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Diffstat (limited to 'nuttx/drivers/pipes/pipe_common.h')
-rw-r--r-- | nuttx/drivers/pipes/pipe_common.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/nuttx/drivers/pipes/pipe_common.h b/nuttx/drivers/pipes/pipe_common.h new file mode 100644 index 000000000..44822e07f --- /dev/null +++ b/nuttx/drivers/pipes/pipe_common.h @@ -0,0 +1,139 @@ +/**************************************************************************** + * drivers/pipe/pipe_common.h + * + * Copyright (C) 2008-2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * 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 __DRIVERS_PIPES_PIPE_COMMON_H +#define __DRIVERS_PIPES_PIPE_COMMON_H + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> +#include <sys/types.h> + +#include <stdint.h> +#include <stdbool.h> +#include <poll.h> + +#ifndef CONFIG_DEV_PIPE_SIZE +# define CONFIG_DEV_PIPE_SIZE 1024 +#endif + +#if CONFIG_DEV_PIPE_SIZE > 0 + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/* Maximum number of threads than can be waiting for POLL events */ + +#ifndef CONFIG_DEV_PIPE_NPOLLWAITERS +# define CONFIG_DEV_PIPE_NPOLLWAITERS 2 +#endif + +/* Maximum number of open's supported on pipe */ + +#define CONFIG_DEV_PIPE_MAXUSER 255 + +/**************************************************************************** + * Public Types + ****************************************************************************/ + +/* Make the buffer index as small as possible for the configured pipe size */ + +#if CONFIG_DEV_PIPE_SIZE > 65535 +typedef uint32_t pipe_ndx_t; /* 32-bit index */ +#elif CONFIG_DEV_PIPE_SIZE > 255 +typedef uint16_t pipe_ndx_t; /* 16-bit index */ +#else +typedef uint8_t pipe_ndx_t; /* 8-bit index */ +#endif + +/* This structure represents the state of one pipe. A reference to this + * structure is retained in the i_private field of the inode whenthe pipe/fifo + * device is registered. + */ + +struct pipe_dev_s +{ + sem_t d_bfsem; /* Used to serialize access to d_buffer and indices */ + sem_t d_rdsem; /* Empty buffer - Reader waits for data write */ + sem_t d_wrsem; /* Full buffer - Writer waits for data read */ + pipe_ndx_t d_wrndx; /* Index in d_buffer to save next byte written */ + pipe_ndx_t d_rdndx; /* Index in d_buffer to return the next byte read */ + uint8_t d_refs; /* References counts on pipe (limited to 255) */ + uint8_t d_nwriters; /* Number of reference counts for write access */ + uint8_t d_pipeno; /* Pipe minor number */ + uint8_t *d_buffer; /* Buffer allocated when device opened */ + + /* The following is a list if poll structures of threads waiting for + * driver events. The 'struct pollfd' reference for each open is also + * retained in the f_priv field of the 'struct file'. + */ + +#ifndef CONFIG_DISABLE_POLL + struct pollfd *d_fds[CONFIG_DEV_PIPE_NPOLLWAITERS]; +#endif +}; + +/**************************************************************************** + * Public Function Prototypes + ****************************************************************************/ + +#ifdef __cplusplus +# define EXTERN extern "C" +extern "C" { +#else +# define EXTERN extern +#endif + +EXTERN FAR struct pipe_dev_s *pipecommon_allocdev(void); +EXTERN void pipecommon_freedev(FAR struct pipe_dev_s *dev); +EXTERN int pipecommon_open(FAR struct file *filep); +EXTERN int pipecommon_close(FAR struct file *filep); +EXTERN ssize_t pipecommon_read(FAR struct file *, FAR char *, size_t); +EXTERN ssize_t pipecommon_write(FAR struct file *, FAR const char *, size_t); +#ifndef CONFIG_DISABLE_POLL +EXTERN int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds, + bool setup); +#endif + +#undef EXTERN +#ifdef __cplusplus +} +#endif + +#endif /* CONFIG_DEV_PIPE_SIZE > 0 */ +#endif /* __DRIVERS_PIPES_PIPE_COMMON_H */ |