rtems/score/coremsgbuffer.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSScoreMessageQueue
0007  *
0008  * @brief This header file provides interfaces of the
0009  *   @ref RTEMSScoreMessageQueue which are used by the implementation, the
0010  *   @ref RTEMSImplApplConfig, and the API.
0011  */
0012
0013 /*
0014  * Copyright (C) 2020 embedded brains GmbH & Co. KG
0015  * Copyright (C) 1989, 2009 On-Line Applications Research Corporation (OAR)
0016  *
0017  * Redistribution and use in source and binary forms, with or without
0018  * modification, are permitted provided that the following conditions
0019  * are met:
0020  * 1. Redistributions of source code must retain the above copyright
0021  *    notice, this list of conditions and the following disclaimer.
0022  * 2. Redistributions in binary form must reproduce the above copyright
0023  *    notice, this list of conditions and the following disclaimer in the
0024  *    documentation and/or other materials provided with the distribution.
0025  *
0026  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0027  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0028  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0029  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0030  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0031  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0032  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0033  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0034  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0035  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0036  * POSSIBILITY OF SUCH DAMAGE.
0037  */
0038
0039 #ifndef _RTEMS_SCORE_COREMSGBUFFER_H
0040 #define _RTEMS_SCORE_COREMSGBUFFER_H
0041
0042 #include <rtems/score/basedefs.h>
0043 #include <rtems/score/chain.h>
0044
0045 #ifdef __cplusplus
0046 extern "C" {
0047 #endif
0048
0049 /**
0050  * @addtogroup RTEMSScoreMessageQueue
0051  *
0052  * @{
0053  */
0054
0055 /**
0056  * This define enables the support for priority based enqueuing of messages in
0057  * the Message Queue Handler.
0058  */
0059 #define RTEMS_SCORE_COREMSG_ENABLE_MESSAGE_PRIORITY
0060
0061 /**
0062  * @brief The structure is used to organize message buffers of a message queue.
0063  */
0064 typedef struct {
0065   /**
0066    * @brief This member is used to enqueue the buffer in the pending or free
0067    *   buffer queue of a message queue.
0068    */
0069   Chain_Node Node;
0070
0071   /** @brief This member defines the size of this message. */
0072   size_t size;
0073
0074 #if defined(RTEMS_SCORE_COREMSG_ENABLE_MESSAGE_PRIORITY)
0075   /** @brief This member defines the priority of this message. */
0076   int priority;
0077 #endif
0078
0079   /**
0080    * @brief This member contains the actual message.
0081    *
0082    * This is a zero-length array since the maximum message size is defined by
0083    * the user.  Use a size_t array to make sure that the member offset is at
0084    * the structure end.  This enables a more efficient memcpy() on 64-bit
0085    * targets and makes it easier to inspect the message buffers with a
0086    * debugger.
0087    */
0088   size_t buffer[ RTEMS_ZERO_LENGTH_ARRAY ];
0089 } CORE_message_queue_Buffer;
0090
0091 /** @} */
0092
0093 #ifdef __cplusplus
0094 }
0095 #endif
0096
0097 #endif /* _RTEMS_SCORE_COREMSGBUFFER_H */