293 lines
9.4 KiB
C
293 lines
9.4 KiB
C
/*
|
|
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
|
|
|
|
This file is part of ChibiOS/RT.
|
|
|
|
ChibiOS/RT is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
ChibiOS/RT is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
/**
|
|
* @file channels.h
|
|
* @brief I/O channels
|
|
* @addtogroup io_channels
|
|
* @{
|
|
*/
|
|
|
|
#ifndef _CHANNELS_H_
|
|
#define _CHANNELS_H_
|
|
|
|
/**
|
|
* @brief @p BaseChannel specific methods.
|
|
*/
|
|
struct _base_channel_methods {
|
|
/**
|
|
* @brief Channel output check.
|
|
* @see chIOPutWouldBlock()
|
|
*/
|
|
bool_t (*putwouldblock)(void *instance);
|
|
/**
|
|
* @brief Channel input check.
|
|
* @see chIOGetWouldBlock()
|
|
*/
|
|
bool_t (*getwouldblock)(void *instance);
|
|
/**
|
|
* @brief Channel put method with timeout specification.
|
|
* @see chIOPut()
|
|
*/
|
|
msg_t (*put)(void *instance, uint8_t b, systime_t timeout);
|
|
/**
|
|
* @brief Channel get method with timeout specification.
|
|
* @see chIOGet()
|
|
*/
|
|
msg_t (*get)(void *instance, systime_t timeout);
|
|
};
|
|
|
|
/**
|
|
* @brief @p BaseChannel specific data.
|
|
* @note It is empty because @p BaseChannel is only an interface without
|
|
* implementation.
|
|
*/
|
|
struct _base_channel_data {
|
|
};
|
|
|
|
/**
|
|
* @brief @p BaseChannel virtual methods table.
|
|
*/
|
|
struct BaseChannelVMT {
|
|
/**
|
|
* @p BaseChannel class specific methods.
|
|
*/
|
|
struct _base_channel_methods m0;
|
|
};
|
|
|
|
/**
|
|
* @brief Base channel class.
|
|
* @details This class represents a generic, byte-wide, I/O channel.
|
|
*/
|
|
typedef struct {
|
|
/**
|
|
* Virtual Methods Table.
|
|
*/
|
|
const struct BaseChannelVMT *vmt;
|
|
/**
|
|
* @p BaseChannel class specific data.
|
|
*/
|
|
struct _base_channel_data d0;
|
|
} BaseChannel;
|
|
|
|
/**
|
|
* @brief Channel output check.
|
|
* @details This function verifies if a subsequent @p chIOPut() would block.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseChannel or derived class
|
|
* @return The output queue status:
|
|
* @retval FALSE if the output queue has space and would not block a write
|
|
* operation.
|
|
* @retval TRUE if the output queue is full and would block a write operation.
|
|
*/
|
|
#define chIOPutWouldBlock(ip) ((ip)->vmt->m0.putwouldblock(ip))
|
|
|
|
/**
|
|
* @brief Channel input check.
|
|
* @details This function verifies if a subsequent @p chIOGett() would block.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseChannel or derived class
|
|
* @return The input queue status:
|
|
* @retval FALSE if the input queue contains data and would not block a read
|
|
* operation.
|
|
* @retval TRUE if the input queue is empty and would block a read operation.
|
|
*/
|
|
#define chIOGetWouldBlock(ip) ((ip)->vmt->m0.getwouldblock(ip))
|
|
|
|
/**
|
|
* @brief Channel blocking byte write.
|
|
* @details This function writes a byte value to a channel. If the channel
|
|
* is not ready to accept data then the calling thread is suspended.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseChannel or derived class
|
|
* @param[in] b the byte value to be written to the channel
|
|
* @return The operation status:
|
|
* @retval Q_OK if the operation succeeded.
|
|
* @retval Q_RESET if the channel associated queue (if any) was reset.
|
|
*/
|
|
#define chIOPut(ip, b) ((ip)->vmt->m0.put(ip, b, TIME_INFINITE))
|
|
|
|
/**
|
|
* @brief Channel blocking byte write with timeout.
|
|
* @details This function writes a byte value to a channel. If the channel
|
|
* is not ready to accept data then the calling thread is suspended.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseChannel or derived class
|
|
* @param[in] b the byte value to be written to the channel
|
|
* @param[in] timeout the number of ticks before the operation timeouts,
|
|
* the following special values are allowed:
|
|
* - @a TIME_IMMEDIATE immediate timeout.
|
|
* - @a TIME_INFINITE no timeout.
|
|
* .
|
|
* @return The operation status:
|
|
* @retval Q_OK if the operation succeeded.
|
|
* @retval Q_TIMEOUT if the specified time expired.
|
|
* @retval Q_RESET if the channel associated queue (if any) was reset.
|
|
*/
|
|
#define chIOPutTimeout(ip, b, timeout) ((ip)->vmt->m0.put(ip, b, timeout))
|
|
|
|
/**
|
|
* @brief Channel blocking byte read.
|
|
* @details This function reads a byte value from a channel. If the data
|
|
* is not available then the calling thread is suspended.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseChannel or derived class
|
|
* @return A byte value from the queue or:
|
|
* @retval Q_RESET if the channel associated queue (if any) was reset.
|
|
*/
|
|
#define chIOGet(ip) ((ip)->vmt->m0.get(ip, TIME_INFINITE))
|
|
|
|
/**
|
|
* @brief Channel blocking byte read with timeout.
