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/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @brief POSIX FIFO/pipe File System Support
*
* This include file defines the interface to the POSIX FIFO/pipe file system
* support.
*/
/*
* Author: Wei Shen <cquark@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _RTEMS_PIPE_H
#define _RTEMS_PIPE_H
#include <rtems/libio.h>
#include <rtems/thread.h>
/**
* @defgroup FIFO_PIPE FIFO/Pipe File System Support
*
* @ingroup FileSystemTypesAndMount
*
* @brief Interface to the POSIX FIFO/Pipe File System
*/
/**@{*/
#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;
/**
* @brief Release a pipe.
*
* Interface to file system close.
*
* *pipep points to pipe control structure. When the last user releases pipe,
* it will be set to NULL.
*/
extern void pipe_release(
pipe_control_t **pipep,
rtems_libio_t *iop
);
/**
* @brief File system open.
* Interface to file system open.
*
* *pipep points to pipe control structure. If called with *pipep = NULL,
* fifo_open will try allocating and initializing a control structure. If the
* call succeeds, *pipep will be set to address of new control structure.
*/
extern int fifo_open(
pipe_control_t **pipep,
rtems_libio_t *iop
);
/**
* @brief File system read.
*
* Interface to file system read.
*/
extern ssize_t pipe_read(
pipe_control_t *pipe,
void *buffer,
size_t count,
rtems_libio_t *iop
);
/**
* @brief File system write.
*
* Interface to file system write.
*/
extern ssize_t pipe_write(
pipe_control_t *pipe,
const void *buffer,
size_t count,
rtems_libio_t *iop
);
/**
* @brief File system Input/Output control.
*
* Interface to file system ioctl.
*/
extern int pipe_ioctl(
pipe_control_t *pipe,
ioctl_command_t cmd,
void *buffer,
rtems_libio_t *iop
);
/** @} */
#ifdef __cplusplus
}
#endif
#endif
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