipe_control_t *pipe,
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const void *buffer,
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size_t count,
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rtems_libio_t *iop
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);
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/*
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* Interface to file system ioctl.
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*/
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extern int pipe_ioctl(
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pipe_control_t *pipe,
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uint32_t cmd,
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void *buffer,
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rtems_libio_t *iop
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);
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/*
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* Interface to file system lseek.
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*/
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extern int pipe_lseek(
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pipe_control_t *pipe,
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off_t offset,
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int whence,
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rtems_libio_t *iop
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);
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/*
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* Initialization of FIFO/pipe module.
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*/
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extern void rtems_pipe_initialize (void);
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#ifdef __cplusplus
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}
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#endif
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#endif
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