|
|
* @details This function reads a byte value from a channel. If the data
|
|
* is not available then the calling thread is suspended.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseChannel or derived class
|
|
* @param[in] timeout the number of ticks before the operation timeouts,
|
|
* the following special values are allowed:
|
|
* - @a TIME_IMMEDIATE immediate timeout.
|
|
* - @a TIME_INFINITE no timeout.
|
|
* .
|
|
* @return A byte value from the queue or:
|
|
* @retval Q_TIMEOUT if the specified time expired.
|
|
* @retval Q_RESET if the channel associated queue (if any) was reset.
|
|
*/
|
|
#define chIOGetTimeout(ip, timeout) ((ip)->vmt->m0.get(ip, timeout))
|
|
|
|
#if CH_USE_EVENTS
|
|
/**
|
|
* @brief @p BaseAsynchronousChannel specific methods.
|
|
*/
|
|
struct _base_asynchronous_channel_methods {
|
|
/**
|
|
* Channel asynchronous write method.
|
|
* @see chIOWrite()
|
|
*/
|
|
size_t (*write)(void *instance, uint8_t *buffer, size_t n);
|
|
/**
|
|
* Channel asynchronous read method.
|
|
* @see chIORead()
|
|
*/
|
|
size_t (*read)(void *instance, uint8_t *buffer, size_t n);
|
|
};
|
|
|
|
/**
|
|
* @brief @p BaseAsynchronousChannel specific data.
|
|
*/
|
|
struct _base_asynchronous_channel_data {
|
|
/**
|
|
* Data Available @p EventSource. This event is generated when some incoming
|
|
* data is inserted in the input queue.
|
|
*/
|
|
EventSource ievent;
|
|
/**
|
|
* Data Transmitted @p EventSource. This event is generated when the
|
|
* output queue is empty.
|
|
*/
|
|
EventSource oevent;
|
|
};
|
|
|
|
/**
|
|
* @brief @p BaseAsynchronousChannel virtual methods table.
|
|
*/
|
|
struct BaseAsynchronousChannelVMT {
|
|
/**
|
|
* @p BaseChannel class inherited methods.
|
|
*/
|
|
struct _base_channel_methods m0;
|
|
/**
|
|
* @p BaseAsynchronousChannel class specific methods.
|
|
*/
|
|
struct _base_asynchronous_channel_methods m1;
|
|
};
|
|
|
|
/**
|
|
* @extends BaseChannel
|
|
*
|
|
* @brief Base asynchronous channel class.
|
|
* @details This class extends @p BaseChannel by adding methods for
|
|
* asynchronous I/O in an event-driven environment.
|
|
*/
|
|
typedef struct {
|
|
/**
|
|
* Virtual Methods Table.
|
|
*/
|
|
const struct BaseAsynchronousChannelVMT *vmt;
|
|
/**
|
|
* @p BaseChannel class inherited data.
|
|
*/
|
|
struct _base_channel_data d0;
|
|
/**
|
|
* @p BaseAsynchronousChannel class specific data.
|
|
*/
|
|
struct _base_asynchronous_channel_data d1;
|
|
} BaseAsynchronousChannel;
|
|
|
|
/**
|
|
* @brief Channel non-blocking write.
|
|
* @details The function writes data from a buffer to a channel. The
|
|
* transfer is non-blocking and can return zero if the channel is
|
|
* not read to accept data.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived class
|
|
* @param[out] bp pointer to the buffer where the data is stored
|
|
* @param[in] n the maximum amount of data to be transferred
|
|
* @return The number of bytes transferred.
|
|
*/
|
|
#define chIOWrite(ip, bp, n) ((ip)->vmt->m1.write(ip, bp, n))
|
|
|
|
/**
|
|
* @brief Channel non-blocking read.
|
|
* @details The function reads data from a channel into a buffer. The
|
|
* transfer is non-blocking and can return zero if the channel has
|
|
* no data immediately available.
|
|
*
|
|
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived class
|
|
* @param[out] bp pointer to the buffer where the input data is copied
|
|
* @param[in] n the maximum amount of data to be transferred
|
|
* @return The number of bytes transferred.
|
|
*/
|
|
#define chIORead(ip, bp, n) ((ip)->vmt->m1.read(ip, bp, n))
|
|
|
|
/**
|
|
* @brief Returns the write event source.
|
|
* @details The write event source is broadcasted when the channel is ready
|
|
* for write operations. This usually happens when the internal
|
|
* output queue becomes empty.
|
|
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived class
|
|
* @return A pointer to an @p EventSource object.
|
|
*/
|
|
#define chIOGetWriteEventSource(ip) (&((ip)->vmt->d1.oevent))
|
|
|
|
/**
|
|
* @brief Returns the read event source.
|
|
* @details The read event source is broadcasted when the channel is ready
|
|
* for read operations. This usually happens when the internal
|
|
* input queue becomes non-empty.
|
|
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived class
|
|
* @return A pointer to an @p EventSource object.
|
|
*/
|
|
#define chIOGetReadEventSource(ip) (&((ip)->vmt->d1.ievent))
|
|
|
|
#endif /* CH_USE_EVENTS */
|
|
|
|
#endif /* _CHANNELS_H_ */
|
|
|
|
/** @} */
|